Vaccines

1. Passive given after exposure such as in the case of some rabies virus' or snake toxins

• Antibodies

2. Active given prior to exposure to raise an immune response

a. Live attenuated (MMR, VZV, Small pox, BCG an empiracle)

• Cheap, unstable, humoral, cell mediated, >1, not to immunocomprimised, severe effects, reversion

b. Inactive (Diptheria, Tetanus, Polio, Pertussis)

c. Subunit (HBV for Hep B)

• Expensive, stable, humoral, anyone, local effects, boosters needed, parenteral, no reversion

d. Virus like particles (HPV against cervix cancer)

e. Peptides containing pathogen epitopes  (HCV clinical studies for Hep C)

f. Recombinant chimeric viruses (MVA virus expressing HIV-1 protein still in clinical trials)

Entry is via the CD4+ receptor and co-receptor

• gp120 attaches to CD4+ and brings virus particle into contact with co-receptor
• Co-receptor induces a conformational change in gp120 which releases gp41 fusion domain into  PM
• Formation of 6 a-helices in a bundle forms the leucine zipper with gp41 in both host and virus
• This produces a pore in the PM and virus can gain entry

Course

• CDI: Acute phase, lymphadenopathy, fever, rash, GI, +p24, -anti-HIV, ^ viral load so high infectivity
• CDII: Latent phase, no symptoms, +p24, + anti-HIV, +CD8+ cells
• CDIII: AIDs-related complex, lymphadenopathy, wasting, hot, +p24, low +anti-HIV, low CD8+
• CDIV: AIDs defining disease, Kaposi's sarcoma, toxoplasmosis, mycobacterial infection

Treatment

HAART: (non)nucleosidic reverse trancriptase, protinase inhibitors, entry inhibitors (block adhesion)