A healthy lifestyle may reduce your risk of long COVID, no new coronavirus variants have emerged after China ended its strict zero-COVID policy, and more in this week's roundup of COVID-19 news.

• Merck's COVID-19 antiviral Lagevrio created new mutations of the coronavirus in some patients who took the drug, according to a new preprint study published in medRxiv. Lagevrio works by creating mutations of the coronavirus to prevent it from replicating in the body, which then reduces the risk of severe the disease. In the study, researchers analyzed viral samples from dozens of patients and found several mutations linked to the drug's use. Although none of the mutations were found to make the virus more severe or immune evasive, the findings suggest that more mutations may occur with widespread use of the drug. "There's always been this underlying concern that it could contribute to a problem generating new variants," Jonathan Li, a virologist at Harvard Medical School and Brigham and Women's Hospital. "This has largely been hypothetical, but this preprint validates a lot of those concerns." For its part, Merck has disputed the study's findings, citing limitations in its design. "There is no evidence to indicate that any antiviral agent has contributed to the emergence of circulating variants," said Merck spokesperson Robert Josephson. "Based on available data we do not believe that Lagevrio (molnupiravir) is likely to contribute to the development of new meaningful coronavirus variants." (Lauerman, Bloomberg, 2/1; Carbajal, Becker's Hospital Review, 2/3)

• A healthy lifestyle may substantially cut the risk of long COVID among women, according to a new study published in JAMA Internal Medicine. For the study, researchers analyzed data from 1,981 women who were part of the Nurses' Health Study II and had tested positive for the coronavirus between April 2020 and November 2021. Among the participants, 97.4% were white, 42.8% were active healthcare workers, and the mean age was 64.7 years. Pre-infection lifestyle habits were taken from 2015 and 2017. Overall, 44% of patients reported having long COVID, with 87% saying their symptoms lasted at least two months and 56.5% saying that the condition had occasionally impaired their daily life. Over 19 months of follow-up, the researchers found that patients who reported five to six healthy lifestyle factors — including a healthy BMI, never smoking, a high-quality diet, moderate alcohol intake, regular exercise, and adequate sleep — were 49% less likely to develop long COVID than patients with no healthy lifestyle factors. The researchers also noted that among patients who had developed long COVID, those with higher healthy lifestyle scores had less prevalent symptoms compared to those with lower scores. A limitation to the study is that the participants were primarily middle-aged white women in the nursing profession, which means it is not generalizable to the general public. The researchers recommended that future studies should include other populations and examine whether "implementing lifestyle interventions decreases risk of [long COVID] or benefits persons with [long COVID] or other chronic postinfection syndromes." (Hollowell, Becker's Hospital Review, 2/7; Hein, MedPage Today, 2/6)

• Despite being three years into the pandemic, it is still unclear whether masks are effective at slowing the spread of respiratory viruses such as the coronavirus or influenza, according to a research review published in Cochrane Library. For the review, researchers examined 78 studies that assessed the use of various masks among more than 610,000 participants across different settings in low-, middle-, and high-income countries. Although some of these studies were conducted during the 2009 H1N1 influenza and COVID-19 pandemics, many were conducted during flu seasons "in the context of lower respiratory viral circulation and transmission compared to COVID-19," the researchers wrote. Overall, the researchers found that studies comparing medical or surgical masks to no masks suggesting that masking "will probably make little to no difference" on the number of COVID-19 or flu cases. Similar findings were found for studies that examined healthcare workers N95/P2 respirators. According to the researchers, some potential reasons why masking was not found to be effective include poor study design, low adherence to masking rules, and mask quality. "Our review has provided important insights into research gaps that need to be addressed with respect to these physical interventions and their implementation and have been brought into a sharper focus as a result of the COVID-19 pandemic," the researchers wrote. (Bean, Becker's Hospital Review, 2/7)

   

• The House on Wednesday vote 227-201 to pass a bill ending COVID-19 vaccine requirements for most foreign travelers arriving in the United States. Previously, CDC had required all adult visitors who were not U.S. citizens or permanent residents to show proof of COVID-19 vaccination before boarding a flight to the country. In addition, the bill also prohibits CDC from implementing similar mandates for proof of COVID-19 vaccination. "This policy is out of touch with the rest of the world," said Rep. Brett Guthrie (R-Ky.). Ending this requirement "will align the United States with the rest of North America’s COVID-19 vaccine policy for people coming into the country and recognize COVID-19 is an endemic — rather than a pandemic." In response, the White House said it would review the policy as it prepares to end the COVID-19 public health emergency and that it opposed removing the policy without a scientific review. "Just as the establishment of this public health policy was guided by science, any termination or modification of this policy should be as well," the White House said. "A vote for this bill undercuts that critical principle." (Weixel, The Hill, 2/8)

   

• According to a new study published in The Lancet, no new COVID-19 variants have emerged since China lifted its strict zero-COVID policy late last year. For the study, researchers analyzed 400 COVID-19 vases in Beijing that occurred between Nov. 14 and Dec. 20, 2022 and found that over 90% were due to the omicron subvariants BA.5.2 and BF.7. Although the researchers wrote that the findings "could be considered a snapshot of China," other experts have said that cases in one region of China alone is likely not enough to show the full story. "The SARS-CoV-2 molecular epidemiological profile in one region of a vast and densely populated country cannot be extrapolated to the entire country," said Wolfgang Preiser and Tongai Maponda from Stellenboch University in South Africa. (Bencharif, Politico, 2/8)