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New Zealand researchers have developed a promising vaccine ‘adjuvant’ which could help the body mount a more effective immune response to vaccines, with potentially fewer side-effects.

The team has identified a molecule (the adjuvant) that binds strongly with a specific receptor found in normal, healthy cells. A combination of in vitro and in vivo studies (in mice) have shown that when added to a vaccine, alongside an antigen, this adjuvant can unlock a powerful cellular immune response to combat harmful bacteria and viruses.

Results to date suggest the adjuvant could play a role in the development of vaccines for chronic infections such as HIV, Group A Streptococcus, tuberculosis and S. pneumoniae infection (meningitis). It could also improve existing vaccines, by generating a better, longer-lasting immune response and reducing the need for booster shots.

The research, published in the Journal of Medicinal Chemistry, was funded by the Health Research Council of New Zealand (HRC) and the Royal Society of New Zealand’s Marsden Fund. Associate Professor Bridget Stocker from Victoria University of Wellington led the team, which included Associate Professor Mattie Timmer (VUW) and Professor Sho Yamasaki from Osaka, Japan, among others.

In 2013, Dr Stocker was awarded a $500,000 Sir Charles Hercus Research Fellowship by the HRC to explore ways to switch off dysfunctional immune cells to develop novel cancer therapies – the adjuvant finding is part of that wider research.

Dr Stocker says this adjuvant differs from others currently in use, in that it stimulates a specific type of T-cell response, instead of an antibody-only mediated response, which makes it useful in eliminating a number of particular pathogens.

That means, in theory, it could be used for preventative vaccination such as standard childhood vaccinations, as well as prophylactic vaccination for fighting cancer.

Research into the cancer side is still ongoing, but Dr Stocker notes “that is the bigger context of the work”. She plans to investigate the potential use of the adjuvant in combination with different antigens, such as those that come from outside the body – like bacteria – or those that develop within the body because cells are going “haywire”, she says.

A further plus with this adjuvant is that it uses a defined molecule to target a specific receptor, leading to a consistent and defined immune response.

“There’s been a shift in recent years in looking at whether more precise vaccines can be developed so there are fewer adverse side-effects, or less inflammation at the local site, says Dr Stocker.

“So rather than packing everything into a vaccine, including those parts of a pathogen that don’t facilitate the type of immune response that you want, you’re just adding what you need – very specific ingredients that do the job.”

The next step for Stocker’s team is to test the adjuvant in more specific disease settings by partnering with other collaborators.

“We have a patent on this compound, but we can only take it up to a certain point until you need a partner to help you take it to the next level. Any one group can only progress something so far,” she says.

She adds that without HRC funding, this research wouldn’t be possible. “Up until I got the Hercus Fellowship, I only had a job for six months, so I’m pretty certain that I wouldn’t have an independent scientific career, and a chance to make a difference, without this grant.”

HRC chief executive Professor Kath McPherson says one of the exciting things about this sort of work is its focus on improving our own bodies’ responses to vaccines.

“The field of immunology is developing incredibly fast with both better treatments for infectious diseases and cancer, and work like this – focusing on prevention. New Zealand scientists are at the forefront of some of this work and the HRC is proud to support them, and their work,” she says.