China’s Second Coronavirus Vaccine Still 20% Less Effective than Pfizer Option

This May 2020 picture shows a laboratory technician holding a dose of a COVID-19 vaccine candidate ready for trial on monkeys at the National Primate Research Center of Thailand. (Mladen Antonov/AFP via Getty Images)
Mladen Antonov/AFP via Getty Images

Chinese pharmaceutical company Sinopharm announced Wednesday that Phase III clinical trials found their Chinese coronavirus vaccine candidate to be 72.51 percent effective in preventing infections.

The number is significantly higher than the only Chinese-made vaccine widely approved internationally, “Coronavac” by the company Sinovac, which studies found to be 50.38 percent effective. It is still significantly lower than the vaccines produced by American pharmaceutical companies. Studies show the first vaccine approved by the U.S. Food and Drug Administration (FDA), from Pfizer, to be about 95 percent effective in preventing infections. The second, by the pharmaceutical company Moderna, was found to be about 94.1 percent effective.

Chinese state media has repeatedly attacked the Pfizer vaccine, citing Communist Party-approved experts urging the world not to approve it, while declaring Coronavac “good enough.”

According to the Chinese state outlet Global Times, the Sinopharm vaccine candidate – tested in Wuhan, the origin location of the Chinese coronavirus – requires two doses to achieve its 72 percent efficacy. It uses inactivated viral cells, a different method than the mRNA process used by Pfizer and Moderna. The Chinese government approved the Sinopharm vaccine on Wednesday.

“So far, data from the trials shows that the vaccine can trigger high-titer antibodies in recipients. The neutralizing antibody positive conversion rate reached 99.06 percent after two shots, according to the institute,” the state media outlet reported.

Like Sinopharm, Sinovac initially claimed that its vaccine candidate was highly effective. Initially, Sinopharm’s development partners in Brazil, the Butantan Institute, claimed the vaccine candidate had a 78 percent efficacy. The company later clarified that the number “only included volunteers who suffered mild to severe cases.” The vaccine was only about 50 percent effective in general including those individuals who became infected and contracted “very mild” cases of coronavirus, developers said.

“The vaccine was able to 100 percent prevent severe illness in such a high-risk population, and effectively control the morbidity, and protect at least 50% of people from infection, which is good enough,” a Chinese government-approved infectious disease expert told the Global Times in January.

The American vaccines have proven through several studies that they can prevent infections more efficiently than the Chinese options. The reportedly less effective American vaccine, Moderna’s, protected 94.1 percent of people participating in its trial after a second dose. Pfizer’s protected recipients at a 95 percent rate.

More recently, a study by the Mayo Clinic published this week found the first shot alone of the Pfizer or Moderna vaccines had up to an 83 percent efficacy. The study echoed findings from the Sheba Medical Center in Tel Aviv, which found the Pfizer vaccine to be 75 percent effective two to four weeks after recipients received the first dose.

A third American vaccine candidate, by the New Jersey company Johnson & Johnson, is also in development. The FDA announced on Wednesday it found the Johnson & Johnson candidate had “a favorable safety profile with no specific safety concerns” with 66 percent efficacy. Unlike the Pfizer and Moderna options, the vaccine candidate requires just one dose and does not need to be frozen. The Moderna vaccine requires securing in freezing temperatures. The Pfizer vaccine must be stored between -80ºC and -60ºC (-112ºF to -76ºF), though the FDA may soon approve temperatures possible in standard freezers.

In contrast to its forgiving coverage of the Chinese vaccine candidates, the Global Times has repeatedly published stories questioning the safety of the Pfizer vaccine. The Times has accused the vaccine of threatening the health of the elderly – who many nations have prioritized for receiving vaccinations – and quoted Chinese health experts urging Western nations not to administer it.

Last week, the Global Times claimed that government-approved “experts” “believe it’s [the Pfizer vaccine] too risky and pregnant women should not get any vaccination for trials.”

The newspaper condemned Pfizer studying the effects of its vaccine on pregnant women, claiming that “netizens,” or social media users whose opinions the government has approved, “questioned whether it’s ethical to run tests on pregnant women.”

Multiple reports and eyewitness testimonies indicate that the Chinese Communist Party regularly forces pregnant women to undergo abortions if they belong to persecuted ethnic groups or have already had their legally allotted two children.

Shanghai Fosun Pharmaceutical Group, which owns Sinopharm, announced in December it would purchase 100 million doses of the Pfizer vaccine from the American company’s European partner, BioNTech.

A poll released this week shows less than half of China’s health care workers want to take the Chinese coronavirus vaccine.

Follow Frances Martel on Facebook and Twitter.

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