Researchers discover how antibodies protect against Strep A infections

Researchers discover how antibodies protect against Strep A infections

Researchers have discovered how antibodies help protect against contagious bacterial infections caused by Strep A, including strep throat. And the results are already helping to accelerate the development of a Strep A vaccine.

The research, led by Murdoch Children's Research Institute (MCRI), Monash University and the University of Auckland, using the world's only human challenge model for Strep A, has revealed how antibodies respond to neck-to-neck infections.

McRI Dr. Joshua Osowicki said the research shows the power and potential of the human model to help crack the secrets of Strep A and accelerate vaccine development.

The results, published innature communication,Looking closely at antibodies produced against different parts of Strep -A bacteria, blood and saliva results were compared before and after Strep -A challenge. The challenge involved 25 healthy adults in Melbourne being exposed to low levels of Strep A bacteria in a controlled environment.

Because Strep A is extremely common and every healthy adult who had previously encountered it, all participants had some antibodies to Strep A before the study. “

Dr. Joshua Owocki, MCRI

"We found that each person's pre-existing antibodies made a difference to what happened when they were exposed during the challenge. For some participants, the mix of antibodies before the challenge helped protect them from developing strep throat. Even those who were exposed to strep throat experienced symptoms such as a sore throat and a sore throat."

Importantly, the response to Strep A in the participants was similar to that seen in children first in line for a Strep A vaccine.

Dr. Osowicki said developing an effective vaccine has been difficult because of our limited understanding of how people were protected against Strep A infections.

"The majority of Strep research has used animal models, but only humans are naturally infected by Strep A," he said. This research helps vaccine developers answer this key question and proves that we can use our human model to test promising vaccine candidates and study how they work. “

The results come as Dr. Osowicki and his team were awarded a $10 million grant from Wellcome for further research using the Strep A Human Challenge model to accelerate vaccine development.

After the grant, Dr. Osowicki alongside MCRI colleagues Dr. Hannah Frost and Professor Andrew Steer are leading an international consortium involving six institutes in Australia, Gambia, the UK and New Zealand. Research partners include Monash University, The Gambia Medical Research Council Department, the London School of Hygiene & Tropical Medicine, the University of New South Wales (Kirby Institute), the University of Auckland and the University of Sheffield. The project will also include key international vaccine developers as part of an advisory group.

Wellcome, a UK-based independent charitable foundation, supports innovative projects to solve the world's most pressing health challenges, including infectious diseases.

The project will use the MCRI team's Strep A Human Challenge model in trial participants in Australia and Gambia to test different ideas about what types of immune responses prevent people from getting an infection. A vaccine that can cause similar reactions Spectrum.

Strep a infections affect about 750 million people and kill more than 500,000 worldwide each year, more than influenza, typhoid or whooping cough. Strep A can also cause serious life-threatening infections such as toxic shock syndrome, flesh-eating diseases and post-infectious diseases such as acute rheumatic fever, rheumatic heart disease and kidney disease.

Strep A vaccine research is a response to the dissolution of the World Health Organization (WHO) for a global, coordinated response to rheumatic fever and rheumatic heart disease.

Dr. Frost said our team changed the vaccine development landscape by developing the world's only Strep A human challenge model.

“With this funding from Wellcome, we will answer some of the biggest and most persistent questions standing in the way of developing, licensing and implementing a successful Strep A vaccine,” she said.

“While this has traditionally been a long and difficult process, it would quickly bring efforts together to meet the needs of the fuzzy global public health need for a safe and effective Strep A vaccine.”

Professor Steer said the project could help prevent strep-related disease and death around the world.

“There is a great need for the development of a vaccine to reduce the burden of disease and we are proud to bring this work to MCRI,” he said. Another key benefit of this vaccine would be the reduction in rheumatic heart disease worldwide, a preventable disease that has been identified as a global priority. “

Sources: