Merck’s Ebola vaccine proves effective

A vaccine for the Ebola virus – the first of its kind in the disease’s 40-year recorded history – shows promise in trials in Guinea, according to a report released Friday in the medical journal Lancet.

What Dr. Keita is referring to is the Phase 3 trials results in Guinea of the Merck, Sharp & Dohme investigational Ebola vaccine, rVSV-ZEBOV.

“After a poorly managed global response to the Ebola outbreak last year, news of the phenomenal successes of these vaccine trials in Guinea-100% efficacy in a trial cohort of 4,000 patients-is simply tremendous”, said Michael Weinstein, President of AIDS Healthcare Foundation.

Data from a trial of an Ebola vaccine known as VSV-EBOV developed by Merck and NewLink Genetics are expected to be published later on Friday. The randomization was stopped on Sunday “to allow for all people at risk to receive the vaccine immediately, and to minimize the time necessary to gather more conclusive evidence needed for eventual licensure of the product”, the WHO said. The vaccine comprises of a fragment of the Ebola virus and another safer virus so that the immune system can be trained to beat the Ebola virus.

Researchers say that for both groups – those who got the vaccine immediately and those who received it after a delay – no new Ebola cases were diagnosed starting at six days after vaccination.

The national regulatory authority and ethics review committee of Guinea have approved the continuation of the trials in the country. He said further tests would be necessary to see if the vaccine might also protect pregnant women, children and adolescents; those trials are already under way. “It will change the management of the current Ebola outbreak and future outbreaks”.

Because of the Ebola crisis, a large team was assembled which included scientists, physicians, epidemiologists and other experts from WHO, Norway, Canada, Guinea, Doctors without Borders, the Universities of Florida, Maryland and Bern, and the London School of Hygiene & Tropical Medicine.

Other Ebola vaccines are being studied elsewhere but the declining caseload – there were just seven new patients reported in West Africa last week – is complicating efforts to finish the trials.

All 33 contacts in Liberia who have been followed up since the latest infections there are two days from completing the 21-day period to be declared free of the disease. The rings, or clusters, were randomized; in 48 of them, vaccination occurred as soon as possible after the detection of the Ebola case in their community. This entails that the first people to be vaccinated are those that have been in close contact with a person infected by Ebola.

At a media telebriefing in Geneva today, WHO Director-General Margaret Chan, MD, MPH, noted that over the past few months several groups have weighed in on outbreak response.

Another WHO reform focus is on spearheading research and development work on vaccines, medications, and diagnostic tests, Chan said. After bouncing back to society with a clean bill of health, Dr. Spencer is back in Guinea to treat patients with the hope that an experimental vaccine would be the answer to the medical woes of a region decimated by the deadly virus.

“The United Nations remains steadfast in its commitment to supporting the Governments of Guinea, Liberia and Sierra Leone in getting to and staying at zero cases”, the UN chief said.