inoculate

(transitive, immunology) To introduce an antigenic substance or vaccine into something (e.g. the body) or someone, such as to produce immunity to a specific disease.

1722, John Crawford, The Case of Inoculating the Small-pox Consider'd: And Its Advantages Asserted; in a Review of Dr. Wagstaffe's Letter. Wherein Every Thing that Author Has Advanced Against It, is Fully Confuted: and Inoculation Proved a Safe, Beneficial, and Laudable Practice.:

But you would not willingly thus give up the Cause; therefore endeavour to draw others into your Assistance, and venture to assert, that by the Account Dr. Nettleton gives, as also by the best Observation upon those who have been Inoculated in this City, scarcely a fourth part of them have had a true and genuine Small Pox.

(transitive, by extension) To safeguard or protect something as if by inoculation.

To add one substance to another.

To graft by inserting buds.

(figuratively) To introduce into the mind (used especially of harmful ideas or principles).