Omicron Might Help Shield Against Delta, New Research Suggests

Researchers are still trying to figure out what will happen with both the delta and omicron variants of COVID-19 spreading simultaneously. Now, new lab-based data are suggesting that the newer variant, omicron, might bring one silver lining: It could help individuals who contract it defend against the prior variant, delta.

Scientists in South Africa found that people who have recovered from an infection with omicron produced antibodies that protected them against delta. The reverse did not appear to be true, however.

Because omicron appears to produce less severe illness than delta, its overall effect might end up having a positive side, the scientists said. While the omicron variant is expected to strain health care systems and economies because of its extremely rapid spread, in the longer term -- if it continues to dominate -- there could be fewer hospitalizations and deaths than if delta was to continue to lead.

"Omicron is likely to push delta out," study lead author Alex Sigal, Ph.D., told The New York Times. Sigal is a virologist at the Africa Health Research Institute in Durban, South Africa. "Maybe pushing delta out is actually a good thing, and we're looking at something we can live with more easily and that will disrupt us less than the previous variants."

Earlier studies, using blood from people who were vaccinated or had recovered from cases of COVID-19, confirmed that antibodies derived from a prior delta infection offered little protection against omicron. But Sigal believes that as people contract omicron, they may gain some immunity to both that variant and delta. If that is true, then delta will gradually have fewer people it can successfully infect, leaving omicron to outcompete it. While scientists are not sure why omicron might provide immunity against the delta variant, it is possible that omicron may do the same with other variants as well.

The study included blood drawn from only 13 volunteers, but independent scientists called it sound, according to The Times. The volunteers were a mix of vaccinated and unvaccinated people, and Sigal's group tested the activity of the delta and omicron variants in the blood samples.

The study was posted Monday on the institute's website. It has not yet been published in a scientific journal and has yet to undergo peer review, the newspaper reported.