Emerging scientific data and public health considerations specific to a country are the basis for the time gaps between the doses of vaccines. The additional director general of ICMR, Dr. Samiran panda, has stated that there was no deliberation on decreasing the nine-month gap between the second shot of COVID vaccines and the precautionary dose as there was no scientific evidence currently available. 

According to sources, the Serum Institute of India has asked Union health minister Mr. Mansukh Mandaviya to consider reducing the gap between the second and the precaution dose of Covishield from the present nine months to three, in accordance with the revised guidelines issued for officials on election duty. 

Source: ET Healthworld