The vaccine may need to be modified to mutate the coronavirus, but it’s not an easy overnight fix

Good news: Many of the new COVID-19 vaccines are made with new flexible technologies that are easy to upgrade. Difficulty: Decide if the virus has mutated enough to change the vaccine and what changes to make.

“When do you trigger?” Asked Norman Baylor, a former Food and Drug Administration vaccine director. “This is currently a moving target.”

The WHO and FDA are looking to the global influenza vaccine system in deciding how to handle similar decisions regarding COVID-19 shots.

Influenza mutates much faster than the coronavirus, and influenza vaccination needs to be adjusted almost every year. National centers around the world collect circulating influenza viruses and track how they are evolving. They send samples to WHO-designated laboratories for more sophisticated “antigen” tests to determine vaccine strength. WHO and regulators then agree on a vaccine recipe for the year, and the manufacturer goes to work.

For the COVID-19 vaccine, an important step is to establish a similar monitoring and testing network to flag critical mutations, Webby said. Today, there is geographical variability in tracking and testing mutated versions. For example, the United Kingdom is testing a more variable viral genome than the United States.

The three variants first discovered in the United Kingdom, South Africa and Brazil are worried because of the combination of mutations that make them more contagious.

On Sunday, US researchers reported even more different mutations found in seven variants that occurred in several states. No one yet knows if this mutation facilitates the spread of the virus, but reports that have not yet been scrutinized by other scientists encourage further research to find it. I will.

Just because a mutant is more contagious does not mean that it is impermeable to the vaccine. However, the variants identified in South Africa have raised concerns. David Ho of Columbia University placed blood samples of people vaccinated with Pfizer or Moderna in a laboratory dish with the mutated virus. The antibodies produced by the vaccine are still protected, but they were much less potent.

Preliminary test results from two other vaccine candidates from Novavax and Johnson & Johnson quickly confirmed their findings. Both are still protected, but when tested in South Africa, where the variant predominates, they were weaker than when tested elsewhere. A much smaller test of the AstraZeneca vaccine in South Africa raises questions about its effectiveness.

“If the virus could make one or two more mutations, it could escape further,” Ho warned.

“It’s time to cross the border,” said Dr. Paul Ofit, a vaccine expert at the Children’s Hospital of Philadelphia, who advises the FDA when fully vaccinated people begin to be hospitalized with the mutant virus. It was.

It hasn’t happened yet, but “we have to get ready,” he added.

Moderna is looking for one option. Can a third dose of the original vaccine boost enough immunity to dodge some variants, even if they are not in perfect agreement?

Ho of Colombia recommends testing if the overall antibody level is very high, as people may “still have enough cushion”.

To be on the safe side, major manufacturers are also developing mutant vaccines.

The COVID-19 vaccine produces antibodies that recognize the peplomer that covers the coronavirus. Mutations in the virus can alter peplomers in critical areas, making it difficult for vaccine-produced antibodies to recognize them.

Pfizer and Moderna vaccines are made with a genetic code called messenger RNA that tells the body how to make harmless copies of the spike protein that trains immune cells. To update the vaccine, simply change the payload. Exchanges the original genetic code for the mutated peplomer mRNA.

The AstraZeneca vaccine and Johnson & Johnson Shot will soon be deployed and are made with a cold virus designed to sneak the peplomer gene into the body. To tune the vaccine, the mutated gene must be used to propagate the cold virus. It’s a bit more complicated than the mRNA approach, but it’s not as tedious as rebuilding a traditional flu shot.

The Novavax vaccine is also a final test and is made using a copy of a laboratory-grown peplomer protein. This copy can also be tailored to suit the mutation.

The first-generation COVID-19 vaccine has been tested by tens of thousands of people and confirmed that they are functional and safe. This is a study that took months.

FDA vaccine director Dr. Peter Marks recently said the American Medical Association said that it is not necessary to repeat these studies in thousands of people simply by changing the recipe to better target viral mutations. Told to.

The FDA is still finalizing the requirements, but Marks said the FDA intends to be “quite agile.” If an updated vaccine is needed, he said, testing with hundreds of people would probably be sufficient to determine if it provokes a good immune response.

But there is an even bigger problem. If only some places are facing vaccine-resistant viral variants, do authorities want a variant-only shot or vaccine that protects from two types in one jab? After all, the flu vaccine protects against three or four types at once.

John Grabenstein, a former Merck vaccine executive at the Vaccination Behavior Coalition, said companies first need to do basic research to ensure that the mutant-only version properly restores the immune system. Stated. Second, the combination shot requires further testing to ensure that both types have equivalent responses.