First Dose of Chinese Covid-19 Vaccine Offers Little Protection, Chile Learns

Several days after receiving his first dose of a Chinese-made coronavirus vaccine, Rodrigo Jordán fell ill and tested positive for Covid-19. The 61-year-old was hospitalized near his home in the Chilean capital, Santiago, for nine days and needed supplemental oxygen to pull through.

Across Chile—which has mounted one of the world’s most rapid vaccination campaigns using the vaccine made by Chinese drugmaker Sinovac Biotech Ltd.—health authorities are scrambling to deal with a surge in new infections and deaths.

More than 7.6 million people, half of Chile’s adult population, have already received at least one vaccine dose, most made by the Chinese drugmaker, making the country a real-world testing ground for a vaccine that Beijing is supplying to countries across the developing world.

The problem, public-health officials say, was that people in general overestimated the effectiveness of the vaccine after only one of the two recommended doses and moved to ease up on pandemic-control restrictions too soon.

“With one dose, we know the protection is very weak,” said Claudia Cortés, an infectious disease expert at the Santa Maria Clinic in Santiago, where about 10% of the Covid-19 patients at her hospital have received one shot. “It was not clearly explained that you need two doses—that you need to wait.”