Most Expectant Moms Say They’re Likely to Get Maternal RSV Vaccine

— But one in five soon-to-be parents said they had never even heard of RSV, survey finds

by
Katherine Kahn, Staff Writer, MedPage Today
April 25, 2024

A majority of pregnant individuals or those trying to become pregnant were interested in getting a maternal respiratory syncytial virus (RSV) vaccine once it became available, a nationwide survey found.

Of 1,528 respondents, 54% said they were “very likely” to get an RSV vaccine during pregnancy, Jennifer Saper, MD, of the Ann & Robert H. Lurie Children’s Hospital in Chicago, and colleagues reported in Pediatrics.

“I am excited by the findings that over half of pregnant, or trying-to-be-pregnant people are interested in the RSV vaccine in pregnancy,” Saper told MedPage Today in an email. “This means to me that there are a lot of opportunities to try to protect infants against RSV.”

However, 20% of survey participants had never heard of RSV and other participants varied substantially in their knowledge about the likeliness and severity of the common respiratory scourge, which is one of the most common reasons for infant hospitalization:

• 40% perceived that RSV illness in children was both likely and serious
• 45% thought RSV infection in children was serious, but not likely
• 16% did not think RSV infection was serious

The perception of RSV as a serious illness was the strongest predictor of vaccination likelihood. Of the participants who thought RSV was both serious and likely, 63% reported that they were very likely to get the RSV vaccination during pregnancy, but only 35% of those who thought that RSV illness was not serious — whether or not they thought RSV illness was likely — said they were interested in getting the vaccine (P<0.001).

“We hope that this study highlights the importance of having conversations with people about the importance of RSV prevention,” Saper emphasized.

Whether or not future parents already had one or more children also influenced their perceptions of the RSV vaccine. Of those with one or more children at home, 57% reported they were very likely to receive the RSV vaccine during pregnancy, compared with 50% of those with no children at home (P=0.01).

Also, participants without children at home were less likely to perceive RSV as serious or likely. For example, in this group, just 33% perceived RSV illness among children as both serious and likely, versus 44% who had one or more children at home. Over half (52%) with no children thought RSV illness was not likely but serious, versus 40% of those with children.

“RSV has all along been greatly under-perceived by adults and internists who take care of adults,” Sarah Long, MD, a pediatrician at Drexel University in Philadelphia and member of the CDC’s Advisory Committee on Immunization Practices (ACIP), commented to MedPage Today.

However, Long wasn’t surprised that overall only about half of survey participants were interested in getting the future vaccine, because the survey was conducted in March 2023 — several months before the bivalent RSVpreF vaccine (Abrysvo) received FDA approval for use during pregnancy to protect infants. “Think about it…. [the survey] is before there’s a vaccine and you’re not even pregnant, or maybe you are pregnant. I would say [it’s] not likely I would get the vaccine until I knew a whole lot more about it,” she conjectured.

“Our survey was conducted in spring 2023 before the RSV vaccine had been approved or recommended for pregnant people, and perceptions may have changed once the vaccine was approved or recommended,” Saper and colleagues acknowledged.

Currently, to prevent serious illness in infants from RSV, the CDC recommends either that 1) pregnant people get the maternal RSV vaccine at 32 through 36 weeks of pregnancy during the RSV season, or 2) infants younger than 8 months of age who are born during or entering their first RSV season receive the monoclonal antibody nirsevimab (Beyfortus).

Long indicated that updates to data on the effectiveness and safety of the maternal RSV vaccine are probably coming later this year, but projected that there would likely be no changes to the ACIP’s recommendations for either the maternal RSV vaccine and nirsevimab. She noted that there had been a “huge uptake, much more uptake than we had ever imagined” of both preventive measures since their FDA approvals in 2023.

The survey was conducted from March 1 to March 20, 2023. Of 3,413 people who started the survey, 47% completed it, and the final sample size for analysis was 1,528. About half of respondents were currently pregnant and half were planning to become pregnant during 2023. Approximately 75% of respondents were 35 years of age or younger, and about one-third were 18 to 25 years of age. Of respondents, 41% resided in the South U.S. census region and a majority (59%) identified as non-Hispanic whites. Nearly all (96%) respondents had health insurance, 50% had commercial insurance and 46% had public insurance.

Among respondents who had previously been pregnant, 59% reported receiving the tetanus, diphtheria, and pertussis (Tdap) vaccine and 62% had received the influenza vaccine. The authors pointed out this was a similar proportion of respondents who indicated they were likely to get an RSV vaccine in pregnancy.