[One of my patients has] tested positive for SARS-CoV-2, the virus that causes Covid-19, for a second time — three months after a previous infection.
Covid-19 may also be much worse the second time around. During his first infection, my patient experienced a mild cough and sore throat. His second infection, in contrast, was marked by a high fever, shortness of breath, and hypoxia, resulting in multiple trips to the hospital.
In my opinion, my patient’s experience serves as a warning sign on several fronts.
First, the trajectory of a moderate initial infection followed by a severe reinfection suggests that this novel coronavirus might share some tendencies of other viruses such as dengue fever, where you can suffer more severe illness each time you contract the disease.
Second, despite scientific hopes for either antibody-mediated or cellular immunity, the severity of my patient’s second bout with Covid-19 suggests that such responses may not be as robust as we hope.
Third, many people may let their guard down after being infected because they believe they are either immune or incapable of contributing to community spread. As my patient’s case demonstrates, these assumptions risk both their own health and the health of those near them.
Last, if reinfection is possible on such a short timeline, there are implications for the efficacy and durability of vaccines developed to fight the disease.