THERE’S no effective vaccine against malaria but researchers have discovered a vital clue as to why malaria vaccines keep failing. 

After looking into vaccinations against malaria, which is a major global killer, the ANU research shows that a negative feedback system may be overcome by strategically tailoring?vaccines to target a diversity of the parasite’s surface proteins.

Lead author and PhD scholar Hayley McNamara says effective vaccines work by generating antibodies against infectious diseases, allowing the immune system to successfully provide long-term protection. However, current malaria vaccines have been failing to produce enough protection.

“We have found that antibody based protection against malaria is difficult to achieve as the body cannot generate enough protective antibodies through the vaccine,” she says.

“A negative-feedback mechanism prevents malaria-specific antibody from reaching the necessary protective levels.

“The protective level needed to combat malaria is unsustainable using current vaccine strategies and stays only a few weeks after the first vaccination.

“Using a novel model, we found that the negative feedback-mechanism may be overcome by strategically designing vaccines to direct antibody responses?against different targets on the malaria parasite.”

Ms McNamara says the easiest diseases to vaccinate against require only small amounts of antibodies for protection, however, complex diseases like malaria and HIV require large amounts of antibody for immunity to develop.

“Malaria vaccines are failing because they only provide immunity against one surface protein of the parasite,” she says.

“Our research shows that vaccines should instead target an array of the parasite’s surface proteins in order to provide protection from malaria.”

The researchers say the finding could help vaccine design for other diseases like HIV – a complex virus which also requires high levels of antibodies for protection.

“The discovery could be “critical for a host of other diseases without effective vaccines,” study lead Associate Prof Ian Cockburn says.

“This discovery could apply to all manner of diseases and particularly for the ones that don’t have effective vaccines.

“We have highlighted an important mechanism that future vaccine?design should take into consideration.”

The findings have been published in “Cell Host & Microbe”. The research was funded by the NHMRC.