The SARS-CoV-2 or COVID-19 coronavirus pandemic, which has caused 771 million infections and 6.8 million deaths worldwide to date since it began in March 2020, has diminished in importance over the past 6 to 12 months since the number the number of infected and dead is decreasing in almost all countries. This is why the World Health Organization (WHO) declared the end of the pandemic on May 5, 2023.

Silence becomes dangerous

The virus, however, has shown an enormous ability to mutate and emerge new variants, which has given virologists and epidemiologists more than one headache.

A “variant” of a virus is basically a new mutation of that virus. COVID-19 has a very high potential to continue spreading its genetic material, thanks to the huge number of copies of the virus that are produced in an infected person. Virologists estimate that up to one billion copies of the virus are produced in the respiratory tract of a person without immunity against COVID-19. With such a large number of virus copies, mutations will inevitably be spontaneously generated. 99.999% of these mutations are defective and do not survive, but 0.001% increase the virus’s ability to more easily infect people without immunity.

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The last major variant of COVID-19 was Omicron, or BA.2, discovered in November 2021. Although Omicron was the more infectious variant, its ability to cause severe respiratory infections was much lower, and the COVID-19 vaccines from Pfizer, Moderna and AstraZeneca provided adequate protection against omicrons. Furthermore, millions of people already had natural immunity from natural infection.

After this variant, the virus continued to mutate and create “sub-variants”, almost all with a slightly higher capacity of infection, but whose virulence and aggressiveness are low.

About six weeks ago, a descendant subvariant of BA.2 appeared with 34 mutations in its spike protein, a leap in the evolution of the virus that closely resembled an omicron. The infectious capacity of this subvariant, which they named BA.2.86, is almost the same as that of other omicron subvariants and has so far caused a large number of infections in northern hemisphere countries, especially in the USA, Israel and Denmark. In its latest update, WHO classified BA.2.86 as a “variant under surveillance”, a lower classification than “variant of interest”. The BA.2.86 subvariant is almost identical to the JN.1 subvariant and to most virologists both subvariants are the same.

The commercial vaccine companies, Pfizer, Moderna and AstraZeneca, are working to expand vaccine coverage to include the new BA.2.86 mutations.

The BA.2.86 or JN.1 subvariant showed a high degree of infectivity, but not a high degree of virulence or the ability to cause severe pneumonia. But that could change, so a Pfizer, Moderna or AstraZeneca vaccine is recommended. (OR)