As expected emerging SARS-CoV-2 variants are now becoming the major issue with respect to elimination of the virus. The most popular variant in the past couple of months is the variant first identified in India; first designated as B.1.617 and now referred to as
the delta variant. The delta variant was the major driver of the second devastating COVID-19 wave in India; peaked at 414,188 reported cases on May 6, 2021 and 4,454 deaths on May 23, 2021. Cumulative cases in India are now almost 30 million and over 350, 000 deaths.
COVID-19 has been associated with a wide range of pathologies and the recent surge in India popularized a new pathology (secondary infection) – mucormycosis (black fungus). This a very rare but deadly (overall ~50%), fungal infection typically associated with immunocompromised people; existing diabetes appears to also be an important risk facotr. In the context of COVID-19, it has been associated with the use of steroids (dexamethasone). Exact numbers are sketchy; many thousands of cases were reported out of India around the peak of the second wave. This relatively unheard of infection, become the major global headline for a few days.
Back to the delta variant. The issue with emerging variants of concern, to date, is that are more transmissible; for example, the delta variant is thought to be ~60% more transmissible than the alpha variant. In turn, the alpha variant first identified in the UK (B.1.1.7), is ~50% more transmissible than the original strain. There is a fear that the delta will become the dominant strain in the US in the coming months, and it now constitutes over 90% of new coronavirus cases in the UK. The variant is going around, and also is lurking in Australia – we have it under control for now. Thankfully, data suggests that current vaccines are appear to be effective against the delta variant. On the topic of vaccinations, in a recent finding (that is not surprising), it has been shown that infections are dropping where people are vaccinated and rising where they are not vaccinated!
Unfortunately, there are now early reports of a delta plus variant; it appears that this new variant is characterized by a new K417N mutation in the spike protein which renders the virus resistant to monoclonal antibody cocktails. This is not a variant of concern just yet (low levels detected), but it does highlight the battle we can anticipate between effective vaccination and emerging variants.
To date, we are kind of lucky; the variants identified are more highly transmissible but are not more deadly (there are some questions about the delta variant), and available vaccines still work against them. Hopefully, herd immunity can achieved before some kind of super-variant emerges.
The current thinking is that variants will get ahead of vaccinations and COVID-19 will probably become endemic! We’ll discuss what that might mean another time.
Until next time …