Several South Asian countries have raised doubts regarding China's COVID-19 vaccine 'Sinovac' after its citizens who received Sinovac Biotech shots are testing positive for the coronavirus.
Thailand's health ministry on Sunday said more than 600 medical workers who received two doses of China's Sinovac vaccine have been infected with COVID-19, as authorities weigh giving booster doses to raise immunity.
Of the 677,348 medical personnel who received two doses of Sinovac, 618 became infected, health ministry data from April to July showed. According to Reuters, a nurse has died and another medical worker is in critical condition.
Indonesia and Thailand are considering offering a booster shot to their medical workers immunized with Sinovac's 's Covid-19 vaccine, a move likely to reduce public trust in the Chinese product that has been their main inoculation tool.
Indonesia has vaccinated millions of its healthcare workers with the Sinovac shot and thousands of them are now testing positive for Covid-19.
Some countries including Turkey and the United Arab Emirates have already started giving a booster shot to those inoculated with Chinese vaccines amid concerns that they may not be as effective against new and more transmissible coronavirus variants.
In another major setback to China's COVID vaccines, Singapore is not counting its citizens who received Sinovac Biotech shots as being vaccinated against Covid-19 due to lack of data to show that the doses are effective against coronavirus, especially the Delta strain.
"We don't really have a medical or scientific basis or have the data now to establish how effective Sinovac is in terms of infection and severe illnesses on Delta," local media cited health minister Ong Ye Kung as saying at a press conference on Wednesday.
The decision comes close on the heels of serious doubts arising over Chinese vaccines in Indonesia as those who have received the shots are also contracting Covid-19 and infections are surging in the country.
While some real world data showed the Sinovac vaccine is effective against hospitalization and severe Covid-19 cases, there is no detailed data yet on its effectiveness against the Delta variant, first identified in India.
