Subunit vaccines contain only specific parts or proteins from the pathogen. Recombinant vaccines are produced by genetically engineering a harmless organism to produce the pathogen’s antigens. Conjugate vaccines combine antigens from a bacterium with a protein to enhance immune response. Examples include the hepatitis B vaccine (subunit), the HPV vaccine (recombinant), and the Haemophilus influenzae type b (Hib) vaccine (conjugate).
