What counseling techniques have been shown to be the most effective in helping people cope after an event like this?

COVID-19 is a traumatic event for many people including children. Children have been yanked out of school, away from their friends, and can’t see relatives. During and after a disaster, it is natural to experience different and strong emotions. What counseling techniques have been shown to be the most effective in helping people cope after an event like this? Are there different techniques for adults than children?