While Singapore is busy administering the Moderna and Pfizer-BioNTech COVID-19 vaccines, China’s Sinovac vaccine still remains under review by the Health Sciences Authority (HSA).
More information has just surfaced in a study conducted in Brazil, though its accuracy is yet to be determined.
Key Brazilian Study Shows That China’s Sinovac Vaccine Can Reduce Risk of Symptomatic COVID-19 By 50%
According to Bloomberg, a key Brazilian study involving 9,823 volunteers was posted online, showing that the Sinovac Biotech Ltd’s coronavirus vaccine cut the risk of developing symptomatic COVID-19 by half.
The results of the study supported the findings from a larger Brazilian study last week, which found a 50% protection rate 14 days after the first dose of the Chinese vaccine.
This implies that two doses of the Sinovac shot have lower efficacy in preventing the virus as compared to the mRNA vaccines—like Moderna and Pfizer-BioNTech—which have been shown to prevent about 94% of infections.
The trial also found that the Sinovac was more effective at protecting against dangerous infections.
However, the study has not yet been reviewed by independent scientists.
The lower efficacy may be one reason some Chinese officials have floated the idea that the country’s vaccines may need to be given in combination with other shots.
Researcher Says Sinovac’s COVID-19 Vaccine Appears to be Safe, Can Trigger Immune Responses in Children
Sinovac gave the world some good news on 22 March, as it announced its vaccine appears to be safe and able to trigger immune responses among children and adolescents.
The preliminary findings were observed in Phase I and II clinical trials involving over 500 people between the ages of three and 17.
The subjects received two shots of either medium or low dosage of the vaccine, or a placebo.
Interestingly, the vaccine seemed to be most effective in children.
The lower dose of the vaccine was sufficient to trigger antibody responses in children three to 11 years old, while the medium dose worked well for those aged 12 to 17.
The antibody levels triggered in these children were higher than those seen in adults aged 18 to 59 and in elderly people in earlier clinical trials of the vaccine.
Most adverse reactions were mild. Some children experienced a high fever.
However, these preliminary results have not yet been published in a peer-reviewed medical journal.
HSA Reviewing Sinovac Vaccine; Will Not Be Used Without Authority’s Approval
HSA has started to review data on the Sinovac COVID-19 vaccine and has asked the biopharmaceutical company for more data.
The additional data is “required to assess if it can meet the required standards for quality, safety and efficacy for interim authorisation under the Pandemic Special Access Route,” said HSA.
The Pandemic Special Access Route allows early access to vital novel vaccines, medicines, and medical devices during a pandemic. Companies can only apply to HSA using this route for designated health products that the Singapore Government requires during a pandemic.
According to the Health Ministry’s director of medical services Kenneth Mak, HSA had designed a pandemic-specific approval framework that allowed vaccine companies to submit their data whenever it became available instead of waiting for the complete set of data.
Under the framework, HSA was able to approve of the Moderna and Pfizer-BioNTech vaccines just after, or even before they arrived due to the two companies submitting their data promptly.
Professor Mak noted that the process was in fact based on a timeframe that had already been planned for and committed to under the advanced purchasing agreements.
Unfortunately, as Sinovac did not submit their complete package of data, the vaccine’s evaluation was delayed.
Prof Mak also assured that the Sinovac vaccine will not be used until the HSA has approved it, “because we want to show all Singaporeans that the vaccines have been fully evaluated and deemed to be both effective and safe for us”.
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