Ebola Vaccine induced longest reported immune response

By Esther Nakkazi

An investigational “prime-boost” Ebola vaccine regimen, induced a durable immune response in 100% of healthy volunteers over one year, the longest duration follow-up reported researchers said.

The data was reported in The Journal of the American Medical Association (JAMA) on 14th March. The Phase 1 study is the longest duration follow-up reported for any heterologous prime-boost Ebola vaccine regimen.

This follows recent evidence of the persistence of Ebola virus in bodily fluids and the potential for sexual transmission among Ebola survivors, which reinforce the urgent need for a robust and durable vaccine for the disease.

“The world needs a vaccine to help prevent or mitigate future Ebola outbreaks, and ideally it should provide sustained protection for at-risk populations,” said Paul Stoffels, M.D., Chief Scientific Officer, Johnson & Johnson in a press release.

Janssen’s investigational Ebola vaccine regimen was developed in collaboration with the National Institutes of Health (NIH). The regimen is based on Janssen’s AdVac® technology and MVA-BN®technology from Bavarian Nordic A/S. Johnson & Johnson’s partners in the Ebola program also include Europe’s Innovative Medicines Initiative, the London School of Hygiene & Tropical Medicine, Inserm, and BARDA.

In the Phase 1 study, led by the Oxford Vaccine Group at the University of Oxford, UK, healthy volunteers were given one vaccine dose to prime their immune system and the alternative vaccine to boost their immune response.

The Phase 1 study enrolled healthy participants aged 18 to 50 years. Of 75 active vaccine recipients, 64 attended follow-up at day 360, the latest time point analyzed. No vaccine-associated serious adverse events were observed from day 240 to day 360. All of the active vaccine recipients maintained Ebola virus-specific antibody (immunoglobulin G) responses from the first post-vaccination analysis conducted through to day 360. 

Dr Matthew Snape, Chief Investigator of the study reported that this is the longest duration follow-up for any heterologous prime-boost Ebola vaccine regimen yet published. 

Phase 1, 2 and 3 studies are ongoing to confirm these findings.

A total of 10 clinical studies are being conducted on a parallel track across the U.S., Europe and Africa in support of potential eventual registration for the Ebola vaccine regimen. The first study of the vaccine regimen in a West African country affected by the recent Ebola outbreak began in Sierra Leone in October 2015.

In September 2016, Janssen completed a submission to the World Health Organization (WHO) for Emergency Use Assessment and Listing (EUAL) for the investigational preventive Ebola prime-boost vaccine regimen. 

Janssen in partnership with Bavarian Nordic rapidly scaled up production of the vaccine regimen and now has approximately 1,800,000 regimens available, with the capacity to produce several million regimens if needed.

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