Elliott Associate Professor of Biology Dr. Kristian M. Hargadon ’01 recently published a Viewpoint article on SARS-CoV-2 vaccine hesitancy in the Journal of Global Health Reports. His article focuses on lack of perceived threat from COVID-19 as a commonly documented reason for vaccine hesitancy and highlights the need for improved public education about risk factors for severe COVID-19 as a means of increasing vaccine acceptance. Though many risk factors for COVID-19 complications are widely publicized, including age and certain underlying health conditions, other less visible risk factors for severe COVID-19 disease have emerged from several studies over the course of the pandemic. Dr. Hargadon’s article highlights in particular multiple defects in the interferon antiviral defense system as clinically silent, or “invisible,” risk factors for severe COVID-19. These defects include genetic mutations in interferon pathway genes and autoimmune blockade of interferon proteins as significant risk factors for COVID-19 disease complications, though patients harboring such defects are typically unaware of their presence since the anomalies do not produce any symptoms until one is infected with a highly virulent pathogen.

Named as such because they typically “interfere” with viral replication, interferons normally provide early protection against any viral infection, limiting the propagation of viruses in an infected host. In the case of a highly pathogenic virus like SARS-CoV-2, defects in this system allow the virus to replicate out of control and result in severe disease, and there is now strong evidence that many critically ill COVID-19 patients, but not those who experience mild disease, harbor defects in the interferon defense system. These data explain many of the previously unexplained cases of severe COVID-19 that occur in young patients or in those who do not exhibit visibly apparent risk factors for serious illness. Dr. Hargadon’s article brings attention to these “invisible” risk factors for severe COVID-19 and discusses the importance of improved public education efforts to increase awareness of COVID-19 risk factors that we cannot see in ourselves or in others as a way of overcoming misperceptions of COVID-19 disease risk and encouraging SARS-CoV-2 vaccine acceptance.

Dr. Hargadon’s article is available at: https://www.joghr.org/article/26142-educating-society-about-the-unseen-but-not-unknown-risk-factors-for-severe-covid-19-a-step-towards-overcoming-vaccine-hesitancy-through-a-more-info