Abstract:
In many regions of sub-Saharan Africa, both HIV and helminth infections are prevalent. HIV-1
(human immunodeficiency virus type 1) and helminth infections can both compromise immune responses in humans. To determine whether the presence of helminth infection or the
treatment of helminth infection alters unstimulated vaccine responses among HIV-1 infected
individuals, we conducted two nested serologic studies. Blood samples were collected for HIV
disease monitoring and vaccine-specific serologic assays, while stool was evaluated by direct
microscopy methods. We compared antibody responses to measles and tetanus vaccines in helminth-infected (Ascaris, Trichuris, hookworm and/or Schistosoma mansoni) and uninfected
adults 18 years and older (n = 100). We also compared measles and tetanus antibody responses in Ascaris only-infected adults receiving 400 mg albendazole daily for 3 days (n =
16) vs. placebo (n = 19) in a separate study. In both cohorts, over 70% of participants had
measles and tetanus responses above the protective threshold. Prevalence of measles responses
were similar between helminth-infected and uninfected individuals (82%, 95% CI: 71–93% vs
72%, 95% CI: 59–85%), as well as log10 tetanus antibody levels (−0.133 IU/mL vs −0.190 IU/
mL, p N 0.05), and did not differ by helminth species. In the Ascaris-infected cohort, changes
in measles responses and tetanus responses did not differ between those who received
anthelminthic vs. placebo (p N 0.05 for both). In these studies, neither helminth infection,
nor deworming, appeared to affect previously administered vaccine responsiveness in HIV-1
infected, ART naïve, adults in Kenya.
