Several countries, including Indonesia, Turkey, and Singapore performing mass public vaccination programs using a Chinese coronavirus vaccine where tens of millions of people are expected to receive doses of the CoronaVac shot made by Beijing-based company Sinovac.
On Wednesday, Indonesian President Joko Widodo was shown receiving the country’s first CoronaVac shot, after the government authorized it for emergency use. While on Thursday, Turkish President Recep Tayyip Erdogan announced he had also received the vaccine.
Yanzhong Huang, a senior fellow for global health at the US-based Council on Foreign Relations and expert on the Chinese health care system stated that “Since many countries are planning to order, or have already ordered Sinovac’s vaccines, it might undermine people’s willingness to take them, because people may question the usefulness of the vaccines,”
Brazil has been one of the countries worst affected by Covid-19. Last week researchers at the Butantan Institute, which has been conducting the trials in Brazil, announced that the vaccine had a 78% efficacy against “mild-to-severe” Covid-19 cases. But as per new Brazilian clinical trials, CoronaVac results show the vaccine is significantly less effective than previous data suggested.
On Tuesday they revealed that calculations for last week’s figure did not include data from a group of “very mild infections” among those who received the vaccine that did not require clinical assistance.
With the inclusion of this data, the efficacy rate is now 50.4%, said, researchers. Which is far less effective than vaccines developed by Pfizer-BioNTech and Moderna, which have an efficacy rate of about 95%. Russia says its Sputnik V vaccine has an efficacy of 91%, while the UK’s vaccine, developed by Oxford University and AstraZeneca, has an average efficacy of 70%.
The latest news comes as Brazil is dealing with a major spike in cases. The country currently has the third-highest number of Covid-19 cases in the world at over 8.1 million, just behind the US and India.
Different efficacy rates.
Part of the confusion over Sinovac’s vaccine has been around different efficacy rates and the data made available.
Last month Turkish researchers said the Sinovac vaccine was 91.25% effective, they also approved the Sinovac vaccine for emergency use on Wednesday.
Data from Brazil, meanwhile, showed 50.38% efficacy for those who suffered very mild cases of Covid-19. But the rate rose to 78% for mild to severe cases.
while Indonesia, which rolled out its mass vaccination program on Wednesday, said it was 65.3% effective. Both were interim results from late-stage trials.
Prof. Lawrence Young, virologist and Professor of Molecular Oncology at the University of Warwick, said in a statement “It is difficult to interpret all this information without seeing the full datasets. This highlights the problem of issuing data by press release rather than publication in a peer-reviewed journal”.
It’s only possible with the full data from all trials of this vaccine are published that scientists can analyze its real efficacy. Only limited data for this Sinovac vaccine is currently available – and experts say that is confusing the picture.