Key TakeawaysPfizer earned a breakthrough therapy designation status for an RSV vaccine for pregnant people to help protect infants against severe RSV illness in their first year of life.Phase 2 clinical trial results show that the RSVpreF vaccine is effective at providing fetal antibodies. It will now move to phase 3 trials.RSV is a common seasonal virus that can cause bronchitis and pneumonia in infants, children, and older adults who are at high risk for severe respiratory illness.There is currently no vaccine to prevent RSV.

Key Takeaways

Pfizer earned a breakthrough therapy designation status for an RSV vaccine for pregnant people to help protect infants against severe RSV illness in their first year of life.Phase 2 clinical trial results show that the RSVpreF vaccine is effective at providing fetal antibodies. It will now move to phase 3 trials.RSV is a common seasonal virus that can cause bronchitis and pneumonia in infants, children, and older adults who are at high risk for severe respiratory illness.There is currently no vaccine to prevent RSV.

Early results of a phase 2 clinical trial show Pfizer’s investigational RSVpreF vaccine provides newborns antibody protection against RSV.RSV—respiratory syncytial virus—is a common cause of infant hospitalization and childhood pneumonia for an estimated 58,000 children under the age of 5 each year.

What Is RSV and Who Is at Risk?

RSV is a common contagious respiratory virus that circulates each year similar to influenza. It’s a major cause of acute lower respiratory tract infection (bronchitis, pneumonia) hospitalizations for infants and children younger than 5 years old.

There is not currently a vaccine to prevent RSV.

Symptoms of RSV typically occur in stages and include:

While the majority of children infected with RSV will have mild symptoms and make a complete recovery, there is a subset of infants, children, and older adults who are at a high risk for serious RSV complications resulting in hospitalization, and possibly, death.

Infants and children with specific risk factors are more susceptible to severe RSV illness. These groups include:

How RSV Is Currently Treated

Palivizumab is a monthly injection for premature infants (delivered at or before 35 weeks) and babies with a pre-existing condition that puts them at risk for hospitalization and severe illness from an RSV infection.It’s only administered during RSV season (fall, winter, and spring).

An RSV Vaccine Is in the Works

There May Be an RSV Vaccine for Infants Soon

Moderna is also in the process of testing a single dose RSV vaccination for adults over the age of 60. Currently called mRNA-1345, the vaccine is in phase 3 of clinical trials.Researchers hopes it will help prevent over 177,000 hospitalizations and 14,000 deaths associated with RSV complications in people over 65.

What’s Next?

The RSVpreF vaccine for pregnant people will move into phase 3 of clinical trials to establish if it is safe without the chemical compound aluminum hydroxide, which was associated with local reactions and side effects in earlier phases of the study.

Currently, the immunizations recommended for pregnant people include the annual influenza vaccine and the Tdap vaccine to prevent neonatal pertussis (whooping cough).

Tdap Vaccine: Uses, Side Effects, Schedule, and More

If your child is at high risk for severe RSV disease, talk with your healthcare provider to see if Synagis is a preventative option during RSV season.

What This Means For You

10 Sources

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Healio.Moms who receive investigational RSV vaccine pass antibodies to infants.

Centers for Disease Control and Prevention.RSV in infants and young children.

Simões EAF, Center KJ, Tita ATN, et al.Prefusion F protein–based respiratory syncytial virus immunization in pregnancy.N Engl J Med.2022;386(17):1615-1626. doi:10.1056/NEJMoa2106062

Centers for Disease Control and Prevention.Increased interseasonal respiratory syncytial virus (RSV) activity in parts of the southern United States.

Centers for Disease Control and Prevention.RSV symptoms and care.

National Library of Medicine: DailyMed.SYNAGIS- palivizumab injection, solution[drug label].

Hammitt LL, Dagan R, Yuan Y, et al.Nirsevimab for prevention of RSV in healthy late-preterm and term infants.N Engl J Med.2022;386(9):837-846. doi:10.1056/nejmoa2110275

BioSpace.Moderna initiates phase 3 portion of pivotal trial for mRNA respiratory syncytial virus (RSV) vaccine candidate, following independent safety review of interim data.

Centers for Disease Control and Prevention.RSV in older adults and adults with chronic medical conditions.

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