Online Teachers' Professional Development programs, both synchronous and asynchronous, are relatively new in the educational arena. They have been available in the business sector for nearly two decades. In the wake of the closure of schools due to the COVID-19 outbreak, the Kerala Infrastructure and Technology for Education (KITE), in association with the Education department of Kerala, has come up with a novel idea of imparting online training to over 81,000 primary teachers in the state, spanning over 11,274 schools. It has been decided to provide specific vacation training to all primary and upper primary teachers during April and May to enhance their professional development. The KITE-VICTERS channel telecasted a special program on the training, which took place in May 2020. This study may pave the way for additional research that can offer more insights for future online training courses. This, in turn, may lead to the study of the impact of online training courses on the academic achievements of school children. The investigator conducted the study through a survey method. The findings of the study show that teachers with more than fifteen years of teaching experience showed more interest in online vacation training courses than their younger counterparts. Online classes enabled the teachers to think differently in new situations and use modern social media and mass media technology innovations. Mass education may change to individualized education in the coming year due to the COVID-19 pandemic. Proficiency in diverse areas is required, rather than specified skills, to cater to the needs of students in post-COVID-19 situations.