The US Food and Drug Administration (FDA) yesterday announced it has approved Merck's Ebola vaccine, a key development that brings a licensed vaccine to the market for public health preparedness.
In other Ebola developments, two new cases were reported in the Democratic Republic of the Congo (DRC) outbreak, as the World Health Organization (WHO) noted that young children in the affected areas aren't as likely to be referred to Ebola treatment centers as their older peers are.
FDA announcement caps 6-month review
The FDA completed its review of Merck's VSV-EBOV vaccine, known as Ervebo, in less than 6 months. The FDA had granted the application priority review and a tropical disease priority review voucher. It also granted a breakthrough therapy designation.
VSV-EBOV was developed by scientists at the Public Health Agency of Canada. In 2010, NewLink Genetics obtained marketing rights, and then in 2014, it signed a deal with Merck that helped advance the vaccine to clinical trials and scaled up manufacturing.
Shown to be highly effective in clinical trials in West Africa's outbreak, the vaccine has been used on an emergency basis in the DRC outbreak. The FDA approval comes a little more than a month after European regulators gave VSV-EBOV its final approval, which was quickly followed by prequalification from the WHO, which paved the way for United Nations agencies and Gavi, the Vaccine Alliance, to buy the vaccine for use in at-risk countries.
Peter Marks, MD, PhD, who directs the FDA's Center for Biologics Evaluation and Research, said in an FDA press release that the approval is a major advance in helping to protect against Ebola and helps advance US government preparedness efforts. "The research approach used to study the effectiveness and safety of this vaccine was precedent-setting during a public health emergency and may help create a model for future studies under similar circumstances," he said.
Roger Perlmutter, MD, PhD, president of Merck Research Laboratories, said in a company press release that the FDA approval marks another important milestone in the global response to Ebola and is a tremendous accomplishment by a unique global partnership. "I wish in particular to recognize the heroic efforts being made by frontline responders to the ongoing outbreak in the Democratic Republic of the Congo. We are proud and honored to play a role in supporting their vital activities, and we remain focused on the important work ahead," he said.
So far, Merck has shipped 275,000 doses of the vaccine, and 258,225 people have been vaccinated in the DRC's latest outbreak.
Merck said it has submitted VSV-EBOV licensing applications to regulatory authorities in African countries, which will allow it to be registered in countries at risk for Ebola outbreaks.
Cases back to small but steady rises
Two new cases have been reported in the DRC, raising the outbreak total to 3,356, according to the WHO's online Ebola dashboard. Health officials are still investigating 488 suspected cases.
The number of deaths held steady at 2,220.
The DRC's Ebola technical committee (CMRE) in its latest daily update noted that all 3 cases reported yesterday were in Mabalako, one of the few remaining hot spots.
Issues surrounding children's care
In its weekly snapshot of the outbreak yesterday. the WHO said all 11 cases for the week ending Dec 17 are linked to a case in Mabalako's Aloya health area involving a patient who had what appears to be a rare relapse of the disease.
And, in the wake of security incidents a few weeks ago, response indicators have mostly returned to earlier levels, the agency said.
Also, the WHO provided some in-depth analysis on Ebola care in children, and age-group accounting for more than a quarter of patients in the outbreak. Of people who died in the community, a higher percentage involve younger children—those up to age 4—than older children.
Though children with Ebola symptoms are taken to health facilities sooner than adults are, the proportion of kids referred to Ebola treatment centers is lower than among adults. The WHO said that, of patients admitted to health facilities, 38% of kids ages 1 to 4 and 32% younger than 1 year die outside of Ebola treatment centers (ETCs) without referral, compared with 15% of adults.
Reasons require investigation but may include healthcare workers not recognizing Ebola symptoms in children or parents' reluctance to transfer children to Ebola treatment centers.
"There are ongoing efforts to better understand healthcare workers knowledge, attitudes, and understanding of risk factors for transmission among children," the WHO said, adding that protocols are in place for kids treated in ETCs with pediatric equipment and specialists available. They also receive nutritional care and support from psychologists and are enrolled in treatment trials when consent is given.
Dec 19 FDA news release
Dec 19 Merck press release
WHO online Ebola dashboard
Dec 19 CMRE report
Dec 19 WHO update