China has for the first time released data on adverse reactions in recipients of coronavirus vaccines , reporting a very low rate of incidents. The Chinese Centre for Disease Control and Prevention said on Friday that among the 265 million doses given between mid-December and the end of April, there 31,500 cases of adverse events. That was equivalent to around 12 cases for every 100,000 doses. “The incidence rate of adverse reactions following [taking] the Covid-19 vaccines is lower than the average level of other vaccines in 2019,” the CDC said. “Current assessment shows that severe unusual reactions [globally] are extremely rare. The benefit of getting vaccinated against the coronavirus is much higher than the risk.” The CDC said mild reactions were the most common type reported, accounting for more than 80 per cent of the total. These included a temperature of over 38.6 Celsius and swelling. The rest of the cases were “unusual reactions”, including allergic rash, deep facial swelling, and severe allergic reactions. The vaccination drive was slow to take off in China, with the public initially hesitant to get the shots. But the campaign gathered momentum this month and by Thursday nearly 585 million doses had been administered. The doses comprise seven vaccines developed in China, including one by state-owned Sinopharm which was listed for emergency use by the World Health Organization this month. The CDC’s report came two days after Chinese drug maker Sinopharm published the interim results from a phase 3 trial of its Covid-19 vaccine . The 40,411 trial participants, mostly healthy adults aged 18 to 59, were equally divided into three groups, inoculated either with the vaccine from Sinopharm’s Beijing subsidiary, its Wuhan subsidiary or a placebo. Trial data showed a vaccine made by Sinopharm’s Beijing subsidiary could offer 78.1 per cent of protection against symptomatic Covid-19 but the rate dropped to 73.5 per cent after taking asymptomatic cases into account. A total of 142 symptomatic cases were recorded, 26 from the Wuhan vaccine group, 21 from the Beijing vaccine group, and 95 from the placebo group. Only two severe cases were identified in the placebo group, and none in the two vaccinated groups, which the researchers said did not provide enough data to make a conclusion. “These results should be interpreted with caution given the small number of incident severe cases,” the authors wrote. “Conclusions about prevention of severe cases cannot be made.” In Britain, by comparison, immunised people can voluntarily report suspected adverse reactions or side effects following vaccination to the regulatory agency, even if the person may not be not sure if it was caused by the jab. Up to May 19, British health authorities had analysed nearly 247,000 reports of suspected side effects after administering nearly 58.5 million doses.