Omicron Variant Could Boost Immunity Against Delta and Eventually Displace It: Study

Omicron coronavirus infections may provide individuals with increased protection against the Delta variant and pave the way for Delta to eventually become displaced, according to a new study published in South Africa.

Researchers from the Africa Health Research Institute (AHRI) conducted a small study and found that people who are infected with Omicron, especially those who are vaccinated, gain stronger immunity against Delta.

The research involved 13 Omicron patients, seven of which were vaccinated and one who had received a booster shot. To conduct the study, the scientists measured how well participants were able to neutralize Omicron and Delta upon enrollment, and 14 days later. During that time-frame, they found that neutralization of Omicron generally increased 14-fold, while Delta neutralization increased 4.4-fold.

According to the paper, vaccinated participants "were able to mount a better neutralizing response against Delta" while those who were unvaccinated had "more variable" responses.

The study, which has not yet been peer-reviewed, ultimately suggests that increased immunity from Omicron may work to halt Delta infections and phase out the variant over time.

"The increase in Delta variant neutralization in individuals infected with Omicron may result in decreased ability of Delta to re-infect those individuals," wrote Alex Sigal, lead author of the study and a professor at the Africa Health Research Institute. Sigal then added that displacing Delta would depend on whether or not Omicron is a less pathogenic variant.

"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," he said.

Omicron Could Displace Delta: Study
Infection with the Omicron coronavirus variant may provide increased immunity against Delta, according to a new South African study. Here, a passenger of a flight from South Africa is tested for the virus at Amsterdam Schiphol airport on December 2 in Amsterdam, Netherlands. Pierre Crom/Getty Images

Scientists are still working to uncover information about the rapidly spreading Omicron variant, but studies have so far suggested that it is more transmissible than Delta, but less likely to cause severe disease and hospitalization. The latest variant was first detected in South Africa in November, and has since taken over over as the dominant strain in the U.S. and elsewhere.

Cases in the U.S. are now reaching more than 240,000 per day, resulting in a bigger surge than the last wave of Delta infections, according to the New York Times. Omicron infections have also resulted in disruptive labor shortages and sparked an increased demand for testing across the country.

To combat the spread of the virus, the U.S. Centers for Disease Control and Prevention (CDC) maintains that getting vaccinated and boosted is most effective.

"Current vaccines are expected to protect against severe illness, hospitalizations, and deaths due to infection with the Omicron variant," the CDC said on its website. "Vaccines remain the best public health measure to protect people from COVID-19, slow transmission, and reduce the likelihood of new variants emerging."