Photo: Xinhua

By THÉRÈSE MARGOLIS

Despite not having yet been approved by any international health organization or having had its Phase 3 clinical trials published or peer-reviewed by external sources, Mexico on Wednesday, Feb. 10, approved emergency use of the controversial Chinese CanSino covid-19 vaccine.

Produced by the Beijing-based CanSino Biologics, the still-experimental one-shot vaccine is alleged by China to have a 65.7 percent efficacy rate for preventing contraction of the disease and a 90.98 percent efficacy rate in preventing severe symptoms, based on initial studies conducted in China on members of the Chinese Army. (A vaccine must have at least a 50 percent protection rate to be considered effective.)

Notwithstanding, besides only requiring a single dose to be administered, the less costly (as compared to the more universally recognized Pfizer, Moderna and AstraZenica alternatives) CanSino vaccine does not require deep-freeze storage, a key concern for the logistics of distribution.

Also it is less likely to go bad if optimum storage conditions are not maintained.

Unlike the cutting-edge messenger RNA (mRNA) Pfizer and Moderna vaccines — which use a specially designed RNA that is injected into the body to trick it into producing an immune response rather than a deactivated form of the live virus — the CanSino AD5-nCOV vaccine usea a traditional adenovirus vector to deliver a coronavirus antigen.

CanSino Biologics has said that its vaccine has no serious adverse effects and that it will continue to advance its Phase III clinical trials of the vaccine.

Although CanSino Biologics got the drop on Western vaccines by being the first in the world to begin human clinical trials in China last March, the company had problems on an international level because of a political spat between China and Canada, which had initially agreed to cosponsor the drug’s trials.

Also, because China has been reluctant to release its research data for international review, Chinese vaccines have faced considerable global skepticism due to confusion over efficacy rates and a lack of transparency.

These issues have threatened to undermine trust in the vaccines that Chinese President Xi Jinping had promised to share with the rest of the world as a global public service.

However, CanSino Biologics is expected to release the interim data of its Phase 3 clinical trials later this week, after they are unblinded.

CanSino’s Phase 3 clinical trials allegedly included more than 40,000 volunteers in 78 clinical trial sites across five countries, including Mexico.

CanSino has agreed to supply 35 million doses of its vaccine to Mexico.

CanSino Biologics is currently working to get approval from the World Health Organization (WHO) for its vaccines so that it can be distributed through the United Nations Covax Facility program.

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