A study found that more than 50% of Covid-19 survivors experience long-term symptoms, the National Institute of Allergy and Infectious Diseases (NIAID) enrolled its first participant in a long-term study on Covid-19's impact on children and young adults, and more in this week's roundup of Covid-19 news.

Vaccines for younger kids: The 5 most important considerations

• The White House on Wednesday announced that around 10% of eligible children ages five to 11 have received their first shot of the Pfizer-BioNTech Covid-19 vaccine in the two weeks since its authorization for the age group, AP/Modern Healthcare reports. According to Jeff Zients, the White House Covid-19 response coordinator, 1.7 million kids were vaccinated in the last week alone, bringing the total number of children vaccinated to around 2.6 million nationwide. "Just 10 days into our program being in full strength, we're at 10% of kids," Zients said. "For perspective, it took about 50 days for us to reach 10% of adults with one shot. And when the polio vaccine was first rolled out for kids in the 1950s it took about three months to cross two and a half million shots in arms." In addition, Zients said the administration expects the pace of pediatric Covid-19 vaccination to increase in the coming days. (AP/Modern Healthcare, 11/17; Stolberg, New York Times, 11/17)

• A study published in the British Medical Journal found that wearing masks is the most effective non-pharmaceutical public health measure against the coronavirus. For the study, researchers examined 72 global studies that evaluated non-pharmaceutical public health measures against the coronavirus, including mask wearing, physical distancing, and hand washing. The researchers found that mask wearing reduced the incidence of new Covid-19 infections by 53%, while physical distancing reduced incidence by 25%. Handwashing was also found to reduce Covid-19 incidence by 53%, but the researchers said this finding was not statistically significant due to the small number of studies assessing the measure. "This systematic review and meta analysis [of non-pharmaceutical interventions] suggests that several personal protective and social measures, including handwashing, mask wearing, and physical distancing are associated with reductions in the incidence of Covid-19," the researchers wrote. "Public health efforts to implement public health measures should consider community health and sociocultural needs, and future research is needed to better understand the effectiveness of public health measures in the context of Covid-19 vaccination." (Chen, Axios, 11/17; Hart, Forbes, 11/18)

• Pfizer on Tuesday requested FDA grant emergency use authorization for its antiviral Covid-19 treatment, Paxlovid. In a clinical trial of more than 750 people, Paxlovid was found to reduce the risk of hospitalization and death from Covid-19 by 89% when given within three days of symptom onset. According to Axios, the Biden administration plans to purchase 10 million courses of Paxlovid for $5.29 billion if it is authorized by FDA. According to HHS Secretary Xavier Becerra, Pfizer's antiviral drug "could help accelerate our path out of this pandemic by offering another life-saving tool for people who get sick with Covid-19." (Coleman, The Hill, 11/16; Knutson, Axios, 11/18; LaFraniere/Robbins, New York Times, 11/16)

• NIAID, which is part of NIH, on Monday enrolled the first participant in its large-scale study on Covid-19's impact on children and young adults, The Hill reports. For the study, researchers will follow up to 1,000 children and young adults, ranging in age from birth to 21, who have previously tested positive Covid-19 for three years to examine the long-term health and immune effects of the disease. "In adult patients, the long-term sequelae of Covid, including post-acute Covid-19, can significantly affect quality of life," said Anthony Fauci, director of NIAID. "Our investigations into the pediatric population will deepen our understanding of the public health impact that the pandemic has had and will continue to have in the months and years to come." (Carbajal, Becker's Hospital Review, 11/17; NIH news release, 11/15; Coleman, The Hill, 11/15)

• A study published in JAMA Network Open found that more than 50% of Covid-19 survivors experience long Covid, or lingering physical and psychological health issues, for six months after their initial recovery. For the study, researchers analyzed data from 57 studies, which included 250,351 participants who had recovered from Covid-19. The mean age of participants was 54.4 years, and 56% were male. The researchers found that 54% of participants experienced at least one long Covid symptom after one month, and the rate remained similar for between two and five months (55%) and at six months (54%). Commonly reported symptoms included fatigue or muscle weakness (37.5%), generalized anxiety disorder (29.6%), and difficulty concentrating (23.8%). "These findings confirm what many health care workers and Covid-19 survivors have been claiming, namely, that adverse health effects from Covid-19 can linger," said Vernon Chinchilli, the study's co-lead investigator and chair of the department of public health sciences at the Penn State College of Medicine. (Downey, Healio News, 10/14; Groff et al., JAMA Network Open, 10/13; Searing, Washington Post, 11/15)