An effective vaccine to protect against the Mers virus is a step closer, a report in the journal Science suggests.

European scientists genetically modified a version of the smallpox vaccine to display Mers virus protein on its surface.

The vaccine was able to protect camels - the animal reservoir for the virus - from developing Mers virus symptoms.

Experts hope the vaccine might stop the virus spreading in camels and may also protect humans at risk from infection.

Mers-coronavirus infection of humans was first described in Saudi Arabia in 2012. Since then there have been more than 1,600 reported cases. More than a third of reported infections have resulted in death.

Individuals with other illnesses - such as diabetes, long term lung disease or kidney failure - are particularly prone to developing life-threatening symptoms.

Virus spread is limited to people who have close contact with those who are infected, such as family members and healthcare workers.

Mers: The new virus explained

Infections have been reported in 26 countries around the world with the outbreak epi-centre located in the Arabian Peninsula.

There are no treatments for Mers but scientists are trying to develop an effective vaccine.

One such scientist is Prof Bart Haagmans, who is based at the Erasmus Medical Centre in the Netherlands. He has been busy developing and testing vaccines in camels.