Waning immunity, the emergence of a more transmissible coronavirus variant capable of escaping the immunity shield and lockdown relaxations can be the likely causes of a possible third wave of COVID-19, AIIMS Director Randeep Guleria said on Thursday.
Speaking at an event, he said the third wave can be mitigated by following Covid-appropriate behaviour such as maintaining social distancing, using masks, and taking vaccine.
He said several studies and modelling have been conducted to project the trajectory of a possible third wave of the pandemic under different scenarios.
"One such model from an IIT shows that if all restrictions are lifted and if a virus (variant) is also able to escape immunity then the next wave can be bigger than the second wave. If some restrictions are kept and the virus also remains stable then cases will not be much and if we keep more restrictions then cases will further reduce," he said.
Guleria said even if new variants emerge, the available vaccines can be tweaked.
Guleria said the third wave of COVID-19 is being seen in other countries but hospitalisation has come down, indicating that the vaccines are working.
Listing possible reasons that can precipitate the third wave, Guleria said waning immunity -- which restores previously exposed individuals to a susceptible state -- the emergence of a new more transmissible variant of the virus capable of escaping immunity, and relaxation of current lockdowns can be the likely causes.
He said that apart from Covaxin, Covishield and Sputnik V, several other vaccines are in the pipeline in the country.