Also read: Countries already vaccinating children against Covid-19. Full list here The critically ill mice were treated with monoclonal antibodies, which were effective if given before or in earlier stages of the disease but were ineffective if given in later stages.
Conversely, the immune suppressant dexamethasone was fatal if given in early stages as it suppressed the initial immune response to the virus.
But, if it was given during later stages, it proved effective as it suppressed inflammatory response that could have damaged organs. "Early in the course of the disease, a strong immune response is crucial for survival.