This nearly happened to us a few times. Thankfully, our last Pastor was a strong-willed one
The Bishop told us that if this happens after the Consecration, and we can’t get another Priest, then the Mass should be discontinued, and the server should then consume the consecrated host(s) the consecrated host(s) in the Tabernacle.
If it happens to happen
during the consecration, one should adopt the theory that the Mass is invalid if the Consecration Prayer is not said correctly, by a Priest. Therefore, the host should be consumed by a server/deacon/layperson with caution that the hosts may/may not be validly consecrated, but remembering that the hosts are still blessed.
He also said that if there was such a great demand for Holy Communion distributed, then a Service of the Distribution of Holy Communion may be conducted by a layman afterwards - remembering that it should be treated as a
seperate service from the Mass that was incomplete.
Howzat?