London, Feb 11 : British Prime Minister Boris Johnson on Wednesday called on around 2 million people in Britain's most vulnerable groups to come forward and get their Covid vaccines. Speaking at a virtual Downing Street press briefing, Johnson stressed that Covid vaccines are "safe and effective", the Xinhua news agency reported. "Great strides" have been made in Britain's vaccine rollout, said Johnson. More than 13 million people in Britain have been given the first jab of the coronavirus vaccine, according to the latest official figures. More than 90 per cent of everyone aged over 75 and more than 90 per cent of eligible residents of care homes have received their first jabs, he said. However, around 2 million people in the most vulnerable groups in Britain have still to be reached, according to Johnson. Britain aims to complete the vaccination of the top priority groups, which cover 15 million people, by mid-February. Johnson said his call is not to help the government reach its "numerical target" for February 15, but rather to "save lives, prevent serious illness and so the whole country can take another step on the long and hard road back to normality". Meanwhile, the Prime Minister reiterated that he will set out more details on the roadmap for exiting lockdown restrictions in the week of February 22. Also at the press briefing, the British government's Chief Scientific Adviser Patrick Vallance said that the number of people testing positive is falling, but is still high. Another 13,013 people in Britain have tested positive for Covid-19, bringing the total number of coronavirus cases in the country to 3,985,161, according to official figures released Wednesday. The country also reported another 1,001 coronavirus-related deaths. The total number of coronavirus-related deaths in Britain now stands at 114,851. These figures only include the deaths of people who died within 28 days of their first positive test. England is currently under the third national lockdown since the outbreak of the pandemic in the country. Similar restriction measures are also in place in Scotland, Wales and Northern Ireland. To bring life back to normal, countries such as Britain, China, Germany, Russia and the US have been racing against time to roll out coronavirus vaccines. /IANS