What we know and don’t know about virus variants and vaccines

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About 20 states across the country have detected the most transmissible B.1.1.7 SARS-CoV-2 variant to date. Given the unknowns of the emerging situation, experts from the Infectious Diseases Society of America (IDSA) examined the effectiveness of vaccines, the ability of the United States to keep up with new mutations and shared their impressions of executive orders. by President Joe Biden on COVID-19.

One of the major concerns remains the ability of COVID-19 vaccines to work on new strains. “All of our vaccines target the spike protein and attempt to elicit neutralizing antibodies that bind to that protein,” said Mirella Salvatore, MD, assistant professor of medicine and population health sciences at Weill Cornell Medicine in New York City. , during an IDSA press briefing. Thursday.

The B.1.1.7 mutation occurs in the “very important” spike protein, a component of the SARS-CoV-2 virus required for binding, which allows the virus to enter cells, added Salvatore, a member. from IDSA.

Evidence suggests that SARS-CoV-2 should be able to produce one or two mutations per month. However, the B.1.1.7 variant surprised UK researchers when they first discovered that the strain contained 17 mutations, Salvatore said.

It’s still unclear why this particular strain is more transmissible, but Salvatore hypothesized that the mutation gives the virus an advantage and increases binding, allowing it to enter cells more easily. She added that the mutations could have occurred in immunocompromised people infected with SARS-CoV-2, but “this is only a hypothesis.”

On a positive note, Kathryn M. Edwards, MD, another member of IDSA, explained during the briefing that existing vaccines target more than one location on the virus spike protein. Therefore, “if there is a mutation that changes a structure of the spike protein, there will be other areas where binding can occur.”

This polyclonal response “is why the vaccine may still be effective against this virus,” added Edwards, scientific director of the Vanderbilt vaccine research program and professor of pediatrics at Vanderbilt University School of Medicine in Nashville, Tennessee.

Salvatore pointed out that while the new variant is more heritable, it doesn’t appear to be more deadly. “It could affect overall mortality but not for the individual who contracts the infection.”

Stay one step ahead

When asked for assurances that COVID-19 vaccines will work against emerging variants, Edwards said, “We may need to change the vaccine to better respond to the newer variants, but at this point, This does not seem to be the case. . “

If vaccines need updating, mRNA vaccines have an advantage: researchers can revise them quickly. “All you have to do is put all the little nucleotides together,” Edwards said.

“A number of us are studying how it will work and we are looking at the flu,” she added. Edwards drew an analogy for choosing – and sometimes updating – flu strains each year for the annual flu shot. With proper funding, the same system could be replicated to cope with any evolutionary changes in SARS-CoV-2, she said.

On funding, Salvatore said more money would be needed to optimize the system for monitoring emerging strains in the United States.

“We actually have this system – there’s a wonderful network that sequences strains of influenza,” she said. “The structure is there, we just need the funding.”

“The CDC is in the process of preparing the system to sequence more viruses,” Edwards said.

Both experts praised the CDC for its website with up-to-date surveillance information on emerging strains of SARS-CoV-2.

Biden’s support for science

A reporter asked each infectious disease expert to share their impression of Biden’s newly signed COVID-19 executive orders.

“The biggest benefit is the role of science and the lessons we’ve learned from masks, hand washing and distance,” said Edwards. “We must heed the advice …[especially] with a more contagious variant.

“It is encouraging that science is being listened to – that is the overall message,” she added.

Salvatore agreed, saying the orders give “the feeling that we can now act by following science”.

“We have a lot of papers that show the effectiveness of masking,” she said. Salvatore acknowledged that there are “a lot of contrasting ideas about masking” across the United States, but stressed their importance.

“We need to follow measures that we know are working,” she said.

Both experts said more research is needed to stay ahead of this evolving scenario. “We still need a lot of basic science to show how this virus replicates in the cell,” Salvatore said. “We really need to characterize all of these mutations and their functions.”

“We need to worry, do follow-up studies,” she added, “but we don’t need to panic.”

This article was based on a press briefing by the Infectious Diseases Society of America on January 21, 2021. Salvatore revealed that she was an IP of the site on a study by the Verily life sciences LLC / Brin Foundation on Predictors of Severe COVID -19 Outcomes (PRESCO) and IP for a study initiated by a researcher and sponsored by Genentech on combination therapy in influenza. Edwards disclosed the NIH and CDC grants; consultancy for Bionet and IBM; and serve on data security and oversight committees for Sanofi, X-4 Pharma, Seqirus, Moderna, Pfizer and Merck.

Damian McNamara is a journalist working in Miami. It covers a wide range of medical specialties, including infectious diseases, gastroenterology and intensive care. Follow Damian on Twitter: @MedReporter.

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