I have taken covishield vaccine on 9th June 2021, at 11.30 am. Post vaccination I felt normal till now, on the day of vaccine I had very mild fatigue and very mild headache, these are for an hour, rather I can say post vaccination  effects are none. I have one concern here,  Is Vaccine really working on me and creating antibodies as expected? . Many of my colleagues who has taken Vaccine  10 days before had post vaccination effects for 4-5 days with fatigue, fever..