Table 2

Current strategies for an HIV-1 vaccine.

Approach Limitations
Live, attenuated virusesEventual pathogenicity in vaccinees
Inactivated viruses with adjuvants Protection based on anti-cell rather than antiviral antibodies
Subunit vaccines
Recombinant monomeric envelope protein Absence of antibodies that neutralize patient isolates of HIV-1; absence of CTLs
Peptides Absence of antibodies that neutralize patient isolates of HIV-1
Live vector-based vaccines (pox viruses, single-strand RNA viruses, adenovirus, bacille Calmette-Guérin, and enteric bacteria) Immunogenicity, and level of in vivo replication and pathogenicity of vector closely correlated
DNA plasmids Little experience with approach