The new omicron variant of the coronavirus is significantly more contagious and reduces the effectiveness of COVID-19 vaccines, according to a South African study published Tuesday.
Despite the fact that the variant appears to cause mostly mild disease so far, world health leaders have warned that it could cause a wave of illness that overwhelms health-care systems.
“Omicron is spreading at a rate we have not seen with any previous variant,” said World Health Organization Director-General Dr. Tedros Adhanom Ghebreyesus.
“We underestimate this virus at our peril,” he said in a press conference from Geneva on Tuesday. “Even if omicron causes less severe disease, the sheer number of cases could overwhelm unprepared health-care systems once again.”
According to preliminary data released Tuesday by Discovery Health, South Africa’s largest private health insurer, people who are fully vaccinated are still largely protected against severe disease.
The omicron variant, discovered in southern Africa, appears poised to take over the world in the same way that delta did before it. Omicron is responsible for 90% of COVID-19 cases in South Africa and is becoming more prevalent in Europe.
According to Ghebreyesus, it has now been discovered in 77 countries. It has been detected in at least 30 states in the United States, though the delta variant continues to dominate the American outbreak.
Although omicron was officially identified the day before Thanksgiving, details about its characteristics, including how contagious and dangerous it may be, are still emerging.
According to a new Discovery Health study, two shots of the Pfizer-BioNTech vaccine, which provided more than 90% protection against the original virus, are only 33% protective against omicron infection.
Full vaccination continues to provide 70% protection against severe disease, which appears to be consistent across high-risk groups, though it has declined slightly in people over 60 and even more in those over 70.