An update on COVID variants – The Willits News
(To help keep the Mendocino Coast community informed of updates on the coronavirus, Dr. William Miller, Chief of Staff at the Mendocino Coast District Hospital, offers The Miller Report: A Hyperlocal Weekly Column on the progress of COVID-19 in our community.)
There has been a tendency to name outbreaks after where they were first discovered. One example is to call the 1918 influenza pandemic the “Spanish flu”, although it probably evolved in the United States. It was named so because Spain was the first country to freely admit they had cases, while countries like the United States have kept the fact a secret for fear it would give out intelligence information. to his enemies during the First World War. When this happened again in 1977 during the Cold War, it was called the “Russian flu”.
One problem with this naming, beyond being simply inaccurate, is that a stigma is often associated with it. This was used politically at the start of the COVID epidemic to blame China by some who insisted on calling it the “Chinese virus” or the “Wuhan flu”. The use of these terms appears to have fueled the recent increase in anti-Asian hate crimes in the United States.
The virus is scientifically called SARS-CoV-2, which stands for Severe Acute Respiratory Syndrome Coronavirus 2. Le 2 distinguishes it from SARS-CoV-1, which caused the initial outbreak of SARS in 2003.
As the SARS-2 virus mutated we now have several variants and true to our nature we have labeled them according to where they were first identified, calling them the South African or Brazilian variant. These names all bear the same stigmata.
The scientific naming of the variants was not very helpful either. This nomenclature uses the location of the mutation on viral genes. Thus, the “UK variant” becomes B.1.1.7, the South African variant is B.1.351 and the new variant recently identified in India is called B.1.617.2. Very disturbing.
The World Health Organization has proposed a new system for naming these variants using letters of the Greek alphabet which will hopefully help to distinguish them more easily and reduce the stigma associated with them. For example, UK B.1.1.7 is now alpha, South Africa’s B.1.351 is now beta, Brazil’s P.1 is now gamma and India’s B.1.617.2 is now delta.
Globally, these four variants are the most significant variants identified to date. Incidentally, the variant that accounted for about 60% of all COVID cases in California last winter, previously known as B.1.429 / B.1.427, will now be referred to as “epsilon.”
In the Miller report of March 1, we discussed the development of new virus strains by mutation and compared the main new variants in terms of virulence, ease of transmission and resistance to vaccines. All previous Miller reports are now available for easy reference by going to my personal blog at WMillerMD.com.
As of March of this year, we had no knowledge of the delta variant that developed during the recent large epidemic seen in India. Before going into the details of Delta, a review might be helpful. Viruses such as SARS-2 undergo continual mutations as a strategy to evade the immune system. This is seen with many viruses, including influenza and HIV, for example.
It should also be remembered that on the surface of coronaviruses, there are so-called peak proteins which act as a key inserting into a lock of the host cell, thus allowing the entry of the virus into the cell. If the spike protein mutates to become a more suitable key, then it is easier for it to take hold and cause infection and the new variant is said to be more infectious / contagious.
Since the spike protein is also a primary site for our antibody binding, mutations in the spike protein can help the virus escape the immune system. These mutations are of particular interest to scientists. They have major implications for vaccine efficacy and are the reason why we identify them as unique variants. The delta variant, like the others, contains mutations in the spike protein.
Delta appears to be twice as infectious as the original SARS-2 virus. This means that during the ten or so days that a person with COVID is contagious, they will infect 5.2 more people on average than the original SARS-2 in which only 2.6 more people will be infected on average.
When I wrote about the other variants in March, we didn’t have clear information about gamma (P.1) which is the main variant found in Brazil. We now know that gamma is even more infectious, causing about 6.8 new infections on average. These numbers have serious implications for the continued spread of this pandemic around the world.
Current vaccines are less effective against delta and gamma. However, vaccines still offer protection at around 70% level instead of the 95% we would expect with vaccines like Pfizer and Moderna. The good news is that even if a vaccinated person is infected with gamma or delta, they do not get as sick as if they had not been vaccinated.
Studies using recovery serum (antibodies from someone who has had COVID before) have shown that these antibodies are even less effective. In other words, vaccination is more protective against the newer strains than having had an infection with one of the older strains.
The last big question is do the new strains cause a worse case of the disease? For alpha, beta and epsilon, this does not appear. However, for gamma it is more lethal with an overall death rate of around 3-4% compared to 2-3% for the other variants. Prior vaccination considerably reduces this lethality. We do not yet have enough data to say whether or not the delta is causing a worst case of COVID.
Hopefully, this new nomenclature using Greek letters will make the discussion about the different new strains a bit easier and thus reduce the stigma associated with using place names. It remains to be seen whether this new system will succeed or not.