GlaxoSmithKline (GSK.US) RSV vaccine receives FDA expanded approval, adding 21 million adults to the market to compete with Pfizer.

According to Tonghuashun Finance APP, GlaxoSmithKline (GSK.US) developed the RSV (respiratory syncytial virus) vaccine Arexvy, which received expanded approval from U.S. regulators on March 13 (Friday). The approval now covers all high-risk adult populations. Considering the Trump administration’s increased scrutiny of vaccination-related matters, this news is undoubtedly a reassurance for pharmaceutical companies.

This vaccine was previously approved by the U.S. Food and Drug Administration (FDA) for all adults aged 60 and over, as well as those aged 50 to 59 with at least one condition that increases the risk of severe infection. The new approval will add approximately 21 million adults in the U.S. who are eligible for vaccination, allowing Arexvy to compete on equal footing with Pfizer’s (PFE.US) similar vaccine in the market.

RSV (respiratory syncytial virus) is a highly dangerous virus that can be fatal, especially threatening infants and the elderly. In the U.S. alone, tens of thousands are hospitalized each year due to infection. About 17,000 adults aged 18 to 49 are hospitalized annually due to RSV infection. GSK’s developed vaccine uses an adjuvant provided by Agenus, which enhances the immune response.

For vaccine supporters, this approval is a significant positive development. Previously, senior health officials in the Trump administration criticized vaccination efforts and raised standards and thresholds for future vaccine approvals. Notably, Vina Prasad, former head of the FDA’s vaccine division, announced he will step down next month, ending his turbulent second term. The approval decision was announced just one week after his announcement.

The approval was based on a study with fewer than 1,000 participants. The study found that the immune response in the 50-59 age group was roughly comparable to that in the approved 60+ population. Additionally, 600 participants were followed for safety monitoring.

Next, the U.S. Advisory Committee on Immunization Practices (ACIP) will consider whether to include the 50-59 age group in the Arexvy vaccination recommendation. This committee plays a key role in determining insurance coverage for vaccines. Previously, it voted to expand RSV vaccination recommendations to adults aged 50-59. However, it has not yet decided whether to recommend booster doses, which has led to market uncertainty regarding the potential for repeat vaccinations.

The committee will hold a meeting next week, but so far, there has been no clear indication of when they might consider expanding the RSV vaccination recommendation. It is important to note that “expanding” here refers to the recommendation for repeat doses, not the age range for vaccination.