The items below are highlights from the free newsletter, “Smart, useful, science stuff about COVID-19.” To receive newsletter issues daily in your inbox, sign up here.

Both Moderna and Pfizer/BioNTech now have applied to the U.S. Food and Drug Administration (FDA) for full approval of their vaccines against COVID-19, reports Daniel E. Slotnik at The New York Times. Currently, both are authorized on an emergency-use basis by the agency. Many people, me included earlier this year, mistakenly have referred to the Moderna, Pfizer/BioNTech, and Johnson & Johnson vaccines as approved in the U.S. I mention this not because the distinction influences my confidence in these vaccines. Rather, an upgrade could prove important for vaccine hesitancy. More people in the U.S. who have been hesitant are deciding to get a COVID-19 shot, according to a 5/28/21 Kaiser Family Foundation survey noted by Slotnik. Now, if the FDA gives full approval to COVID-19 vaccines, it’s possible that hesitancy will decline further and we can get closer to herd immunity (6/1/21).

Failing this quiz by Dr. Arnaud Gagneur of the University of Sherbrooke and Dr. Karin Tamerius for The New York Times (5/20/21) taught me how to be more effective and helpful in conversations with people who have questions and concerns about COVID-19 vaccines.

Moderna’s mRNA vaccine against COVID-19 has been shown to strongly protect teens, the company said on 5/25/21, reports Lauran Neergaard for the Associated Press on the same day. In May, the Pfizer/BioNTech COVID-19 vaccine was authorized for use in children ages 12 and up. Moderna reportedly plans to submit its results to U.S. regulatory agencies early this month. So, there might be a second COVID-19 vaccine authorized for use in teens within weeks. “Both Pfizer and Moderna have begun testing in even younger children, from age 11 down to 6-month-old babies. This testing is more complex: Teens receive the same dose as adults, but researchers are testing smaller doses in younger children. Experts hope to see some results in the fall,” Neergaard reports.

At the Your Local Epidemiologist site, Katelyn Jetelina has published two posters, one in English (5/20/21) and one in Spanish (5/28/21), with answers to seven parental concerns about the COVID-19 vaccine that has been authorized for use in teens in the U.S. The covered topics include concerns about side effects, the effectiveness of the vaccine, the need to vaccinate teens against COVID-19, and what mRNA (messenger RNA) does once it gets into the body: (English); (Spanish).

The U.S. Centers for Disease Control’s 5/29/21 guidance on summer camps, vaccinations and mask-wearing is rounded up here by Roni Caryn Rabin at The New York Times. Details reportedly include: 1) encouraging vaccination among people ages 12 and up who plan to attend camps, 2) recommending that campers and staff can go mask-free at camps with 100% vaccination, and 3) recommending that unvaccinated campers can go mask-free outdoors in most cases. Camps with unvaccinated attendees should keep up other coronavirus prevention measures such as physical distancing, grouping children in pods or cohorts that don’t mix, and improving indoor ventilation, the CDC advises, according to the story (5/28/21).

In the U.S., COVID-19 vaccine distribution initially was left for states to figure out and administer, as you probably know. Fortunately, federal funds were made available in 2021 to assist, and some vaccination mega-sites have been set up to target communities heavily affected by COVID-19, people of color, and other marginalized or underserved areas. On April 20, I got to help report on the experience of patients visiting such a site, in Newark, NJ, for their second doses of the Pfizer/BioNTech vaccine. It was a wonderful experience, including the opportunity to interview people immediately after they were vaccinated and the opportunity to work with photographer Grant Delin. Here’s the 6/1/21 story that Grant and I collaborated on (feel free to skip scroll immediately to the photos and captions with quotes from the photographed individuals).

One problem that has slowed the U.S. response to the pandemic has been inconsistent findings and public-health messages about the effectiveness of cloth and surgical face masks, especially compared with N95 respirators. The latter technically are not masks, an epidemiologist recently told me. N95s are in a separate category of protective gear because they fit tightly on the face, are made of material that filters air (surgical and cloth masks don’t), and protect the wearer from breathing in particles carried in the the air. By contrast, surgical and cloth face masks protect others from particles exhaled or emitted by the person wearing the mask. A new study published 5/20/21 in Science provides a quantitative explanation of the “contrasting results” on how protective masks and N95s are in preventing the spread of SARS-CoV-2. If accurate, the findings are an intellectually satisfying answer to some of the issues that vexed public-health efforts to require people to wear masks. Bottom line: Face masks are effective as a measure to prevent the spread of SARS-CoV-2, the researchers conclude. A summary of the study abstract: Surgical masks are effective at preventing virus-spread in most settings, where little virus is present; and a combination of “advanced masks” with measures such as ventilation and distancing are effective in indoor settings such as medical centers and hospitals, where potentially higher levels of the virus are present. In modeling exposures to the virus in air, the researchers found that cloth and surgical masks still work in non-medical environments to prevent SARS-CoV-2 transmission because there is so little of the virus in the particles we exhale. Tweets by cardiologist Eric Topol at the Scripps Research Translational Institute alerted me to this study.

Are you looking to reduce your Covid-19-risk in packed outdoor crowds and at outdoor events this summer? In this 5/28/21 story for The New York Times, I looked into the latest advice for how to reduce your risk of catching or spreading SARS-CoV-2 outdoors this summer. The reporting reinforced my habit of checking online coronavirus dashboards. Experts say to look at these key stats at the state, county and city level where available: 1 - local infection (case) rates, 2 - hospitalization rates, and 3 - percent vaccinated. For instance, infection/case rates below 3 per 100,000 people, averaged across several days, is an outdoor safety threshold mentioned by one expert, although another expert who I quoted in the story opposed using a statistical threshold to make individual covid-safety decisions.

You might enjoy, “Best STEM toys for one-year-olds, also, calm down,” by Keith James (6/2/21).