Group A Streptococcus: vaccines are now back on the agenda

Group A Streptococcus (Streptococcus pyogenes) is one of the most common bacterial pathogens in humans. It causes an estimated 616 million cases of pharyngitis a year, more than 18 million cases of severe disease and around 517,000 deaths [1].

High-income markets have seen a sharp resurgence of invasive GAS (iGAS). In the United States, iGAS incidence more than doubled, from 3.6 to 8.2 per 100,000 between 2013 and 2022 [2]. In England, the 2022/23 season recorded 3,287 iGAS cases and 426 deaths within seven days of diagnosis [3]. Notifications in 2025/26 again ran above the five-season average [4].

The heaviest long-term burden falls on low- and middle-income countries. There, repeated infections drive acute rheumatic fever and rheumatic heart disease (RHD). RHD affects more than 40 million people and causes over 300,000 deaths a year [5]. The World Health Assembly has called for action on RHD [6], and WHO has published preferred product characteristics for a GAS vaccine [7]. No licensed vaccine exists.

After decades of setbacks, two industry programmes are now in the clinic, both in Australia:

• GSK's four-component Strep A vaccine. It combines SLO, SpyCEP, SpyAD and the group A carbohydrate, formulated with alum or AS37 adjuvants. Dosing began in July 2025 in a 108-participant Phase 1 study in adults aged 18 to 25, with primary completion due in mid-2027 [8]. The programme is backed by CARB-X, BARDA, Wellcome, the UK Global AMR Innovation Fund, Germany's BMBF and the European Commission's HERA [8,9].
• Vaxcyte's VAX-A1. It targets SLO, C5a peptidase, SpyAD and the group A carbohydrate. It entered a first-in-human, dose-escalation Phase 1 study in 80 adults aged 18 to 40 in June 2026, with completion expected in late 2027 [10,11]. Vaxcyte is funding the programme alone.

The MarketVIEW analysis (VAMV027) treats GAS as two distinct commercial propositions, each with its own model.

• Western model. It forecasts annual demand and NET revenue to 2045 across North America, Europe and Asia-Pacific, for pharyngitis and invasive disease. It is built country by country, with launch sequencing, public and private channels and uptake anchored on observed vaccine introductions.
• Developing-world model. It addresses RHD prevention in endemic regions. It covers alternative immunisation strategies and the approval, prequalification and financing steps that gate demand there.

Both are fully interactive MS-Excel tools. Users can change dosing schedules, protection and acceptance assumptions, and pricing market by market, and the forecast recalculates throughout. The report also includes an executive presentation with a competitive review, a target product profile and schedule-fit analysis, and updated epidemiology. Licences cover the Western model, the developing-world model, or both.

VacZine Analytics, established in the UK since 2007, provides disease and commercial analysis for the vaccine and gene therapy sectors. More information: www.vaczine-analytics.com or [email]

VacZine Analytics is a trading division of Assay Advantage (VacZine Analytics) Ltd, UK Company No. 5807728.

References

1. Carapetis JR, Steer AC, Mulholland EK, Weber M. The global burden of group A streptococcal diseases. Lancet Infect Dis. 2005;5(11):685-694. doi:10.1016/S1473-3099(05)70267-X
2. Gregory CJ, et al. Invasive group A streptococcal infections in 10 US states. JAMA. 2025;333(17):1498-1508. doi:10.1001/jama.2025.0910
3. UK Health Security Agency. Update on scarlet fever and invasive group A strep, 15 May 2023 (England, 12 September 2022 to 7 May 2023).
4. UK Health Security Agency. Group A streptococcal infections: third update on seasonal activity in England, 2025 to 2026. 28 May 2026. https://www.gov.uk/government/publications/group-a-streptococcal-infections-seasonal-activity-in-england-2025-to-2026
5. Craik N, et al. Global disease burden of Streptococcus pyogenes. In: Streptococcus pyogenes: Basic Biology to Clinical Manifestations, 2nd edn. University of Oklahoma Health Sciences Center; 2024. https://www.ncbi.nlm.nih.gov/books/NBK587099/
6. World Health Organization. Resolution WHA71.14: Rheumatic fever and rheumatic heart disease. 2018. https://apps.who.int/gb/ebwha/pdf_files/WHA71/A71_R14-en.pdf
7. World Health Organization. WHO preferred product characteristics for group A streptococcus vaccines. WHO/IVB/18.07, 2018.
8. ClinicalTrials.gov. NCT07085702: Phase 1 study of the GSK 4-component Strep A vaccine with alum or AS37 in healthy adults 18 to 25 years. https://clinicaltrials.gov/study/NCT07085702
9. CARB-X. GSK Strep A vaccine project profile. Award announced 1 March 2021. https://carb-x.org/gallery/glaxosmithkline-3/
10. ClinicalTrials.gov. NCT07616934: Phase 1 first-in-human study of VAX-A1 in healthy young adults. https://clinicaltrials.gov/study/NCT07616934
11. Vaxcyte. Vaxcyte doses first participant in Phase 1 study evaluating VAX-A1. Press release, 2 June 2026. https://investors.vaxcyte.com/