A nurse prepares a dose of pneumococcal conjugate vaccine (PCV) in a government hospital. | Photo credit: Representative photo
Researchers at the BITS Pilani-Hyderabad campus say they have developed and tested a new experimental vaccine against Streptococcus pneumoniae, the bacterium responsible for some of the world’s deadliest infections, raising hopes for more effective protection against pneumonia and related diseases.
Streptococcus pneumoniae is the leading bacterial cause of pneumonia, meningitis and sepsis and was responsible for nearly 740,000 child deaths worldwide in 2019 alone. While existing vaccines such as polysaccharide “PPV23” and pneumococcal conjugate vaccines (PCV) target the bacterial envelope and play a key role in disease control, their coverage remains limited.
With more than 100 known strains, or serotypes, current vaccines only protect against select variants, allowing non-vaccine serotypes to emerge and spread, the researchers said. The BITS Pilani-Hyderabad team, led by Kirtimaan Syal, took a novel approach that does not rely on the whole bacterium or its capsule.
Using advanced computational tools, researchers designed a synthetic “multiepitope” vaccine from scratch, capable of targeting multiple strains while being safer and more accurate. “In our previous study, we used immunoinformatics tools based on bioinformatics and artificial intelligence to identify the most immunogenic fragments of bacterial proteins recognized by the human immune system,” said doctoral student Yogeshwar Devarakonda from Mr. Syal’s lab.
Selected epitopes or antigens recognized by the immune system from outer cell wall proteins such as ‘Ply, PspA and PsaA’ were linked together in silico (computer simulation) to create a virtual vaccine candidate. The new study translated this digital blueprint into biological reality, he said.
The team synthesized the corresponding gene and inserted it into Escherichia coli, effectively using the bacterium as a production platform for the vaccine protein. After purification and reconstitution, an experimental vaccine construct was obtained.
When administered to mice, the vaccine elicited a strong immune response and activated a broad spectrum of immune cells. Cytokine profiling showed increased levels of interleukins, indicating a mixed Th1/Th2 immune response, suggesting activation of both cellular and humoral immunity, the researchers said.
Importantly, the “multi-epitope” vaccine did not damage red blood cells, demonstrating its non-toxic nature and suitability for further development. Combining this construct with capsular polysaccharides could pave the way for a strain- or serotype-independent pneumococcal vaccine, they said.
Mr Syal said the next step would involve testing the vaccine in larger animal models and conducting challenge studies to assess whether the antibodies induced could neutralize live bacteria and prevent infection. Other researchers involved in the study include MVN Janardhan Reddy and Arunima Binu.
Published – 05 April 2026 19:15 IST
