• Antibodies are given either from one donor who has a high level of Ab for a specific disease in their blood, or is pooled from the blood of many donors. These Abs work in viral disease by opsonization or preventing the virus from binding to cells. Unfortunately, they are useless once the virus enters a cell.
• Applicable Diseases –
• (1) Poliovirus – passive immunization results in viral opsonization.
• (2) Hepatitis A Virus

• attenuated strains of live viruses are used. Virus prompts extensive and long lasting protective immune response (all elements of immunity involved). These vaccines carry a small risk of disease, especially in immunocompromised patients
• side effects: fever (may be delayed, 10-14 days), rash, local inflammation, vaccine specific (ex: parotitis with mumps)
• contraindication: immunocompromised patients (exception: HIV patients should get this), pregnancy (virus can cross placenta), risk of anaphylaxis to agent, recent immunoglobulin exposure.
• Applicable Diseases – Measles, mumps, rubella – 1^st dose at 12-15 months, 2^nd dose at school entry age or age 12.

• Virus is collected and then inactivated by treatment with a chemical agent such as formalin. Carries no risk of disease. Durability of conferred immunity is variable.
• Applicable Diseases:
• (1) Influenza – most common inactivated whole virus vaccine. Does not carry great durability due to antigenic shifts in HA and NA. Please note that HA₅ antigen has recently emerged in Hong Kong. Side effects: fever, malaise, local reaction, anaphylaxis rarely.
• (2) Hepatitis A – indicated for day care, travelers, lab workers, and primate care-takers. Vaccine remains the same because there is minimal (none?) antigenic variation with this virus.
• (3) Rabies

 Inactivated Subunit Vaccines

• Purified preparations of viral antigens. Prepared by using recombinant DNA technology to produce antigens in a variety of cells (bugs, yeast, euk cells). Carry no risk of disease. Durability is variable, and vaccine may not induce a complete immune response. Further, parenteral (by means other than via the GI tract) immunization may not be effective against mucosal infections.
• Applicable Diseases:
• Hepatitis B – Hep B surface antigen (HBsAg) was cloned in yeast, harvested, and purified.
• differentiating between viral exposure and vaccine – viral exposure will result in HBsAb only, while vaccine will result in both HBsAb and HBcAb (core protein antibody)

 DNA Vaccines

• future of vaccines
• these vaccines contain gene/genes coding for the antigenic portion of the virus
• injected in plasmid form, and contain a viral promoter
• induce the expression of the viral antigen and consequent stimulation of cytotoxic T-cells, and are usable in immunocompromised patients
• disadvantages: insertional mutagenesis, and possible tolerance.