An epidemiologist says Dr Ashley Bloomfield saved thousands of lives.
Dr Bloomfield is stepping down as Director-General of Health at the end of July.
University of Auckland professor Rod Jackson told Morning Report Dr Bloomfield was integral to a leadership group that saved the country's health service during the Covid-19 pandemic.
Jackson says he's concerned New Zealand is losing someone with Dr Bloomfield's level of expertise and more public health professionals need similar training.
"We need to produce more public health professionals with his expertise and his training."
