SINGAPORE – As Southeast Asia grapples with a record-breaking surge in Covid-19 infections and deaths, regional nations are turning away from Chinese-made vaccines in favor of Western-made shots amid growing evidence the former are less effective against the highly contagious Delta variant.
Beijing’s leading vaccine developers, private biopharmaceutical firm Sinovac Biotech and state-owned Sinopharm, have shipped hundreds of millions of doses worldwide and are key to the World Health Organization’s COVAX scheme aimed at distributing shots to poorer countries.
China’s indigenously developed vaccines, studies show, offer a measure of protection and are still considered to be highly effective against severe disease and hospitalization. They also are more easily stored and transported than certain Western-made jabs, making them comparatively cost-effective.
But it is increasingly less clear how well Chinese shots protect against more transmissible Covid-19 variants, not least the fast-spreading Delta strain that is now causing runaway caseloads and pushing regional health systems to the brink of collapse. Emerging data shows diminishing efficacy levels against variants in several major Covid-19 vaccines.