Before revision:  COVID-19 can be eliminated if the community-to-community reproductive number---i.e. the expected/ average number of other communities to which a single infected community will transmit the virus---is reduced to less than one.
After revision:  COVID-19 can be eliminated if the community-to-community reproductive number---i.e. the average number of other communities to which a single infected community will transmit the virus---is reduced to less than one.