Prime-boost vaccination involves giving an initial dose to prime the immune system, followed by a booster dose at a later date with the goal of potentially strengthening and optimising the duration of immunity.
‘We are confident that we have the potential to contribute to end the Ebola problem,’ says Johan van Hoof, global therapeutic area head, infectious diseases and vaccines, Janssen Pharmaceutical Companies headquartered in Belgium.
The immune system has been found to persist beyond one year, which is pretty good, van Hoof notes.
Last month (12 September), big pharma Johnson & Johnson, announced that its subsidiary Janssen Vaccines & Prevention B.V, has submitted its investigational preventive Ebola prime-boost vaccine regimen to the World Health Organization (WHO) to be used in such instances.
This was announced at the 8th International Symposium on Filoviruses in Antwerp, Belgium, hosted by the Antwerp Institute of Tropical Medicine, last month (12-15 September). The symposium focused on the 40-year history of Ebola.
‘If listed for emergency use, the investigational Janssen vaccine regimen could be a vital prevention tool for rapid outbreak response,’ van Hoof explains. It has already been tested in animal models and for safety.
The application is considered under the WHO Emergency Use Assessment and Listing (EUAL) procedure to fast-track R&D for potential Ebola diagnostics, treatments and vaccines.
‘Over the past four decades, we have seen 25 Ebola outbreaks, with the most recent in West Africa killing seven times more people than all previous outbreaks combined,’ says Paul Stoffels, the chief scientific officer, Johnson & Johnson, in statement released last month (12 September). ‘If the WHO grants an emergency use listing, this will accelerate the availability of Janssen’s investigational vaccine regimen to the international community in the event another Ebola crisis occurs.’
However, even if WHO approved it, the national regulatory authorities would have to look at the data to gain a level of comfort and decide if they want to use the vaccine, van Hoof says.
While EUAL potentially allows for deployment of a vaccine in an emergency, the vaccine remains investigational pending formal regulatory agency review and approval.
‘As things stand now the vaccine cannot go to phase III because there is no place for it at the moment. I think this will be a poor understanding of science,’ says Omu Anzala, director, KAVI Institute of Clinical Research, and professor of virology and immunology, University of Nairobi, Kenya.
This story was produced by SciDev.Net’s Sub-Saharan Africa English desk.