GSK Licenses Shigella Vaccine Candidate to Bharat Biotech

 GSK has announced a licensing agreement with Hyderabad, India-based Bharat Biotech for its Shigella vaccine candidate, altSonflex 1-2-3. This collaboration signifies a step in addressing the global burden of Shigella, a bacterial infection that causes severe diarrhea and is responsible for thousands of deaths annually, predominantly among children under five.

Shigella infection, or shigellosis, is a significant public health concern worldwide. While antibiotics can treat the infection, the increasing prevalence of multidrug-resistant and extensively drug-resistant Shigella strains has severely limited treatment options and underscored the urgent need for a preventive vaccine. GSK’s altSonflex 1-2-3 has shown promising results in early-stage clinical trials, meeting immunogenicity success criteria in both Phase 1 and interim Phase 2.

 Bharat Biotech’s established partnerships with global health organizations such as Gavi, the Vaccine Alliance, and UNICEF,  make them a good collaborator to lead the Phase 3 trials and facilitate broad access to the vaccine.

Shigella remains a persistent health issue in  low- and middle-income countries as well as in high-income countries. In the United States,  CDC estimates that approximately 450,000 cases of shigellosis occur in the country every year, making it the third most common bacterial enteric disease. Although most cases are mild and resolve without antibiotics within 5 to 7 days, complications such as arthritis, bloodstream infections, and even seizures in children can occur.

Of particular concern in the U.S. is the rise of antibiotic-resistant strains. Since 2017, the Centers for Disease Control’s National Antimicrobial Resistance Monitoring System has noted an increasing percentage of Shigella isolates resistant to commonly used antibiotics such as azithromycin and ciprofloxacin.

Outbreaks of extensively drug-resistant Shigella have been reported in various states. In 2024, California alone reported 4,365 cases, with Los Angeles County identifying a unique mutation of Shigella sonnei that is resistant to multiple antibiotic classes, including cephalosporins. These resistant strains disproportionately affect vulnerable populations, including young children, and the  homeless.

The global and domestic challenges posed by Shigella, particularly the growing threat of antimicrobial resistance, highlight the critical need for effective preventive measures such as vaccines. The collaboration between GSK and Bharat Biotech is a testament to the international effort required to combat this pervasive pathogen and improve public health outcomes worldwide.