5/23/20 - smart, useful, science stuff about COVID-19
VACCINE:
1) Early results from a study of a vaccine tested on healthy adults aged 18 to 60 in Wuhan suggest that it is safe and protects people from the new coronavirus, reports Apoorva Mandavilli for The New York Times (5/22/20). The results were published the same day in the Lancet. Only one other vaccine currently at the stage of testing in humans has published results in a scientific journal, Mandavilli reports. Some caveats: this experiment was designed primarily to test the safety of the vaccine, not its effectiveness. The study participants were not randomly assigned to receive the vaccine candidate (as is typical for studies tested for safety). No subjects over 60 were tested, but COVID-19 is most life-threatening for people over 60. People over 45 in the study had weaker immune responses than others did to the vaccine, the story states. Only some people in the study produced neutralizing antibodies, the type “needed for immunity,” Mandavilli writes: https://www.nytimes.com/2020/05/22/health/coronavirus-vaccine-china.html.
2) A 5/22/20 story by science writer Bob Holmes for Knowable expands that last bit. “There’s a big difference between an immune response and a protective immune response,” says a University of California, Los Angeles, infectious disease specialist quoted in Holmes' story. To be effective, vaccines must prompt our bodies to not only make antibodies but prompt “the right sort of activity” from immune cells that direct our “immune response to the virus,” he writes. And the vaccine must prompt our bodies to create so-called neutralizing antibodies that prevent the virus from entering our cells. The story also explains why it takes so long for vaccines to be developed and ready for use. Some of the most time-consuming steps are testing the effectiveness of a vaccine candidate on a large number of people who are exposed naturally to the virus (Phase 3) and then manufacturing large batches of a vaccine for distribution, Holmes writes. Then he lists some ways that the current process to develop a SARS-CoV-2 vaccine has already proceeded quickly and might continue to do so. An expected wave of infections this fall would allow researchers to administer the vaccine where outbreaks occur, the story states. The story also includes these positive snippets: 1) “it’s possible but unlikely” that researchers will never develop a vaccine for the virus; and 2) how soon will a vaccine come? “Next spring at the earliest or perhaps the fall of 2021,” Holmes writes: https://www.knowablemagazine.org/article/health-disease/2020/how-long-will-a-coronavirus-vaccine-take.
3) Now the bad news, a hint of which appears in the New York Times story above. Journalist Brendan Borrell reports for Medium’s OneZero (5/22/20) that the first successful SARS-CoV-2 vaccine might not protect people over 65 very well. This story not only explains the complications of developing vaccines for seniors but also some of the ways researchers get around them. As we age, our immune burden increases and our immune responses weaken, “which means that older adults don’t develop a vigorous defense following vaccinations,” writes Borrell. There are other factors too. To be protected by a vaccine, older people typically require a “second arm” of their immune system to be prompted, beyond generating neutralizing antibodies, the story states. The second arm "involves killer T-cells, a type of white blood cell that can destroy infected cells and halt virus replication,” he writes. The story explains how vaccine makers try to solve that by making “adjuvants,” which are secondary ingredients that boost or aid a vaccine’s primary active ingredient: https://onezero.medium.com/amp/p/3fc176f75751.
TESTING:
4) Earlier this month, the U.S. Food and Drug Administration approved on an emergency-use basis the first of a third type of test related to the new coronavirus — called an antigen test. The diagnostic, nasal-swab test shows the presence of fragments (complex molecules called proteins) of SARS-CoV-2, whereas the older and more common nasal or oral swab tests show the presence of the virus’s genetic material (RNA) (both of these tests show a current infection not a past one, as an antibody test would). Antigen tests return results in minutes and are less expensive. Doctors should be able to process tests in their offices or in clinics, and it’s so easy to perform that we could possibly test ourselves at home, too. All this raises the potential for daily large-scale testing of all people in a region or country, which could dramatically aid efforts to stop unmanageable outbreaks. The downside of antigen tests reportedly is a high rate of false negatives for now — incorrectly indicating that one doesn’t have the virus when they actually do. The approved antigen tests currently find positive cases 80 percent of the time, whereas the most accurate of the more common “molecular” tests for the virus find positive cases 98% of the time, reports Robert F. Service at Science. His 5/22/20 story explains how antigen tests work and quotes various levels of enthusiasm for and skepticism about the tests among infectious-disease scientists and medical researchers: https://www.sciencemag.org/news/2020/05/coronavirus-antigen-tests-quick-and-cheap-too-often-wrong.
5) Jonathan Wosen created a helpful graphic on all 3 types of novel coronavirus testing for a Q&A on the subject in the San Diego Union-Tribune (5/18/20). For each type of test, the graphic shows how samples are collected, how each test works, and each test's limitations. The graphic also lists the names of some makers of the tests and where Southern Californians can get the tests. Thanks to Wosen and others on Twitter for helping me track down the full story by Paul Sisson: https://www.sandiegouniontribune.com/news/health/story/2020-05-18/q-a-testing-everything-you-always-wanted-to-know-about-testing-for-the-coronavirus.
HEALTH CARE:
6) New data suggest that COVID-19 patients receiving oxygen but not on ventilators are most likely to benefit from treatment with the anti-viral drug remdesivir, by recovering in fewer days, according to a 5/22/20 story by Deena Beasley for Medscape: https://www.medscape.com/viewarticle/931063.
ENTERTAINMENT:
7) Actor Sam Neill (@twopaddocks) tweets this video starring Helena Bonham Carter and himself (sound on):
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