Immunological Escape

Yesterday, I reaffirmed my conviction that the pandemic will be effectively over in the US by early this spring. Today, I’ll share the one caveat about which I remain deeply worried.

First, it is tragic what has been unfolding in the UK as the B.1.1.7 variant has spread there; however, I’ve yet to hear any argument that that variant is either more deadly, or that it has evolved such that existing vaccines (or infection-acquired immunity) would not be effective against it. (That is, immunological escape by this, or other variants, of SARS-CoV-2 has thus far appeared an unlikely eventuality.) It is wreaking havoc because it is just as deadly as other strands, but far more infectious, so spreading more rapidly, and thus killing and hospitalizing a larger number of people than less infectious strains would have in the same amount of time.

Shortly after sending out yesterday’s newsletter, though, I listened to this podcast episode from the New England Journal of Medicine featuring “South African infectious disease physician Salim Abdool Karim”; long-short, Dr. Karim explains that, while until recently, evolutions of SARS-CoV-2 observed by his team had been modest and gradual, the recently-emerged variant that has been spreading rapidly in South Africa appears to have undergone a large number of mutations at once, including some which bear on the structure of key viral proteins, and that there is some risk that this could lead to immunological escape. He further speculates that these mutations could have been the result of the virus passing from humans into a non-human species and then back again. Be the case as it may, were a new and highly-infectious variant to actually undergo escape, all bets would be off, and it would put us back where we started (or almost, as I have to imagine that all the vaccine progress to date would further speed the creation of still newer vaccines to address new mutant viral strains), confronted with the necessity of controlling a novel pathogen for which no cure or vaccine exists.

Here’s hoping that it never comes to that. That this risk highlights the need to vaccinate rapidly, and otherwise control the spread of COVID-19, not just in rich countries, but all over the world, should go without saying.