Abstract
An emm-cluster based system was proposed as a standard typing scheme to facilitate and enhance future studies of group A Streptococcus (GAS) epidemiological surveillance, M protein function, and vaccine development strategies. We provide an evidence-based distribution of GAS emm clusters in Africa and assess the potential coverage of the new 30-valent vaccine in terms of an emm cluster-based approach. Two reviewers independently assessed studies retrieved from a comprehensive search and extracted relevant data. Meta-analyses were performed (random-effects model) to aggregate emm cluster prevalence estimates. Eight studies (n = 1,595 isolates) revealed the predominant emm clusters as E6 (18%; 95% confidence interval [CI], 12.6% to 24.0%), followed by E3 (14%; 95% CI, 11.2% to 17.4%) and E4 (13%; 95% CI, 9.5% to 16.0%). There was negligible variation in emm clusters with regard to regions, age, and socioeconomic status across the continent. Considering an emm cluster-based vaccine strategy, which assumes cross-protection within clusters, the 30-valent vaccine currently in clinical development would provide hypothetical coverage to 80.3% of isolates in Africa. This systematic review indicates the most predominant GAS emm cluster in Africa is E6 followed by E3, E4, and D4. The current 30-valent vaccine would provide considerable coverage across the diversity of emm cluster types in Africa. Future efforts could be directed toward estimating the overall potential coverage of the new 30-valent vaccine based on cross-opsonization studies with representative panels of GAS isolates from populations at highest risk for GAS diseases.IMPORTANCE Low vaccine coverage is of grave public health concern, particularly in developing countries where epidemiological data are often absent. To inform vaccine development for group A Streptococcus (GAS), we report on the epidemiology of the M protein emm clusters from GAS infections in Africa, where GAS-related illnesses and their sequelae, including rheumatic fever and rheumatic heart disease, are of a high burden. This first report of emm clusters across the continent indicates a high probably of coverage by the M protein-based vaccine currently undergoing testing were an emm-cluster based approach to be used.
Highlights
IMPORTANCE Low vaccine coverage is of grave public health concern, in developing countries where epidemiological data are often absent
The vaccine composition was based on extensive group A Streptococcus (GAS) surveillance data from developed regions such as the United States and Europe on those isolates that are involved in invasive disease, those associated with superficial infections, and those causing autoimmune diseases [9, 11]
Using prevalence data obtained from eight studies representing five countries within Africa, this report identified the predominant emm clusters in Africa, namely, E6 followed by E3, E4, and D4
Summary
IMPORTANCE Low vaccine coverage is of grave public health concern, in developing countries where epidemiological data are often absent. To inform vaccine development for group A Streptococcus (GAS), we report on the epidemiology of the M protein emm clusters from GAS infections in Africa, where GAS-related illnesses and their sequelae, including rheumatic fever and rheumatic heart disease, are of a high burden. This first report of emm clusters across the continent indicates a high probably of coverage by the M protein-based vaccine currently undergoing testing were an emm-cluster based approach to be used. Given the Ͼ200 GAS emm types characterized to date [12], the absence of highly prevalent GAS subtypes in the current vaccine formulation may diminish the coverage of at-risk populations outside western countries
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
