Infection with the highly transmissible omicron COVID-19 variant may lead to a fourfold increase in protection against the delta strain, according to early study findings from the Africa Health Research Institute published Dec. 28.
The preliminary study included 13 people, seven of whom were vaccinated. Using plasma samples from participants, researchers measured antibodies in the lab to test the antibodies' ability to neutralize omicron and delta at the time of enrollment and again about two weeks later.
After two weeks, participants infected with omicron appeared to have enhanced immunity against the delta strain, with neutralization increasing more than fourfold, researchers found. The team also observed a 14-fold increase in antibodies' ability to to block reinfection from omicron. Overall, vaccinated participants demonstrated stronger protection.
Researchers emphasized that it's unclear whether the observed increase in immune protection is due to vaccination, previous infection or omicron-elicited antibodies.
"The increase in delta variant neutralization in individuals infected with omicron may result in decreased ability of delta to reinfect those individuals," said Alex Sigal, PhD, a faculty member at the Africa Health Research Institute, who led the study. "If omicron does prove to be less pathogenic, then this may show that the course of the pandemic has shifted — omicron will take over, at least for now, and we may have less disruption of our lives."
To view the full study, click here.