University of Otago women’s and children’s health clinical trial co-ordinator and research fellow Melanie Millier said measles immunisation had been central to measles elimination.
However, increasing evidence from both the 2019 outbreak in New Zealand and from similar countries which had not had any measles circulating for a long time, showed immunity could wane over 15 years or so after vaccination.
"Our Maxxed Study has been going for a couple of years, and we have been looking at measles immunity in young adults and how that can wane since the childhood measles vaccination, which is the MMR vaccination.
They had been running a clinical trial of an inhaled vaccine, she said.
"It’s inhaled kind of like an asthma medication."
Researchers were now testing to see if the "one-off" inhaled vaccine would provide invoke a stronger immune response than the injected vaccine.
"There’s nothing different about the vaccine — just the way we’re giving it.
"It’s delivering it straight to the lungs, and that actually is the same way of being exposed to the virus if there was an outbreak.
"So because measles is spread by respiratory transmission, having the vaccine this way could actually ramp up your respiratory response, which is kind of a cool aspect that we’re looking into, whether or not that’s going to help strengthen the immune response."
It was not just the measles vaccine being given in the spray — it was the whole MMR vaccine, which also included vaccines for mumps and rubella, she said.
"It is actually immunity for all of those things, but we’re just focusing on measles as part of our research.
"We will go and look at mumps and rubella as well further down the line, but at the moment we’ve just got the capacity to look at measles."
At present, the researchers were studying people in the 65-and-over age group because they were the generation who did not get the vaccine and gained their immunity by actually being infected with measles, she said.
"Because we know that people who have had the actual measles infection create this really strong immunity to measles, they never really get infected again and their immunity is much more superior than the vaccine, even though the vaccine’s immunity is really good.
"So we’re really interested as part of our study in looking at the immunity generated by the actual infection.
"We’re looking at how they respond when we give them the aerosol measles vaccine.
"It’s going to be a good comparator group, to see how much stronger their response to the vaccine is.
"Then we’re going to compare how they compare to people who have that immunity just based on the vaccine alone."
Ultimately, the aim was to make the aerosol vaccine stronger and longer-lasting, so it would give a level of immunity closer to that generated by having a measles infection, she said.
