Excuse me. It is know to be safe for 70 years. It used widescale in the whole world. It is cheap and easily manifacturable (only India is doing it right now). It is known to be working as COVID-19 prophylaxe (not as treatment).
There is no vaccination in sight.
https://www.icmr.gov.in/pdf/covid/techdoc/V5_Revised_advisor...