Of the more than 18 million AstraZeneca coronavirus vaccine doses administered in Britain, only around 30 cases of blood clots were reported, British regulators have said.The new number of cases is 25 more than what was reported last month.Britain's Medicines and Healthcare products Regulatory Agency (MHRA) on Thursday described the risk of blood clots associated with the vaccine as "very small," dpa news agency reported.As of March 24, a total of 22 cases of cerebral vein thrombosis and eight other types of thrombosis had been reported, the agency said.Another document from the authority listed a total of 24 cases of cerebral vein thrombosis, without providing details about the discrepancy."On the basis of this ongoing review, the benefits of the vaccines against Covid-19 continue to outweigh any risks and you should continue to get your vaccine when invited to do so," the regulator said.In total, more than 31 million people in Britain have received the first dose of the vaccination, more than 18 million of them with AstraZeneca.The number of cases has improved significantly, with the seven-day incidence figure at 55 per 100,000 inhabitants.Two Covid-19 vaccines, Pfizer/BioNTech and Oxford University/AstraZeneca, are currently being used in the UK.