The omicron variant of the coronavirus is spreading twice as quickly as the delta variant and may be three times as likely to reinfect those that have already recovered from Covid-19, according to a pair of preliminary studies out of South Africa this week.
Preliminary data from nine South African provinces shows the omicron variant has spread more than twice as quickly as the delta variant, according to South African Covid-19 Modelling Consortium figures shared on Twitter Friday by London School of Hygiene & Tropical Medicine mathematical modeler Carl Pearson, though the data has not been peer-reviewed or published in a scientific journal.
Pearson told the New York Times researchers aren’t sure whether the omicron variant’s quick spread is primarily due to its contagiousness or an ability to evade the immune system, adding, “It’s possible that it might even be less transmissible than Delta.”
South African researchers also estimated Thursday that omicron is at least three times more likely to reinfect people who have recovered from a Covid infection than previous variants, citing a large increase in the rate of coronavirus reinfection during the country’s most recent wave, according to a non-peer-reviewed preprint article.
The omicron variant accounted for 73% of all sequenced genomes from positive Covid-19 tests in South Africa in the month of November, according to the country’s National Institute For Communicable Diseases, though only a small fraction of samples from tests are sequenced each week.
“The studies appear to illustrate what we’ve been seeing anecdotally come out of the data from South Africa,” Dr. Amesh Adalja, senior scholar at Johns Hopkins University’s Center for Health Security at the Bloomberg School of Public Health, told Forbes. “This variant has the ability to transmit efficiently and has the ability to cause reinfections at a higher rate than we’ve seen with other variants.”
16,055. That’s how many new Covid-19 cases South Africa reported on Friday, jumping from 11,535 on Thursday and 8,561 on Wednesday.
Covid-19 cases have surged in South Africa since the omicron variant was first identified in southern Africa on November 25. The World Health Organization deemed omicron a “variant of concern” shortly after, though it clarified the transmissibility and severity of disease resulting from the variant remain unclear. Some researchers are hopeful that current Covid-19 vaccines will offer robust protection against the variant: South Africa’s NCID said in a report Thursday that while omicron may be able to evade some immune protection, “the protection against severe disease and death from vaccines should be less affected.” Fewer than 25% of South Africans have been fully vaccinated against coronavirus, according to data from Oxford University’s Our World In Data project.
WHAT TO WATCH FOR
The United States detected its first confirmed case of the omicron variant on Wednesday and has since detected cases in six different states. It is unclear whether infections will spike in the U.S. as they have in South Africa as the variant spreads. “The key thing will be trying to extrapolate what’s going on in South Africa where there are different dynamics in terms of immunity from vaccination versus immunity from prior infection,” Adalja said. “It’s hard to completely extrapolate what’s going on in a place where only 25% of the population is fully vaccinated to a place where 60% of the population is fully vaccinated.”
New evidence shows omicron likely spreads twice as fast as delta in South Africa (NPR)
By Mason Bissada, Forbes Staff