Dear Reader:

Based on Wikipedia on Viral evolution: Most mutations are “silent” and do not result in any obvious changes to the new generation of viruses, but some mutations cause the new viral generation (new viral strain) to be so  different from the earlier strain that the antibodies that developed for the earlier strain do not recognize the new strain. This is how re-infection occurs: a person who recovered from a first infection, having produced effective antibodies for the earlier strain virus, gets re-infected by a new strain of the same virus, and the person’s antibodies don’t recognize the new strain. The new strain,  not having been attacked and stopped by antibodies, proceed to cause illness.

Vaccines and antiviral drugs that were developed for the earlier strain will not be effective for a very different new strain, if the new strain is too  different from the earlier strain.

www. latimes. com/ California/ story/ 2020-05-05/ mutant coronavirus has emerged more contagious than original(May 5): “Scientists have identified a new strain of the coronavirus that has become dominant worldwide and appears to be more contagious than the versions that spread in the early days of the Covid-19 pandemic… The new strain appeared in February in Europe, migrated quickly to the East Coast of the United States and has been the dominant strain across the world since mid-March.. In addition to spreading faster, it may make people vulnerable to a second infection after the first bout with the disease, the report warned. The 33-page report was posted Thursday on BioRxiv, a website that researchers use to share their work before it is peer-reviewed, an effort to speed up collaborations with scientists working on Covid-19 vaccines or treatments.

Scientists with major organizations working on a vaccine or drugs to combat the coronavirus have told The Times that they are pinning their hopes on initial evidence that the virus is stable and not likely to mutate the way influenza virus does, requiring a new vaccine every year. .. The mutation identified in the new report affects the now-infamous spikes on the exterior of the coronavirus, which allow it to enter human respiratory cells. The report’s authors said they felt an ‘urgent need for an early warning’ so that vaccines and drugs under development around the world will be effective against the mutated strain.

In  many places where the new strain appeared, it quickly infected far more people than the earlier strains that came out of Wuhan, China, and within weeks it was the only strain that was prevalent in some nations, according to the report… The report was based on a computational analysis of more than 6,000 coronavirus sequences from around the world collected by the Global Initiative for Sharing All Influenza Data, a public-private organization in Germany. Time and again, the analysis found the new version was transitioning to become dominant.

www. msn. com/ en-us/ news/ world/ china’s new outbreak shows signs the virus could be changing, May 19:

One of China’s top critical care doctors, Dr. Qiu, said yesterday that Covid-19 patients in the northeast of China, in comparison to patients in Wuhan, take longer than 1-2 weeks to develop symptoms after infection (longer incubation period). These north-east patients “carry the virus for a longer period of time and take longer to test negative” than Wuhan patients. “The longer period during which infected patients show no symptoms has created clusters of family infections”, and “it is harder for authorities to catch cases before they spread”. Lockdown measures in two north east provinces in China, a region of 100 million people, have been put in effect as a result of this development. Also, Dr. Qiu said that patients in the northeast cluster “seem to have damage mostly in their lungs, whereas patients in Wuhan suffered multi-organ damage across the heart, kidney and gut”, and among the northeast cluster, only 10% have turned critical. Officials believe that the new cluster stemmed from contact with infected individuals arriving from Russia. Genetic sequencing showed a match between the northeast cases and Russian infections.

But it is not certain that the virus has changed since Wuhan. It may be that the differences observed in the north-east have to do with Chinese doctors observe patients in the north east from an earlier stage of the disease and more thoroughly than did the overwhelmed doctors in Wuhan who attended only to the most serious cases.

“Researchers worldwide are trying to  ascertain if the virus is mutating in a significant way to become more contagious as it races through the human population, but early research suggesting this possibility has been criticized for being overblown.. In theory, some changes in the genetic structure can lead to changes in the virus structure or how the virus behaves.. However, many mutations lead to no discernible changes at all… It’s likely that the observations in China don’t have a simple correlation with a mutation and ‘very clear evidence’ is needed before concluding that the virus is mutating”.

anita

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