Tokoroa's Kinleith Mill closure is to be decided by the end of the month and politicians and family gather for the final day of Dame Tariana Turia’s tangihanga. Video / NZ Herald
Pioneering new research led by US and New Zealand scientists is changing what we know about how our bodies fight off infections.
Their early studies have suggested a person’s history of infections with other viruses can indeed influence their susceptibility to Covid.
The researchers say their insights could pave the way for “next-generation” vaccines – administered directly to the lung.
Ever wondered if catching one viral nasty spares you from being hit hard by another?
Pioneering research led by New Zealand and US scientists suggests that’s not such a far-fetched idea – and it could pave the way for new, smarter vaccines.
Throughout our lives, we’re exposed to all sorts of bacteria, viruses and other bugs.
These infections don’t arrive one by one – they’re often overlapping, and our immune system is constantly working to keep them at bay.
New research conducted by New Zealand and US scientists suggests "infection interference" may be the key to unlocking broader protection from viral nasties – paving the way for better vaccines. Photo / 123rf
But what happens when our bodies are already fighting one infection? Could that help us fend off new threats, like Covid or the flu?
It’s a question Dr Kerry Hilligan, of Wellington’s Malaghan Institute of Medical Research, has been tackling with colleagues at US-based National Institutes of Health.
“Our research explores the question of whether prior infection or inflammatory stimulation of the lung alters susceptibility to other kinds of infection,” she said.
Specifically, they’ve been looking at whether the population’s diverse “infectious history” could be a factor in why there’d been such a wide range in outcomes to Covid cases.
It’s well-known getting sick can make you more vulnerable to other illnesses: a bad viral infection, for instance, can leave you more likely to develop pneumonia.
But Hilligan’s research also shows the reverse can happen: a mild infection might actually help protect you from other bugs.
She and colleagues have been seeking to understand this phenomenon better from an immunological standpoint.
“In our series of preclinical studies, we found that, yes, infectious history does dictate Covid risk,” she said.
In experiments with mice, her team found animals which had already dealt with a lung infection were temporarily protected against Covid.
That supported findings from an earlier Yale University study, which showed children – who often have lots of viruses and bacteria in their airways – were less likely to get seriously ill from Covid during the pandemic.
The Malaghan Institute of Medical Research's Dr Kerry Hilligan.
In short, she said, when the immune system in the lung was already busy dealing with one mild infection, it was much more well-equipped to prevent other infections taking hold.
The researchers’ latest study, published in the journal Science Immunology, showed this cross-protective effect had a much broader application beyond just Covid.
“Vaccine-induced immunity is generally directed against a specific virus like measles, polio – or disease-causing bacterium like pneumococcus,” Hilligan said.
“But what our research shows is that it is also possible to generate ‘broad-acting’ or ‘non-specific’ immunity by delivering immune stimulants – things that mimic a viral or bacterial particle – directly into the lung.
“This opens up the possibility of designing next-generation vaccines that are administered directly to the lung and generate both specific and non-specific protection, giving a much more robust defence.”
The Malaghan Institute team, supported by the Royal Society Te Apārangi and Health Research Council of New Zealand, is already working on ways to put these findings into practice.
“We’re particularly interested in how exposure to microbes shapes lung immune responses in both the short and long term.”
Hilligan’s colleague, Dr Kit Moloney-Geany, is studying how prior flu infections form clusters of immune cells in the lungs and how these cells co-ordinate responses to new infections.
“We are also really interested in studying how inhalation of fungal spores – of which we inhale thousands every day – alter susceptibility to viral infection and allergy,” Hilligan said.
Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.
