An agent containing antigens produced from killed, attenuated or live pathogenic microorganisms, synthetic peptides or by recombinant organisms, used for stimulating the immune system of the recipient to produce specific antibodies providing active immunity and/or passive immunity in the progeny.
PAC, 1992, 64, 143. 'Glossary for chemists of terms used in biotechnology (IUPAC Recommendations 1992)' on page 167 (