[nudephil (OP)]

Robert asks:

There has been much said on my Twitter feed about herd immunity being lower than expected, due to the work of T cells and their alleged ability to provide COVID-19 immunity rather than just antibodies.

I was wondering if you could comment on this, and possibly confirm, debunk, or reserve judgement pending more evidence.

[likehumansdo]

The role of t-cells in this pandemic is still to be discovered. However some very interesting studies have been published recently. First of all the main focus in determining how likely a herd immunity is lies on the antibodies. They can disappear after a couple of months. However the T Cells which activate the B cells which then activate the antibodies persist significantly longer. Probably several years. Looking at the antibodies in order to predict a possible herd immunity, the picture looks a but dire as there are not enough antibodies to be found. A recent study called “Targets of T Cell Responses to SARS-CoV-2 Coronavirus in Humans with COVID-19 Disease and Unexposed Individuals” found that even in the blood of donors from the time before the pandemic carry immune potential. This suggest, that other coronaviruses have made our bodies better prepared for covid 19.