New study shows 17 years of potential T cell immunity in SARS-infected patients
God has a way of prepping the human body for potentially deadly viruses to somewhat mitigate the amount of death we’d otherwise suffer every year from all sorts of microbiological threats. COVID-19 is not different.
The latest research on T cells, white blood cells produced by the immune system to ward off infections through memory of past pathogens, show that even those patients who never develop antibodies or have lost them over time will retain T cell immunity that remembers to fight off coronaviruses in the future. Moreover, the study provides new evidence for the theory that herd immunity could be achieved at an approximately 20% infection rate for most cities, thanks to T cell cross-immunity from other coronaviruses.
The latest version of panic porn being propagated by the media is that many people don’t produce antibodies and that even more of those infected will lose them over time, potentially opening them up to reinfection.
Why we automatically assume the worst of this virus and base our response on the idea of this virus defying all known patterns remains a mystery, but this study from Singapore should place the onus on naysayers to show why this form of coronavirus would be different from others.
Researchers in Singapore conducted a study, first out in preprint in May and now peer-reviewed and published at Nature, of 23 patients who recovered from SARS in 2003 and found that all 23 retained memory T cells induced by that original pathogen still in their systems. That in itself is terrific news to find this immunity after 17 years. Then they studied 36 convalescent SARS-CoV-2 patients and found that they had also produced similar T cells. While SARS-CoV-2 is a new virus and distinct from SARS-CoV-1, there is strong reason to believe that T cell memory produced by the body to protect from future relapses of this virus would not be weaker or more short-lived than T cell memory from SARS-1.
If the implications of this research turn out to be true, it would mean that all those infected with SARS-Cov-2 will retain at least partial immunity to the virus. This doesn’t necessarily mean they will be fully immune. This would likely mean, for many previously infected patients, that they could theoretically test positive again with a PCR test, but the T cells would ward off the symptoms and reduce their infective capabilities to transmit to others.