South Africa study suggests Omicron infection could boost immunity

Becoming infected with the Omicron variant of COVID-19 could boost immunity against the earlier Delta strain, according to a new study from South Africa.

In the small study, scientists at the Africa Health Research Institute in Durban found that people who were infected with Omicron — particularly those who were vaccinated — developed enhanced immunity to Delta.

The research, which has not yet been peer-reviewed, involved 15 vaccinated and unvaccinated Omicron patients in South Africa, according to Bloomberg News, which noted that two were excluded because they didn’t detectably neutralize Omicron.

The authors, led by Alex Sigal and Khadija Khan, found that while the neutralization of Omicron increased 14-fold over 14 days after the enrollment, there also was a 4.4-fold increase in neutralization of the Delta variant.

“The increase in Delta variant neutralization in individuals infected with Omicron may result in decreased ability of Delta to re-infect those individuals,” the authors said.

The study showed that vaccinated people who were infected with Omicron developed enhanced immunity to Delta.
REUTERS/ Sumaya Hisham/File Photo

They added that the findings are “consistent with Omicron displacing the Delta variant, since it can elicit immunity which neutralizes making re-infection with Delta less likely.”

Such a displacement would hinge on whether or not Omicron is less pathogenic compared to Delta, according to Reuters.

“If so, then the incidence of COVID-19 severe disease would be reduced and the infection may shift to become less disruptive to individuals and society,” the study said.

Sigal has previously found that a two-dose course of the Pfizer-BioNTech jab, as well as a previous infection, may provide stronger protection against Omicron.

Scientists at the Africa Health Research Institute in Durban, South Africa, work on the omicron variant of the COVID-
The latest findings are being submitted to MedRxiv, a preprint medical publication.  
AP Photo/Jerome Delay

“If we are lucky, Omicron is less pathogenic and this immunity will help push Delta out,” Sigal said, according to Bloomberg News.

According to a previous South African study, there is a reduced risk of hospitalization and severe illness in people infected with Omicron compared with Delta — though the authors suggested that some of that is likely due to high population immunity.

The latest findings are being submitted to MedRxiv, a preprint medical publication.