Much debate has focused on the possibility that the Ab response to SARS-CoV-2 may be short-lived, while T cell recognition may be strong, durable, and more common. Mild or asymptomatic infections are very common but are not usually diagnosed, making an assessment of the durability of immunity in this common group challenging.

A study was done on an exposed health care worker (HCW) cohort at 16-18 weeks after the UK lockdown, who had mild or asymptomatic infection picked up by repeated PCR and serological testing. Neutralizing antibodies (nAb) were present in 89% of previously infected HCW. T cell responses tended to be lower following asymptomatic infection than in those reporting case-definition symptoms of COVID-19, while nAb titers were maintained irrespective of symptoms.

The findings suggest that the majority of individuals with mild or asymptomatic SARS-CoV-02 infection carry some level of immunity at 16-18 weeks after mild or asymptomatic SARS-CoV-2 infection. This is great news! Just when you thought we couldn’t hear good news, here it is! Remember, don’t let your guard down, we need to maintain infection control practices and prevent the spread of infection! Stay the course, stay well, mask up and stay tuned!