China admits CoronaVac inefficacy after Turkey inoculates millions

Reuters

China's top disease control official said on April 10 that the country is formally considering mixing COVID-19 vaccines as a way of further boosting vaccine efficacy, although Ankara has already inoculated millions of citizens with the Chinese CoronaVac. 

Available data shows Chinese vaccines lag behind others including Pfizer and Moderna in terms of efficacy, but require less stringent temperature controls during storage.

Giving people doses of different vaccines is one way to improve vaccines that "don't have very high rates of protection", Gao Fu, the director of the Chinese Centers for Disease Control and Prevention, said on April 10, without specifying whether he was referring to foreign or domestic vaccines

"Inoculation using vaccines of different technical lines is being considered," Gao told a conference in the Chinese city of Chengdu.

Gao said that taking steps to "optimise" the vaccine process including changing the number of doses and the length of time between doses was a "definite" solution to efficacy issues.

Two injections of a vaccine developed by China's Sinovac Biotech, when given shorter than three weeks apart, was 49.1% effective based on data from a Phase III trial in Brazil, below the 50% threshold set by World Health Organization, according to a paper published by Brazilian researchers on Sunday ahead of peer review.

But data from a small subgroup showed that the efficacy rate increased to 62.3% when the doses were given at intervals of three weeks and longer. The overall efficacy rate for the vaccine was slightly above 50% in the trial.

China has developed four domestic vaccines approved for public use and a fifth for smaller-scale emergency use. An official said on April 10 that the country will likely produce 3 billion doses by the end of the year.

No detailed efficacy data has been released on vaccines made by China's Sinopharm. It has said two vaccines developed by its units are 79.4% and 72.5% effective respectively, based on interim results.

Both vaccine makers have presented data on their COVID-19 vaccines indicating levels of efficacy in line with those required by WHO, a WHO panel said in March.

China has shipped millions of its vaccines abroad, and officials and state media have fiercely defended the shots while calling into question the safety and logistics capabilities of other vaccines.

"The global vaccine protection rate test data are both high and low," Gao told state tabloid Global Times on April 11.

"How to improve the protection rate of vaccines is a problem that requires global scientists to consider," Gao said, adding that mixing vaccines and adjusting immunisation methods are solutions that he had proposed.

Gao also rejected claims by some media reports that he said Chinese COVID-19 vaccines have a low protection rate, telling Global Times that it was "a complete misunderstanding." 

Turkey - which has the highest level of daily new COVID-19 cases in Europe and the Middle East - again tightened measures last week to contain the rapid spread after calls for action by doctors and opposition politicians.

Turkey has administered around 18 million doses of COVID-19 vaccines so far, roughly enough to cover about 11% of the population, according to a Reuters tally.

The government has dismissed criticisms over its handling of the pandemic and the measures it has implemented, saying public health is the priority.

It has adopted fresh stay-at-home orders for weekends and will halt dining at restaurants starting Tuesday for the Islamic fasting month of Ramadan.

But the country has remained largely open for business since last June and many have hit the streets and cafes as the weather has warmed - worrying some who have stayed home.

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