LONDON (Reuters) - Britain has authorised the temporary use of the Flublok flu vaccine and ordered millions of doses as it seeks to give jabs to more people during the coronavirus pandemic. A surge in demand for vaccines to ward off winter flu has led to shortages in some European cities, raising the risk of a potentially lethal “twindemic” as COVID-19 cases spike. Britain is targeting the vaccination of more than 30 million people, nearly half the population, and said it had given authorisation for the supply of Flublok, which has been used in the United States for the last three winters. “Flublok has been in regular use in the United States – and the evidence shows that it is an excellent product,” deputy Chief Medical Officer Jonathan Van Tam said. “I want to reassure everyone that all vaccines have undergone robust clinical trials and rigorous checks by the regulator to ensure they are safe, effective and of a high quality.” Flublok received authorisation for temporary supply from the Medicines and Healthcare products Regulatory Agency (MHRA). The MHRA has the power to take such a step when it is satisfied that a medicine is safe and effective in response to a public health threat. The regulator has been given extra powers during the course of the pandemic, such as being able also to temporarily authorise any coronavirus vaccine that meets safety and quality standards before it has received a full licence.