How Ebola brought the world together, helped birth a blueprint for virus control
Among the lessons to be learnt from the outbreak of 2014 - 16, is that countries can address shared healthcare challenges when they work together, cut the red tape.health Updated: Oct 21, 2017 21:42 IST
The rVSV-ZEBOV vaccine against Ebola has got the World Health Organization (WHO) nod after it was found to protect against the virus in a large trial in Guinea in West Africa.
The vaccine was tested in Guinea’s coastal region of Basse-Guinée, which was still experiencing new Ebola cases when the trial started in 2015.
It was found to be 100% effective in preventing infection in the trial that involved 11,841 people. None of the 5,837 people vaccinated developed Ebola, while 23 of those who were not vaccinated developed the disease.
The vaccine does not contain any live Ebola virus and works by replacing a gene from a harmless virus known as vesicular stomatitis virus (VSV) with a gene encoding an Ebola virus surface protein.
Vaccinators used the ‘ring vaccination’ approach that was used to eradicate smallpox, where the people at most risk — healthcare workers in the hot zone and the initial and secondary contacts of those infected with Ebola — were vaccinated to stop further spread of the disease.
rVSV-ZEBOV was developed by the Public Health Agency of Canada (PHAC) and licenced to NewLink Genetics, which further licenced it to pharmaceutical company Merck.
The development was funded by WHO, with support from the UK-based biomedical research charity Wellcome Trust, the governments of the UK, Norway and Canada, Médecins Sans Frontières (MSF), and other international partners.
These partnerships enabled faster regulatory review from the US Food and Drug Administration and European Medicines Agency in 2016. An agreement between GAVI, the Vaccine Alliance and Merck made 300,000 doses of the vaccine available.
“The unprecedented partnership and the speed at which it was done should be the model for public health organisations to come up with a vaccine to prevent future outbreaks,” said Dr Beth Ann Griswold Coller, molecular biologist and executive director of global clinical development at Merck.
On average, vaccine development takes 10 to 15 years, but in this case, clinical trials were done in less than two years.
“What helped was that we had a candidate. The PHAC invented the vaccine and did the early development work, so when the West Africa outbreak occurred in 2014, the clinical supplies were ready to be deployed. The Phase 1 trial was in October 2014 and the Combined Phase 2 and Phase 3 clinical trials designed to assess the safety and efficacy took place in February 2015,” said Dr Coller, speaking last week at the Uppsala Health Summit on Tacking Infectious Disease Threats, in Sweden.
Building on the work done to fast-track the development and testing of this vaccine, the WHO published an R&D Blueprint to help cut the time taken in future, to develop vaccines and drugs against new and emerging infectious diseases, including Lassa Fever and MERS-Coronavirus.
“The vaccine is now waiting for a licence, which should come by 2020. In May 2017, the Democratic Republic of the Congo (DRC) approved the use of the unlicenced vaccine under an MSF protocol for vaccination, but the country controlled the outbreak without vaccination,” said Dr Coller.
On 2 July 2017, the WHO declared the end of the last wave of Ebola in the DRC. A total of eight were infected this time, four of whom survived the disease.