COVID-19 reinfections among people who’ve already battled the virus appear to be more likely with the Omicron variant than other strains, South African scientists warned Friday.
A surge in coronavirus reinfections occurred in the country as the new “variant of concern” emerged, according to the National Institute for Communicable Diseases, which tracks reinfections.
By contrast, there was no reinfection spike upon the arrival of other variants such as the highly contagious Delta strain, the scientists told the World Health Organization on Thursday.
“Previous infection used to protect against Delta, and now with Omicron, it doesn’t seem to be the case,” one of the researchers, Anne von Gottberg of the University of Witwatersrand, said at a WHO briefing.
But she added, “We believe that vaccines will still, however, protect against severe disease.”
In conversation with Dr. Michael Ryan (head of emergency at WHO), Ryan stated that reinfections could be mild.
“The data we’re really looking to see is going to be around severity of infection and whether or not the vaccines continue to protect against severe disease, hospitalization and death,” Ryan said. “And right now, there’s no reason to suppose that they won’t. We just haven’t got the details yet.”
The findings, posted online by the research group Thursday, haven’t yet undergone scientific review. It’s also unclear how many reinfections were confirmed as Omicron cases or whether they caused serious illness.
But the timing of the reinfection spike likely “demonstrates substantial population-level evidence for evasion of immunity from prior infection,” the researchers wrote.
Omicron is now known to have spread to at most 23 countries. At least five Omicron cases were reported in New York City.