Coronavirus could kill 45 million people as it is dubbed a ‘greater global threat than terrorism’, experts have warned.

Experts believe each person that tests positive with the virus will go on to infect 2.5 more people, meaning such a high ‘attack rate’ could infect 60 per cent of the world’s population if it is not controlled.

Professor Gabriel Leung, chair of public health medicine at Hong Kong University, warned those infected who have never visited China could be just the ‘tip of the iceberg’.

His warning came as the World Health Organisation (WHO) called the virus, which has been officially named COVID-19, ‘the worst enemy you can ever imagine’ and that it poses a greater global threat than terrorism.

WHO officials urged the world to ‘wake up’ and be as aggressive as possible in efforts to tackle the spread of the virus which has so far infected more than 44,600 people and killed at least 1,100.

Dr Tedros Adhanom Ghebreyesus said it would still be another 18 months until a vaccine is ready. He said: ‘To be honest, a virus is more powerful in creating political, social and economic upheaval than any terrorist attack.

It’s the worst enemy you can imagine.’ Dr Ghebreyesus added that 99 per cent of cases are in China, meaning the virus ‘remains very much an emergency for that country, but one that holds a very grave threat for the rest of the world’.