Otago University epidemiologist Professor Michael Baker wants the government to look at legislating stay-at-home orders for the flu and to reintroduce compulsory masks in schools to short-circuit flu strains sweeping across New Zealand.
Baker said the lessons of the two-year-old pandemic should be applied across the winter months as the country's health system groans under a twindemic of Covid and influenza.
"That's one of the big things we have learned from Covid-19, it's not okay if you get a respiratory infection just to go back to school or work or go out socialising until you've got over it.
"I think the same rules should apply.
"You should stay at home until you don't have any symptoms," he told the AM show.
Asked if a seven-day stay-at-home isolation order for flu should mandated in law, Baker said it should be looked at.
"At the moment most of the people getting admitted to hospital have influenza and the symptoms do overlap, but you cannot tell from your symptoms what you have."
Taking a strict mandatory stance was better than the alternative of infecting classmates and workmates.
He said it was necessary to put yourself out of circulation when you had a respiratory illness and to wear a mask indoors when you were in settings outside your family.
"We need a mask mandate at schools again to get us through winter," he warned.
It comes as hospital bosses warn this year's flu season could last until the end of August with a lack of immunity seeing the usual month-long sickness window extend up to three months.
Hospital emergency departments around the country have been flooded with patients as a result of winter illnesses, including influenza, rhinovirus and enterovirus.
Auckland's Middlemore Hospital has this month had to deal with a spike in patient numbers, with up to 400 people a day visiting its emergency department. The DHB has attributed the surge in patients to winter viruses and the impact of staff taking time off due to Covid-19.
This week the Government announced more free flu vaccines and a second Covid-19 booster for groups of people at risk of hospitalisation.
Health Minister Andrew Little said in recent weeks there had been a number of pre-school children hospitalised with the flu.
"We've already seen more than one million New Zealanders get a flu shot, but with significant pressure on our health system we're ramping up efforts to get as many people vaccinated as possible," he said.
Baker, who has not yet tested positive, said around half of the population was now likely to have had Covid-19 since the outbreak started in 2020. Some may have been reinfected in as little as three weeks.
"You're absolutely not in the clear once you've had this infection. You can be reinfected many times."
A US study of 5.7 million people showed people had tested positive for a second or third Covid infection, with more than half falling sick again under three months.
Baker said a find he found particularly alarming was that each time a person was reinfected they were not being protected from getting the virus and could get seriously ill.
"You still have to avoid this virus at every point," said Baker.
