COVID-19 Alert: Herd Immunity

At a time of the novel SARS CoV-2 global pandemic, many healthcare providers, politicians, and community leaders keep calling for herd immunity to save us, but is this possible? Previous papers have shown that SARS CoV may posses antibody dependent enhancement (ADE) similar to that of Dengue Fever and Human Immunodeficiency Virus. Besides utilizing the traditional virus spike protein and host cell method of infection, some coronaviruses have displayed an ability to use antibodies as a method of entry into host cells via antibody/immune complexes bound with virus proteins to Fc Receptors.

This method of viral entry utilizes the host's immune system to create a deadly binding capacity to host cells. An illness that would normally be mild becomes profoundly more deadly due to the ADE characteristic. Previous exposure to SARS-CoV could lead to a more deadly experience for COVID-19 patients related to a 75% similarity between the two viruses.

If SARS CoV-2 also posses ADE, then herd immunity is unlikely an option as many in the field have hoped for. Reinfection could become common and far deadlier than previous disease. Vaccines would not be a viable option as previous exposure can create antibodies that SARS CoV-2 would utilize against host cells to improve binding capacity. This would explain why SARS has yet to have a successful vaccine despite it's emergence in 2003. Please see source at the bottom and thank you to all healthcare providers out there on the front lines.

-Mason Peck MS

Source: Yip, M. S., Leung, H. L., & et al. (2016). Antibody-dependent enhancement of SARS coronavirus infection and its role in the pathogenesis of SARS. Retrieved from https://www.hkmj.org/system/files/hkm1603sp4p25.pdf