A recommendation to expand the indication for respiratory syncytial virus vaccines developed by Pfizer (PFE) and GSK (GSK) is being reviewed by a top aide to US Health Secretary Robert Kennedy, Reuters reported Tuesday, citing documents it reviewed and two people familiar with the matter.

The Advisory Committee on Immunization Practices recently recommended that the Centers for Disease Control and Prevention expand eligibility for RSV vaccination to high-risk adults aged 50 to 59, down from the current threshold of 60 years.

While the CDC is not required to follow ACIP recommendations, its adoption would establish formal guidance for clinicians, according to the news outlet.

Dr. William Archer III, a counselor in the secretary's office at the Department of Health and Human Services and a longtime vaccine critic, has asked for more evidence to support the recommendation, pointing to what he called a "possible decline in efficacy with a second dose," Reuters reported.

Archer reportedly requested more details on the adjuvants and platforms used in the vaccines under discussion, as well as their duration of protection.

The companies did not immediately respond to a request from MT Newswires on Tuesday seeking comment.

The US Department of Health and Human Services also did not respond to a request from MT Newswires for comment. However, an agency spokesperson told Reuters it would ensure all recommendations adhere to the "Gold Standard of Science."

(Market Chatter news is derived from conversations with market professionals globally. This information is believed to be from reliable sources but may include rumor and speculation. Accuracy is not guaranteed.)

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