The potential for a rise in infections and reinfections from the new COVID-19 variant XBB.1.5 appears to be in the “rearview mirror,” according to one expert.
University of Toronto epidemiologist Prabhat Jha told Global News that he is “cautiously optimistic” as the variant nicknamed “Kraken” doesn’t appear to be leading to a big increase in hospitalizations.
“If (XBB.1.5) causes reinfections in people or new infections in the uninfected, then we could have a problem,” he said. “But if that were going to happen, it should have happened by now.
“I’m cautiously optimistic it’s mostly in the rearview mirror.”
While infection data is not as compressive as at the beginning of the pandemic due to governments not participating in active collection anymore, Jha said that wastewater indications have been encouraging, based on patterns he is seeing and what has happened in the past.
XBB.1.5 is essentially the “niece or nephew” of the main Omicron strains, such as BA.4 and BA.5, that were circulating in August and onward, Jha said. Its symptoms are flu-like, similar to Omicron, but do not seem to include the earlier COVID symptom of loss of smell.
Dr. Theresa Tam, Canada’s top doctor, said earlier in January that it does not appear XBB.1.5 has more severe symptoms. However, the World Health Organization has said XBB.1.5 is the “most transmissible” variant so far.
Jha attributes the better-than-expected outlook on “hybrid immunity” from people both getting infected with COVID-19 and receiving vaccination. He said this has created an “immunity wall” that has been more effective than experts had previously hoped.
“We’re in far better shape than we could have imagined last year.”
Still, Jha notes that those over 60 years old are vulnerable and should keep on wearing masks in crowded indoor areas and get a vaccination booster when eligible.
New data from the U.S. Centres for Disease Control found that the updated vaccines from Pfizer and Moderna that were geared toward the BA.4 and BA.5 variants are nearly as effective on XBB.1.5. While they were 52 per cent effective against BA.5 infections, they were 48 per cent effective against XBB.1.5 among those 18-49 years old. The vaccines fared better against XBB.1.5 for those older, with 43 per cent effectiveness against the variant for those over 65 years old compared to 37 per cent for BA.5.
XBB.1.5 is still a highly transmissible virus, though, and all it takes is one infection in a crowded room for it to spread, Jha said.
“We’ve got to be careful.”
Meanwhile, in the U.S., Jha said XBB.1.5 is causing most of its new infections and is leading to more hospitalizations, which he attributes to a lower vaccination rate in the country. The CDC reported Friday that XBB.1.5 accounts for 61.3 per cent of U.S. COVID-19 cases and is likely the dominant variant now.