University of Otago's Michael Baker among health experts calling for better face mask use in New Zealand after international study on effectiveness

University of Otago epidemiologist Professor Michael Baker is among health experts calling on New Zealand to have better use of face masks to limit the spread of illnesses. 

In August, the then-Labour Government removed all the remaining COVID-19 public health requirements, including the seven-days mandatory isolation and wearing of face masks for visitors to health care facilities. 

However, Prof Baker wants to see better infection prevention and control policies reinstated, especially in four areas: 

  • Personal protection of at-risk groups  
  • Protection in specific settings, including workplaces and healthcare facilities  
  • Protection for seasonal respiratory infections 
  • Protection for pandemics 

"Updating our policies will allow all New Zealanders to benefit from the effective and versatile protection that masks provide against seasonal, epidemic and pandemic infections," he said in a statement on Thursday. 

The call comes after an international review found masks were effective in reducing the transmission of respiratory infections. 

Prof Baker and Amanda Kvalsvig, an Associate Professor at the Department of Public Health, were part of an interdisciplinary team of 13 researchers who conducted what's believed to be the most extensive review of masks ever published. 

Led by University of Oxford's Professor Trisha Greenhalgh, researchers reviewed scientific evidence on the transmission of COVID-19 and other respiratory pathogens, reanalysed randomised controlled trials of masks and examined more than 400 peer-reviewed studies. 

Their findings, published in the high-impact journal Clinical Microbiology Reviews, show masks - particularly respirators - were effective in reducing respiratory infections. 

Kvalsvig said indoor air quality was generally poor in workplaces, transport and other public settings in New Zealand, which allowed viruses to spread easily during the winter months. She believes masking in these settings could help people to avoid catching infections and passing them on. 

She also said that, while "the benefits of wearing a mask have been hotly debated over the past few years", they could reduce coronavirus reinfections that are driving the rise in Long COVID. 

"The findings of this rigorous review and reanalysis put an end to that uncertainty. We now have a clear pathway to action, including reducing the number of respiratory infections in winter 2024.  

"Masks can also provide effective protection in a public health emergency, for example if avian influenza (bird flu) starts to spread between humans," Kvalsvig said. 

The review also found that New Zealanders needed better access to effective masks, stating cloth face coverings and disposable medical masks could help reduce infection risk, but respirators such as N95 and FFP2 provide a significantly higher level of protection.

Kvalsvig, who is deaf and a lip-reader, said the review also identified practical solutions to these difficulties. 

"We need to see these challenges as a call to action," she said. "By investing in better design, more inclusive policies and clearer communication, we can optimise masks for real-world use and ensure that everyone can benefit from this valuable public health protection." 

Health New Zealand/Te Whatu Ora said it "strongly recommends" mask use to protect vulnerable Kiwis.

"On August 15, 2023, the mandatory COVID-19 public health requirement for the wearing of face masks for visitors to health and disability care facilities was removed. Despite this change, the wearing of face masks by visitors to healthcare settings has still been strongly recommended by Health New Zealand/Te Whatu Ora to help protect the vulnerable," the national health service told Newshub.

"Masks have never been mandated for healthcare workers, however national Health NZ infection prevention and control (IPC) guidance has consistently recommended that masks should be worn by healthcare workers in health and disability care settings according to the risk of transmission of respiratory illnesses, including COVID-19, at any given time.

"Health NZ national IPC recommendations for mask use in these settings are based on levels of virus transmission in the community, the healthcare interaction that is occurring, the physical environment where care is provided and the individual’s risk of severe disease. Our guidance continues to provide the minimum recommendations for mask use for all Health NZ employees, volunteers and contractors of Health NZ healthcare facilities, and patients/clients and visitors of a broad range of healthcare settings."

Health NZ said the approach allows hospitals to establish their own mask policies and adjust them according to the burden of disease in their community.

"Maintaining these measures for both the public and healthcare workers continues to be an important way that we can prevent the spread of respiratory illnesses, including COVID-19, in health and disability care settings, especially as we move into winter."