Wednesday’s published results, from a mass vaccination campaign in Israel, give strong reassurance that the benefits seen in smaller, limited testing persisted when the vaccine was used much more widely in a general population with various ages and health conditions.

The vaccine was 92 percent effective at preventing severe disease after two shots and 62 percent after one. Its estimated effectiveness for preventing death was 72 percent two to three weeks after the first shot, a rate that may improve as immunity builds over time.

It seemed as effective in folks over 70 as in younger people.

“This is immensely reassuring … better than I would have guessed,” said the Mayo Clinic’s Dr. Gregory Poland.