People should wear well-fitting N95 respirators instead of surgical masks to best protect themselves against the highly transmissible Covid-19 variant Omicron, public health experts say.
Ministry of Health officials are reviewing emerging advice from overseas that N95 masks are better than cloth and surgical face coverings.
Covid-19 Response Minister Chris Hipkins said surgical masks would likely become the default face covering to help contain community spread of the virus.
But University of Otago Wellington Department of Public Health research fellow Dr Lucy Telfar-Barnard said well-fitting N95 or P2 respirator masks were a better option.
"Surgical masks are not good enough in an Omicron outbreak," she said.
"We do need to be making those respirators accessible to people across the population.
"I'm trying to come up with some sort of explanation as to why they are not recommending people wear N95s if they can access them, it just doesn't make sense to me."
High-grade N95 masks have become the international gold standard in efforts to stop the spread of Omicron.
When they are worn properly, N95s can filter out at least 95 percent of airborne particles, including the coronavirus.
University of Auckland aerosol chemist Dr Joel Rindelaub said N95 or P2 masks offered the best protection.
"If we want to do the best we can to try to stamp out Omicron we need the best technology available and that of course would be the N95 or P2 varieties," he said.
Dr Rindelaub said people who did not have N95 masks could instead wear a surgical mask with a cloth one on top, or knot the loops for a tighter fit.
The government is expected to give updated advice on face coverings on Wednesday, with a likely focus on surgical masks.
Dr Telfar-Barnard said the government should urgently release a national mask strategy so people knew what sort of face covering they should wear to best prevent infection.
"These are all piecemeal decisions being made separately and we do need a national mask strategy that covers what masks should be worn, where, and making sure that when people buy masks they know what level of filtration it's providing," she said.
She said the government should consider distributing enough masks so that everyone had at least one or a set they could rotate over a week.
Children as young as eight years old will have to wear masks at school when the new term begins under the red traffic light setting.
While research on masks was still evolving, Hipkins said the government would act on any new advice quickly.
"We know that N95 masks are more effective at stopping the spread of Covid-19, having said that, an N95 mask needs to be the right fit, otherwise it can potentially be less effective," he said.
"Surgical masks are probably likely to be the best masks for the public's use."
Hipkins said there were plenty of N95 masks in stock for healthcare and other essential workers.
RNZ
