Some accounts say Indian physicians practised smallpox inoculation (variolation) long before Edward Jenner's 1796 vaccine.
18th-century European reports (e.g. J.Z. Holwell, 1767) describe 'tikā' — deliberate inoculation with smallpox matter — by itinerant practitioners in Bengal.
— J.Z. Holwell, An Account of the Manner of Inoculating for the Smallpox in the East Indies (1767)
Variolation and, later, Jenner's vaccination — the foundation of immunology.
A popular claim that doesn't hold up — here's the honest story.
Variolation (deliberately exposing someone to a mild dose to build immunity) was practised across Asia, and 18th-century Europeans documented a sophisticated Bengali version. That much is real, and it predates Jenner's cowpox vaccine.
Why it's contested: the claim that this is an ancient Vedic practice is shaky — the detailed evidence is 18th-century, and the supposed older Āyurvedic source ('Sacteya' verses) is widely regarded as a later or misattributed text. Variolation also wasn't unique to India (China and the Ottoman world practised it too). So: a genuine, documented pre-Jenner inoculation tradition in India — yes; proof that the ancient Ṛṣis invented vaccination — no.