By WSJ Staff 

Studies are under way exploring whether we will need to take booster shots to stay protected against Covid-19, and drugmakers are working on the shots. Here is what we know and don't know about the need for boosters.

Do I need a booster shot for my Covid-19 vaccine?

You probably will need a booster shot, though the matter is still under study. Though some vaccines, such as the one for measles, offer lifelong protection against a virus, other shots don't. The vaccine for tetanus and diphtheria requires a booster every 10 years, for instance, and women are supposed to get the whooping-cough vaccine each time they are pregnant, according to the Centers for Disease Control and Prevention's vaccine recommendations.

Many researchers suspect the immunity provided by Covid-19 vaccines will wane over time. They have that expectation partly because the natural immunity people develop against milder coronaviruses declines. "Historically, at least with the coronaviruses, the mild common cold coronaviruses, the durability of the protection from infection isn't very long," Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, said at The Wall Street Journal's Tech Health conference in June. Another reason researchers say we will probably need a booster shot is to protect against any emerging coronavirus variants that are able to evade current vaccines.

When should I get a booster shot?

It may be every year, 18 months or even two years. It could be a different time frame. We really don't know yet. Whether and how often we would need to get a booster shot is under study right now. Remember, the Covid-19 vaccines haven't been around long, so not much time has passed to assess how long their protection lasts. In April, Pfizer Inc. released data indicating its vaccine remained effective six months after the second dose. Researchers can sort out how often we would need to get a booster shot after figuring how long the vaccines provide their fullest protection against Covid-19.

Is it safe for me to get a booster shot from a different vaccine brand?

That is under study right now. In June, NIAID, which is part of the National Institutes of Health, started a study looking at whether mixing and matching vaccines and boosters could prolong immunity and better protect against variants. One thing the study will explore is the best combination of shots. It may be that getting a vaccine from one manufacturer and a booster from another might actually produce stronger protection, researchers say. The ability to mix-and-match might also simplify the logistics of giving people boosters.

Will boosters better protect against coronavirus variants?

Researchers say the current vaccines appear to work well against variants of concern that have emerged so far. Yet they may not work as strongly against variants as they do against early strains. For that reason, we may want booster shots to ensure we get the fullest level of protection possible against the variants. And we would want booster shots if any variants emerge that prove better able to evade current vaccines. Drugmakers are working on shots targeting variants.

 

(END) Dow Jones Newswires

June 11, 2021 11:05 ET (15:05 GMT)

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