A man wears a face mask in Seoul during the recent MERS epidemic (Image: JUNG YEON-JE/AFP/Getty Images)

Breathe easy, the South Korean public have been told. The outbreak of Middle East respiratory syndrome (MERS) is over. There have been no new cases for 24 days, and yesterday the prime minister urged people to resume “normal daily activities”. In total, the outbreak infected 186 people, killing 36.

The declaration came on the same day as two people suspected of having MERS in the UK tested negative. The two patients were admitted to Manchester Royal Infirmary on Monday, temporarily shutting the hospital’s emergency department.

There are currently no treatments for MERS, which can cause shortness of breath, fever and sometimes gastrointestinal problems. But progress is being made.


This week it was reported that an experimental vaccine seems to reduce symptoms of MERS in monkeys. The vaccine, the first to be tested in non-human primates, provoked the animals’ immune systems into producing antibodies that neutralised the virus.

However, it is difficult to tell how effective it really is because, unlike in people, the virus only triggers mild symptoms in the animals. “The controls didn’t become severely ill, so it isn’t possible to say with certainty how the data would translate to humans,” says Barney Graham of the US National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, who is involved in the vaccine’s development.

MERS doesn’t spread easily between people outside hospitals, so any approved vaccine would probably be given only to healthcare workers, and people working with camels – the suspected source of the virus. Another option is to vaccinate the camels themselves, says Graham.

Antibody option

A drug based on an antibody isolated from a person infected with MERS is also showing promise. It successfully neutralised several strains of the virus in mice, binding to a protein that helps the virus recognise and invade cells. Giving mice injections of the antibody before or after they were exposed to the virus reduced the number of viral particles in the animals’ lungs.

“The beauty of an antibody is that it can work immediately, so it can potentially cure individuals who are infected – although we still need to prove that,” says Antonio Lanzavecchia of the University of Lugano in Bellinzona, Switzerland, head of the team who developed the antibody. “In an acute situation, an antibody has distinct advantages over a vaccine, which takes several weeks to work,” he says. “But basically, you need both.”

“They are both important and both very welcome,” says Maria Zambon at Public Health England, whose team is also involved in the antibody development. “We hope to get a green light for testing its safety in people next year in London,” she says. The other advantage of the antibody, she adds, is that its immediate effect means it can be deployed in emergencies.

Journal references: Nature Communications, DOI: 10.1038/ncomms8712; Proceedings of the National Academy of Sciences, DOI: 10.1073/pnasx.151099112