China’s risky COVID-19 vaccine development strategy paid off

The WHO found that Sinovac’s inactivated COVID-19 vaccine is “safe, effective, and quality assured” in a two-dose regimen, Tedros Adhanom Ghebreyesus, director-general of the WHO, said in a statement on Tuesday. “It’s now crucial to get these lifesaving tools to the people that need them quickly,” he said.

Initial Phase III trial results showed that Sinovac’s vaccine is just over 50% effective in preventing COVID-19 infections. But real-world data suggests that its efficacy may be as high as 67% in preventing infections and 98% effective in preventing deaths related to COVID-19 vaccines.

Sinovac is the eighth COVID-19 vaccine to be authorized by the WHO, and the second Chinese COVID-19 vaccine to get the green light in under a month. The WHO approved a COVID-19 vaccine from China’s state-owned vaccine maker Sinopharm in early May.

China took an unorthodox and somewhat risky approach to developing its COVID vaccines, rolling them out at a blistering pace and with little transparency early on about their efficaciousness. But the WHO’s endorsement of the jabs confirms that the bets paid off. Now, with the WHO’s blessing, China is positioned to take a lead role in delivering vaccine supplies to the countries that need them most.

The process

In February 2020, China got off to the races in developing a viable COVID-19 vaccine when Chen Wei, epidemiologist and major general in the People’s Liberation Army, appeared on state-run television and injected herself with a COVID-19 vaccine the military developed in partnership with private maker Cansino that had yet to be tested on animals, let alone humans.

The move was an early indication that China’s approach to developing and distributing COVID vaccines would divert from the regimented clinical trial processes that places like the U.S. and Europe adhered to.

In July, China launched its controversial emergency use program, distributing doses from Sinovac, Sinopharm, and private Beijing firm Cansino to the Chinese population before the companies had completed Phase III trials to test how well the vaccines protected against the virus. By November 2020, Sinopharm alone reported that it had distributed over 1 million COVID-19 jabs to the public.

In September, nine Western vaccine makers banded together to explain that they would be as transparent as possible and not cut corners in vaccine development amid pressure from the Trump White House to speed up the process. The vaccine makers like Pfizer, Moderna, and Johnson & Johnson stuck to the clinical trial process, publishing results in peer-reviewed medical journals before seeking approval for distribution.

Sinopharm and Sinovac, meanwhile, provided little data about their vaccines beyond headline efficacy figures, even as they began widespread distribution in late 2020 and early 2021.

The lack of data dismayed some experts, but some foreign governments were quick to buy up doses and distribute the vaccines. As of Wednesday, Sinovac had distributed 340 million doses of its vaccine in China and roughly 260 million doses to 35 countries around the world, the company says. Sinopharm has provided less detailed information about the reach of its vaccine, but its shots have been distributed in over 60 countries, and the company expects to have the capacity to produce 5 billion doses per year by the end of 2021.

When the WHO approved Sinopharm’s vaccine in May, the firm had yet to publicly release preliminary or peer-reviewed data proving its safety and efficacy. Sinopharm has since released peer-reviewed Phase III data showing that its vaccine is safe and effective, but still, its vaccine gained approval without abiding by the long-standing practice.

“It’s a big deal because it was the first time ever a vaccine has been approved without the Phase III data being publicly peer-reviewed,” says Nicholas Thomas, a professor of global health governance at the City University of Hong Kong.

COVAX

The WHO approvals will help the two Chinese vaccine makers clear regulatory hurdles in getting their jabs into more countries around the world, and may pave the way for China to potentially lead the global effort to democratize access to the lifesaving supplies.

Notably, Sinovac and Sinopharm are now both eligible to distribute doses via the WHO’s lagging COVAX program, an initiative that is focused on distributing COVID-19 vaccines to lower- and middle-income countries.

Neither Sinovac nor Sinopharm have yet to announce agreements to supply COVAX, but China’s foreign ministry committed to donating at least 10 million doses to the initiative in February. Sinopharm said this week that its first doses bound for the COVAX initiative are now rolling off manufacturing lines.

“Having another source of vaccines for the COVAX program when there’s an overwhelming need for vaccines in the world right now is certainly beneficial,” says Ashley St. John, an immunologist at Duke-NUS Medical School in Singapore.

Thomas suggests that the WHO may have sped up its approvals because of the enormous second COVID wave in India, which infected millions of people and strained global vaccine supplies. The Serum Institute of India, the world’s largest vaccine manufacturer, had pledged to supply COVAX with up to 1.1 billion doses of vaccines from AstraZeneca and Novavax, including 800 million doses this year. But the SII retracted its 2021 pledge to COVAX to focus instead on supplying its home market amid the devastating outbreak.

The WHO’s approval of Sinopharm before the publication of peer-reviewed data reflected “a measure of desperation,” given the global shortage of vaccine supplies and India’s inability to deliver on its COVAX pledge, Thomas says.

“The huge surge in cases in India sort of forced the WHO’s hand in this respect,” he says.

St. John argues that even though Chinese vaccine makers have not been as forthcoming as Western counterparts, she has seen enough data to be confident that Sinopharm and Sinovac vaccines can be crucial tools in ending the pandemic. “The key take-home message is that the [Chinese vaccines] have some efficacy against preventing disease,” she says.

Real-world studies in Indonesia, Brazil, and Chile have also indicated that Sinovac’s vaccine is working. In one study, called Project S, researchers in Brazil vaccinated 75% of residents of the town of Serrana (population 46,000) with Sinovac’s vaccine. The researchers said this week that after they completed the mass inoculation drive, symptomatic cases in the town fell by 80% and deaths plunged by 95%.

The real-world studies are encouraging, says St. John, but should not be substituted for evidence from clinical trials.

“Real-world efficacy is very different,” says St. John, explaining that clinical trials give a better picture of how vaccines perform because researchers can compare vaccinated groups to people given a placebo. Sinovac has published preliminary data on its vaccine from clinical trials, but the study has not been peer-reviewed.

Thomas warns that the extraordinary circumstances of the COVID era mean China’s tactic may not have set a new precedent. “The state the world finds itself in now means that the validation should only be seen as context specific,” he says.

But at least for this once-in-a-century pandemic, China’s approach worked.

“China now has a singular opportunity to provide its vaccine doses to the developing world where these doses are most critically needed,” says Thomas.