New Merck pneumococcal vaccine wins FDA approval

The Food and Drug Administration on Monday approved Merck’s new pneumococcal vaccine for adults 18 and older.

The vaccine, which will be sold under the name Capvaxive, is designed to protect against pneumococcal pneumonia, which hospitalizes about 150,000 adults in the United States every year and kills about 1 in 20 who develop it, according to the National Foundation for Infectious Diseases.

The vaccine is also designed to protect against infections that progress to the rarer but more life-threatening invasive pneumococcal disease, which can take the form of bloodstream infections or pneumococcal meningitis; these conditions kill roughly 1 in 6 older adults who develop them. The NFID estimates that about 3,000 older adults die of these conditions annually.

Capvaxive is the first pneumococcal vaccine specifically aimed at protecting against the serotypes of Streptococcus pneumoniae — the bacteria that cause pneumococcal disease — that most commonly infect older adults. It covers 21 different serotypes of Strep pneumoniae, including eight that are not targeted by any of the other available vaccines. Until now, the vaccine that protected against the most serotypes of the bacteria was Pfizer’s Prevnar 20.

“We are proud to provide Capvaxive as a new option specifically designed to help protect against the majority of invasive pneumococcal disease-causing serotypes in adults,” Dean Y. Li, president of Merck Research Laboratories, said in a statement.

The serotypes targeted by the vaccine were responsible for roughly 85% of the cases of invasive pneumococcal disease that were diagnosed during 2018 to 2021, Merck said in its statement, citing data from the Centers for Disease Control and Prevention.

Capvaxive was licensed based on what is known as immunogenicity testing, in which immune responses of people who received it were compared to those of people who received a competitor vaccine. Separate trials were conducted on people who had previously been vaccinated against pneumococcal disease, and people who had not.

The company said it will conduct a clinical trial to determine real-world effectiveness of the vaccine.

The vaccine was well tolerated among people who received it, with older adults in particular reporting few side effects. For people over age 50, pain at the injection site, fatigue, and headache were the most commonly reported after-effects. Adults 18 to 49 years old reported those complaints, as well as muscle aches and redness and swelling at the site of the injection.

There were no reports of Guillain-Barré syndrome among people who received Capvaxive. GBS is a progressive and generally temporary form of paralysis that is a rare side effect associated with some vaccines.

Before Capvaxive can be put into use, it must receive a recommendation from the CDC. The Advisory Committee on Immunization Practices, which advises the CDC on vaccination policy, meets next week for one of its three regularly scheduled meetings. A draft agenda for the meeting shows that a vote on Capvaxive is scheduled for Thursday, June 27.