COVID-19 shots from Pfizer Inc. and Moderna Inc. should be updated to include components that target the highly transmissible omicron variant, the version of the virus that causes most of the world’s cases, U.S. regulatory advisers said.
Members of the panel that advises the Food and Drug Administration voted 19-2 Tuesday in favor of recommending adding an omicron-specific element to the shots. The FDA doesn’t have to follow the recommendations of the Vaccines and Related Biological Products Advisory Committee, but it usually does.
Whether, how and when to alter shots to target omicron has become an increasingly important question as the coronavirus continues to spread and mutate. Although transmission is currently low in most communities across the U.S., new variants have shown increasing signs of ability to evade the effects of vaccines, adding urgency to determining how to control them with new shots.
Panel member Mark Sawyer, a professor of clinical pediatrics at the University of California, San Diego, pushed the committee to recommend updating the COVID-19 vaccines’ strain composition. Given the speed of evolution of new variants, he said, “we are going to be behind the eight ball if we wait any longer.”
While most panel members felt that an updated booster shot would help prepare the country for a potential surge in the fall, some expressed concern about the lack of data.
“We need to continue to encourage the companies to collect as much data as possible on the safety and immunogenicity on whatever strain is chosen,” said Amanda Cohn of the Centers for Disease Control and Prevention’s National Center on Birth Defects and Developmental Disabilities.
While currently available vaccines continue to offer protection against the worst outcomes of COVID-19, the future remains uncertain. Booster doses have become an increasingly relied-on tool, but health officials are hoping to come up with a more robust strategy.
Vaccines that are now in use were built to fight the ancestral Wuhan strain of SARS-CoV-2. As the virus continues to mutate over time, variants are becoming increasingly distinct from the original strain, allowing variants to evade immunity afforded by the shots.
“We believe that we’ve found possible solutions as we head into this next chapter of the pandemic and will continue to share our available data to health experts and regulators,” Pfizer said Tuesday in an email. Moderna didn’t immediately respond to a request for comment.
Earlier this year, the National Institute of Allergy and Infectious Diseases started a clinical study to test combinations of second booster doses to determine what the optimal shot would be. The results will be made public next month, an agency spokesperson said last week.
Novavax Inc.’s original vaccine still hasn’t been authorized by U.S. regulators, although the advisory panel voted in favor of its clearance for adults on June 7. The company participated in the meeting, as it’s developing an omicron-specific vaccine of its own.
The appearance of the highly transmissible omicron strain led to a sharp increase in cases that has since fallen back. Back in April the FDA advisers reviewed data showing a roughly 20% chance that there will be another “omicron-like” event in the next 12 months.
Some panelists suggested that the agency needs to come up with a single standard for updating COVID-19 shots to prevent a confusing situation where vaccine manufacturers come out with different updates. Other members have said that a multiple-strain vaccine makes the most sense for the next iteration of the COVID-19 shot, given the great uncertainties about future viral evolution.
