NEW DELHI : The Indian Academy of Sciences, a Bengaluru-based body of scientists, has said the Indian Council for Medical Research's (ICMR) target to launch a coronavirus vaccine by August 15 is "unfeasible" and "unrealistic".The IASc said while there is an unquestioned urgent need, vaccine development for use in humans requires scientifically executed clinical trials in a phased manner.While administrative approvals can be expedited, the "scientific processes of experimentation and data collection have a natural time span that cannot be hastened without compromising standards of scientific rigour", the IASc said in a statement.In its statement, the IASc referred to the ICMR's letter which states that "it is envisaged to launch the vaccine.