Episode 136 - The RSV Vaccine in Pregnancy
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[00:00:00] Mel: Welcome to the Great Birth Rebellion podcast. I'm your host, Dr. Melanie Jackson. I'm a clinical and research midwife with my PhD, and each episode I cast a critical eye over current maternity care practice by grappling with research and historical knowledge to help you get the best out of your pregnancy, birth, and postpartum journey.
[00:00:25] Mel: Welcome to today's episode of the Great Birth Rebellion podcast. This episode is about the newly recommended RSV vaccine during pregnancy, and this is now being rolled out and offered to pregnant women. Here in Australia, every woman will be offered a free RSV vaccine in addition to the already recommended flu vaccine and whooping cough vaccine, and some practitioners still recommending the COVID vaccine during pregnancy.
[00:00:53] Mel: So every pregnant woman will be confronted with the opportunity to take or not take these vaccines. And so this episode offers some information to consider when making this choice. So I'm a clinical midwife myself. I'm still caring for clients. And so I'm doing the work to understand the research and evidence behind this vaccine for the purpose of educating my clients.
[00:01:19] Mel: It's a new vaccine. Uh, it's not been offered before here in Australia. And so my clients will be asking about it and I'm doing all this research so that I can give them the information. Evidence based answers. And so I'm already doing the work to facilitate their informed choice. So now I'm offering you, the listeners, the fruit of this work.
[00:01:40] Mel: Also, I completely acknowledge that I am an endorsed midwife, registered midwife here in Australia. And as such, I am under a regulatory framework of the Nursing and Midwifery Board of Australia. And my registration board prohibits. Midwives from speaking against the immunization regime that's recommended in the Australian National Immunizations Handbook and the handbook is considered evidence based by the Nursing and Midwifery Board and midwives are expected to uphold this information.
[00:02:14] Mel: So in the resource folder, That if you're part of the mailing list for this podcast, I've provided a link to the NMBA statement regarding how midwives share vaccination information to our clients. So midwives listening, you might just want to have a look at that and remind yourselves of the code of conduct around that.
[00:02:33] Mel: And in this statement, the NMBA has offered a link to the immunizations handbook. This link. Doesn't work. So I have hunted down the RSV vaccine information from the Australian National Immunizations Handbook for your information. So that's in the resource folder for reference. So midwives and maternity care providers are required to endorse and offer you women the information in the Australian National Immunizations Handbook.
[00:03:04] Mel: And our code of conduct and standards of care require that we provide evidence based and woman centered care. So as part of their vaccine statement, the NMBA expects all registered nurses, enrolled nurses, midwives to use the best available evidence in making practice decisions. So today I'm here to provide you with the best available information and evidence that I could find regarding the RSV vaccine.
[00:03:35] Mel: I am writing this in January of 2025, and to the best of my knowledge, I've referred to all the major research studies on pregnant women that were available at this time regarding the RSV vaccine. Research in these areas often grows rapidly, so if you're listening at a later date, it's possible that there's Information that I've not accounted for here.
[00:03:58] Mel: So it's current to date. I'm not here to suggest that you don't take the vaccine. I'm here to offer my translation of the current research about the RSV vaccine for pregnant women and give easy access to others so that you can access the resources and information. So you can decide for yourself if this vaccine is important to you.
[00:04:22] Mel: So I suggest that any vaccine and maternity care decisions are discussed with your care provider. In this episode, I will explain what RSV is. The development of the vaccine, also the research about how well the vaccine works, and then the risks and benefits of taking the vaccine during pregnancy, both for you as the woman and for your baby.
[00:04:47] Mel: So let's get into it. What is RSV? RSV is short for respiratory syncytial virus. So RSV is a viral, not bacterial infection, and there's no widely available treatment. Treatment, you can't use antibiotics on a virus. You mostly have to just support a person's body's own defenses and await the body to fight the virus itself.
[00:05:14] Mel: There are some immunoglobulin treatments, but they're usually reserved for very unwell people or as a preventative strategy for very vulnerable people. That's not really a widely available.
[00:05:33] Mel: So RSV, it's a respiratory virus, so in your lungs, and it causes infections of the lungs, respiratory tract. It's very common. Some articles suggest that by the age of two, most people have had RSV. And in adults and well children, the symptoms are usually mild and they mimic a common cold. So it's typically easy to recover from, but in vulnerable members of the population, such as young babies before the age of 12 months old, it And people who are immunocompromised and elderly, they can experience more severe symptoms.
[00:06:16] Mel: So we know that anytime viruses is rampant, it's the vulnerable members of our population who are more likely to suffer. And babies. Before the age of one, their immune systems are less mature and they're relying a lot on the immunity that they're getting through breast milk, for the most part, that's a whole other topic.
[00:06:41] Mel: And we also have to acknowledge here that here in Australia. That statistics, complications and hospitalizations from RSV are significantly higher in our First Nations people. So they're considered an at risk group. So the most likely symptoms from RSV in milder cases are congested or runny nose, a dry cough, low grade fever, a sore throat.
[00:07:07] Mel: Uh, sneezing and headache, you know, common cold symptoms. In more severe cases, you can experience fever, a more severe cough, wheezing, rapid breathing or difficulty breathing, and Signs of lack of oxygenation, a bluish coloring of the skin, and in infants who are severely affected by RSV, they will do things like short, shallow, rapid breathing.
[00:07:36] Mel: They might struggle to breathe. So you can see that they're sucking in their chest to try and get more oxygen in. There's a cough, poor feeding. They're very lethargic. So they're difficult to rouse and they can be irritable. You know. It's, it's a nasty cold. Here in Australia, there is a National Notifiable Diseases Surveillance System.
[00:07:59] Mel: And so RSV is newly a reportable disease, meaning that if a person is diagnosed with RSV, then it has to be reported for statistical collection. And so this is usually the more severe cases where people actually need More medical care, the ones that go to their doctor for a diagnosis, for example. So we've got some information about how many people.
[00:08:23] Mel: Severely affected by RSV because they are the ones that seek medical care. And then their doctor is required to notify that to our reporting system. And actually these stats are publicly available and they can be found just like simply Googling. RSV statistics and you, you'll find these things. So you can look at the statistics yourself and sometimes knowing the extent of an outbreak or the number of severe cases that have been reported can help families make decisions about their vaccine choices.
[00:08:56] Mel: So some years are certainly more extreme than others and that's just the nature of viral outbreaks. So it's January 2025 now. So the stats I'm giving you are the ones I found from last year, 2024 from between January and December. So here in Australia for the year of 2024, there were a total of 170 deaths from RSV and everyone who died was over the age of 50 and 140 of the deaths were in people who were over 70 years old.
[00:09:30] Mel: So no pregnant women. Babies or children died of RSV in 2024 here in Australia. So you can see that information on the Australian Respiratory Surveillance Report for 2024. And that was released by the Australian Centre for Disease Control. That's in the resource folder, if you want to have a good look at the stats.
[00:09:50] Mel: So here in Australia, there's a population of around 27 million people. So we had a total of 170 deaths over that whole population. And all of them were over 50 years old. If we compare that to bigger population in America, the population is about 345 million people. And in the U S there were estimated to be 300 to 600 deaths for children from RSV across the country.
[00:10:21] Mel: Their whole population, but the research paper that I got that from also makes a point to say that these children had significant underlying cardiopulmonary disease and have fallen through the safety net of early medical care. So remembering that the US health system is very different from here in Australia.
[00:10:43] Mel: Here in Australia we have free healthcare and in the US user pays and that could contribute to people accessing care. Later and possibly not getting the care that they need. Nonetheless, in a population of 345 million people, the US recorded approximately 300 to 600 deaths from RSV for children, but that's different for us here in Australia.
[00:11:09] Mel: And in this Australian respiratory surveillance report, we can also see the year 2024. The number of RSV cases that were notified have been broken up into age groups. So we can see that children in the age bracket of zero to four, there was a total of 84, 800 cases of RSV. So the number of. Zero to four year olds who actually had RSV was higher than that.
[00:11:40] Mel: That's just the number of cases that were reported. So of these 84, 800 cases, none of these children died, but it's clear that RSV is causing a healthcare burden, but it doesn't seem to be deadly here in Australia. And since. RSV surveillance started on the 1st of April 2024 to date, there have been 2, 180 children have been admitted to hospital with RSV and the average age was the age of one, so between zero and two.
[00:12:16] Mel: It's the most likely time that a child would be admitted for RSV. So it shows that younger children between the ages of zero and two are the more likely group of children that will require hospitalization for RSV and all of them recovered. The, the main concern from many governments is that RSV admissions to hospital put a burden on the healthcare system.
[00:12:39] Mel: And also it's stressful for families to have your child admitted to hospital. Very destructive and stressful. So they're highly motivated to avoid hospital admissions. That's the main concern with RSV. And I had a little look back to see if I can find some older stats on RSV incidents. And so another research paper that I found, again, it's in the resource folder, if you're on the mailing list, and that reported on statistics between 2006 to 2015, to date.
[00:13:09] Mel: Where they tracked Australian hospitalizations from RSV and then what happened to these people. So in the paper, they say that, that over this nine year period between 2000 and 2015, 21 children under the age of five died in hospital from RSV or with RSV and seven children were under six months of age.
[00:13:36] Mel: So this paper and another from a New South Wales hospital did also highlight that death from RSV was very rare and commonly the children who died also had comorbidities and other health conditions that compounded their condition. So that's where we're at here in Australia, 21 children under the age of five died from RSV related complications over a nine year period from this study and seven of those were under six months of age.
[00:14:06] Mel: And that's the age group really under six months is the focus of the age group that the research papers that I'll be sharing on focus on that eight, that vulnerable age group between zero and six months. And that's the vulnerable group that this maternal vaccine program is targeting babies under the age of six months.
[00:14:29] Mel: So that's a picture of what the. RSV is doing amongst the population from last year, 170 deaths from RSV 2024. And all of these were people above the age of 50 and 140 of them were over 70, but there were. 84, 800 reported cases of RSV in children under the age of four and they all recovered. But 2, 180 of them were admitted to hospital for management and the children at most risk of being hospitalized were between zero and two years old.
[00:15:05] Mel: So, if you are elsewhere in the world, your stats might be different depending on if you are living in a low, medium or high income country. But I encourage you to do a search for RSV infections or morbidity and mortality statistics in your area to fully understand the context. Within which you're making your decisions.
[00:15:30] Mel: So you might make different decisions if the disease burden and mortality rates are high compared to countries who have a lower burden of disease. So in these circumstances, we're making decisions. It's not really useful to look at the global statistics of. RSV because they're not specific to you. Just because Australia has very few deaths from RSV, that doesn't mean that that's the case in your country, or maybe it is, I just encourage you to look into the statistics in your location.
[00:16:03] Mel: And what we know about death of children from RSV is that 97 percent of them happen in low to middle income countries. Only 3 percent of RSV deaths in the world are in children in high income countries. So RSV carries a mortality risk for the most part, 97 percent of the time in lower to middle income countries.
[00:16:30] Mel: So if you're listening from a high income country, just know that the impact of RSV upon you is different to if you were in a low to middle income country. So now before we have a look at vaccine recommendations for women and at which gestation you might be offered this vaccine, we'll first have a look at the development of the RSV vaccine.
[00:16:54] Mel: It's only very Newly been invented and tested on pregnant women over the last few years. So the amount of information is actually very consumable. There isn't years and years and years of data to wade through, only a few years. And this does mean that by default, we don't have any. any long term studies on the risks or benefits of the RSV vaccine when given during pregnancy.
[00:17:21] Mel: So I won't be able to comment on that. By nature of its newness, there's only short term outcome data. So the first RSV vaccines approved ever for use have been approved since 2023. And so it's the same for the pregnancy vaccines. And only recently here in Australia. So in the U S they're a little bit ahead of us.
[00:17:45] Mel: So the product that we will look at is the one that goes by the name of Abrisvo. A B R Y S V O. And it's manufactured by the pharmaceutical company Pfizer. And it's the only RSV vaccine approved for pregnancy. So this is the only product that we'll look at today. Only the research on this particular product.
[00:18:08] Mel: I'm going to go through these research papers one by one. And again, as I said, there's only a few and I can start with this one. It's called RSV perfusion F protein based maternal vaccine, preterm birth and other outcomes. And it's the first paper that's listed in the resource folder for those who want to have a good read of this and check my work.
[00:18:30] Mel: It's there in full text. All of these papers are. So the research project, this paper was funded by GlaxoSmithKline Bioceticals, which is a biopharmaceutical company that Had invented this particular vaccine for maternal use. So they started testing their vaccine in 2020 and they ceased their trial in 2022.
[00:18:54] Mel: And the article explains this right up front. So you can have a look at the full story yourself. They're very open in the article about not only funding the study. But also for employing the authors of the study who designed and executed it. So the inspiration for this study is that there is a theory that if women are vaccinated in their pregnancy, that this might offer some protection to their baby after birth, but that research was needed to confirm this and the safety and efficacy of such a vaccine is yet known.
[00:19:29] Mel: So this study enrolled pregnant women. And gave them either the vaccine or the placebo between 24 and 34 weeks of their pregnancy. And they wanted to see if there were any or severe RSV cases in the infants from birth to six months. That was the idea. Two groups, vaccinate one, don't vaccinate the other, see what happens for the babies.
[00:19:54] Mel: In this particular study, they had a target to enroll 10, 000 pregnant women, but enrollment was stopped early after the observation of a higher risk of preterm birth in the vaccine group compared to the placebo group. Hold on that to that for a second, we're going to discuss the exact stats around this.
[00:20:15] Mel: So what the study says so far is that there was enough of a concern about this risk of preterm birth to stop the study early. And they chose not to give the vaccine to any more women in this particular study. So in the end, they had a total of 3, 426 infants in the vaccine group and 1, 711 in the placebo group that they followed up to six months of age.
[00:20:43] Mel: So of the 3, 426 babies in the vaccine group, 16 were diagnosed with RSV within the time period. So that's 0. 46%. And in the non vaccinated group? There were 24 babies of the 1, 711. So that's 1. 4%. So 0. 46 percent still got RSV in the vaccine group and 1. 4 in the non vaccinated group. And they also looked at the severe cases and found that there were eight babies in the vaccine group who were diagnosed with severe RSV, so that's 0.
[00:21:22] Mel: 23 percent and 14 In the non vaccinated group, 0. 181%. So the paper explains this in another way, you know, numerically for people who are following along, trying to keep track of the numbers, that the research paper explains that in the vaccine group, 14. 5 of a thousand babies got RSV in the, vaccine group.
[00:21:53] Mel: And in the non vaccinated group, 46. 2 per 1, 000 babies got RSV. So about three times the amount. So from these small study numbers, it seems that the RSV vaccine did make some impact on whether or not the baby would contract RSV at all. And the numbers who would have had severe RSV before the age of six months.
[00:22:17] Mel: So that's a good thing. The vaccine didn't prevent RSV completely, but it does appear to reduce the incidence for babies whose mum had the vaccine. However, there was an increase in preterm birth and neonatal death for the vaccine group, which was the reason for RSV. They stopped it early. So the, we'll have a look at those stats.
[00:22:39] Mel: So preterm birth occurred for 237 of the 3, 494 vaccinated babies. So that's a rate of 6. 8 percent compared to 89 of the 1, 739 non vaccinated babies, which is a rate of 4. 9%. So 6. 8 percent in the vaccine group, 4. 9 percent in the placebo group. There was also a difference in the neonatal death rate between the groups.
[00:23:10] Mel: So 0. 4 percent in the vaccinated group and 0. 2 percent in the placebo group. And the authors suggest that this imbalance, so it was twice as likely for a neonatal death in the vaccine group, but they suggested that. Because there was an increase in preterm births that seemed to flow on to cause an increase in neonatal deaths.
[00:23:35] Mel: That's the theory around what led to that. So if we present the preterm birth data and the neonath data in babies per thousand, so in the vaccine group, preterm births occurred at an incident of 68 babies per thousand babies. We're born premature compared to 49 babies in a thousand in the placebo group and four in one thousand vaccine great group babies died after birth compared to two in one thousand in the placebo group.
[00:24:06] Mel: So the research paper puts it in this way for every 54 infants born to women who received the vaccine rather than the placebo during pregnancy one additional preterm birth occurred. There's so many different statistical ways. We've just given you that information. So hopefully one of those ways of explaining it makes sense.
[00:24:30] Mel: This research paper also explains that when the research team were recruiting candidates for this study, only babies without known congenital abnormalities And women with clinically important complications during the pregnancy, or if they had two or more previous stillbirths or neonatal deaths, they were excluded from participating.
[00:24:51] Mel: So they tried to gather a relatively healthy, low risk group of women whose babies were expected to be well. So this change in the number of babies who, It compares to the placebo group who were preterm, term born, seems to not be specifically related to complications through their pregnancy because they were all a similar group.
[00:25:15] Mel: The other thing to note here is that there was approximately a 50 50 split in that 50 percent of the women were recruited from low to middle income countries and the other 50 percent were from high income countries. And we heard at the beginning of this podcast that I was saying that the vast majority, 97 percent of RSV deaths happen in low to middle income countries with only 3 percent happening in high income countries.
[00:25:44] Mel: So these statistics hit differently depending on where you are living. And the authors of this research concluded that the results of this trial in which enrollment was stopped early because of safety concerns suggest that Risks of any or severe medically assessed RSV, low respiratory tract infections, among infants were lower in the group who received the RSV vaccine than in placebo, that the risk of preterm birth was higher in the vaccine group.
[00:26:17] Mel: So they're saying, yep, that's true. The vaccine did reduce the number of babies who had RSV. However, it increased the risk of preterm birth. Now the authors do break down the preterm birth circumstances for a bit more detail, which I feel is important to highlight. So the preterm birth risk seems to only be apparent for people living in low to middle income countries when they break down the preterm birth stats based on country or location.
[00:26:50] Mel: When they looked at the high income countries, the risk of preterm birth was similar for each group. So 3. 7 percent for the vaccine group and 3. 6 percent for the placebo group. But when they had a look at the low to middle income countries and this risk of preterm birth, it's 9. 8 percent for the vaccine group compared to 6.
[00:27:13] Mel: 3 for the placebo group. So if you're listening. to this and getting this information and you're from a low to middle income country, then this study is a completely different piece of information compared to if you're in a high income country, like here in Australia. So we can't really, You know, when you generalize the statistics, yes, there was an increased risk of preterm birth, but that increased risk was disproportionate if you were living in a low to middle income country.
[00:27:48] Mel: There's less of a risk of preterm birth, it appears, from, as they break down the, There's stats. There's less of a risk of preterm birth if you're from a high income country. Now the authors don't know the mechanism by which the vaccine may have led to preterm birth. They say that the mechanism is unknown.
[00:28:08] Mel: So the intervals from vaccination to preterm birth, they ranged from weeks to months. So the authors suggest that the, there's an absence of a direct effect of vaccination on the mechanisms that initiated a preterm birth. In light of this preterm birth risk, there are some research papers and commentators who are suggesting that women get the vaccine somewhere.
[00:28:34] Mel: after 28 weeks, so somewhere between 28 weeks and 34 weeks, rather than the early gestation, the 24 weeks that was used in the study. And the medicine insert in the, in the vaccine package does state that it can be given from 24 weeks, but there's been some caution offered around that, that after 28 weeks might help reduce the impact of prematurity and the suggestion that Is to get it by 34 weeks for proper immunity to develop.
[00:29:03] Mel: So, although these studies were tested from 24 weeks, some commentary is suggesting that Maybe if you plan to get it later, we might be able to counteract some of that risk of preterm birth. Now, of course, when these research papers come out, there's going to be some social and academic commentary going on around these studies and other studies that we're going to talk about today.
[00:29:25] Mel: There's always going to be a response to research from the community and from other academics, which is excellent. That's what we need. Balanced discussion. I'm not going to weigh into that discussion. My intention today is not to pick a side or to advocate for one piece of information over another. So if you want to see what's being said about the vaccine in other sources, I've included some of these in the resource folder for those who are on the mailing list, and that gets sent out every Monday when you, or when you sign up.
[00:29:57] Mel: Uh, so if you want to get all those resources, sign up to the podcast mailing list. I don't have the capacity to discuss the social commentary in this podcast episode. Um, okay, we're going to move on to the next paper. This one was funded by Pfizer, who is the manufacturer and distributor of the current vaccine that's available for administration here in Australia.
[00:30:23] Mel: And it's the only RSV vaccine approved for use in pregnant women. Which is called abrisfo, and I've added the information leaflet for that medicine in the resource folder. So you can see more information on that, what's in the insert. So this study was published in April 2023. The one we just talked about was from March 24, so about a year apart.
[00:30:46] Mel: The title of this paper is Bivalent Profusion F Vaccine in Pregnancy to Prevent RSV Illness in Infants. And This study acknowledged that it was uncertain if vaccinating pregnant women could reduce the disease burden of RSV in newborns, so that's why they were conducting a double blind trial, just like the last one, where one group was given the vaccine and the other was given a placebo.
[00:31:14] Mel: It was conducted in 18 different countries and women could receive their dose between 24 and 36 weeks pregnant, similar to the other study. And this study aimed to follow babies up at 3 months, 4 months, 5 months and 6 months after their birth. So they had 3, 682 women in the vaccine group. And a very similar number, 3, 676 in the placebo group.
[00:31:42] Mel: So, this is very convenient. Similar numbers, unlike the last study, which I had to do some more maths on. So this had very close and even numbers. Uh, so it was kind of easier to compare the stats. So, in this study, within 90 days or 3 months, medically attended severe RSV cases, there were 6 babies in the vaccine group, so 6 babies in the vaccine group had RSV out of 3570, and 33 babies from the placebo group had RSV out of 3570.
[00:32:21] Mel: So that's 0. 2 percent compared to 0. 9 percent for the unvaccinated babies. So now if we look at the stats after three months, after 90 days, so those previous stats were for the first three months of the baby's life, 0. 2 percent compared to 0. 9, so the severe RSV occurred in 24 babies in the vaccine group.
[00:32:45] Mel: and 56 babies in the placebo group. So that's 0. 7 compared to 1. 6 percent for babies who are over three months. The authors concluded that when the vaccine is administered through pregnancy, and let's just remember that this study was done over 18 countries. So these statistics might not be representative of the stats in your country.
[00:33:08] Mel: So low to middle income countries have the highest incidence and mortality rates. So these are the severe RSV stats and the stats for just medically attended RSV infections where parents sought medical care. So for the vaccine group, it was 0. 7 percent and for the placebo group, it was 1. 6. So that was for medically attended sort of more severe cases.
[00:33:37] Mel: For more mild RSV infections, the stats are after three months, they approximately doubled in unvaccinated babies. So after three 1. 6. 139 children had RSV in the vaccine group compared to 297 in the non vaccinated group. So these stats do show a reduction in incidence by about 50 percent for infants whose mums had the vaccination.
[00:34:04] Mel: So that's clear, but just note that the vaccination is not going to prevent every case of RSV. So by using it, you approximately half your chance of your baby contracting RSV. This study also explains the mechanism by which maternal vaccination works. So essentially the woman receives the vaccine and then her body produces antibodies against RSV and these are circulating in maternal blood and then This article states that these antibodies can cross the placenta.
[00:34:38] Mel: So now the baby has the antibodies in their own bloodstream. The baby can't make these antibodies on their own. It's relying on their mother's body to make these. So once they're born, their immunity will reduce over time as the Maternal antibodies break down. And this paper also discloses that Pfizer sponsored, designed, conducted the trial and that the medical writers were paid by Pfizer, who wrote the research manuscript under the direction of the authors who were also paid and employed by Pfizer, so they also manufactured the vaccine and the placebo that was used in this study.
[00:35:18] Mel: So this study was different from the first that we looked at because they also collected data from women regarding their own experience of receiving the vaccine. So the first one only looked at baby outcomes. This one actually asked women if they had any reactions, how did it feel, you know, they collected data for one month.
[00:35:38] Mel: Uh, from the mothers and they only accepted data after one month if the reaction was considered severe. So the more common short term side effects were collected and they differed compared to the vaccine versus. Unvaccinated group, so the most common side effect that they discovered was that the vaccine group had more pain at the injection site and mild fever, which was reported by 41 of the vaccinated women and only 10 of the placebo group.
[00:36:09] Mel: And the other difference was muscle pain, which was experienced by 27 of the vaccinated women compared to 17 of the placebo group. So I'm looking at table one in this research paper, and I can see a lot of. So I'll just highlight the ones where I can see a difference. So if you're looking at this paper from the resource folder, you'll easily be able to decipher it.
[00:36:34] Mel: It's actually quite well explained in the paper. It's a simple visual. So here's where I see differences between the vaccine group and the Non vaccinated group. So, gestational age at birth in the vaccine group, 0. 6 percent were born between 28 and 34 weeks, compared to 0. 3 percent in the placebo group.
[00:37:01] Mel: So that's double the pre term birth age. in that gestation 28 34 weeks, although the relative number is small. There were 20 in the vaccine group and 11 in the placebo group. Then if we look at preterm birth between 34 and 37 weeks in the Vaccinated group, it was 5 percent compared to 4. 4 percent in the placebo group.
[00:37:28] Mel: So again, that's a small difference. There was 180 in the vaccine group and 157 in the placebo group. So combined, that's a preterm birth rate of 5. 6 percent for the vaccine group. and 4. 7 percent for the placebo group. Compared to the first study we looked at, the preterm birth occurred at a rate of 6. 8 percent in the vaccinated group in our first study.
[00:37:59] Mel: And in this group, the vaccinated group was 5. 6 percent preterm birth. And the placebo group had 4. 9 percent of preterm births. In the very first study compared to 4. 7 in this group. So the placebo group numbers are similar, but the preterm birth rate for the vaccine group was lower in this Pfizer study, but still higher than the placebo group.
[00:38:29] Mel: Now, one commentary explained that the Pfizer study actually had less women from low to middle income countries compared to the first study we spoke about, and that study was stopped. because of preterm birth fears. And they comment that many of the preterm births were in low to middle income country groups.
[00:38:49] Mel: So perhaps the lower inclusion of this demographic in the Pfizer study has also reduced the overall preterm rate in the vaccine group. I'm just speculating, but based on what we saw in the first study, the women from low to middle income countries were at higher risk of preterm birth. If they had the vaccine, the Pfizer study had less women in it from low to middle income countries, and also a reduced preterm birth rate.
[00:39:18] Mel: So again, speculating, but some of the commentaries also made a similar observation. So aside from that, newborn outcomes were very similar to each other when comparing the vaccine groups to the placebo groups when we look at this Pfizer study. Now the big issue that I see in both of these trials is that they both excluded women who had risk factors or complicating factors, which means that the study sample was largely low risk and we can't use this information to make conclusions about if any of these Same outcomes can be expected for women who have risk factors or for babies who are unwell in utero.
[00:40:01] Mel: So that's a limitation of both of these trials. We don't have any information about if yours or your baby's response to the vaccine will be different if there are complicating factors. That's something that you'll navigate with your healthcare provider, but from the research, we, there's no information to give you.
[00:40:20] Mel: Now, there's one more study that I will make reference to, and it's a meta analysis. So it's a combination of the studies that exist, the double blind studies of randomized control trials that exist around the RSV vaccine in pregnancy. I've just covered two of the papers that are in this meta analysis.
[00:40:42] Mel: And they've got one other one, which was also a Pfizer study. It was a phase two version of their phase three study, which we've already covered. So the reason I'm including this study. Is that it's the only research paper that was not written by one of the manufacturers of the vaccine. This is written by a team of academics who are affiliated with the university.
[00:41:05] Mel: They had no conflict of interest to declare. They weren't affiliated with the pharmaceutical industry. And it combines the findings of the existing studies to give us an overall view of the landscape, a bit of a zoom out. And so this is the last paper I'll be looking at today. And I'll start by reading the abstract summary and then we'll break it into more detail.
[00:41:29] Mel: So again, this is available in full text in the resource folder, but on Google, anyone can read it in full. I am not making this up. So the paper's called RSV PREV, PREV, vaccination in pregnancy, a meta analysis of maternal fetal safety and infant. Efficacy, it was published in 2024 in the Journal of Obstetrics and Gynecology Science.
[00:41:55] Mel: Now the abstract says, in May 2023, the United States Food and Drug Administration approved the Pfizer sponsored bivalent respiratory syncytial virus perfusion F protein based vaccine, RSV PREF, and it's called abrisfo, for use during pregnancy to prevent neonatal on infant RSV infection. In February of 2022, trials sponsored by GSK on a similar RSV vaccine were halted because of the identification of a safety signal relating to preterm births.
[00:42:32] Mel: As these vaccines use identical prefusion F protein technology, we sought to synthesize the existing data on their effectiveness and safety. We identified all randomized control trials to perform the analysis with 95 percent confidence intervals and risk ratios. We found many maternal side effects were more prevalent in the RSV vaccine group, with more local reactions, blood disorders, fatigue, joint pain, cardiac disorders, headache, fever, gastrointestinal disorders, and pregnancy complications.
[00:43:06] Mel: The vaccinated group demonstrated significant reductions in RSV infections, severe respiratory illness, and hospitalizations. RSV vaccination was associated with higher incidence of preterm birth. No significant differences in neonatal deaths were observed. In conclusion, RSV vaccination results in systemic adverse events and an increase in preterm birth.
[00:43:33] Mel: Vaccination appears to have acceptable short term newborn safety, but is not related to a significant decrease in neonatal death. The article also asked an important question later in the paper, stating that through vaccination, It's possible to envisage a future in which, in which RSV related morbidity and mortality in infants are significantly mitigated, is the word they use.
[00:44:02] Mel: However, this may occur at a cost in terms of maternal fetal safety and mutational pressure on RSV strains that will invariably become resistant to the vaccinated human host. What they're saying here is that we also have to remember that viruses have the ability to mutate in order to survive. And these authors are asking the question of what happens next after it mutates to become resistant to this current vaccine.
[00:44:34] Mel: So let's have a look at this paper closer and see what their conclusions are. So they found three papers that match their search criteria, the two that we've already covered and one more, which was the phase two trial done by Pfizer. And that was done before the phase three one that we've already spoken about.
[00:44:52] Mel: So efficacy outcomes, how well did the vaccine work? Here's what they've done when they pooled all the research. Among 7, 326 vaccinated women, there were 76 reported cases of RSV, so that's 1. 03%. When they compare that to the unvaccinated placebo group, There were 5, 294 people in that group and they reported 146 cases of RSV, which is 2.
[00:45:26] Mel: 75%. So that's 1. 03 percent compared to 2. 75%. So there's no doubt that the vaccine has the capacity to reduce RSV cases by around two and a half times if we go by these stats. So it's not completely protective, but it does have some effect on the baby's chances of getting RSV. And the next question to ask is, but at what cost?
[00:45:55] Mel: What are the consequences of vaccinating? We get less cases of RSV. Yes. And the cost is that there are minor. Things, for example, for the woman that we know of, pain at the injection site was significantly higher in the vaccine group, that women's arms were more sore than in the placebo group. So 50 percent of the vaccine group had a sore arm compared to 10 percent of the placebo group.
[00:46:22] Mel: Twice as many women in the vaccine group reported muscle pain compared to the placebo group. And redness, inflammation, and swelling at the injection site was about 6 percent in the vaccine group compared to 1 percent for the placebo group. So these were pretty minor and they didn't, they didn't seem to collect information on any immediate major consequences for.
[00:46:48] Mel: For women these are the only ones that they've reported. If we look at the babies there are lots of things that were looked at and all of them showed no differences in outcomes for babies with the vaccine group compared to the placebo group except that the authors when they pulled the data they state that the RSV vaccination was associated with a Significantly higher incidence of preterm birth occurring in 470 of the 7,152 mothers.
[00:47:18] Mel: So that's 6.6% of the ones who received vaccination, but only 285 of the 5,387 mothers who received placebo. So that was 5.3%, so 6.6% versus 5.3%. So the author's conclusions read. We found that the RSV vaccination was associated with a 24% increased risk of preterm birth. In addition, although vaccination resulted in a decrease in severe illness and hospitalization, there was no significant difference in neonatal mortality with 23 0 0.31% and 12 0.21% of deaths reported in the vaccination and placebo group respectively.
[00:48:12] Mel: So. Small percentage, less deaths in the placebo group, but in total in this study, 0. 31 percent of the babies whose mothers had been vaccinated died compared to 0. 21 percent in the placebo group. They go on to say that the consequences of preterm birth, including the need for neonatal intensive care, fetal complications and maternal complications were not described in the original manuscript and are concerning for application in practice on a broad scale.
[00:48:50] Mel: The authors state that these data curb enthusiasm for the RSV, maternal mass vaccination, and they stress the importance of informed consent for mothers, including serious warnings about the risk of premature labour. However, it is important to note that the exact pathogenesis of preterm labour, infectious or not infectious, has not yet been identified.
[00:49:12] Mel: So they go on to say that in this study. The RSV vaccine showed promising results that over a 360 day observation period, the vaccine notably reduced but did not eliminate instances of RSV associated lower respiratory tract illnesses in babies. However, There were no significant reductions in RSV hospitalization, hospitalizations or deaths.
[00:49:37] Mel: And it says that the reductions in mild cases of RSV appear to have come with a significant trade off as there was an observed increase in preterm birth among the participants who received the vaccine. So RSV vaccination in the third trimester of pregnancy is associated with a 24 percent increased risk of preterm labour and birth and this may cause avoidable maternal fetal complications with unknown long term consequences.
[00:50:05] Mel: So although the vaccine demonstrated notable efficacy in reducing mild RSV illnesses over a year after delivery, there was no significant decrease in neonatal mortality. These authors have suggested that additional research and continued surveillance are essential to determine the balance between the risks and benefits of the RSV vaccination.
[00:50:30] Mel: I'm going to leave that paper there and encourage you to read it in full. If you want further information about the, any of the details on that. And finally, and very briefly, since there are a number of vaccines recommended during pregnancy here in Australia, let's also just ask the question about what happens when all of these vaccinations are given at once, or perhaps if there's a recommendation to stagger them throughout your pregnancy and have them one at a time.
[00:50:58] Mel: So the immunization handbook says that pregnant women can receive a BRISVO at the same time as, or separate to, the Whooping cough, flu, and COVID 19 vaccines. So data on co administration in pregnant women are still emerging, but there are no theoretical concerns. So studies on co administration in non pregnant women showed no safety concerns.
[00:51:26] Mel: There was a reduction in the antipertussis antibodies when a Brisbo and the whooping cough vaccine were given at the same time. However, they've said that the clinical significance of this is uncertain. So they haven't recommended any additional whooping cough doses. And they said there's no differences in the immune response to the RSV vaccine when they tested the combination in non pregnant women.
[00:51:52] Mel: So a few things to know here is that the combination of all three vaccinations, including Whoopie Cough, flu, RSV and COVID have not been tested together in pregnant women. These are the three or four that are now recommended for all pregnant women in Australia. And the Australian government provides those for free.
[00:52:11] Mel: So some resources state that theoretically combining all three should be fine, but this is just a theory. And we. Can't really give you any further information on that but certainly that's the information that's offered in the Australian Immunisation Handbook. The other things to note is that the total study size of all the studies put together on this vaccine is around 7, 300 women who received the vaccine.
[00:52:42] Mel: So, more rare risks are unknown, so we can't offer you information on the more rare things that might happen in one in 10, 000 situations. And all of the vaccines, this particular one that's offered, they're only a few years old, so there's no long term data to draw from. All of that will kind of unfold and be discovered over time.
[00:53:05] Mel: And the other thing to remember is to consider yours and your baby's risk within your own context and location where you live. If you consider that you and your family are in higher risk circumstances with a baby or children who have comorbidities, or if you're living in a low to middle income country, This vaccine might feel more important to you.
[00:53:26] Mel: Now, the vast majority, 97 percent of RSV mortality happens in low to middle income countries, with only 3 percent occurring in high income countries. So there's no doubt the burden of RSV Um, the healthcare system is significant enough to warrant the introduction of this vaccine. So it's up to you to decide if it's right for you and your circumstance.
[00:53:51] Mel: So this is the information that I'll be offering to my clients that firstly, the Australian government is now funding and recommending RSV vaccine in pregnancy for women between 28 and 34 weeks pregnant. pregnant in addition to the two existing vaccines, the flu vaccine and the whooping cough vaccine.
[00:54:09] Mel: And there's been the theoretical suggestion that these could all be given together, but no one's really tested that. And in the circumstances where it has been checked, the whooping cough vaccine had a slight reduction in antibody production. So in short, we don't fully understand. And haven't researched all three together in pregnant women.
[00:54:28] Mel: So their safety in combination is theoretical. The Nursing and Midwifery Board of Australia uses the Australian Immunization Handbook as their authoritative resource on vaccination in pregnancy and midwives and maternity care workers are required to advise our clients in accordance with that. So that I've included that resource in the.
[00:54:50] Mel: Resource folder for anybody who wants to have a look and as midwives and maternity care workers, our regulatory body requires us to recommend vaccination regimes that are in accordance with government recommendations, which are listed there in the book. So my code of conduct and midwife standards for practice require that I support women's well being by providing safe, quality, midwifery healthcare using the best available evidence and resources, which is what I've offered here today in the podcast.
[00:55:22] Mel: And this information that I've shared today is what I will draw on when I am answering questions from my clients. So, Finally, it's not my position to determine which women should and should not take this vaccine. That is a choice for women to make with the information that they have. I recommend that any women who has questions about the RSV vaccine make decisions in conjunction with their care provider, because everyone's circumstances are different.
[00:55:51] Mel: Do your own work and thinking around this. And I'll see you next time. Uh, some women have concerns around additional ingredients that are in vaccinations and I won't be commenting on those today, but certainly if that's your concern, then it's your prerogative to do research on that. That is all from me today.
[00:56:11] Mel: That's been the RSV vaccine in pregnancy, and I will see you in the next episode of the Great Birth Rebellion podcast. To get access to the resources for each podcast episode, join the mailing list at melaniethemidwife.com. And to support the work of this podcast, wear the rebellion in the form of clothing and other merch at thegreatbirthrebellion.com. Follow me, Mel, @MelanieTheMidwife on socials, and the show @TheGreatBirthRebellion. All the details are in the show notes.