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.

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.”