The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practice will meet this week to consider and recommend who should get respiratory syncytial virus (RSV), influenza, and COVID-19 vaccines.

In the presentation slides to the U.S. agency, Moderna Inc ( MRNA ) shared safety set data, with a cut-off date of March 8, 2024, based on the median of 18.8 months of follow-up.

The data showed that vaccine efficacy fell to around 50% after 18 months on participants aged 60 years and above.

Vaccine efficacy in the infection with more than two symptoms was 50.3% and 49.9% in disease with three or more symptoms.

After a median of 3.7 months of follow-up, vaccine efficacy stood at 78.7% and 80.9%, respectively, falling to 62.5% and 61.1% after a median of 8.6 months.

Efficacy of a single dose of GSK Plc’s Arexvy over two calendar years showed vaccine efficacy of 73.3% (W/o season covariate) and 78.6% in severe infection.

Pfizer Inc’s Abrysvo demonstrated an overall efficacy of 77.8% in the second season and 81.5% across two seasons.

Last year, GSK’s Arexvy and Pfizer’s Abrysvo went head to head for adults over 60.

Reuters notes that GSK won two-thirds of the market, mostly due to its contracts with retail pharmacies, including CVS Health Inc .

Last month, Moderna Inc. ( MRNA ) received FDA approval for its shot, mRESVIA, to protect adults aged 60 and older.

Earlier this year, Moderna’s longer-term trial analysis revealed a faster decline in the effectiveness of its RSV vaccine.

Follow-up data from Phase 3 mRNA-1345 Trial ReSViNET suggests the vaccine efficacy is declining faster than RSV vaccines from GSK and Pfizer ( PFE ).

Read Next: Pfizer Seeks Expanded Use Of Abrysvo As Vaccine Shows Potential In 18+ Patients.

Pfizer ( PFE ) secured a major contract with the U.K. to supply millions of doses of its Abrysvo respiratory syncytial virus (RSV) vaccine, edging out local pharmaceutical giant GSK.

This agreement includes over 3.5 million doses for older adults and more than 1.4 million doses for pregnant mothers in England and Northern Ireland over the next two years.

Price Action: MRNA shares are down 6.98% at $128.08 at the last check on Wednesday.