A nurse is giving the vaccine to students at a high school. The scientists are trying to figure out if the vaccines will protect against the omicron variant.
Frederic J. Brown is pictured.
The vaccine's effectiveness is predicted to take a hit when it comes to stopping infections of omicron, because researchers in South Africa and Botswana just detected the variant. If omicron spreads here in the U.S., there will be more breakthrough infections.
There's hope that vaccines will still offer good protection against severe disease and hospitalization, especially with a third dose.
A lab version could hold answers.
What is the reason for the pessimism?
A study published in September predicted the emergence of a variant called omicron, which is a variant with an extremely large number of mutations. The study offers important information about how well vaccines will work against omicron.
The scientists were trying to understand how the body's key defense against viral infections is learned.
Paul Bieniasz wondered if the ability to detect and kill the virus could be knocked out by the evolution of the disease. The goal was to answer the question: Is it possible for the disease to completely evade the immune system? Bieniasz says something.
He and his team engineered a supermutant version of the virus, but not the full one. They focused on the spike portion of the virus, which binding to human cells and is the target of important antibodies. Bieniasz tried to make the spike impervious to the immune system.
They took about 20 different genes and put them all together onto a single spike protein, which they call a polymutant spike mutant. These were already found in several different variations around the globe but never all together.
"They are the same thing that happen naturally and we combined them," Bieniasz says. They were shown to help the virus evade detection.
Bieniasza says that the omicron variant has the same polymutant spike protein. He says that it has more changes. omicron has about 30 different variations on the spike protein. "Omicron appears to have certain combinations ofmutations that together would confer more pervasive resistance to individual classes of antibodies," he says.
Bieniasz and his team took the antibodies from people who had had two doses of the vaccine. They tested the antibodies against the spike. They were looking to see if those antibodies could partially neutralize it. They couldn't do it all.
Bieniasz says that the polymutant spike protein was almost completely resistant to the neutralizing antibodies.
"Based on those findings, we expect that omicron will be resistant to the antibodies that are circulating in individuals who have convalescence or have had a vaccine," Bieniasz says. The magnitude of that loss of sensitivity has to be determined.
Even with a booster added in, faith in vaccines is not lost.
Scientists all over the world are trying to figure out what the magnitude will be. Researchers at Pfizer are looking at the neutralization capabilities of people who have had two or three shots of the vaccine, to see if they have any.
"We are cautiously optimistic that after three doses you will have some protection," says Dr. Mikael Dolsten, who is the chief scientific adviser for Pfizer.
The hope is that protection against severe disease and hospitalization will hold up. Your body uses antibodies to stop an initial infections. Even if the effectiveness of your antibodies goes down, you might still be able to keep yourself out of the hospital.
T cells, which are part of the immune system, can clear out infections quickly if one occurs, and thus, help to protect you from serious illness. T cells are less likely to lose effectiveness when the virus changes. Preliminary data shows that T cell activity remains high even against a polymutant spikeProtein similar to the one created by Bieniasz and colleagues. The picture does not look terrible for T cells according to members of the Bertoletti lab.
Pei-Yong Shi, a researcher at the University of Texas Medical Branch in Galveston, says there's more hope that a third shot of an mRNA vaccine will work better than two shots. He says the third dose doesn't just return your levels to what they were before the second shot. The level is higher.
The booster can help broaden out your defense so that you can fight off many different versions of the same thing. Shi says that the booster increases the level of antibodies that can push back against the variant. That's another advantage for the booster.
It's possible that extra exposure could help the body stay one step ahead of the virus and teach the immune system how to fight off future versions.
