Could we get closer to the global vaccine against streptococcus A?

The search for a global vaccine against type A streptococcus shrank after researchers sequenced the DNA of more than 2,000 group A streptococcus samples from around the world.

Researchers from the Wellcome Sanger Institute, the University of Cambridge, the Peter Doherty Institute for Infection and Immunity (Doherty Institute) in Australia, and the University of Queensland, Australia, revealed the differences between strains. from more than 20 countries and identified a potential target vaccine present in most strains – could this lead to an effective global vaccine against streptococcus A?

Published in Nature Genetics, the 10-year project revealed that some molecular targets present in bacterial strains from 20 countries, including the UK, Australia, and India, indicate the potential for developing a global vaccine effective against Strep A.

What do you know about Streptococcus bacteria?

The group A streptococcus bacteria, better known as streptococcus A, is one of the top 10 causes of infectious disease deaths worldwide. It is estimated that it causes more than half a million deaths a year, mainly in low-income regions of the world. It can cause many different infections, ranging from the streptococcal throat, widespread in developed countries, to scarlet fever and rheumatic heart disease, which are constantly present and considered endemic in low-income regions of the world.

There is still no effective vaccine against streptococcus A and the variety of strains of streptococci prevents the search for a vaccine. Until now, most of the information came from high-income regions such as the United Kingdom and the United States. However, very little is known about Strep A in low-income areas of the world where it poses the most problems. This means that current vaccine candidates may not be effective in all areas.

Gordon Dougan, author of the Wellcome Sanger Institute and the University of Cambridge, said, "Millions of people around the world are affected by Streptococcus A. It can cause a variety of ailments, including sore throats and epidemics. of scarlet fever in the United Kingdom. , to infections leading to rheumatic heart disease in populations such as the Australian Aboriginal population.

"In addition to helping with vaccine research, the genomic data from our study will help researchers understand how Streptococcus A causes disease and why it is different from high-income regions of endemic regions." . "

Details of the study

To remedy this, the researchers collected more than 2,000 streptococcus A samples from 22 countries around the world, including countries in Africa and the Pacific, indigenous communities in New Zealand, and Australia.

By sequencing and badyzing the DNA of each sample, they were able to determine the genes present in each strain and see the variety of strains in the world.

The project found that the current major vaccine candidates for streptococcus A would have limited coverage in low-income areas where streptococcus A is endemic and the vaccine is most needed.

Dr. Mark Davies, lead author of the Wellcome Sanger Institute and the Doherty Institute of the University of Melbourne, said, "With the help of large-scale genomic sequencing, we have identified the 39 existence of more than 290 genetically different Strep A lineages, of clinical significance, highlighting the challenges of conception. an effective global vaccine. However, using all the data we collected, we restricted common genes in almost all Strep A strains in the world. This is a great step forward in identifying what could work as a candidate for the global vaccine. "

Professor Mark Walker, lead author of the journal and director of the Australian Center for Infectious Disease Research, University of Queensland, said: "This research could potentially enable rapid detection of the long-awaited streptococcal A vaccine. by both the developers and the scientific community We can now use our database to identify the most common genes as vaccine targets.

"I believe that a global vaccine is possible and that the results of this research, in addition to increased funding commitments, will spur the momentum towards the search for a global vaccine."