Determining whether being infected by SARS-CoV-2 once can provide immunity on subsequent exposure is essential for the vaccine development process and future modeling of the disease. Researchers wanted to test if exposure to SARS – CoV – 2 can prevent infection on exposure of the virus again in rhesus macaques. 3 groups, each with 3 rhesus macaques were infected with different doses of the virus. On infection with the virus, higher levels were found in the upper and lower respiratory tracts, lungs, while lower levels were found in liver, kidney and gastrointestinal tract. On exposure to the virus for a second time, the level of new, replicated virus detected was considerably lower than the first time. Moreover, there were few or no clinical symptoms observed in the animals after re-challenge. Thus, being infected with the virus once renders some immunity to the rhesus macaques.
However, none of the models led to respiratory failure or mortality which has been observed in humans. Additionally, more information is needed on the durability of the immunity against the virus. Thus, more research needs to be done to accurately determine the effects of re-infection of SARS-CoV-2 virus in humans.
By: Sanya Bansal