Merck outflanks Pfizer's 20-valent shot with pneumococcal vaccine approval for kids
Back in April, the FDA asked for more analysis from Merck on its 15-valent pneumococcal vaccine for children and pushed back its approval deadline by three months. As the three-month mark approaches, the FDA appears to be satisfied.
Merck announced today that the FDA approved its vaccine for children ages 6 weeks and up, making it the third pneumococcal shot approved for children. The vaccine, which is marketed as Vaxneuvance, was already OK’d for adults back in July 2021.
The FDA approved Vaxneuvance for children and infants based on results from seven trials that compared Vaxneuvance to Pfizer’s Prevnar 13, which, as the name suggests, is a 13-valent pneumococcal vaccine. Merck’s shot covers the 13 strains of pneumococcal bacteria in Prevnar, along with two additional strains — 22F and 33F.
“Despite decreases in incidence of invasive pneumococcal disease in children, certain key serotypes continue to cause serious illness that can lead to death in children under the age of 5, with serotypes 3, 22F and 33F responsible for more than a quarter of all invasive pneumococcal disease cases in this population,” Steven Shapiro, the lead investigator for Merck’s pediatric Vaxneuvance trial, said in a statement.
Pneumococcal bacteria can cause an array of serious diseases, including pneumonia, bacteremia and meningitis, which can cause long-term neurological damage.
Merck’s early pneumococcal vaccine, known as pneumococcal polysaccharide vaccine 23, or PPSV23 for short, was approved in the early 1980s. However, it was not effective in kids under 2 since they didn’t respond much to the polysaccharides. As a result, vaccine manufacturers turned to conjugate vaccines, which attach polysaccharides to a protein and elicit a stronger immune response.
According to Ulrike Buchwald, Merck’s section head for pneumococcal vaccines, linking the polysaccharide from the bacteria to a protein can help recruit T cells, in what is known as “T cell help.”
Pfizer is also working to get its newer 20-valent pneumococcal vaccine approved in kids. Prevnar 20 was approved in adults a month before Vaxneuvance but is still in clinical trials for kids. Merck also has a 21-valent vaccine for adults in the works, set to enter Phase III clinical trials later this year.
Buchwald noted that the 21-valent vaccine, dubbed V116, is meant to address the “residual burden of disease” in adults. V116 includes 8 serotypes that aren’t in any current vaccines, but it does not contain certain serotypes that are important for infants, she said. Buchwald called it a “population-specific approach” for adults, adding that the vaccine isn’t being developed as a primary shot for children.
Pfizer and Merck were also tangled in a patent dispute over the pneumococcal conjugate vaccine designs that ended with Merck agreeing to pay Pfizer a small percent of its net sales on all of its pneumococcal conjugate shots through 2035.
Meanwhile, Vaxcyte — previously known as SutroVax — has a 24-valent vaccine in Phase I/II trials, with an expected Phase I readout by the end of this year. And Inventprise, a Seattle-based biotech backed by the Bill and Melinda Gates Foundation, is trying to create a shot that covers 25 strains.
Editor’s note: This story was updated to include comment from Ulrike Buchwald.