COVID-19 vaccines may need to evolve to keep up with changing virus

Nov. 9 (UPI) -- Researchers working to develop a vaccine against COVID-19 must consider the inevitable mutation of the virus and monitor its evolution to ensure that inoculations continue to prevent infection, the authors of a commentary published Monday by PLOS Biology argue.

Even as new vaccines become available -- perhaps as soon as later this year -- researchers should use virus samples collected during testing to check for new strains that may not respond to the formulation, they said.

Multiple strains of the new coronavirus already have been identified, suggesting that the virus that originated in China is evolving and that new vaccines will need to keep up to provide immunity, according to the authors, both biologists at Penn State University.

The commentary was published on the same day that drugmaker Pfizer announced that its two-dose COVID-19 vaccine is 90% effective at preventing new infections, based on preliminary data from Phase 3 trials.

"I hope that the first licensed vaccine is safe, effective, and easy to produce and administer, but even if that is the case, [virus] evolution can undermine vaccine protection," commentary co-author David A. Kennedy told UPI.

"Examples of resistance have been seen against many different types of vaccines ... [so] I don't think we can make blanket statements about which types of vaccine, or which types of diseases for that matter, will have problems with resistance," said Kennedy, an assistant professor of biology.

Research suggests at least six different strains of the coronavirus that causes COVID-19 are circulating globally, although it appears to be evolving more slowly than it spreads, researchers said.

Roughly 200 vaccines against COVID-19 are being developed, with more than 40 already in clinical trials designed to assess safety and efficacy, according to the World Health Organization.

What Kennedy and his colleagues are proposing doesn't call into question the trial process or delay it in any way, they said.

Instead, what they suggest is that researchers learn lessons from the antibiotic resistance crisis -- in which infection-causing bacteria have become resistant to currently available antibiotics, leading to severe illness and death -- and continue to track the evolution of the new coronavirus after vaccines come to market.

This would entail using samples collected during vaccine trials -- including both nasal and throat swabs and blood -- for new strains of the virus, Kennedy said.

For example, blood samples can be used to assess "the redundancy of immune protection generated by" vaccines by measuring the types and amounts of antibodies -- proteins produced by the immune system to fight infection -- that inoculated people develop against the virus.

"The data necessary to quantify the risk of vaccine resistance can be assessed concurrently with clinical trials," Kennedy said.

"The question is, what do we do if we learn that an otherwise promising vaccine candidate is very likely to be undermined by pathogen evolution?" he asked.

One positive that can be taken from the need to develop a vaccine against COVID-19 is that the process, which has progressed at record pace, can be used to improve vaccines overall, according to Stephen S. Morse, an expert in emerging infectious diseases.

"Our knowledge of how vaccines work, and how to make them work better, still has many gaps," Morse, a professor of epidemiology at Columbia University, who was not part of the PLOS Biology commentary, told UPI.

"This is a great opportunity to fill in some of the gaps [and] provide the opportunity for more precise assessments of the immune response to these vaccines, and help us learn how to design better ones," which is essentially what the authors are proposing, he said.