Australian researchers steam ahead with life-saving vaccine

A vaccine developed by Australian researchers whose potential ranges from preventing throat infections to saving the lives of up to 400,000 children each year has gone into production, with human trials expected to commence as early as next year.

The trial vaccine has proved effective against group A streptococcus (GAS) infections, the most common cause of bacterial throat infections in both children and adults, with an estimated 616 million new cases each year. However, when left untreated, GAS infections can lead to the deadly conditions of acute rheumatic fever (ARF) and rheumatic heart disease (RHD).

Presenting at the Heart Foundation – Hearts in Focus – Conference in Brisbane, Dr Michael Batzloff, Laboratory Head, Bacterial Vaccines Laboratory at Queensland Institute of Medical Research (QIMR), said the trial vaccine can make a huge difference to the lives of the most disadvantaged people around world.

"While ARF and RHD are rare in the western world today, RHD is the most frequent form of heart disease in children worldwide with Australian Aboriginal and Torres Strait Islander populations experiencing the highest rates of ARF and RHD in the world," said Dr Batzloff.

Sixty-three per cent of all cases of ARF in Australia were in children 9–14, all of them Aboriginal and Torres Strait Islander children.

ARF is an inflammatory disease that affects many of the body s connective tissues, especially those of the heart, joints, brain or skin. While anyone can get ARF, it usually occurs in children aged five to 15 years. The RHD that can result lasts for life.

"Our pre-clinical research found that the trial vaccine is safe and creates the desired immune response which will protect against almost all GAS infection strains found around the world," said Dr Batzloff. "Our latest studies also indicate that the immune response created by our vaccine lasts at least several years."

The exciting potential for this vaccine attracted funding from the National Institutes of Health (NIH), the primary US agency for conducting and supporting medical research. The Heart Foundation has also helped fund this world class research since 2002.

"Being given the green light to proceed with production from the US regulatory authorities is a huge hurdle, so we’re optimistic we’ll be in a position to commence phase one trials in Brisbane next year," he added.

While researchers in other countries, such as the United States (US), have also been investigating GAS vaccines, their vaccine s benefit is limited to GAS strains found only in the US.

"This Australian-led initiative has much greater relevance as our vaccine has demonstrated its effectiveness against most GAS strains including those found in Australia, New Zealand, India, Thailand and Fiji," said Dr Batzloff.

"Ultimately, we hope this vaccine will become a part of early childhood immunisation for all preschoolers, so even severe throat infections become obsolete."

GAS is the seventh leading cause of global mortality behind respiratory diseases, HIV, diarrhoeal diseases, tuberculosis, malaria and measles.

If human tests prove successful, the vaccine is expected to be used initially with children in at risk populations and in developing countries.

Heart Foundation CEO – National Dr Lyn Roberts said that this research has the potential to make ARF a disease of the past and reduce Indigenous death and suffering caused by cardiovascular disease (CVD).

"CVD remains the number one killer of Aboriginal and Torres Strait Islander populations. They are up to eight times more likely than other Australians to be hospitalised for ARF and RHD, and nearly 20 times as likely to die," said Dr Roberts.

"The Heart Foundation believes a nationally coordinated, comprehensive control program with improved screening, management and treatment and a national ARF/RHD register is essential in preventing and managing ARF and RHD," she added.

The Heart Foundation, in conjunction with the Cardiac Society of Australia and New Zealand published the first national guidelines for Diagnosis and Management of Acute Rhematic Fever and Rheumatic Heart Disease in Australia in 2006 to help policy makers and health professionals address inadequate diagnosis and management of ARF and RHD in Australia.

The Hearts in Focus Conference is part of the Heart Foundation’s 50th anniversary celebrations and was held on the Gold Coast 14–16 May.

(Source: Heart Foundation: Hearts in Focus Conference, Brisbane: June 2009)