Beijing: China’s CoronaVac and Sinopharm Covid vaccines may be waning in immunity levels, several studies have shown. CoronaVac and Sinopharm — both inactivated vaccines, which use killed SARS-CoV-2 virus — account for almost 50 per cent of the 7.3 billion Covid-19 vaccine doses delivered globally. China administered about 2.4 billion doses of the vaccines to its […]
