U.S. Hits Record Number of New Covid Cases Twice in Same Week

The new record comes just after the seven-day average hit 265,427 on Tuesday. The post-Christmas surge in cases has pushed that average past its previous peak of 251,989 set on Jan. 11, 2021, although there was less testing during the earlier stages of the pandemic.

As of Thursday, the seven-day daily average of hospitalizations for confirmed or suspected Covid-19 was 81,831 a day, according to data from the U.S. Department of Health and Human Services. That is an increase of about 19% over the past two weeks.

The seven-day average of hospitalizations, though increasing, is below both the pandemic peak of 137,510 on Jan. 10, 2021, and the smaller peak of 102,967 on Sept. 4, 2021, during the Delta surge.

More countries have cut isolation times and testing requirements as new cases haven’t so far led to significant increases in hospitalizations. The WHO, though, on Wednesday said there is a risk that some people will go on to develop and spread the disease after shorter quarantine periods expire. “So it is a trade-off between the science and being absolutely perfect in what you try to do, but then having the minimal disruption that you can possibly have to your economy and society,” said Michael Ryan, the WHO’s emergencies director. “And governments are struggling to find that balance.”

The rising caseloads are affecting industries across the U.S. On Thursday, Amtrak canceled trains on the Northeast Corridor and some of its long-distance routes, beginning Friday, as the railroad struggles with staffing shortages amid the latest surge in Covid-19 infections. Many of the company’s critical functions require safety certification and employees can’t be readily replaced when out sick.

An Amtrak spokesman said winter weather also affected some train cancellations.

“Throughout the pandemic, Amtrak’s experience with the frequency and location of cases has mirrored the larger U.S., and this week is no exception. While nearly 97% of Amtrak employees are fully vaccinated, this requires a temporary short-term adjustment to our service levels,” he said.

The Centers for Disease Control and Prevention recommended that travelers avoid cruises, regardless of vaccination status, saying the new guidelines reflect increases in cases aboard cruise ships since Omicron was first identified.

U.S. officials have pointed to growing evidence that the illness caused by the fast-spreading Omicron variant is less severe than that of previous strains of the virus as hospitalizations continued to lag behind a record surge of new infections.

In a briefing at the White House on Wednesday, CDC Director

Rochelle Walensky

said that while caseloads have rocketed, hospitalizations and deaths have remained comparatively low.

Anthony Fauci,

the Biden administration’s chief medical adviser, said all indications point to Omicron being less severe than the Delta variant and that vaccine booster shots will be critical to the U.S.’s approach to tackling the rise in infections.

“We must remember that hospitalizations and deaths are lagging indicators,” he said. “However, the pattern and disparity between cases and hospitalization strongly suggest that there will be a lower hospitalization-to-case ratio when the situation becomes clear.”

Dr. Fauci also said that a second booster shot might be needed to top up immunity levels, but there isn’t enough data yet to determine the durability of the protection provided by the current round of boosters.

Other countries, including France and the U.K., have also seen hospitalizations lag behind record-high numbers of new infections in recent days, prompting some to reassess self-isolation periods for people infected or exposed to the virus to minimize the disruption to healthcare and other critical sectors. Employee absences due to infection from the Omicron variant led to thousands of flight cancellations over the Christmas weekend, while officials in the U.S. and elsewhere have expressed concern over how quarantines are affecting hospital staffing levels.

Spain on Wednesday said it would reduce the quarantine period for people who have tested positive for Covid-19 to seven days from 10 as infections surged to record highs. Italy said it would abandon self-isolation requirements for those coming into contact with people testing positive, provided they have been vaccinated or have recently recovered from infection.

The CDC this week advised that infected people who are asymptomatic can leave isolation after five days and should wear masks when around other people for another five days; those who are vaccinated and exposed to someone with Covid-19 should wear a mask for 10 days and try to get tested five days after exposure.

In South Africa, where the Omicron variant was first detected, data from the National Institute for Communicable Diseases said average daily hospital admissions in Gauteng province, which includes Johannesburg, fell by more than 20% in the two weeks to Dec. 25 compared with the two weeks before. On a weekly basis, average daily admissions were down nearly 40% with declines also recorded in other provinces.

Two doses of

Johnson & Johnson’s

Covid-19 vaccine reduced hospitalizations from the Omicron variant by up to 85%, another South African study found. The paper, which hasn’t been peer reviewed, indicated that there was a significant increase in protection in the weeks and months after receiving a booster—an important finding as many African nations are depending on the J&J vaccine for their immunization campaigns.

—Sarah Toy and Ted Mann contributed to this article.

Write to Anthony DeBarros at [email protected] and James Hookway at [email protected]