A compound that greatly boosts the effect of vaccines against viruses like flu, HIV and herpes in mice has been discovered by Oxford Scientists.
The Oxford University team, along with Swedish and US colleagues, have shown that a type of polymer called polyethyleneimine (PEI) works to enhance the immune response and offer better protection against infection in test vaccines against HIV, flu and herpes in mice.
Mice given a single dose of a flu vaccine including PEI via a nasal droplet were completely protected against a lethal dose of flu. Researchers now plan to further test PEI n order to understand how long the protection lasts.
“Gaining complete protection against flu from just one immunisation is pretty unheard of, even in a study in mice,” says Principal Investigator, Professor Quentin Sattentau, Senior James Martin Fellow at the Institute for Vaccine Design. “This gives us confidence that PEI has the potential to be a potent adjuvant for vaccines against viruses like flu or HIV, though there are many steps ahead if it is ever to be used in humans.”
Most vaccines include an adjuvant, a substance added to a vaccine to enhance the immune response and offer better protection against infection. The main ingredient of the vaccine – whether it is a dead or disabled pathogen, or just a part of the virus or bacteria causing the disease – primes the body’s immune system so it knows what to attack in case of infection. The adjuvant is needed to stimulate this process.
Developing vaccines against HIV and flu is challenging as the viruses are able to evolve and escape the immune responses stimulated by vaccines. No effective vaccines have yet been developed against HIV and herpes, and not only does the flu vaccine need reformulating each year, it doesn’t offer complete protection to everyone who receives it. According to Sattentau, finding better adjuvants could help in developing more effective vaccines against these diseases.
Professor Sattentau predicts that one day; “You could imagine people would have one dose of flu vaccine that they’d sniff up their nose or put under their tongue and they’d be protected from flu for a number of years.”