NEW YORK (AP) – How long does protection against COVID-19 vaccines last?
Experts do not know yet, as they are still studying vaccinated people to see when the protection may expire. How well the vaccines work against emerging variants will also determine when and how often additional staff may be needed.
“We only have information as long as the vaccines have been studied,” said Deborah Fuller, a vaccine researcher at the University of Washington. “We need to study the vaccinated population to see when people become vulnerable to the virus again.”
So far, ongoing Pfizer tests show that the company’s two-dose vaccines remain highly effective for at least six months և, probably longer. People who received the Moderna vaccine also had significant amounts of antibodies against the virus six months after the second shot was needed.
Antibodies also do not tell the whole story. To fight off viruses, our immune system also has another line of defense called B և T cells, some of which may be dependent long after the antibody level drops. If they are exposed to the same virus in the future, the cells that performed the test can act faster.
Even if they do not completely prevent the disease, they can help alleviate its severity. But it is not yet clear exactly what role such “memory” cells can play with the coronavirus.
Although COVID-19 vaccines are currently likely to last at least a year, they are unlikely to provide lifelong protection, as with measles shots, said Dr. Kathleen Neuzil, a vaccine expert at the University of Maryland.
“It will be in the middle of that very wide range,” he said.
Options մեկ This is one reason we may need an extra shot.
The current vaccines are designed to work against the cocaine virus specifically against the acute protein, says Mehul Sutar of the Emory Vaccine Center. If the virus mutates enough over time, vaccines may need to be updated to increase their effectiveness.
So far, the vaccines seem to be safe against emerging variants, slightly less than those first found in South Africa.
If it turns out that we need another shot, one dose may extend the protection of the current shot or include vaccinations for one or more options.
The need for further shootings will depend in part on the success of vaccination, virus transmission, and emerging options around the world.
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