What to know about Covid as 2023 comes to a close

Covid hasn’t impacted the US as severely as it did in the 2022 winter season, but public health officials are warning Americans to still get vaccinated, as new variants spread and some hospital systems have chosen to return to mask mandates.

Coronavirus cases typically increase during the winter, as more people are inside and travel increases for the holidays.

Cases are once again on the rise – with deaths up 10 per cent and test positivity at 12.7 per cent as of late December, per the CDC – but the 2022 winter of the “tripledemic” and the Omicron variant was worse.

“It’s not seeming to be more severe than what we were seeing last year at this time, which is good news," CDC director Mandy Cohen told NBC News.

"That’s exactly why we want folks to get the updated Covid vaccine, because it does map to the changes that we’re seeing in the virus," she added.

Covid hospitalisations remain drastically lower than the January 2022 peak of the Omicron wave, and about half as high as last winter when a triple wave of Covid, RSV, and the flu hit at the same time, according to a The New York Times analysis.

Nonetheless, Covid remains the primary cause of new hospitalisations for respiratory illness across the US, and is killing about 1,000 people a week.

“It’s continuing to go up, but it’s not as dramatic as, certainly, even two winters ago or even last winter, yet. So time will tell if the numbers that we see continue to go up,” Dr Nancy Gin, regional medical director of quality and clinical analysis for Kaiser Permanente Southern California told The Los Angeles Times. “It’s not causing intensive care units to be full of COVID-related illness, which is good.”

Despite the guarded optimism overall, officials are still monitoring the ascendant JN.1 variant, now the most dominant strain in the US, which leapt from causing 7 per cent of Covid cases in November to nearly 45 per cent as of mid-December.

The WHO has declared JN.1 a “variant of interest.”

“JN.1’s continued growth suggests that the variant is either more transmissible or better at evading our immune systems than other circulating variants,” according to a December CDC update. “It is too early to know whether or to what extent JN.1 will cause an increase in infections or hospitalizations.”

“It’s important to know that existing vaccines, tests, and treatments still work well against JN.1, so this variant does not affect CDC’s recommendations,” the agency added.

Hospital systems in Massachusetts, Washington, and Wisconsin have all returned to masking rules as Covid and other respiratory diseases continue to spread.

The persistence of Covid and its many variants underscores the continued need for vaccination and vigilance, according to experts

“I would say the most important thing for people to know is that the virus is out there, as are respiratory syncytial virus [RSV] and the flu,” DR  Heidi Zapata, a Yale Medicine infectious diseases specialist, said in an interview about JN.1 earlier this month. “Any new subvariant is a sign that the SARS-CoV-2 virus is still evolving; it’s still here with us, and we can’t ignore it.”