BENGALURU, Aug 20 (Reuters) - Johnson & Johnson (JNJ.N) has sought approval from Indian drug regulators to conduct a study of its COVID-19 vaccine among 12- to 17-year-olds, the company said on Friday. Conducting vaccine clinical trials among adolescents is imperative to achieve herd immunity against the coronavirus, J&J said in an emailed statement. The U.S. pharma giant had received emergency use approval for its single-dose vaccine in India earlier this month, making it the fifth authorised vaccine in the country. read more While J&J has a supply agreement with Indian vaccine maker Biological E Ltd to bring its shot to the country, the company had said that it was too early to give a delivery timeline. Reporting by Shivani Singh in Bengaluru; Editing by Ramakrishnan M. Our Standards: The Thomson Reuters Trust Principles.