Kiwi adults living with asthma are being urged to check they are up to date with whooping cough vaccinations as winter kicks in.
Thousands of New Zealanders living with common respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD), risk potentially life-threatening complications from pertussis, commonly referred to as whooping cough.
The country is just returning to normal numbers of the potentially deadly illness after a two-year epidemic.
More than 4690 New Zealanders contracted the disease since the outbreak began in 2017.
Dr Helen Petousis-Harris, vaccinologist and senior lecturer at the University of Auckland, said adults with asthma or COPD would suffer more from whooping cough complications.
"The message we want to get out there is your immunity wanes over the years and adults vaccinated as children may not be protected," she said.
"In the same way we advise protecting infants from exposure to whooping cough, it is important for adults living with asthma as well as their whānau to look at immunising themselves against this highly contagious disease."
Petousis-Harris said those living or working with vulnerable people such as elderly and children also needed to check their immunity.
Guidelines recommend booster vaccinations every 10 years for at-risk adults.
Under a new proposal, Pharmac was to widen access to the whooping cough vaccination for adults aged between 45 and 65, pregnant women in their second and third trimesters, as well as for parents and primary caregivers of infants admitted to intensive care for more than three days.
"It is possible to reduce the risk of catching and spreading this disease," Petousis-Harris said.
"If you're pregnant, in close contact with an infant or have asthma/COPD you need to talk to your healthcare professional about getting a booster shot."
Public awareness of influenza vaccination was high but Petousis-Harris said the burden of whooping cough among the adult population was widely underestimated.
The colder months and greater exposure to colds and influenza impacted the body's ability to protect itself.
According to latest figures from the Institute of Environmental Science and Research, more than half (51 per cent) of the 2110 whooping cough cases recorded over the past 12 months were adults aged 20 and over, with this age group representing 45 per cent of hospitalisations.
Māori and Pasifika make up the bulk of adults who contract the disease.
Local research into Kiwis' awareness of pertussis suggested they underestimated how easily the disease could spread.
The research found that almost all (96 per cent) of respondents had heard of whooping cough. However, only a quarter of respondents said they were vaccinated for whooping cough and had received a booster shot.
Meanwhile, the Ministry of Health confirmed on Friday it had distributed "record amounts" of the influenza vaccine this year.
A total of 1.38 million vaccines were being made available in New Zealand this year.
"It's great to see New Zealanders are understanding the benefits of vaccination and protecting themselves," a ministry spokesperson said.
"The more people who are vaccinated, the more people who are protected."
Free influenza jabs are available for pregnant women, children aged 4 and under with serious respiratory illnesses, people with severe asthma, heart disease, diabetes and other health conditions that could make them more susceptible to influenza, and those aged over 65.
"As well as vaccination, it's also important to remember the other ways to help keep healthy during flu season," the spokeswoman said.
"Washing hands, safe sneezing, and staying home if you're unwell are other ways we can reduce the spread of winter illnesses including flu."