​​​COLUMBUS, Ohio — Health authorities and vaccine researchers are increasingly interested in the pursuit of a “universal” COVID-19 vaccine that is resistant to variants.

What You Need To Know

  • Researchers are seeking vaccines that protect against multiple variants

  • The White House is asking Congress to provide funding for these studies

  • A true universal vaccine is likely at least a few years away, experts say

After the omicron wave demonstrated that the virus’s ability to mutate can jeopardize the efficacy of existing vaccines, U.S. health officials have acknowledged that creating more durable vaccines will be key to a successful long-term vaccine strategy.

Jonathan Karn, Case Western University School of Medicine’s chair of microbiology and molecular biology, said the word “universal” is a bit of an exaggeration. 

The idea of a universal vaccine is something that would offer strong protection against all current and future variants of the virus.

“The true universal vaccine is a tough thing to do. It's been a pipe dream for 30 years with flu,” he said. 

It remains to be seen if developing one is even possible. While it might be possible down the road, in the nearer term, Karn says researchers are looking at developing a vaccine that offers fairly broad protection against variants. 

The Walter Reed Army Institute of Research is researching a pan-coronavirus spike ferritin nanoparticle vaccine, know as SpFN, which has received significant attention in recent months in discussions of universal vaccines. 

The Army reports it performed a small phase one trial on the vaccine that began in April 2021, and the researchers said the pre-clinical studies show that it may “provide broad protection against SARS-CoV-2 variants of concern as well as other coronaviruses," like the SARS-CoV-1 virus that emerged in 2002.

“They made these particles, nanoparticles that had lots and lots of envelopes. The spike protein is actually from the original Wuhan strain, so they didn't genetically modify that strain or the sequences of the antigen, but they have, because of this high concentration, and the way it was delivered on this particle, it turned out there was a pretty broad immune response that was elicited by it,” Karn said. 

The Army’s vaccine isn’t the only drug that’s being studied in the realm of universal vaccines. Karn said there are two approaches to trying to make a universal vaccine. 

The first involves using a mixture of antigens or mRNAs to target multiple existing variants as well as potentially targeting variants that researchers predict will come next. 

If a new strain emerges, the hope is that it will be close enough to a version of the virus that the vaccine targeted, either a previous variant or a forecasted new variant.

“This kind of mixing is the flu vaccine strategy. You take the three strains that were circulating the previous year, and add in a fourth strain that you think is going to be a risk, and make a cocktail, and you use that for the year. And that's never been fully successful with flu,” he said.

Trying to predict the next variant is the challenge. Researchers can conduct laboratory studies to identify possible mutations that could evade antibodies from the existing vaccines. This strategy can give an indication of how the virus might evolve, but it's an imperfect science, Karn said.

Dr. Anthony Fauci, White House chief medical advisor, said earlier in the month that researchers are making "good progress" in the realm of pan-coronavirus vaccines. 

"We have several candidates that look good — some are in preclinical, some are in phase one,” he said. 

On Tuesday, the White House released a statement calling for Congress to fund additional federal COVID-19 response spending, noting that among other priorities, the administration needs the funds to accelerate research to create “a next-generation, pan-COVID vaccine that would provide broad protection against a range of variants."

Existing vaccines in the U.S. were built to target the original strain that was detected in Wuhan. Research on variant-specific vaccines is ongoing, and the drug manufacturers are reporting developments on efforts to target multile variants in one vaccine.

Moderna is studying a vaccine candidate designed for omicron, as well as a bivalent version that combines its original vaccine with the omicron-specific candidate, which is in a phase two study, the company said last week. 

Pfizer is also studying an omicron-specific version, and Pfizer CEO Albert Bourla said in a CBS interview Sunday that the company is now aggressively pursuing a pan-coronavirus vaccine that would target multiple variants.

“What we are trying to do, and we are working very diligently right now, it is to make not only a vaccine that will protect against all variants, including omicron, but also something that can protect for at least a year,” Bourla said.

In the meantime, Pfizer is seeking authorization in the U.S. for a fourth dose of its current vaccine for adults 65 and older.

Beyond those two drug manufacturers, other researchers in the U.S. and globally are studying technologies that fall in this broad category of pan-coronavirus vaccines.

The National Institute of Allergy and Infectious Diseases has awarded tens of millions of dollars in grants to academic institutions for pan-coronavirus vaccine research, including awards to the University of WisconsinDuke University and Harvard Medical School’s Brigham and Women’s Hospital

HDT Bio, a biopharmaceutical company based in Seattle, is studying its own nanoparticle vaccine platform that founder CEO Steve Reed said could offer advantages over current vaccines because it's amenable to combining many variants into one shot.

“These can be several variants of the SARS-COVID virus, or it could be a mixture of SARS-COVID with influenza for example,” he said.

Reed said that to be able to target multiple variants it will be necessary to develop a vaccine platform that only takes a low dose to produce an immune response. 

“If you’re using a very high dose of RNA such as the most commonly administered vaccines, it becomes impossible to combine more than one variant in any single vaccine," he said.

HDT Bio's vaccine is being studied in Brazil, Korea and India and is in phase two and three studies, Reed said. While he believes a vaccine that packs defenses against multiple variants into one shot is the future, he said it’s likely that the formula would still need to be updated from time to time to respond to significant mutations. For that reason, being able to quickly develop and manufacture new versions of vaccines will be critical in the years to come as researchers work to respond to new variants. 

Karn said that a true universal vaccine that wouldn’t need to be updated for new variants likely won't be developed for at least a few years because accomplishing that would require finding an antigen that targets a part of the virus that never changes.

He said research on pan-coronavirus vaccines as well as the long-term pursuit of a truly universal vaccine is vital because new variants are likely to at some point threaten the grip we're getting on the pandemic after the winter virus wave. 

“There are a lot of people declaring premature victory,” Karn said. “The worry is that as more and more people get exposed to the existing strains, and new mutations arise and new strains come out, there will be something like omicron that is not only pathogenic, but gets away from the vaccine responses.”