LONDON (REUTERS) - British spies are trying to defend Covid-19 vaccine work against hostile powers who are seeking to either steal or sabotage research data in the race for the global prize of a jab that can provide immunity, the head of MI5 said on Wednesday (Oct 14).

Oxford University's vaccine candidate, which has been licensed to AstraZeneca, is in late-stage trials, while a vaccine candidate being developed by Imperial College London is in early-stage clinical trials.

"Clearly, the global prize of having a first useable vaccine against this deadly virus is a large one, so we would expect that a range of other parties around the globe would be quite interested in that research," Security Service director-general Ken McCallum told reporters.

Mr McCallum, in his first major remarks since being named as the new boss of MI5 in March, when Britain was under national lockdown, said there were a range of threats against the vaccine work.

"I guess there are two bits we are on the lookout for: attempts either to steal unique intellectual property that's been generated in that research or potentially to fiddle with the data," he said.

"And then the second risk we've got to be alive to is the possibility that the research is still high integrity and sound, but that somebody tries to sow doubt about its integrity."

Britain's National Cyber Security Centre (NCSC) said in July that hackers backed by the Russian state were trying to steal Covid-19 vaccine and treatment research from academic and pharmaceutical institutions around the world.

More than 150 potential vaccines are being developed and tested globally to stop the Covid-19 pandemic, with 42 in human trials, according to the World Health Organisation (WHO).

MI5, which traces its history back to 1909, when Britain tried to counter German espionage ahead of World War I, is tasked with protecting British national security. Its main job is currently countering international terrorism though it is also a counter-intelligence agency.