As Saudi Arabia Grapples With MERS Outbreak, a Vaccine Is in Sight

Just one month before the beginning of the hajj, the annual pilgrimage of more than 2 million Muslims to Mecca, an outbreak of Middle East respiratory syndrome (MERS) in Saudi Arabia’s capital of Riyadh has sparked fears that the country could become the epicenter for a global health crisis. In the span of a week, Riyadh has seen more than 40 cases of the disease, 15 of them affecting health workers. Three people have died, and the outbreak has forced the closure of the emergency ward at King Abdulaziz Medical City, one of the country’s largest medical facilities.

But amid fears that the annual arrival and departure of pilgrims could spread the virus around the globe, researchers at the University of Pennsylvania have made a breakthrough in the fight against MERS, which has claimed over 480 lives since it was discovered in 2012. A team led by David B. Weiner, Ph.D., announced Wednesday it has developed an experimental vaccine able to protect 100 percent of test cases in an animal study. As camels are thought to be a major source of transmission to humans, an animal vaccine could be a major step forward in preventing the disease.

A human vaccine, however, is likely further off. Trials for a human version are expected to start later this year, meaning that the discovery will likely be of little help to Saudi during the hajj, which starts this year on Sept. 20.

Fears that the hajj could facilitate the virus’s global spread are amplified by its rapid transmission. During the outbreak in South Korea that began in May, one single case infected 181 others through “rapid human-to-human transmission … with in-hospital transmission the most common route of infection,” according to a press release from Weiner’s team.

The arrival in Saudi Arabia of travellers from more than 180 countries — and the subsequent crush of disparate crowds towards Mecca — is one of the largest gatherings of people on Earth, and has in the past acted as a massive petri dish. A study conducted by the Saudi Ministry of Health, in concert with French researchers, found that one-fifth of pilgrims carried viruses at the beginning of the hajj — a figure that nearly doubled by the end of the annual pilgrimage.

Still, the international transmission of serious virus outbreaks via travellers have been contained before reaching the point of catastrophe. Fears of a global Ebola outbreak last year, like MERS the year before and SARS in 2009, never emerged.

Last year, the Saudi Ministry of Health administered doses of polio vaccines to more than 172,000 pilgrims and vaccinated another half-million against meningitis. It also deployed 22,000 medical workers to Mecca and Medina. This July, the health ministry announced that meningitis vaccination would be a mandatory requirement for obtaining a hajj visa.

Photo credit: MOHAMMED AL-SHAIKH/AFP/Getty Images