Russian President Vladimir Putin says his country has developed a coronavirus vaccine that’s ready for public use — but many scientists are skeptical about its safety.
No one really knows when a vaccine will become available. President Trump has said a vaccine could be ready by November. Dr. Anthony Fauci said we may have one by early next year, while some scientists and researchers say more time is needed than that.
Dr. Richard Kennedy, who leads the vaccine research group at the Mayo Clinic in Minnesota, says the development of coronavirus vaccines is proceeding at an unprecedented pace, but it’s unlikely that one will be available in 2020.
“If we’re all wrong and we get there faster, that’d be fantastic,” he says.
Right now, front-runner vaccines are just starting Phase 3 clinical trials, which is the last step before a vaccine can be licensed. He predicts at the minimum, it will be about another three to four months until scientists have the necessary data to make smart decisions on whether their vaccine is safe and effective.
Large populations of susceptible or at-risk people need to be studied in order to gauge the safety and efficacy of a coronavirus vaccine, he says. That means testing tens of thousands of people.
An ideal coronavirus vaccine would be protective, what scientists call “sterile immunity,” where the response is so strong that the virus can’t establish a foothold within the body, he says.
But the immune system’s response to a vaccine isn’t always black and white.
“It’s not like a light switch where it’s off or on,” he says. “It’s more like a dimmer switch.”
Different vaccines provide various levels of immunity, he says.
For example, take the flu vaccine. In a good year, the flu shot protects you against infection. But in a bad year, the flu vaccine may prevent serious illness but some symptoms can still occur, he says.
“We don’t know what we’re going to see with the vaccines to coronavirus,” he says. “That’s one of the things we’re looking at during these Phase 3 clinical trials.”
Kennedy’s lab is working on one type of vaccination called a peptide vaccine that would use parts of the coronavirus the body already recognizes. It would generate an immune response to fight the disease off and then produce antibodies which will then be protective when the real virus comes along.
He says other labs are testing RNA vaccines, which act like a Trojan horse to bring a molecule that helps the body develop a protective disease-specific antigen into the body. RNA vaccines are made without the infectious elements of a whole virus vaccine, which uses a weakened live virus.
“The purpose of all of these different types of vaccines is to produce viral proteins in your body so that your immune system can recognize them and produce antibodies,” he says.
For the most part, vaccines are “very safe,” he says. But it’s important to test on large and diverse populations in order to determine potential “rare adverse events” such as high fever, nausea or vomiting.
There are concerns from some that because of the immense global pressure for a coronavirus vaccine, scientists will sidestep usual safety protocols for vaccinations.
Kennedy says the current process in the U.S. for developing, testing and evaluating vaccines “results in very safe, very effective vaccines.”
Without cutting corners on safety, he says there are actions that can be taken to shorten the timeline for a coronavirus vaccine, such as running Phase 1 and 2 trials together or making trials larger to begin with.
“We’re also seeing a lot of companies create millions of doses of vaccine before they get the results back from the clinical testing,” he says. “That way, if the trials are successful, they’ve already saved months of production time.”
Depending on the vaccine, production can take anywhere from weeks to months to develop. And since no company has had to create billions of doses of a vaccine so quickly, Kennedy predicts multiple companies will have to work together to get it done.
Plus, recipients of the early vaccines will likely be chosen based on the individual’s risk profile. Frontline health care workers, first responders, older and immunocompromised communities will likely be first in a phased vaccine rollout, he says.
Although many are anxious for a vaccine, Kennedy stresses that no compromises should be made to meet the demand, saying it would be “a disaster” if a vaccine was put on the market that caused harm or didn’t work properly.
Kennedy’s research group is on the forefront of a potentially life-saving coronavirus vaccine, an experience he says feels both surreal and exhausting.
“There’s a sense of urgency and there’s a little bit of pressure to get this done and get it done properly, but get it done in the shortest amount of time as possible,” he says. “And the faster we get it done, the more lives we’re able to save.”
Karyn Miller-Medzon produced and edited this interview for broadcast with Tinku Ray. Serena McMahon adapted it for the web.
This article was originally published on WBUR.org.
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