[Covid-19 reinfections: what is the clinical relevance?]

Every day additional confirmed case of SARS-CoV-2 reinfection are being reported across the globe. In the Netherlands more than 50 cases of probable reinfections have been identified. With more than 500 thousand people in the Netherlands who have been infected with SARS-CoV-2 up till now this number does seems to be quite low. Still, important questions have to be asked. How do we define reinfection and how do these reinfections compare to other (corona) viruses? What is the immunological significance? What is the duration of protective immunity? And what does Covid-19 reinfections mean for the prevention and development of a vaccine? The described cases of re-infections do teach us that a SARS-CoV-2 vaccine should also be considered for people with a documented Covid-19 infection in the past and that general precautions, such as the use of face masks and social distancing, still apply to those with a previous SARS-CoV-2 infection.