Calls to lower age limits for fourth doses

An epidemiologist wants the age limit for the second COVID-19 booster shot lowered from 65 to 50. (AAP)

A fourth COVID vaccine dose should be offered to all Australians over 50 as a way to reduce the risk from rising virus infections across the country, an epidemiologist says.

As Australia's death toll from the pandemic surpassed 10,000, infectious diseases pediatrician Professor Robert Booy said lowering the age limit for a fourth vaccine dose, or second booster, should be considered.