President Joe Biden has signed a bill to declassify information on the origins of COVID-19, frequent COVID-19 testing in nursing homes may have helped reduce cases and deaths among residents, and more in this week's roundup of COVID-19 news.

• World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus last week said he expects the organization to officially declare an end to the COVID-19 pandemic later this year as cases and deaths continue to decline. For the first time, the weekly number of reported COVID-19 deaths over a four-week period was lower than what it was when WHO first declared COVID-19 a global pandemic three years ago. "We are certainly in a much better position now than we have been at any time during the pandemic," Tedros said. "I am confident that this year we will be able to say that COVID-19 is over as a public health emergency of international concern." In the United States, COVID-19 hospitalizations and deaths continue to trend downward. For the week ending March 15, there were 2,636 hospitalizations and 1,706 deaths. The number of deaths is the lowest it has been since March 25, 2020. The U.S. public health emergency for COVID-19 is expected to end May 11. (Ellis, WebMD, 3/18; Rudy, Fox News, 3/19)

• Frequent COVID-19 testing among staff at nursing homes was associated with lower COVID-19 case and death rates among residents, according to a new study published in the New England Journal of Medicine. For the study, researchers examined 13,424 nursing homes and assessed their staff testing volumes during weeks without COVID-19 cases against other facilities in the same county. They also analyzed the number of cases and deaths among residents during potential outbreaks, which were defined as a case occurring after two weeks with no cases. Overall, there were 519.7 COVID-19 cases per 100 potential outbreaks in high-testing facilities compared to 591.2 cases in low-testing facilities. High-testing facilities also had lower death rates at 42.7 deaths per 100 potential outbreaks, compared to 49.8 deaths in low-testing facilities. According to the researchers, frequent staff testing was most effective in the period before COVID-19 vaccines were available and when the turnaround time for results was two days or less. However, they noted that frequent testing in nursing homes was difficult to achieve before 2021 due to testing and staffing shortages, supply chain issues, and slow test turnaround times. "We found that greater surveillance testing of staff members in skilled nursing facilities was associated with clinically meaningful reductions in COVID-19 cases and deaths among residents," the researchers wrote. "Greater surveillance testing was also associated with more COVID-19 cases among staff during potential outbreaks, findings that were consistent with the protection of residents through the increased detection of COVID-19 among staff members." (Hein, MedPage Today, 3/22; Rowland, Washington Post, 3/22)

• President Biden on Monday signed a bill to declassify information about the origins of COVID-19 after it was passed by both the House and Senate earlier this month. The bill, known as the COVID-19 Origin Act of 2023, requires the Director of National Intelligence to declassify all information about potential links between China's Wuhan Institute of Virology and the origin of the coronavirus within 90 days. "I share the Congress's goal of releasing as much information as possible about the origin" of the coronavirus, Biden said after signing the bill. "We need to get to the bottom of COVID-19's origins to help ensure we can better prevent future pandemics." Currently, there is an ongoing debate about the origins of COVID-19, with some intelligence agencies, including the Federal Bureau of Investigation, subscribing to a lab leak theory while others have been more supportive of zoonotic transmission. (Wang/Johnson, Washington Post, 3/21; Paun, Politico, 3/20)

• FDA is considering authorizing a second round of updated booster shots for older adults and other individuals with a high risk of severe COVID-19, the Wall Street Journal reports. According to people familiar with the situation, FDA could authorize a second booster of the omicron-targeted shots for people ages 65 and older or with weakened immune systems within the next few weeks. However, officials have not yet reached a final decision. According to some providers, they have had several patients, particularly those who are older, reach out to them about getting a second dose of the updated booster. "For those who want it and have risks, they should be able to get it," said Michael Osterholm, an epidemiologist and director of the Center for Infectious Disease Research and Policy at the University of Minnesota. So far, less than 17% of the total U.S. population has received an updated booster, and around 40% of those ages 65 and older have done so. "We continue to closely monitor the emerging data in the United States and globally, and we will base any decision on additional updated boosters upon those data," FDA said. "Importantly, individuals who have not yet received an updated (bivalent) booster are encouraged to speak with their health care provider and consider receiving one." (Amour/Whyte, Wall Street Journal, 3/21; Goodman, CNN, 3/21)

• The overall risk for venous thromboembolism (VTE), or blood clots, was low for most COVID-19 outpatients, although certain groups had higher rates, according to a new study published in JAMA Network Open. For the study, researchers from the University of California, San Francisco, analyzed data from 398,530 non-hospitalized COVID-19 patients from Jan. 1, 2020 to Jan. 31, 2021, with a follow-up through Feb. 28, 2021. All participants were enrolled in either Kaiser Permanente Northern California or Kaiser Permanente Southern California. Patients' mean age was 44 years, and 54% were women. Overall, there were 292 VTE events reported, or 0.26 VTE events per 100 person-years, which was not much higher than the rate seen in the general population. However, certain groups had a higher risk of VTE, including people with a prior VTE, those with primary or secondary thrombophilia, and those who were ages 75 to 84. Although prior studies of COVID-19 outpatients have shown no benefit from anticoagulants, the researchers said it may be helpful for certain groups with a higher risk of VTE. "Although the low rates of VTE reported in our study do not support the universal use of antithrombotic agents in nonhospitalized patients with COVID-19, our results support the importance of clinical trials that are evaluating whether some higher-risk subgroups may benefit," the researchers said. A notable limitation of the study is that it was conducted before vaccines became common. Other research has suggested that the risk of VTE is much lower among those who are vaccinated than those who are not. (Hein, MedPage Today, 3/16)