What you need to know about Omicron


The arrival of the fast-spreading Omicron variant has prompted health officials worldwide to urge booster shots for all

“If we can’t get our vaccination rate up, we’re basically waiting for everyone who still has no immunity to Covid to get infected instead,” Atlantic science and health reporter Sarah Zhang says.

We reach endemicity when essentially everyone has some immunity to the virus, she says.

“Either vaccination or infection would get us there, but vaccines would get us there with a lot less death and a lot less misery.”

While much is still unknown about Omicron, most experts agree that a booster shot is likely to give you additional protection, according to a recent report in the New York Times, on which the following is based.

Do booster shots work against the Omicron variant?

The variant carries more than 50 genetic mutations, more than 30 of them on the virus’s spike, a protein on its surface that is the main target for current Covid vaccines.

While these changes may help the virus sidestep some vaccine antibodies, it appears unlikely the variant will fully outsmart vaccines.

It’s important to remember that your immune system has multiple lines of defence.

A booster shot gives your body more neutralising antibodies to fight the virus.

Laboratory tests by Pfizer and BioNTech have been promising. Blood samples obtained from people one month after they had received a booster shot showed significant levels of neutralising antibodies against the variant.

No vaccine or booster offers 100 percent protection, and some people may still become infected after vaccination. If that happens, your immune system will keep working to clear the virus, which is why vaccinated people are less likely to develop severe illness or be hospitalised.

Will there be booster shots targeted specifically for the Omicron variant?

While it’s possible a variant-specific booster could be developed, it’s too soon to know whether it will be needed. Preliminary reports suggest Omicron spreads quickly but causes less severe illness. However, we’ve known about the variant for only a short time, and concerns could change as more data come in.

It would probably take three to four months to develop a variant-specific shot, but additional study would be needed to determine the timing for giving it. The best strategy is to get the booster shot that is available now.

Do I need a booster shot if I’ve already had Covid?

Experts recommend booster shots even if you’ve had Covid. Early data from South Africa suggest that antibodies from prior infection aren’t enough to consistently ward off the Omicron variant. One study, which has not been peer reviewed, found that re-infection is more than twice as likely with Omicron as with other variants. The study looked only at immunity related to prior infection and did not look at whether Omicron sidesteps vaccine antibodies.

How long does it take a booster shot to start working?

While it takes your immune system about a week to 10 days to mount a strong response to the first series of shots, booster shots should start having an effect in just a few days. To understand why, think about what happens if you get exposed to the coronavirus. A fully vaccinated person’s immune system gears up the moment it detects the virus. This is why vaccines work.

Your booster shot has a similar effect. Your immune system already has been trained by the first series of shots, so the booster triggers a much faster response. After the booster, your immune system continues to build even stronger protection over the next 10 to 14 days, so the sooner you get your shot, the better.



The US continues to lead the world in quickly dealing with all aspects of Covid 19 and its variants. This article was prepared by Tara Parker-Pope for the New York Times in mid December 2021