The World Health Organization (WHO) hopes to be able to fast-track the testing of various Marburg candidate vaccines following outbreaks of this rare and deadly viral haemorrhagic fever in Tanzania and Equatorial Guinea.

“WHO is leading an effort to evaluate candidate vaccines and therapeutics in the context of the outbreak,” WHO Director General Dr Tedros Adhanom Ghebreyesus told a media briefing on Thursday.

“The developers are on board the clinical trial protocols are ready. The experts and donors are ready. Once the national government and the researchers give the green light,” he added.

Four or five candidate vaccines already have doses ready for human trials, WHO’s Dr Ana Maria Restrepo told a media briefing.

Restrepo, who heads the WHO’s R&D Blueprint team, said that a Marburg consortium had been working together since the Equatorial Guinea outbreak had been confirmed in January.

“We are working through a platform that is cooperative that involves all the regulatory and ethics committees in Africa,” stressed Restrepo.

There are 28 potential candidate vaccines for Marburg, according to WHO R&D Blueprint. The virus is from the same family as Ebola and has an 88% fatality rate.

“Marburg belongs to the same family of viruses as Ebola, causes similar symptoms, transmits between humans the same way and like Ebola, has a very high fatality ratio,” warned Tedros.

“In the meantime, we’re not defenceless. Careful contact tracing isolation and supportive care are powerful tools to prevent transmission and save lives.”

Tanzania reports first-ever outbreak

Meanwhile, Tedros said that Tanzania had confirmed eight cases, including five deaths, by testing samples at a WHO-supported mobile laboratory set up last year “to prepare for viral haemorrhagic fever outbreaks, including Ebola and Marburg”.

National responders, WHO and the US Centers for Disease Control and Prevention (CDC)  “have been deployed to the affected region to carry out further investigations, monitor contacts and provide clinical care,” added Tedros.

A week ago, Tanzanian health authorities initiated a frantic search for the cause of the mysterious disease that had claimed several lives in the country. 

Five of the eight cases, including a health worker, have died and the remaining three are receiving treatment. A total of 161 contacts have been identified and are being monitored.

Tanzania Chief Medical Officer Tumaini Nagu said multiple isolation units to help monitor and isolate people displaying symptoms are now operational. 

“The government is closely monitoring the situation and taking appropriate measures to contain the disease,” Nagu told Health Policy Watch.

Lack of capacity

Equatorial Guinea has struggled to identify cases because of a lack of laboratory capacity but had confirmed nine cases with a further 20 probable cases. 

The first case from the eastern province of Kié-Ntem was confirmed in early February by the Institute Pasteur in Senegal. Two other people from Kié-Ntem province were diagnosed by a mobile laboratory at the Regional Hospital of Ebibeyin. 

A month later another case was identified in Litoral province in the western part of the country that was epidemiologically linked to a confirmed case in Kié-Ntem, while cases have also been confirmed in Centro Sur province.

The wide geographic distribution of cases and uncertain epidemiological links between cases “suggests the potential for undetected community spread of the virus”, according to WHO.

The provinces that share international borders with Cameroon and Gabon, and the WHO is working with those countries identify any potential cases, Tedros confirmed.

At the Africa CDC press briefing on Thursday, acting director Dr Ahmed Ouma, said the center is providing Equatorial Guinea with needed technical support, infrastructural development and capacity building required to test for Marburg virus disease. 

“The government is responsible for the testing and to release those results to us,” he said, adding that the turnaround time for result is currently five days and this is being improved upon by the authorities and partners.

“The capacity is still being built,” he said. “The main lab is still not fully functional. We are finalizing calibration this week. And that main lab should be up and running in a few days as soon as the calibration and capacity building is done. And I think before the middle of next week when all that has been completed, they should be up and running. And that will make it easier to do more samples and [will be] a little bit faster.”

Meanwhile, health authorities are expecting genomic analysis results soon to see whether there is any connection between the outbreaks in Equatorial Guinea and Tanzania.

Dr Matshidiso Moeti, WHO Regional Director for Africa, said that gene sequencing analyses are being conducted in both countries to reveal any possible connections for both outbreaks. “We know that the world is interconnected in many ways, [but] the likelihood is not that high,” Moeti told journalists.

“The confirmation of these new cases is a critical signal to scale up response efforts to quickly stop the chain of transmission and avert a potential large-scale outbreak and loss of life,” said Moeti. “Marburg is highly virulent but can be effectively controlled and halted by promptly deploying a broad range of outbreak response measures.”

At the Africa CDC press briefing on Thursday, acting director Dr Ahmed Ouma, said the center is providing Equatorial Guinea with needed technical support, infrastructural development and capacity building needed to test for Marburg virus disease. 

“The government is responsible for the testing and to release those results to us,” he said, adding that the turnaround time for result is currently five days and this is being improved upon by the authorities and partners.

“The capacity is still being built,” he said. “The main lab is still not fully functional. We are finalizing calibration this week. And that main lab should be up and running in a few days as soon as the calibration and capacity building is done. And I think before the middle of next week when all that has been completed, they should be up and running. And that will make it easier to do more samples and [will be] a little bit faster.”

Image Credits: Muhidin Issa Michuzi.