New Delhi: Faced with the problem of circulation of rumours about the efficacy of COVID-19 vaccines, the Centre has asked the states to check the spread of such misinformation and advised them to take penal action against those who are found to be involved in dissemination of wrong and ill-informed news.In a communication to chief secretaries of all states and UTs, Union Home Secretary Ajay Bhalla also strongly emphasised that the National Regulatory Authority in the country has found that the two vaccines -- Covishield, manufactured by the Serum Institute of India, and Covaxin, developed and manufactured by the Bharat Biotech Limited -- were safe and immunogenic.The central government, in close collaboration with the state governments and.