Those who had omicron in the winter could get it again, Duke doctors say
People who contracted COVID-19 from the omicron variant during the winter surge aren’t necessarily protected against a widely spreading omicron subvariant, two Duke doctors said at a press conference Wednesday morning.
Dr. Cameron Wolfe, infectious disease specialist at Duke Health, said his sequencing lab has found cases in which people who were infected with omicron in December or January have been recently reinfected with BA.2, the dominant strain in North Carolina.
Earlier in the pandemic, reinfection typically happened when someone was exposed to a completely different variant. Though it’s not clear why, the immunity developed from an omicron infection is less robust, Wolfe said.
Previous infections appear to make subsequent COVID-19 symptoms milder, he said, making it unlikely that someone reinfected would be hospitalized.
New cases of COVID-19 slightly declined last week compared to the week before, according to data from state Department of Health and Human Services. Still, new cases remain high — about nine times the weekly reported cases in March — and almost all counties in the Triangle are considered to have “medium” or “high” levels of community transmission by the Centers for Disease Control and Prevention.
The number of COVID-related hospitalizations rose for the seventh week in a row, from 574 during the week that ended on May 21 to 657 last week.
Dr. Adia Ross, chief medical officer at Duke Regional Hospital in Durham, said the majority of hospitalized COVID-19 patients are either unvaccinated or have a pre-existing condition that puts them at risk for severe illness.
Wolfe said it’s unlikely that this surge in new COVID-19 cases will translate to a surge in hospitalizations as substantial as the winter omicron wave.
“We have an imperfect vision of the future but we do have a pretty good vision of the next month or two,” he said.
How much protection do vaccines offer against BA.2?
Existing COVID-19 vaccines are very useful for preventing severe illness and avoiding an overloaded health care system, Ross said.
However, researchers now know that vaccine-generated immunity wanes faster than they initially expected.
“We now understand that that sort of resiliency of vaccination is not as good as we would have liked it to be,” he said. “It’s not a tetanus vaccine that lasts 10 years.”
Boosters are important for groups of people who lose their immunity more rapidly, like people older than 50 or those who are immunocompromised, he said.
Vaccines may also serve a role in preventing long COVID, a condition in which patients have symptoms— like fatigue, brain fog, and depression— for weeks or months after their infection.
Recent data from a study conducted in the United Kingdom suggests that vaccinated people are about 50% less likely to develop long COVID.
“I would not say that that’s been exclusive — I certainly saw plenty of people who still came down with lung symptoms that remained present for weeks after the virus cleared,” he said. “So it’s not an excuse to be flippant.”
When to end isolation after positive COVID-19 test
To figure out when to stop isolating, Wolfe said the best plan of action is to abide by the guidance from the CDC, which recommends people isolate for five days and wear a mask in public for at least 10 days after symptoms start.
The full 10 days of precaution is especially important for those who are immunosupressed and can shed the virus for longer, and for those who interact with high-risk groups like older adults.
These recommendations stand regardless of whether someone tests negative on a rapid antigen test before the 10-day mark. Wolfe said most people are probably not infectious before then but the guidance is intentionally conservative to prevent people from spreading the virus further.
This story was originally published June 1, 2022 at 2:35 PM with the headline "Those who had omicron in the winter could get it again, Duke doctors say."
