Serum Institute joins race for Bundibugyo Ebola vaccine as outbreak widens

The world is once again confronting the terrifying spectre of Ebola, but this time the enemy is a lesser-known and poorly understood strain for which no approved vaccine exists. As the Bundibugyo virus spreads across parts of the Democratic Republic of the Congo (DRC) and Uganda, global health agencies are scrambling to accelerate vaccine development before the outbreak spirals further out of control.

Also joining this urgent effort is India’s Serum Institute of India (SII), the world’s largest vaccine manufacturer, which is now positioning itself as a critical player in the race to produce doses of a promising experimental vaccine based on the ChAdOx platform developed with the University of Oxford, UK.

The outbreak has already triggered alarm bells across international health networks.

According to the latest figures released by the DRC and Uganda Ministries of Health, there have been 575 suspected cases, 51 confirmed infections, and 148 suspected deaths linked to the Bundibugyo strain of Ebola. The spread into Kampala has heightened fears of cross-border transmission in densely populated urban areas.

The World Health Organization has declared the outbreak a Public Health Emergency of International Concern, while the Africa Centres for Disease Control and Prevention has labelled it a Public Health Emergency of Continental Security.

Yet despite the escalating crisis, there is still no licensed vaccine or therapeutic specifically designed for the Bundibugyo species of Ebola.

That gap in global preparedness is now driving an unprecedented push involving governments, vaccine alliances, research institutions and pharmaceutical manufacturers.

WHO adviser Dr Vasee Moorthy recently warned that it could take up to nine months before a vaccine against this particular Ebola species is ready for deployment.

Two experimental vaccine candidates are currently under consideration, but neither has entered clinical trials.

RACE AGAINST TIME

The first candidate is based on the recombinant vesicular stomatitis virus, or rVSV, platform – the same technology used in Ervebo, the licenced vaccine against the Zaire strain of Ebola. However, there are currently no doses available even for clinical testing, and experts estimate it could take six to nine months just to manufacture trial-ready supplies.

The second candidate, for which the Pune-based SII is tying up with the University of Oxford and the Coalition for Epidemic Preparedness Innovations (CEPI), uses the ChAdOx platform.

This platform became widely known during the COVID-19 pandemic through the Oxford-AstraZeneca vaccine manufactured at scale by SII as Covishield.

Unlike the rVSV approach, the ChAdOx candidate could potentially move faster into production because manufacturing systems already exist, and the technology is well understood. But it comes with its own challenge: there are currently no animal or human studies validating its effectiveness against Bundibugyo virus disease.

That is where India’s vaccine manufacturing giant believes it can make a difference.

“At SII, we have always believed that our manufacturing capabilities exist not just for commerce, but for global health security,” a Serum Institute spokesperson said in response to a query by India Today.

“The moment we received word of the Bundibugyo Ebola outbreak, we activated our emergency response framework in partnership with the University of Oxford and CEPI.”

The spokesperson said Oxford’s master viral seed could allow SII to rapidly inoculate its cell banks and begin producing vaccine doses “in record time”.

“We are looking at a 20 to 30-day window,” the spokesperson added.

“This is exactly the kind of agility India’s biopharmaceutical sector brings to the world. The ChAdOx vector platform is well understood by our teams, and we are fully prepared to scale.”

The statement marks one of the clearest signals yet that India could once again emerge as a frontline supplier during a global health emergency, much as it did during the COVID-19 pandemic when SII became one of the largest producers of coronavirus vaccines worldwide.

GLOBAL HEALTH EMERGENCY

The urgency is difficult to overstate. Gavi, the Vaccine Alliance, has described the outbreak as “deeply concerning” because it is unfolding in conflict-affected and hard-to-reach regions where healthcare infrastructure is already fragile.

More than 500 suspected cases and over 130 deaths have been reported in the DRC alone, with the appearance of confirmed cases in Uganda underscoring the risk of regional spread.

Health officials are particularly worried because there are no approved vaccines for Bundibugyo virus disease and little evidence that existing Ebola vaccines designed for the Zaire strain would offer meaningful protection.

Gavi currently funds the global stockpile of Ebola vaccines, including Ervebo, which is licenced only for the Zaire species.

That stockpile contains around 500,000 doses and has previously been deployed successfully during outbreaks in the DRC, including a major vaccination campaign in September 2025 that immunised more than 47,000 people.

But experts caution that cross-protection against Bundibugyo remains uncertain.

As of now, Gavi, CEPI, WHO, Africa CDC, UNICEF, the World Bank and the Pandemic Fund are coordinating closely to evaluate whether any experimental candidates can be accelerated into emergency use.

The ChAdOx platform may offer one important advantage in that race: speed.

Unlike entirely new vaccine technologies, ChAdOx manufacturing infrastructure already exists at an industrial scale because of its extensive use during COVID-19. SII’s facilities are already optimised for the vector platform, potentially reducing the time required to transition from laboratory development to large-scale production.

That manufacturing agility could prove decisive if early studies show promising immune responses.

HIGH-STAKES GAMBLE

Still, major scientific hurdles remain. The ChAdOx candidate has not yet undergone animal testing or human trials for Bundibugyo virus disease, meaning regulators and global health agencies will need to balance urgency against safety and efficacy concerns.

The rVSV candidate, while more closely related to the successful Ervebo model, faces severe manufacturing delays that could limit its usefulness during the current outbreak.

This leaves the global health community confronting a difficult calculation: whether to accelerate a less-tested but rapidly manufacturable platform, or wait longer for a vaccine approach with more established Ebola precedents.