At this point, we can’t be sure, although the available evidence suggests recovered patients are becoming immune to COVID-19. Recent studies showed that recovered patients developed high levels of SARS-CoV-2 antibodies.
These antibodies are proteins that linger in the blood after the infection and can neutralise or call in an immune attack against the same virus if it enters the body again. Chinese researchers conducted a small study analysing the blood of 14 COVID-19 patients after they recovered. In 13 cases they showed high levels of SARS-CoV-2 antibodies, suggesting protection from reinfection. Another team infected rhesus monkeys with the novel coronavirus and waited until the animals recovered. 28 days later the scientists tried to re-infect them. The researchers did not find traces of the virus in the swabs taken from the monkeys nor did they observe the replication of the virus in their tissues 5 days after re-infection. COVID-19 did not reappear in them, suggesting that a primary infection by SARS-CoV-2 could protect from a secondary one.
How long can immunity last? It is important to re-iterate that longer-lasting immunity has not been proven yet by longitudinal studies. Recent research has mentioned up to 2 weeks of immunity in patients who have recovered from the disease. Scientists are relying on studies of similar coronaviruses that caused the SARS-1 and MERS epidemics. Those results confirmed that immunity could persist for 2-3 years after recovery, but more research is needed to convincingly answer the question in the case of SARS-CoV-2.
Here is the current state of science on a Sparrho pinboard. NB: The pinboard contains research papers that have not been peer-reviewed yet, meaning that they have not gone through the standard scientific validation process yet.
Endre Szvetnik is Senior Editor at Sparrho. Endre works with Sparrho Heroes to curate, translate and disseminate scientific research to the wider public.