By Ransdell Pierson
(Reuters) - An influential U.S. medical advisory panel on Wednesday recommended that people 65 and older be given Pfizer Inc's blockbuster Prevnar 13 vaccine to protect against pneumococcal bacteria that can cause pneumonia and other infections.
The Advisory Committee on Immunization Practices (ACIP), in a 13-2 vote, recommended that elderly patients take Pfizer's vaccine, even if they had previously been vaccinated with Merck & Co's leading Pneumovax vaccine.
But the panel, which provides medical advice to the U.S. Centers for Disease Control and Prevention, expressed concern that the federal Medicare insurance program for the elderly currently is unable to cover Prevnar 13 for patients who have already taken Pneumovax.
A Medicare official, speaking to the panel in Atlanta, said his agency would have to change its rules in order to qualify such patients for reimbursement, and that its evaluation would likely extend until January 2016.
Prevnar 13 and an older version of the vaccine known as Prevnar 7 have combined annual sales of almost $4.5 billion, making them Pfizer's second-biggest franchise. Prevnar 13 is approved for children 6 weeks through 17 years of age, and for adults 50 and older.
Although used mainly to prevent infections in young children, data in March from a large-scale trial showed Prevnar 13 was highly effective in those 65 and older. Based on its brightened prospects in the elderly, industry analysts raised their long-term sales forecasts for the vaccine by as much as $3 billion a year.
But the forecasts hinged on a positive recommendation from ACIP, whose endorsements doctors and insurers rely upon in deciding whether to prescribe and reimburse vaccines.
"They (ACIP) are probably the most senior body in the United States that makes recommendations for use of vaccines, and once they make a recommendation, that is what insurers follow," said Susan Silbermann, president of Pfizer Vaccines. She noted, however, that the director of the Centers for Disease Control must ratify the advisory panel's decision.
The panel recommended that adults 65 years or older who have not previously received either Prevnar or Pneumovax, or whose previous vaccination history is unknown, should first receive a dose of Prevnar 13, followed by a dose of Pneumovax.
Adults in that age range who have not previously received Prevnar 13, but have received Pneumovax, should receive a dose of Prevnar, the panel recommended.
The panel also recommended that Prevnar 13 be re-evaluated in 2018, and revised as needed. That is because far fewer people are expected to be prone to infections after others are widely vaccinated - a phenomenon known as herd immunity.
Pneumovax had global sales of $653 million in 2013, with 8 million doses distributed in the United States. But many doctors have said they consider the product minimally effective.
Pfizer shares were up 1.2 percent in after-hours trading, from their closing price on Wednesday of $28.08.
(Reporting by Ransdell Pierson; editing by Gunna Dickson)