Can Omicron Protect You Against Reinfection? CDC Chief Answers

Prior Omicron infection increases protection against Delta fourfold, Omicron reinfection 14-fold, according to a study by researchers in South Africa.

The Omicron variant of coronavirus is rapidly becoming the predominant variant in many countries, with cases increasing at substantial rates. India's, overall tally has crossed 3,000-mark. In the US, Omicron variant accounted for 95 per cent of new coronavirus infections last week, as per the Centres for Disease Control and Prevention (CDC) estimates. But some studies have come up with promising findings that prior infection with Omicron vastly reduces the odds of reinfection. This means those who got Omicron and have recovered from it are less likely to get reinfected.

When asked about the post-Omicron immunity during a press briefing, CDC director Dr. Rochelle Walensky said, "We don't yet know whether, if you've had Omicron, you are more susceptible or less susceptible to another infection with Omicron. We have indication that if you've had Delta, you are susceptible to an infection with Omicron and that Omicron in the lab may protect you against infection against Delta, but we don't yet have data, that has demonstrated at least clinically, that Omicron protects you against Omicron."

While breakthrough infections in people who are fully vaccinated are likely to occur, current vaccines are expected to protect against severe illness, hospitalizations, and deaths due to Omicron, the agency said in its website.

Omicron infections generate strong immune response

One study conducted by the Africa Health Research Institute in South Africa found that prior Omicron infection increased protection against Omicron reinfection 14-fold, while the protection against Delta increased fourfold two weeks after participants joined the study.

These results imply Omicron could displace Delta as the dominant strain of the virus, the scientist team led by Khadija Khan, wrote in their findings.

Further, they noted that if Omicron, which appears to cause less severe symptoms, displaces Delta, "the incidence of COVID-19 severe disease would be reduced, and the infection may shift to become less disruptive to individuals and society."

In addition, a study by Oregon Health & Science University suggested that breakthrough infections in vaccinated individuals may lead to "super immunity." The researchers said that antibodies generated after breakthrough infections are more effective than antibodies produced two weeks after a second dose of the Pfizer vaccine.

The study didn't examine the Omicron variant specifically. But the researchers anticipate that breakthrough infections with Omicron variant will generate a similarly strong immune response among vaccinated people.

CDC Chief on the fourth Covid dose

Israel has started administering a fourth Covid dose to certain section of its population. However, many experts have expressed that boosting every few months is not a viable strategy.

A journalist asked Dr. Walensky whether the US would be moving toward a fourth dose too. She replied, "We have boosted about 35 per cent of the population that's eligible, 73 million people, and importantly, about 60 per cent of our people over the age of 65. So right now, I think our strategy has to be to maximize the protection of the tens of millions of people who continue to be eligible for a third shot before we start thinking about what a fourth shot would look like."

She also said that they are working closely with Israeli colleagues to see what kind of data they have. The CDC will also be following its own data carefully to see how these boosters are working in terms of waning effectiveness, not just for infection, but importantly for severe disease, she added.

Masks can offer protection against all variants of coronavirus, the agency stated, asking people to continue wearing a mask in public places, regardless of your vaccination status.