It has long been expected that the COVID-19 vaccines need to be reformulated to better protect against currently circulating variants. The Food and Drug Administration in June recommended that the next generation of COVID-19 boosters use a “bivalent” approach that equally targets the original version of SARS-CoV-2 and the BA.4/5 strains of the virus.
Pfizer plans to start the clinical trial for the BA.4/5-containing vaccine it’s developing with BioNTech BNTX, +0.14% “in the near future,” a company spokesperson told MarketWatch this week.
The submission to the FDA for these shots will be slightly different in order to speed up their availability, according to Dr. Mikael Dolsten, Pfizer’s chief scientific officer, based on a FactSet transcript of Thursday’s earnings call. He told investors that Pfizer and the FDA have agreed that the application for the updated booster will include “safety and immunogenicity data generated in adults with an omicron-modified BA.1 vaccine and supported by BA.4/5 bivalent-specific preclinical data and BA.4/5 bivalent chemistry, manufacturing and controls data.”
The drug maker this week announced the launch of a Phase 2 trial studying COVID-19 vaccines that include either a BA.1 or a BA.2 component.
Moderna also has a bivalent booster targeting BA.1 in development and is planning to soon launch a clinical trial for a booster that includes BA.4/5.
“We are discussing the trial details with the FDA,” the Moderna spokesperson said in an email. “The trial will be structured similarly to other variant-of-concern studies.”
BA.5, which is now the most dominant strain of the virus in circulation, is the most transmissible form of SARS-CoV-2 so far. It’s driving the surge in new cases — the U.S. is averaging about 127,000 new cases every day — and the omicron subvariant is also behind the uptick in hospitalizations. There are about 43,000 people in the hospital right now who have tested positive for the virus.
“This virus has continued to prove more than a formidable foe, with variants of concerns emerging, each with a bit of enhanced transmissibility,” Dr. Anthony Fauci, the president’s chief medical adviser, said earlier this week during a White House summit. “How do we know that? It keeps bumping off the prior variants, as we’re starting to see now with the highly transmissible BA.5. Now, innovative approaches are clearly needed to induce broad and durable protection against coronaviruses, known and unknown.”
The U.S. is at a critical point in the pandemic. The public has largely ignored the official messaging around boosters, and only about one-third of people who qualify for a third dose of the vaccine have gotten one. Americans have largely moved on from caring about the virus, and that’s creating a problem as immunity wanes and BA.5 circulates.
This puts the Biden administration in a tricky spot. Only a few weeks ago there were media reports that the White House and health officials were considering making adults younger than 50 years old in the U.S. eligible for a second booster of the currently available shots. That never happened.
The Washington Post reported last Friday that the plan is on hold and officials are instead trying to move up the timeline for next-generation vaccines to mid-September, citing people familiar with the issue. The vaccine makers previously told an FDA advisory committee that they could have new shots ready in October.
The U.S. has contracted with both companies to supply the new vaccines, most recently with Friday’s announcement that Moderna signed a $1.7 billion contract with the government to provide 66 million doses of a new COVID-19 vaccine booster.
Though the currently available vaccines continue to do a good job preventing severe disease, they are less and less effective at preventing infections. And experts say convincing individual Americans to get a booster every six months or so isn’t a sustainable solution to the pandemic.
“We need vaccines with longer duration and greater breadth of protection,” Dr. David Kessler, chief science officer for the White House’ COVID-19 response team, said Tuesday at the summit.
In the short term, this means the bivalent vaccines being developed right now by BioNTech/Pfizer and Moderna that are expected to arrive in time for a fall booster campaign. In the longer term, there are several different ideas to consider, including pan-coronavirus vaccines that can protect against current and future strains of SARS-CoV-2 — Dr. Eric Topol, a cardiologist and director of the Scripps Research Translational Institute, refers to this as a “variant-proof vaccine” — or nasal vaccines that are believed to be more effective than intramuscular vaccines at generating the kind of antibodies that prevent infection and transmission.
Pfizer told investors this week that it plans to initiate research into a pan-coronavirus vaccine by the end of this year.
“We aspire to continue leading with the science and are working to identify vaccines that will help provide strong and durable protection as new SARS-CoV-2 variants emerge,” Dolsten said. “We aim to deliver a next-generation COVID-19 vaccine that can provide durable antibody and T cell immune protection against severe disease and hospitalization for at least one year.”
Read more about the BA. 5 variant: