Promising RSV Vaccine Candidate Raises Hopes

The so-called tripledemic of COVID-19, influenza, and respiratory syncytial virus (RSV) throughout the United States this season¹ highlights the fact that though there are effective and safe vaccines for the coronavirus and the flu, there is no RSV vaccine on the market yet, but that may soon change.

However, there is a promising RSV vaccine in the pipeline. Infants, children, and adults can become infected with RSV. Typically, patients experience cold-like symptoms, such as cough, fever, and rhinorrhea.² More severe symptoms can include pneumonia and wheezing.² Pharmacists can play a key role in providing RSV prevention education and tips about a promising vaccine on the horizon.

RSV Vaccine

Pfizer is studying an investigational RSV vaccine, RSVpreF, for pregnant women and adults aged 60 years and older.^3-5 On December 7, 2022, the FDA accepted for priority review Pfizer’s Biologics License Application (BLA) for its RSV vaccine for individuals aged 60 years and older.³ The FDA is expected to decide on the BLA by May 2023.³ The BLA submission is based on positive results from the phase 3 trial RENOIR.⁴ The efficacy and safety of RSVpreF was evaluated in adults aged 60 years and older. Approximately 37,000 participants were randomized to receive RSVpreF 120 mcg or a placebo.⁴ Top-line results showed that RSVpreF was approximately 86% effective for preventing severe illness, and there were no safety concerns.⁴

Pfizer announced top-line data for the maternal RSVpreF vaccine in November 2022.5 Vaccine efficacy was approximately 82% for severe RSV illness in newborns through the first 90 days of life.⁵ Additionally, the RSV vaccine was approximately 69% effective through the first 6 months of life.5 RSVpreF was well-tolerated, with no safety concerns for pregnant women and their newborns. MATISSE is a phase 3 clinical trial of approximately 7400 pregnant individuals aged 18 to 49 years and their infants.5 Pregnant women were randomized to receive either 1 dose of RSVpreF 120 mcg or a placebo.5 Pfizer is planning to submit its maternal RSV vaccine BLA to the FDA by the end of 2022.⁵

RSV Prevention Strategies

RSV transmission occurs through respiratory droplets and frequently touched surfaces. Individuals infected with RSV are generally contagious for 3 to 8 days.⁶ In fact, some individuals can continue to spread RSV after symptoms have resolved for up to 4 weeks.⁶ Individuals can also be contagious 1 to 2 days before displaying symptoms.⁶ Pharmacists should educate patients and their families about RSV prevention strategies, especially as the holidays approach. Practicing good hand hygiene is an important strategy to prevent the spread of RSV. Individuals should wash their hands with soap and water for at least 20 seconds.⁶ Encourage patients to cover their coughs and sneezes with a tissue or upper shirt sleeve. Frequently touched surfaces, such as doorknobs and mobile devices, should be cleaned frequently.⁶ Wearing a well-fitted high-quality mask, such as K95 or N95, can also prevent the spread of RSV.¹ Masks can also protect against co-infection with other respiratory illness, such as COVID-19 and influenza.¹

Individuals with cold-like symptoms should avoid contact with others. Additionally, individuals at higher risk of severe RSV include:^6,7

• Adults aged 65 years and older
• Children younger than aged 2 years
• Children with neuromuscular disorders
• Individuals with cardiovascular or chronic lung conditions
• Patients who are immunocompromised
• Premature infants

References

1. Transcript: CDC media telebriefing-update on respiratory disease circulation. CDC. December 5, 2022. Accessed December 9, 2022. https://www.cdc.gov/media/releases/2022/t1208-Respiratory-Disease-Circulation.html

2. Respiratory syncytial virus infection (RSV) for healthcare providers. CDC. October 28, 2022. Accessed December 9, 2022. https://www.cdc.gov/rsv/clinical/index.html

3. U.S. FDA accepts for priority review the Biologics License Application for Pfizer’s respiratory syncytial virus vaccine candidate for the prevention of RSV disease in older adults. Pfizer. News release. December 7, 2022. Accessed December 9, 2022.https://www.pfizer.com/news/press-release/press-release-detail/us-fda-accepts-priority-review-biologics-license-0

4. Pfizer announces positive top-line data from phase 3 trial of older adults for its bivalent respiratory syncytial virus (RSV) vaccine candidate. Pfizer. News release. August 25, 2022. Accessed December 9, 2022. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-announces-positive-top-line-data-phase-3-trial-older

5. Pfizer announces positive top-line data of phase 3 global maternal immunization trial for its bivalent respiratory syncytial virus (RSV) vaccine candidate. Pfizer. News release. November 1, 2022. Accessed December 9, 2022. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-announces-positive-top-line-data-phase-3-global

6. RSV prevention. CDC. October 31, 2022. Accessed December 9, 2022. https://www.cdc.gov/rsv/about/prevention.html

7. RSV in adults and adults with chronic medical conditions. CDC. October 28, 2022. Accessed December 9, 2022. https://www.cdc.gov/rsv/high-risk/older-adults.html#:~:text=Adults%20at%20highest%20risk%20for,Adults%20with%20weakened%20immune%20systems