World accepts much-maligned China's Covid-19 vaccine but doubts remain

A study of some 128,000 Jakarta health workers released Wednesday found Sinovac’s vaccine was far more protective than clinical trials had indicated.

Indonesia, one of the first nations to bet its Covid-19 vaccination campaign on Sinovac Biotech Ltd., was about to announce a stunning development, one that would help vindicate a shot that’s been shrouded in controversy for months. Over in Beijing, though, the company’s chief executive officer was unaware.


A study of some 128,000 Jakarta health workers released Wednesday found Sinovac’s vaccine -- known as CoronaVac -- was far more protective than clinical trials had indicated. A day earlier, it wasn’t mentioned by CEO Yin Weidong in a wide-ranging interview with Bloomberg reporters, and representatives later confirmed the company didn’t know the announcement was coming.


It’s a disconnect that echoes the events of Christmas Eve 2020, when the Chinese developer that will be key to vaccinating much of the developing world had little explanation for why Brazil and Turkey released wildly divergent data on its shot within hours of each other. By January, Sinovac’s vaccine had seen four different efficacy rates -- ranging from as high as 91% to as low as 50% -- triggering concern among scientists and putting a question mark over its ability to protect against the virus still paralyzing the globe.


Sinovac has already shipped some 380 million doses, more than AstraZeneca Plc and second only to Pfizer Inc. worldwide. But unlike those companies -- and even Russia’s Sputnik shot -- it still hasn’t published any data in an academic journal, the gold standard experts use to assess a vaccine.



For China’s emerging biotechnology industry, the pandemic was supposed to be an unparalleled opportunity to showcase the advances they’ve made over the past decade -- and in many ways it has, with dozens of nations reliant on shots from Sinovac and its counterpart Sinopharm to emerge from Covid-19. Yet while Chinese-developed pharmaceutical products have never had such reach, the rollout exposed their limitations and the difficulties Chinese companies face when trying to compete on the world stage, where greater levels of accountability and information sharing are demanded than at home.


Sitting in his office at Sinovac’s sprawling factory on Beijing’s southern outskirts Tuesday, CEO Yin was non-plussed by the criticism of the communication around his vaccine, and unperturbed that it may have affected public perceptions toward it.


“I respect all the doubts around CoronaVac, that speaks to the attention we are getting, but more important is seeking approval to use the vaccine in a country -- that doesn’t depend on public opinion but the stringent review by authorities,” Yin said in the interview. “What do you think is more important than this?”


The divergent efficacy rates were simply a function of the different virus strains that were present in the countries where Sinovac’s Phase III trials were taking place, Yin said, adding that Sinovac relied on those nations and their partners on the ground to disseminate and interpret the results.


But the confusing numbers -- and other negative publicity around the shot that the company did little to deflect -- had an impact, fueling criticism in Brazil of the vaccine by President Jair Bolsonaro and undermining faith in Hong Kong, where Pfizer and BioNTech SE’s shot is instead favored. Despite its roster of global orders, CoronaVac is yet to be endorsed by the World Health Organization, which has asked for more detailed information, as have regulators in Singapore. Hong Kong approved the shot, but only after waiving a requirement for data to be published and peer reviewed in a journal.


Once the sole purview of scientists, the pandemic has seen technical details like vaccine efficacy dissected by everyone from investors to ordinary citizens. Western pharmaceutical companies were quick to realize the power of that information and the need to constantly communicate, with most using a unified protocol to collate data into single statements themselves rather than allowing local partners to relay information.


Given the intense attention, public perception of the safety and strength of vaccines has not only affected whether people will take them, but the actions of governments. AstraZeneca’s vaccine was suspended in a number of European Union countries in March amid anxiety over blood clots, despite the bloc’s medicines regulator saying its benefits outweighed the risk of very rare side effects.


In contrast, China’s vaccine developers have communicated much less. Like Sinovac, state-run Sinopharm, whose shot is being administered from the Maldives to Hungary, is yet to publish its clinical trial data in a peer-reviewed journal, though a study did appear in a domestic one. The company typically doesn’t respond to inquiries from foreign media.


Weidong Yin. Photo: Bloomberg


Used to operating within China, where public opinion is censored, the Chinese vaccine makers have had a tough time showing their “growth in front of the world, in a very compressed time, in a period of heightened scrutiny,” said Helen Chen, Greater China managing partner for L.E.K. Consulting, which has advised global pharmaceutical companies on their strategy in the country.


AstraZeneca also faced criticism for testing snafus and adverse effects, but acted to neutralize it, Chen said.


“AstraZeneca was being bashed over the head for giving poor data but you see them trying to explain it.” she said. For Chinese developers, “we just haven’t seen that level of polish and communication around that, which leads everyone to think they must be hiding something.”


Yin built Sinovac from the ground up over the last 20 years, but until now the company has gotten most of its $510 million in annual revenue from within China, and hasn’t had to grapple with the sort of scrutiny seen in the west. Sinovac is more concerned about ensuring safety and rolling out vaccines to the most people possible, as that is key to determining whether countries can emerge from the pandemic, Yin said.


The best way for the Sinovac vaccine to be judged is for its data to be published in peer-reviewed articles, which “provide evidence that these studies and clinical trials have been done in the right way and shown solid efficacy results,” said David Heymann, an epidemiologist at the London School of Hygiene and Tropical Medicine.



So far Sinovac has only provided an unpublished draft of a study by researchers at the company and its Brazilian trial partner that has been submitted for publication to the Lancet. That lack of peer-reviewed scientific data has allowed speculation about Sinovac -- and in turn, Chinese vaccines more generally, for which it is seen as a standard bearer -- to flourish. A WHO expert panel that reviewed Sinovac’s existing data at the end of April said they had a high level of confidence in CoronaVac’s efficacy but there wasn’t enough information to assess the potential for serious side effects in people age 60 or above and those with existing medical conditions.



The irony is that while the divergent efficacy rates have contributed to suspicions around Sinovac’s shot, evidence emerging in the real world is increasingly positive.


Officials in Chile -- which has vaccinated 41.5% of its population, mostly older people -- credit CoronaVac with having brought down rates of death and hospitalization from Covid. While cases have been spiking again there, which Yin says is because younger people haven’t been as broadly vaccinated, Chile’s real-world data shows CoronaVac prevented 80% of deaths in those vaccinated and protected 67% from developing symptomatic Covid.


The Indonesian data that Sinovac was unaware of was even more positive than the results out of Chile, finding the vaccine protected 98% of the health workers studied from death and 96% from being hospitalized as soon as seven days after being jabbed. In addition, the shot protected 94% of the workers against symptomatic infection, far above the deviating rates thrown up in Sinovac’s clinical trials.


That Chinese vaccines are now being administered outside of the country and around the world is a significant achievement, one that would have been “virtually unthinkable” before the pandemic, said Brad Loncar, chief executive officer of Loncar Investments, which owns shares in Chinese vaccine maker CanSino Biologics Inc. and Shanghai Fosun Pharmaceutical Group Co, licensee for the Pfizer-BioNTech vaccine in the greater China region.


“Without a doubt the transparency the Chinese companies and regulators have exhibited is nowhere near the highest levels and needs improvement,” he said. “That’s what is required to gain the public’s highest confidence in medicine, and it is why the United States has achieved this gold standard.”


“If China wants to be a global leader in medicine on that level in the future, at some point it will have to get there from a transparency and regulatory standpoint.”







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