An abundance of data has shown that domestic COVID-19 vaccines are safe and effective for the elderly and other vulnerable groups, drugmakers have said, as experts reiterated the importance of expanding immunization coverage in order to cope with the epidemic. China National Biotech Group, a subsidiary of Sinopharm, said over the weekend that about 3.4 billion doses of its inactivated COVID-19 vaccines have been delivered worldwide. Its widespread use has enabled scientists to collect a great amount of data to validate its safety and efficacy. View More