Update on COVID Variants
Updated: Jul 14, 2021
There has been a tendency to name epidemics after where they were first discovered. An example is calling the 1918 influenza pandemic the “Spanish flu”, even though likely evolved in the United States. It was named that because Spain was the first country to freely admit that they had cases, while countries like the US kept the fact a secret out of fear that it would give intelligence information to its enemies during World War I. When it recurred in 1977 during the Cold War, we labeled it the “Russian flu”.
One problem with this way of naming, beyond simply being inaccurate, is that a stigma is often associated with it. This was used politically during the early part of the COVID epidemic to blame China by some who insisted on calling it the “China virus” or the “Wuhan flu”. Use of such terms are felt to have fueled the recent increase in anti-Asian hate crimes in the US.
The virus is scientifically referred to as SARS-CoV-2, which stands for Severe Acute Respiratory Syndrome Coronavirus 2. The number 2 distinguishing it from SARS-CoV-1, which caused the original outbreak of SARS in 2003.
As the SARS-2 virus has mutated, we now have several variants and true to our nature, we have labeled them as to where they were first identified, calling them the South African or Brazilian variant. These names have carried all the same stigmas.
Scientific naming of the variants hasn’t been very helpful either. This nomenclature (the way of scientifically naming things) uses the location of the mutation on the viral genes. So, the “United Kingdom variant” becomes B.1.1.7, South Africa’s variant is B.1.351 and the new variant recently identified in India is referred to as B.1.617.2. Very confusing.
The World Health Organization has proposed a new system of naming these variants using letters from the Greek alphabet which it is hoped will help tell them apart more easily and reduce the stigma associated with them. Thus, United Kingdom’s 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. On a global scale, these four make up the most significant variants identified thus far. Incidentally, the variant that comprised about 60% of all the 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 1st, 2021, we discussed how new strains of viruses develop through mutation and we compared the major 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: www.WMillerMD.com.
In March, we did not have any knowledge about the delta variant which developed during the recent large outbreak seen in India. Before we go into some specifics about delta, a review might be helpful. Viruses such as SARS-2 are undergoing continual mutation as a strategy to evade the immune system. This is seen with may viruses including influenza and HIV, for example. Also, recall that on the surface of coronaviruses, there are so-called spike proteins which act as a key fitting into a lock on the host cell, thus allowing the virus entry into the cell. If the spike protein mutates to become a better fitting key, then it is easier for it to take hold and cause an infection and the new variant is said to be more infectious/contagious.
Since the spike protein is also a primary site for our antibodies to attach, then mutations in the spike protein may help the virus evade the immune system. These mutations are of particular interest to scientists. They have major implications for vaccine effectiveness and are the reason we are identifying 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 days or so that a person with COVID is contagious, they will infect 5.2 more people on average compared with the original SARS-2 in which only 2.6 more people will get infected on average. When I wrote about the other variants back 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 a concerning 6.8 new infections on average. These numbers have serious implications for continued spread of this pandemic around the world.
Current vaccines are less effective against both delta and gamma. However, the vaccines still do provide protection at a level of about 70% instead of the 95% we have come to expect with ones like Pfizer and Moderna. One piece of good news is that even if a vaccinated person gets infected with either gamma or delta, they do not get as sick as they would if they had not been vaccinated. Studies using convalescent serum (antibodies from a person who previously had COVID) have shown that these antibodies are even less effective. In other words, vaccination is more protective against the new strains than having had an infection from 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, it does not appear so. However, for gamma, is more lethal with an overall mortality rate of about 3-4% versus 2-3% for other variants. Prior vaccination significantly reduces this lethality. We do not have enough data yet to say whether delta causes a worse case of COVID or not.
Hopefully, this new nomenclature using Greek letters will make it somewhat easier to talk about the various new strains and in the process reduce the stigma associated with using place names. It remains to be seen whether this new system will catch on or not.