Tough road ahead for Chinese Covid-19 vaccine after a fall in efficacy rate

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Countries around the world are becoming increasingly skeptical of the Chinese Sinovac Biotech Covid-19 vaccine, the efficacy rate of which has reportedly fallen dramatically over the past few days. A latest study in Brazil, a country where the largest trial of the Chinese vaccine is being carried out, has revealed that the efficacy rate of the CoronaVac vaccine is just over 50 per cent, a massive fall from the 78 per cent initially projected.</p>
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The new revelation has put in a spot of bother countries like Thailand which has ordered two million doses of CoronaVac and others like Malaysia, Singapore, the Philippines, Chile, etc. who have also ordered vaccines from China and are now pondering over their next move. It was after carrying research with 12,500 volunteers in 16 scientific centers in Brazil that the Butantan Institute and the Government of Sao Paulo announced that the coronavirus vaccine achieved 50.38 per cent overall effectiveness when accounting for patients with "very mild" symptoms, a figure which barely exceeds the threshold established by the World Health Organization.</p>
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The institute however added that the vaccine was found to be fully effective in preventing severe cases. On the other hand, in comparison to the Chinese vaccine, those developed by Pfizer-BioNTech and Moderna have shown around 95 per cent efficacy at preventing Covid-19 illness and the AstraZeneca-Oxford vaccine's efficacy has been reported as 70.4 per cent.</p>
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Around a thousand people are dying every day in Brazil, a country with the third-largest caseload in the world, due to Covid-19 with Sao Paulo state alone recording 49,289 overall deaths due to the global pandemic till Thursday. The vaccine was developed by Butantan just over six months ago, in an international partnership with the biopharmaceutical company Sinovac Biotech, based in Beijing. In November, the scientific journal Lancet, one of the most important in the world, published the safety results of the Butantan vaccine in phases 1 and 2, carried out in China, with 744 volunteers.</p>
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The publication showed that the product is safe and capable of producing an immune response in 97 per cent of cases within 28 days after application. Butantan already has 10.8 million doses of the vaccine on Brazilian soil.</p>
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At the end of March, the total load of immunizers made available by the institute is estimated at 46 million doses. Meanwhile, Turkey and Indonesia have announced different efficacy rates of 91 percent and 65 percent, respectively for CoronaVac with trials on a much smaller group of people. No wonder than that countries like Thailand are in a state of confusion right now. "It's understood the Butantan Institute delayed announcing its results three times, which they say was due to a confidentiality clause in the contract with Sinovac.</p>
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The disparity in reporting has raised some questions about the Chinese vaccine, with concerns that it is not receiving the same level of scrutiny as those produced in Europe or the US," said The Thaiger, a Thailand news and information portal.</p>
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The Bangkok Post said that the Thai Ministry of Public Health has requested further information about the vaccine it has ordered from China following a report "it might not be as effective as first thought" even as it goes ahead with its plan to receive and administer the vaccine from Sinovac Biotech. "We are asking for information directly from Sinovac, so we are waiting for their response to get all the facts," Supakit Sirilak, Thailand's Director-General of Medical Science Department, was quoted as saying by the newspaper.</p>
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Singapore too has confirmed that the vaccine developed by China's Sinovac Biotech will have to go through regulatory scrutiny and authorisation by the country's Health Sciences Authority (HSA) before being rolled out for the public. "We will go through the data carefully when it comes, rather than depending on reported numbers. It's better to rely on official data that we receive from Sinovac itself," said Singapore's Health Minister Gan Kim Yong according to a report in <em>The Straits Times</em>.</p>