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.

A 5/5/21 post by Katelyn Jetelina at her site Your Local Epidemiologist lays out the case for getting a COVID-19 vaccine even if you’ve tested positive for SARS-CoV-2 or recovered from the disease it can cause. The vaccines strengthen our immune response to the virus by giving us another “dose” of virus protection (the vaccine), she writes. And “the vaccine looks to better protect against variants than natural infection,” Jetelina writes, describing why Israel recently changed its policy from not vaccinating people with past SARS-CoV-2 infections to vaccinating them. The change was based on research, including a study of blood samples taken from health care workers after a SARS-CoV-2 infection, before vaccination and after vaccination. The researchers “infected” the blood samples with variants of the novel coronavirus, Jetelina writes, and found that “vaccines were better at increasing the number of neutralizing antibodies than natural infection. In other words, you have more soldiers.” And the vaccines appear to have provoked subjects to create more neutralizing antibodies against the variants initially reported in South Africa (B.1.351) and in Brazil (P.1), writes Jetelina, whose day job is at the University of Texas Health Science Center.

Pfizer is poised to advance the reach of its COVID-19 vaccine made in partnership with BioNTech on numerous fronts this spring and summer, according to various reports. First, the U.S. Food and Drug Administration (FDA) is expected, any day now, to authorize Pfizer’s two-dose mRNA vaccine for use in teens aged 12-15 based on effectiveness and safety data submitted to the agency in March. Second, the company plans to apply in September for emergency authorization for the vaccine to be administered to children aged 2-11, according to a 5/4/21 report by Emily Anthes for The New York Times. And third, Anthes also reports that the company plans to ask the FDA this month to bump up its COVID-19 vaccine for adults (ages 16-85) from its current emergency use authorization to full approval. 

Researchers are initiating large-scale studies to look more deeply into how effective COVID-19 vaccines are at protecting people with suppressed immune systems, reports Jennifer Couzin-Frankel at Science (4/27/21). The research could also reveal “ways to help patients whose weakened immune systems make protection against COVID-19 all the more urgent,” Couzin-Frankel writes. The research problem is complex because people’s immune systems can be suppressed in different ways by the variety of drugs used to treat people with cancer, autoimmune diseases, immunologic diseases, or organ transplants. The condition you have matters too, the story states. A lot of the findings so far on how people with suppressed immune systems respond to COVID-19 vaccines focus on antibody production, not T-cell production, (and many have not been vetted yet by experts for flaws). It’s more difficult to measure T-cell responses, but they "play an important role in protection from disease,” the story states. The story includes extensive detail about the results of early research on people with various conditions and on various classes of drugs: 

Don’t assume that a plateau in the U.S. demand for COVID-19 vaccines is due to “vaccine hesitance,” writes public-health communications researcher and content strategist Stefanie Friedhoff in a 4/27/21 essay at STAT. The piece includes survey results that undermine past forecasts for attitudes about COVID-19 vaccines. The essay advises that we “retire the term ‘vaccine hesitancy’” because it can become a self-fulfilling prophesy. She adds that “vaccine confidence is not a fixed mindset.” And it should not be minimized that vaccines are not “easily and equally available to all Americans,” she writes. Friedhoff cites survey results from a research partnership between her team at Brown University School of Public Health and the Rockefeller Foundation: “Even though a majority of Black and Latino Americans want to get vaccinated — 72% in this survey — a surprising 63% said they didn’t have enough information about where to get the shot.” More work needs to be done in “making vaccines ubiquitous and available without complex sign-up procedures” and learning the most effective communication approaches for gaining trust in public-health messages about vaccination.

Also, see this 4/29/21 Washington Post story by Mary Claire Molloy, Lenny Bernstein, Frances Stead Sellers and Nick Anderson about people who want the Johnson & Johnson “one-and-done” COVID-19 vaccine, not the two-shot COVID-19 vaccine, now that the U.S. government has lifted a 10-day J&J COVID-19 vaccine pause over concerns about extremely rare blood clots. The J&J vaccine, which is easier to store than the Pfizer and Moderna vaccines, could be particularly helpful in reaching homeless people, seasonal workers, and college and university students, the story suggests.

Are you vaccinated but still behaving as if you are not, such as continuing to avoid all social contact even with other vaccinated people? A 4/29/21 piece by Katherine J. Wu at The Atlantic reveals that you are not alone. “Readjusting our ideas about what’s safe is going to take time,” the piece states. The anxiety that helped to keep some of us from getting infected with SARS-CoV-2 cannot just be turned off, according to an Emory University psychologist quoted in the piece. “It’s got to power down,” he adds. Also, people in “mixed vaccination households,” such as those with children — most of whom are not eligible for COVID-19 vaccines in the U.S. — still have to make a tricky “risk calculus,” Wu writes. And current public health guidance is “splintering,” she adds, as some of us are vaccinated and others are not. “That punts a lot of the work to us, as individuals, to tailor the rules to our particular lives through ad hoc risk-benefit analyses,” Wu writes.

An interactive story at The New York Times shows how raw material, primarily small rings of DNA each containing a gene for SARS-CoV-2’s spike protein, is transformed into Pfizer-BioNTech’s COVID-19 vaccine. A two-month process that integrates material from Pfizer facilities in three U.S. states yields millions of frozen doses of the vaccine, ready to ship, states the story by Emma Cott, Elliot deBruyn, and Jonathan Corum (4/28/21). Steps include: 1) taking DNA out of cold storage, thawing the gene-carrying DNA and modifying “a batch” of E. coli bacteria to take in the DNA; 2) getting the bacteria to multiply/grow in a warm, sterile environment; 3) harvesting and purifying the DNA from the now multiplied bacteria; 4) testing the DNA for purity; 5) cutting and filtering the DNA; 6) and freezing, packing and shipping bottles of the DNA “with a small monitor that will record its temperature in transit” and ensure that containers are kept at negative 4 degrees F (negative 20 degrees C). At destinations in Germany and in Massachusetts, the DNA is transformed into messenger RNA, “the active ingredient of the Pfizer-BioNTech vaccine.” More steps follow before vaccine doses are tested again and make it into washed and heat sterilized vials.” Some 148 million people in the United States — more than half of the nation’s adults — have received at least one dose of a COVID-19 vaccine. “More than a billion doses have been administered worldwide,’ states the story, which ends with information about how Pfizer and BioNTech are developing new versions of their vaccine that could target SARS-CoV-2 variants.

In Farsi, the weekly Covid Cast features virologist Mahan Ghafari and immunologist Mehrnoush Jafari discussing COVID-19 news and debunking misinformation for Persian-language audiences (Iran, Afghanistan, etc.). The podcast is produced by Montreal-based freelance science journalist Pouria Nazemi.

You might enjoy, “Updated privacy policy from your children,” by Rachel Mans McKenny for McSweeney’s (5/4/21).