Indonesia and Thailand are considering offering a booster shot to their medical workers immunised with Sinovac's Covid-19 vaccine, a move likely to reduce public trust in the Chinese product that has been their main inoculation tool.

Some countries including Turkey and the United Arab Emirates have already started giving a booster shot to those inoculated with Chinese vaccines amid concerns they may not be as effective against new and more transmissible coronavirus variants.

But the challenges facing Southeast Asia...