Document text
Centers for Disease Control and Prevention
Clinical considerations for RSVpreF maternal vaccine
and nirsevimab
Jefferson Jones MD MPH FAAP
CDR USPHS
Co-Lead, Respiratory Syncytial Virus Vaccines -Pediatric/Maternal
Work Group
Coronavirus and Other Respiratory Viruses Division
National Center for Immunization and Respiratory Diseases
June 22, 2023
2Policy questions for ACIP vote
▪Should vaccination with Pfizer RSVPreF vaccine (120µg antigen, 1 dose IM given 24 -
36 weeks gestation) be recommended for pregnant people to prevent RSV disease
in infants?
▪Should one dose of nirsevimab be recommended for infants born during or
entering their first RSV season and <8 months of age at time of immunization?
▪Should one dose of nirsevimab be recommended for children who are at increased
risk of severe RSV disease entering their second RSV season and <20 months of age
at time of immunization?
3Potential advantages of maternal vaccination versus a
monoclonal antibody (mAb)
▪ A maternal vaccine may be lower in price
▪ A mAb is not a traditional vaccine and many issues may complicate implementation
–Insurance coverage, vaccine schedule, immunization registries, safety monitoring
▪ Maternal vaccine provides protection from birth, when infants are at highest risk
–A mAb must be timed correctly to provide protection during the RSV season, and atypical RSV
transmission may lead to unprotected infants
▪ Maternal vaccine induces a polyclonal antibody response, which should be more resilient to
mutations than a monoclonal antibody
–Evidence suggests that mutations resulting in nirsevimab resistance are rare, but naturally
occurring resistant mutations have been detected1,2
–Mutations resulted in poor efficacy of a previous mAb product ( suptavumab )3
1 Abram IDweek 2022. 2 Abram 12th RSV International Symposium 2022. 3Simões CID 2021 .
4Potential advantages of mAb over maternal
vaccination
▪Imbalance for preterm birth observed after RSVpreF vaccine vs. placebo in maternal clinical
trials, but not statistically significant1
▪No head -to-head trials comparing efficacy, but protection from maternal vaccination likely
wanes more quickly1–4
▪Estimated half-lifein nirsevimab trials
–Nirsevimab : 63–73 days5,6
–Infection -induced maternal RSV antibodies: 36 –38 days5
▪Nirsevimab administration can be timed to be given when infant is entering RSV season
1 Kampmann NEJM 2023 . 2 Muller NEJM 2023 . 3Madhi NEJM 2020 . 4Nunes F1000Res 2018 . 5Wilkins Nat Med 2023 . 6Griffin NEJM 2020 .
5Potential advantages of mAb over maternal
vaccination (continued)
▪Protection from maternal vaccination relies on sufficient transplacental transfer of
antibodies, which may be reduced in
–Infants born soon after maternal immunization1
–Infants born premature2
–Maternal disease2
▪Maternal uptake of flu and Tdap vaccines lower than routine childhood vaccines3,4
–Unclear if pregnant people willing to accept multiple vaccines during pregnancy
–However, flu vaccine uptake among children only mildly higher than among pregnant
people
–Uptake of maternal RSVpreF vaccine and nirsevimab unknown
1https://www.cdc.gov/vaccines/pregnancy/vacc -during -after.html. 2Palmerira Clin Dev Immunol 2012 .
3https://www.cdc.gov/flu/fluvaxview/pregnant -women -apr2022.htm. 4Hill MMWR 2023
6Benefits of both products being available
▪Each product has certain advantages
▪Parental preferences may differ, as suggested by survey asking pregnant people
about product preference if both available1
–28% only maternal vaccine
–25% only RSV antibody injection
–38% both
▪Some populations lack access or do not present for prenatal care, precluding
maternal vaccination
▪Scenarios may exist for which use of both products may be warranted to maximize
protection from RSV -associated severe disease–8% none
–1% other
1 Unpublished CDC and University of Iowa/RAND survey of 523 people currently pregnant or pregnant within last 12
months of survey conducted December 21, 2022 -January 2, 2023
7Cost effectiveness summary
▪Cost effectiveness of giving nirsevimab if mother had been vaccinated
–$668,735/QALY if given to all infants
–$486,882/QALY if given to infants born April to September
▪Cost effectiveness of giving RSVpreF to mother if nirsevimab will be
given
–More than $10,000,000/QALY on average
8Challenges if nirsevimab recommendations relate to
maternal vaccination status
▪Maternal vaccination status might be unknown
▪Transferring documentation of maternal vaccination to the healthcare
provider of infant may be difficult
–Limited information available during birth hospitalization
–Less information regarding receipt of prenatal vaccinations may be
available to infant primary care providers
9Draft clinical considerations if both RSVpreF and
nirsevimab are licensed and recommended
▪Either maternal vaccination with RSVpreF or nirsevimab is recommended to
prevent RSV disease, but both products are not needed for most infants
▪Risks and benefits of both RSVpreF and nirsevimab should be considered
when deciding on maternal vaccination
▪If mother vaccinated, nirsevimab can be considered if infant considered to
have insufficient protection from vaccine or is at high risk of severe disease
10Scenarios to consider administration of nirsevimab
when mother has been vaccinated
▪Receipt of maternal vaccine not confirmed by healthcare record
▪Infant born within 14 days of vaccination
▪Infant born premature
▪Healthcare provider recommends maximizing protection because infant at
high risk of severe disease
–Especially important if born >3 months prior to peak of RSV season
For more information, contact CDC
1-800-CDC-INFO (232 -4636)
TTY: 1 -888-232-6348 www.cdc.gov
The findings and conclusions in this report are those of the authors and do not necessarily represent the
official position of the Centers for Disease Control and Prevention.