Turns out most people infected recently with Omicron in England had something in common. Two-thirds said they had COVID-19 previously.
Before Omicron, a previous infection was considered protection — almost on the level of a vaccine — from reinfection. The findings from Imperial College London’s React study, based on more than 100,000 polymerase chain reaction (PCR) test results across the country between Jan. 5 and Jan. 20, confirm Omicron’s elusiveness.
The study, which includes swab-testing volunteers, associated 99 percent of sequenced positive swabs with the Omicron variant and only 1 percent with Delta. The results also pointed to who might be most vulnerable to reinfection: healthcare workers and households with children or multiple members.
React, which updates results monthly, has tested more than 2 million people.
It’s uncertain how many people who tested positive in the most recent results had been fully vaccinated. Two doses have shown little protection against Omicron.
“If you are unvaccinated, you are more likely to do poorly if you contract COVID,” says Dr. Ulysses Wu, Hartford HealthCare’s System Director of Infection Disease and Chief Epidemiologist. “If you are unboosted, you are also more likely to do more poorly as compared to being just vaccinated but not boosted. But those two in their totality, as compared to those who are unvaccinated? The chasm is quite large. If you are to do poorly, you either have major comorbid risk factors and/or you are unvaccinated.”
An earlier study, before Omicron arrived in the United States, found that people infected with COVID-19 can expect reinfection in two years or less if not vaccinated and using safety precautions such as masks in public spaces. It appears Omicron has accelerated that timeline.