Antibody responses and HIV-1 viral load in HIV-1-seropositive subjects immunised with either the MF59 adjuvanted influenza vaccine or a conventional non-adjuvanted subunit vaccine during highly active antiretroviral therapy.

OBJECTIVE: To study immunological and virological parameters in HIV-1-seropositive adults treated with highly active antiretroviral therapy (HAART) for at least 7 months after immunisation with MF59-adjuvanted (FLUAD, Chiron, Siena, Italy) or with non-adjuvanted (AGRIPPAL, Chiron) trivalent influenza vaccine. DESIGN: Blood samples, collected before and after vaccination, were analysed for the presence of antibodies against the vaccine antigens, for number of CD4+ T lymphocytes and HIV-1 RNA levels. RESULTS: Forty-four volunteers received FLUAD and 40 AGRIPPAL influenza vaccine. Thirty days after vaccination both adjuvanted and non-adjuvanted vaccines induced significant increases of anti-influenza virus antibodies. However, antibody titres found in volunteers receiving adjuvanted vaccine were in general significantly higher when compared with those found in the non-adjuvanted vaccine group. The requirements of the European Commission of influenza vaccine for a non-elderly adult population were always met by recipients of the adjuvanted vaccine, even in those with the lowest CD4+ cell counts (<200 cells/mmc). The subjects receiving the non-adjuvanted vaccine failed to met these requirements. The CD4+ T lymphocytes and plasma HIV-1 RNA levels remained stable in the long term, both in people receiving adjuvanted or non-adjuvanted vaccine. CONCLUSION: MF59-adjuvanted influenza induced a significant higher immune responses as compared with conventional vaccine in HIV-seropositive HAART-treated patients. Both vaccines were safe regarding HIV RNA viral replication and loss of CD4+ T lymphocytes.