Research
Through research, health experts have learned that there are more than 120 different strains of group A streptococci bacteria, each producing its own unique proteins. Some of these proteins are responsible for specific group A streptococcal diseases.
With the support of NIAID, scientists have determined the genetic sequence, or DNA code, for five strains of the group A streptococcus bacterium.
By studying its genes, scientists can learn which proteins are responsible for virulence—crucial information that will lead to new and improved drugs and vaccines.
NIAID supports research to develop a group A streptococcus vaccine, and several candidate vaccines are in various phases of development. While some scientists are conducting animal model studies to obtain data to pursue clinical trials in humans, other scientists are close to evaluating group A streptococcus vaccine candidates in Phase I clinical trials.
As a result of NIAID-supported research, the first group A streptococcus vaccine clinical trial in 30 years was started. The vaccine was well tolerated by patients and has led to further clinical evaluation of a similar vaccine candidate.
An effective vaccine will prevent not only strep throat and impetigo but also more serious invasive disease and post-infectious complications like rheumatic fever.
Vaccine development efforts include NIAID-supported epidemiological studies
- To determine the extent of group A streptococcal disease
- To characterize group A streptococcal strains causing illness in the United States and developing countries
NIAID, in collaboration with the Centers for Disease Control and Prevention and the World Health Organization, has developed standard definitions and methods for surveillance of group A streptococcal diseases.
This was accomplished by meetings with experts in the group A streptococcal research community that included research scientists, academic investigators, clinicians, and public health officials.
Two field protocols were developed for use in epidemiological studies to determine current burden of disease information.
- One protocol focused on acute disease (pharyngitis, impetigo, and invasive disease).
- The other protocol focused on the after-effects of acute infections (acute rheumatic fever, rheumatic heart disease, and post-streptococcal glomerulonephritis).
These protocols are being used at NIAID-supported clinical sites in Mali (Africa), Leon (Nicaragua), and Suva (Fiji) to obtain epidemiological data that will be useful for designing future vaccine clinical trials.
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