Study Says Previous Common Cold Coronavirus Infection Could Protect Against COVID-19

According to a study published Monday in Nature Communications, people who build up high levels of immune cells from previous coronaviruses that cause the common cold could have some protection against COVID-19. Human Coronavirus has several different types including common human coronaviruses: 229E (alpha coronavirus), NL63 (alpha coronavirus), OC43 (beta coronavirus) and HKU1 (beta coronavirus). Other types include MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS), SARS-CoV (the beta coronavirus that causes severe acute respiratory syndrome, or SARS), and SARS-CoV-2 (the novel coronavirus that causes coronavirus disease 2019, or COVID-19), according to CDC: https://www.cdc.gov/coronavirus/types.html 

People around the world commonly get infected with human coronaviruses 229E, NL63, OC43, and HKU1. The researchers were curious about why some people exposed to SARS-CoV-2 don't necessarily get infected, and it turned out that these people have high concentration of T memory cells from previous coronavirus infection. The study found that T cells created from other coronaviruses can recognize SARS-CoV-2 and provide immune protection. This elicits new ways to generate universal vaccines that targets the common proteins shared by the coronaviruses family to protect against future variant infection. 

This also posts other questions: why do some of the coronaviruses non-pathogenic or only generate mild symptoms like a cold while others lead to severe respiratory disease? What are the differences between the different strains? Understanding the key determinant of the pathogenic coronavirus strains can also help with universal vaccine production. 

-- Wenqi Song