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Here’s how you should think about your immunity to SARS-CoV-2 after you receive your first shot of a two-dose vaccine, according to a 1/14/21 BBC Futures story: “Pretend it didn’t happen.” In other words, assume you have acquired no immunity to SARS-CoV-2 after that first dose. “…Most vaccines require booster doses to work,” writes Zaria Gorvett. Your immune system’s first response to a vaccine typically activates B cells, which make antibodies, as well as T cells of various types, including memory T cells that stick around. The problems are that B cells are short-lived, and the body makes few memory T cells until “the second meeting” with a virus or other pathogen, the story states. The 2nd dose or booster is a re-exposure that increases the number of memory T cells, the number and quality of memory B cells, and the quality of antibodies to a pathogen, according to an Imperial College London immunologist quoted in the piece. Advice notwithstanding, the story also states the percent effectiveness that recipients can expect to kick in after receiving vaccines currently available in various countries.

For health care professionals, infectious disease specialist Dr. Paul Sax at Harvard Medical School has provided answers to frequently asked COVID-19 vaccine questions. Topics addressed include how the vaccines work; vaccine effectiveness, safety, availability; whether one vaccine is preferable to another for certain patients; guidance for immunocompromised patients; second-dose issues; and guidance for people with COVID-19 or a possible case. Sax’s replies are useful for all of us. In the New England Journal of Medicine (updated 1/11/21).

Advice for avoiding the new coronavirus variant, per this piece by Tara Parker-Pope at The New York Times (1/19/21), includes upgrading to two- or three-layer masks for errands and shopping, spending time indoors only with people from your own household, cutting back on grocery store visits and time spent in stores, avoiding crowds, not entering a store if you arrive and find it crowded, remaining socially distant, washing hands frequently, and not touching your face. But most of us still don’t need N95 medical masks, according to Dr. Ashish K. Jha at the Brown University School of Public Health, the story states. Office and grocery store workers might consider a KF94 masks, Jha is quoted as saying. They resemble N95s but have ear loops rather than elastic head loops.

A computer-simulation study of airflow inside passenger cars, published 1/1/21 in Science, supports advice to keep windows open, ideally all windows, to prevent spreading SARS-CoV-2 to others while riding together in a car, truck or other motor vehicle, writes Emily Anthes for The New York Times (1/16/21). Anthes, the author of a recent book on the air we breathe inside buildings, writes that the study simulated air flow in a "Toyota Prius driving at 50 miles per hour, with two occupants: a driver in the front left seat and a single passenger in the back right.” In the cold weather, it’s uncomfortable to keep all 4 vehicle windows open in a sedan, but half-way open can ventilate just as well as fully open, the study found, according to the story. Another alternative for the two-person ride-sharing or taxi-riding configuration: fresh air flows in a way that creates “a barrier between the driver and the passenger” if each opens the window opposite them rather than the one next to them, the research suggests, Anthes writes.

It seems that the research on the transmissibility and other pandemic effects of new variants of SARS-CoV-2 remains scant. An Oxford University epidemiologist quoted in a 1/15/21 story by Kai Kupferschmidt in Science says that a new variant called P1 and identified in Manaus, Brazil, “might have nothing to do with the new surge in infections [there]; people’s immunity might simply be waning.” And a World Health Organization physician and epidemiologist is described as saying that changes in human behavior remain the driving force behind the pandemic's resurgence. “Even if [a] variant plays a crucial role it might be driving the boost because it is transmitted more easily, like B.1.1.7, not because it can evade the immune response,” Kupferschmidt writes. He writes later in the piece, “So far, the virus does not appear to have become resistant to Covid-19 vaccines,” according to a WHO vaccinologist.

RIP Sharon Begley, one of the best science and medical journalists of our time.  

You might enjoy, “Waiting for To-Go,” by Sam Lipsyte, for the New Yorker (1/18/21).