However, it should be noted that no phase 3 study, that is to say on tens of thousands of people, has been published on the effectiveness of these vaccines, unlike the British or American counterparts. The data available for the best known, CoronaVac, comes only from phase 1 and 2 clinical trials, published in November and February respectively, recalled a report of British Medical Journal, last Friday. A second Chinese vaccine, produced by the firm Anhui Zhifei Longcom, was the subject of a phase 2 study published in March. Both have obtained emergency approval from the Chinese authorities, as have those of the companies Sinopharm and CanSinoBIO, for which the only data available are those provided by the manufacturers.
To this end, the United Arab Emirates, where Sinopharm’s vaccine is used, spoke at the start of winter of an 86% effectiveness, while Turkey spoke of 91% with the CoronaVac. Brazil had instead estimated 79% in January with the latest vaccine, tested on 12,000 health workers.
But according to comments made on Saturday by Gao Fu, director of the Chinese Center for Disease Control, the effectiveness would not be “so high “And the authorities are said to be” taking into consideration “the possibility of reviewing the number of doses or using” different technological lines “. This last possibility has been interpreted, rightly or wrongly, as an open door to the development of a Chinese vaccine using messenger RNA technology, like the vaccines from Pfizer and Moderna.
There had already been red flags. The United Arab Emirates invited a number of those who had already received their second dose last month to go and receive a third one, after antibody tests revealed an immune response deemed insufficient. And as for Brazil, in a second report published this winter, it only mentioned an efficiency rate of 50%.
As of Sunday, Gao Fu’s words were censored on Chinese social media and this one declared in the state newspaper to have been misunderstood. It was indeed a rare admission coming from china who bet a lot, for four months, on the ” vaccine diplomacy ”—That is, the low-cost distribution of its vaccine in dozens of countries who are waiting for those from other rich countries. India and Russia are also engaged in this form of exchange. About sixty countries have approved the use of one or more Chinese vaccines on their territory, but distribution is still far from meeting demand.
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