An English health official has said that Covid-19 booster shots might be needed to protect against new variants but might not be necessary to sustain immunity as high protection offered by current vaccines looks unlikely to wane quickly, Reuters reported.

Mary Ramsay, head of immunisation at Public Health England, said the Covid-19 vaccines being rolled out are much more effective than she expected a year ago, and offer better protection than most flu shots. "There are very high levels of protection. So in fact waning may not be happening as quickly as we might have predicted."

"The issue is probably going to more come down to variants, and the protection against variants, in terms of when we do (boosters), rather than the expectation that we're going to see a rapid decline in protection."