The doctors who treated a Russian former spy and his daughter after they were poisoned with a nerve agent in Britain say they don't know what the pair's long term health outlook is - and initially feared the incident could have been much worse.
Sergei Skripal, a former colonel in Russia's military intelligence who betrayed dozens of agents to Britain, and daughter Yulia were found unconscious on a public bench in the southern English city of Salisbury on 4 March.