Portland, Oregon 2021-04-22 08:34:15 –
New York (AP) — How long will protection from the COVID-19 vaccine last?
Experts are still not sure, as they are investigating vaccinated people to see when protection will diminish. How well the vaccine works against new mutants also determines if additional injections are needed, when and how often.
Deborah Fuller, a vaccine researcher at the University of Washington, said: “We must study the vaccinated population and begin to see when people are again vulnerable to the virus.”
So far, Pfizer’s ongoing trials have shown that the company’s double-dose vaccine is very effective for at least six months, and perhaps even more. People vaccinated with Moderna had significant levels of antibody to fight the virus, six months after the second required injection.
Antibodies also do not convey the big picture. To fight off invaders like viruses, our immune system also has separate lines of defense called B cells and T cells, which can hang long after antibody levels have dropped. In the future, if the same virus is encountered, the cells tested in those battles may take action more quickly.
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Even if they do not completely prevent the disease, they can help slow down its severity. However, it is not yet known what role such “memory” cells play in the coronavirus and how long.
Dr. Kathleen Neuzil, a vaccine expert at the University of Maryland, said the current COVID-19 vaccine is likely to last for at least about a year, but does not provide lifelong prevention like measles vaccination. I said it would be.
“It will be somewhere in the middle of that very wide range,” she said.
Variations are another reason why additional shots may be needed.
Current vaccines are designed to work against specific peplomer proteins of the coronavirus, said Mehul Suthar of the Emory Vaccine Center. If the virus mutates sufficiently over time, it may be necessary to update the vaccine to increase its effectiveness.
So far, the vaccine appears to be defensive against the notable variants that have emerged, although it is slightly inferior to the one first detected in South Africa.
If it turns out that another shot is needed, a single dose can extend the protection of the current shot or include vaccination of one or more variants.
The need for follow-up shots also depends in part on the global success of vaccination and the control of infection with the virus and new variants.
How long does protection from COVID-19 vaccines last? Source link How long does protection from COVID-19 vaccines last?