Wednesday, July 14, 2021

The Delta Variant

Environmental & Science Education, STEM, Health, Medicine, Society, Culture

Ed Hessler

The Washington Post in its free coronavirus series has a story on the highly contagious delta variant. Several FAQs are answered and discussed.

But first, Delta is one of four "variants of concern" according to the CDC. The CDC classification may be found here and includes these categories: Variant of Interest (VOI), Variant of Concern (VOC), and Variant of High Consequence (VOHC). These are the definitions.

Variant of Interest (VOI). A variant with specific genetic markers that have been associated with changes to receptor binding, reduced neutralization by antibodies generated against previous infection or vaccination, reduced efficacy of treatments, potential diagnostic impact, or predicted increase in transmissibility or disease severity.

Variant of Concern (VOC)A variant for which there is evidence of an increase in transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.

Variant of High Consequence (VOHC). A variant of high consequence has clear evidence that prevention measures or medical countermeasures (MCMs) have significantly reduced effectiveness relative to previously circulating variants. 

The CDC report notes "there are no SARS-CoV- 2 variants that rise to the level of high consequence."This report is updated regularly.

Washington Post reporters Lindsey Bever and Joel Achenbach start with a few facts to which I've added material from other parts of their reporting.

--This coronavirus variant is now found in all 50 states and is already dominant in many parts of the United States.

--It accounts for close to 52% of all new infections, "five times the prevalence four weeks earlier (week ending July 3).

--That the Deltaa variant has become the dominant strain was expected but the rapid rise was troubling. In the language of health experts delta is "the most 'fit' variant of the coronavirus," i.e. "it's likely to outcompete other variants to infect more people with covid-19." It is considerably more transmissible than the original coronavirus. The delta variant is likely to "cause surges...where vaccination rates are lower" which in turn will pse "the most serious risk to those who are older, sicker and unvaccinated."

--The best news is that "all three coronavirus vaccines authorized in the United States offer strong protection against severe disease and death from covid-19," (my emphasis) They offer "strong protection against severe disease and death from the delta variant, although they appear to offer less robust protection against minor to moderate infections." 

And if you are not vaccinated continue to wear masks and get vaccinated as soon as possible. Make this a priority. The delta variant is very good at finding the unvaccinated--the best of the variants so far. Not wearing a mask makes it even easier.

And if you've had the two injection vaccines, the increase in protection between one shot and two shots is dramatic, say from 33 percent to 88 percent. Only one study, a small one, on the Johnson & Johnson vaccine, showed "a strong antibody response against the variant. Whether booster shots will be required is an open question. And if you've had one injection, get the second in the series.

The authors provide answers to these commonly asked questions: what the delta variant is, why the delta variant is of concern, vaccines effectiveness, how the delta variant is likely to affect the United States, whether symptoms from delta infections differ from infections from other variants of the coronavirus, and whether booster shots will be needed. They also report on people who are immunocompromised, the risk to children and how they can be protected.

One thing that is maddening is the mixed messages we are and will continue to receive since the decision was made that this is a personal responsibility without informing people about risks regarding choices such as wearing masks (when and where, for example) and returning to "normal" (what that is and what it means for personal responsibility?)

This doesn't seem at all likely to change.

The Washington Post report may be read here which I urge you to do.

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