After more than 18 million people have received vaccinations with AstraZeneca's jab in the UK, the country's health regulator said seven people had died due to rare blood clots, although the cause remains unclear."The benefits in preventing a Covid-19 infection and its complications continue to outweigh any risks and the public should continue to get their vaccine when invited to do so," dpa news agency quoted June Raine, Chief Executive of the Medicines and Healthcare Regulatory Agency (MHRA), as saying.The MHRA previously said there had been 30 cases of rare blood clot events reported out of the 18.1 million AstraZeneca/Oxford vaccine doses administered in Britain.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, noting that here too, it was unclear whether these were connected.Reports of unusual blood clot cases in patients who have received the AstraZeneca vaccine have led some national regulators to place restrictions on who can receive the jab.Canada, for instance, suspended use for those under the age of 55 while Germany has largely halted the jabs for those under 60.Britain has said the vaccine is safe for all age groups.The European Medicines Agency, an EU regulator, said the vaccine is safe, although it is planning more consultations in the wake of the decisions by national health officials.Meanwhile in Britain, more than 31 million people 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.There has also been a significant fall in the number of daily deaths.