Exploring Original Antigenic Sin (OAS) to combat the COVID-19 pandemic

Updated: Mar 14

An aggressive tug-of-war continues between SARS-CoV-2 and scientific developments with a myriad of different options beginning from prevention, diagnostics, vaccination, antibody therapy, and recently some promising oral therapies. However, the balance still seems to be tilted towards the virus, and scientists are searching for any possible information to help combat the pandemic.

One avenue involves understanding the phenomenon known as the Original Antigenic Sin (OAS). As evidenced in seasonal flu, OAS is when some people are better at fighting off seasonal flu when the strain of the flu virus is similar to the first one they encountered in their childhood. Although there is increasing evidence of a similar phenomenon in SARS-CoV-2, it remains unclear to what extent it affects people with COVID-19 and whether it provides enhanced protection or hampers the immune response.

While some studies showed the OAS-induced recall of antibody responses to be beneficial, other studies showed OAS-induced antibodies to be less protective against SARS-CoV-2 and even negatively affecting people. This interplay between seasonal coronavirus infection and the disease outcome upon SARS-CoV-2 infection is more complicated than originally thought and needs further analyses before drawing any conclusions.

The full article can be found here.