The European Medicines Agency (EMA) said Tuesday that its rolling review of data for the vaccine would “continue until enough evidence is available” for the vaccine’s developer, Sinovac BioTech, to file a formal application for authorization.

This process is supposed to reduce the amount of time needed to evaluate the eventual application. Other vaccines in the EMA’s pipeline include Russia’s Sputnik V, Germany’s CureVac, and the U.S.’s Novavax. The agency has already green-lit the BioNTech/Pfizer, Moderna, AstraZeneca, and Johnson & Johnson vaccines.

CoronaVac, or “COVID-19 Vaccine (Vero Cell) Inactivated” as it is more formally known, is unique among these vaccines in that it uses the SARS-CoV-2 virus itself—albeit in killed-off form—to trigger the immune response that leads to inoculation. India’s Covaxin takes the same approach, as do Valneva’s under-development vaccine and QazVac, Kazakhstan’s homegrown jab.

The level of CoronaVac’s efficacy is not certain. Turkish researchers have put it as high as 83.5%, which would make the jab more effective than AstraZeneca or J&J’s vaccines. But it barely cleared the 50% threshold in Brazil—though that could be because trials there were largely dealing with the extremely dangerous P.1 coronavirus variant. CoronaVac’s finalized trial data is yet to be published in a peer-reviewed journal.

Gao Fu, the head of the Chinese Centers for Disease Control and Prevention, caused a stir last month when he admitted that China’s vaccines—including CoronaVac and Sinopharm—”don’t have very high rates of protection.” However, he subsequently claimed reports of the admission were a “complete misunderstanding.”

Approval effects

The European Union is mostly acting as a collective in its approval and purchasing of COVID-19 vaccines. However, the slow start to Europe’s vaccination drive—which has recently picked up significant pace—led some Eastern European countries to consider non-Western alternatives.

Hungary in particular bypassed the European Commission’s bulk purchasing mechanisms to secure its own supplies of Sputnik V and Sinopharm.

EMA approval does not necessarily mean the European Commission will place an order. For example, Internal Market Commissioner Thierry Breton—the head of the Commission’s vaccine task force—has repeatedly said the EU has no need for Sputnik V, even though the EMA is evaluating it.

CoronaVac has already been approved for use in a couple dozen countries, including Turkey, Brazil, Chile, Mexico, Thailand, Zimbabwe, and of course China itself.

The World Health Organization is evaluating both CoronaVac and Sinopharm for potential approval. If it gives the go-ahead, the Chinese vaccines could then be included in the WHO-backed COVAX program, which is distributing low-cost doses to low- and middle-income countries.

Vaccine deals aside, though, an EMA recommendation for the approval of CoronaVac could have a big impact on Chinese tourism in the EU. The European Commission officially proposed this week that the EU should open its borders to travelers who have been fully vaccinated with EMA-approved jabs.