OrganisationUS

IAVI

US non-profit vaccine developer working on Ebola, HIV and other infectious disease research.

IAVI took $3.2 million from CEPI on 1 June 2026 to manufacture seed stock for a Bundibugyo Ebola vaccine candidate; a separate CEPI-funded rVSV shot, from Singapore's Hilleman Laboratories, became the species' first vaccine in trial production on 31 July.

Last refreshed: 31 July 2026 · Appears in 1 active topic

Key Question

Can IAVI's rVSV platform produce usable Bundibugyo seed stock fast enough to matter in an active outbreak?

Timeline for IAVI

#12 31 Jul

Supplied the reference virus used in the candidate

Pandemics and Biosecurity: CEPI puts a Bundibugyo vaccine in trials

#7 8 Jun

Mentioned in: CEPI funds a fourth Ebola vaccine

Pandemics and Biosecurity

#6 1 Jun

Received $3.2m CEPI commitment for rVSV master seed stock

Pandemics and Biosecurity: $112m for vaccines, none for the wards

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Follow Pandemics and Biosecurity →

Background

IAVI (International AIDS Vaccine Initiative) is a New York-based non-profit founded in 1996 that develops vaccines for HIV and emerging infectious diseases in low- and middle-income countries, running its own clinical programmes alongside academic, government and commercial partners. Its core platform is replication-competent recombinant vesicular stomatitis virus (rVSV), the same vector technology behind rVSV-ZEBOV (Merck's Ervebo), the only approved Zaire ebolavirus vaccine.

That track record has extended IAVI's rVSV work from HIV into Filovirus vaccines, positioning it as a niche developer for pathogens with limited commercial markets. On 1 June 2026 it received $3.2 million from CEPI to manufacture master seed stock, the regulatory-compliant biological starting material, for a Bundibugyo-specific rVSV candidate.

Bundibugyo is a distinct species from the Zaire strain Ervebo targets, so IAVI's existing platform validation does not transfer automatically; its own candidate needs its own trial data. IAVI's Bundibugyo work now depends chiefly on European and multilateral funding through CEPI, following cuts to the US health budgets that previously supported the organisation.

Key Issues

Vaccine seed stock

Its seed stock funding preceded a trial

CEPI awarded IAVI $3.2 million on 1 June 2026 to manufacture master seed stock for its rVSV-based Bundibugyo vaccine candidate, the biological starting material a candidate needs before Phase 1 trials can begin. It was the smallest of three initial CEPI grants for rVSV and ChAdOx platform candidates, and a fourth candidate followed on 9 June.

On 31 July, a separate CEPI-funded rVSV candidate from Singapore's Hilleman Laboratories became the first Bundibugyo vaccine to enter trial production, the milestone IAVI's seed-stock work and the wider four-candidate portfolio had been building towards since June.

Common Questions

Its seed stock funding preceded a trial

What did IAVI contribute to the new Bundibugyo Ebola vaccine candidate?

IAVI supplied the reference virus that Hilleman Laboratories, a Merck/Wellcome Trust joint venture, used to bring a Bundibugyo-specific rVSV vaccine candidate into trial production on 31 July 2026.Source: CEPI

What is vaccine master seed stock and why does it matter?

Master seed stock is the GMP-certified biological starting material from which all clinical-grade vaccine doses are derived. Without it, a vaccine candidate cannot enter formal trials. CEPI's $3.2m to IAVI funds production of this foundational material for the rVSV Bundibugyo candidate.Source: CEPI

Why is there no Bundibugyo Ebola vaccine yet?

Bundibugyo ebolavirus is a distinct species from Zaire ebolavirus, so licensed vaccines such as Ervebo, which target Zaire-specific proteins, do not protect against it, and no manufacturer had advanced a Bundibugyo candidate to clinical stage before the 2026 outbreak for lack of prior commercial interest. That changed on 31 July 2026, when IAVI's reference virus and Hilleman Laboratories' manufacturing brought a Bundibugyo-specific rVSV candidate into trial production, though it has not yet been dosed and has no efficacy data.Source: WHO / CEPI

Reference

What is rVSV and why is it used in Ebola vaccines?

rVSV (recombinant vesicular stomatitis virus) is a viral vector technology that can be engineered to display proteins from other pathogens. It was used in Ervebo, the only approved Zaire ebolavirus vaccine, because rVSV-based vaccines can be manufactured rapidly and often generate strong immune responses.

What is IAVI and what vaccines has it developed?

IAVI (International AIDS Vaccine Initiative) is a New York-based non-profit that develops vaccines for HIV and emerging infectious diseases. Its rVSV platform contributed to Ervebo, the only approved Zaire ebolavirus vaccine; it is now developing an rVSV Bundibugyo candidate.

Source Material

International AIDS Vaccine Initiative (Wikipedia)IAVI (International AIDS Vaccine Initiative)

How the World Sees Them

United States

IAVI is a US-incorporated non-profit with significant NIH and USAID funding history; its Bundibugyo work now relies on European multilateral funding via CEPI following US health budget cuts.

Sub-Saharan Africa

IAVI has longstanding partnerships with African research institutions on HIV vaccine trials; the Bundibugyo seed stock programme extends that presence into the active DRC outbreak zone.

Global health community

IAVI fills the niche of developing vaccines for pathogens that lack a commercial market; the rVSV platform's Ervebo track record gives it credibility but Bundibugyo requires a new validated candidate from scratch.