As RSV vaccine showdown looms, Pfizer's Abrysvo wins CDC blessing for maternal protection

While GSK’s Arexvy was first out the gate in this summer’s respiratory syncytial virus (RSV) vaccine race, Pfizer has kept the pressure up with its rival shot Abrysvo. Now, as the RSV season creeps up, Pfizer’s vaccine has received a formal endorsement from the Centers for Disease Control and Prevention to be given during pregnancy to protect infants.

Friday, the CDC’s (CDC’s) Advisory Committee on Immunization Practices (ACIP) voted 11-1 in favor of recommending Abrysvo for people who are between 32 weeks and 36 weeks pregnant. The shot is expected to confer protection against RSV-associated lower respiratory tract infection in infants through the first six months of life, Pfizer said in a press release.

Approximately 75% of RSV-related hospitalizations in newborns and infants take place during that initial six-month span, Luis Jodar, Ph.D., chief medical affairs officer for vaccines, antivirals and evidence generation at Pfizer, said in a statement.

With the endorsement, Abrysvo joins a formal roster of maternal vaccines the CDC recommends before birth, such as those for whooping cough, influenza and COVID-19. The vaccine will roll out this fall alongside other Pfizer shots against COVID-19 and pneumococcal pneumonia.

Abrysvo nabbed its newborn-protecting nod from the FDA in late August.

But while Pfizer’s shot is the first maternal RSV vaccine, it isn’t the only prophylactic on tap to help infants. In July, Sanofi and AstraZeneca’s antibody Beyfortus (nirsevimab) won its own regulatory go-ahead as a preventative for RSV lower respiratory tract disease in babies.

Before that, the RSV rush kicked off in earnest in May with the approval of GSK’s vaccine Arexvy to protect against the disease in adults over 60. The green light made GSK’s shot the world’s first RSV immunization for adults. Pfizer was close behind, however, clinching a rival adult RSV nod for Abrysvo in June.

As with Abrysvo’s maternal indication, Pfizer’s and GSK’s adult vaccine launches were contingent upon a thumbs up from ACIP. The CDC advisory committee gave its blessing in late June, though the endorsement was anything but enthusiastic.

Instead of telling seniors they ought to get vaccinated, the CDC panel said that people may get a dose of GSK’s Arexvy or Pfizer’s Abrysvo if it is right for them. ACIP was hesitant to endorse RSV vaccines for people 65 and older—voting 9-5 to recommend optional use in that population—on account of concerns over a lack of adequate enrollment for that age group in clinical trials.

In people ages 60 to 64, the panel was more willing to recommend the vaccines, voting 13-0, with one abstention.

The RSV season typically starts in the late fall before peaking in the winter. The newly available RSV vaccines are rolling out at roughly the same time as seasonal flu and COVID-19 shots.