COVID-19 vaccine provides guidance to the vaccine developers to ensure that -- vaccines are well-characterised and manufactured consistently.The guidance reads that considering the urgent need for a safe and effective vaccine for prevention of COVID-19, clinical development programs of the COVID-19 vaccine may proceed through an adaptive and seamless approach including data to inform the potential risk of vaccine-associated ERD will be needed.The document has highlighted that the use of COVID-19 preventive vaccines in pregnancy and in women of childbearing potential is an important consideration for vaccination programs."There are three things for a vaccine--(i) the safety, (ii) immunogenicity, and (iii) the efficacy.