Immunologic Response to Oral Polio Vaccine in Human Immunodeficiency Virus–infected and Uninfected Zimbabwean Children

Abstract

BACKGROUND: Poliovirus eradication is dependent on maintaining adequate community-wide levels of serologic protection. Many African countries with conditions that favor continued wild poliovirus propagation also have a high prevalence of pediatric human immunodeficiency virus (HIV) infection. Data are limited regarding the degree of serologic immunity conferred on HIV-infected children after immunization with oral polio vaccine (OPV). METHODS: This was a cross-sectional study correlating HIV infection and neutralizing antibodies against poliovirus serotypes 1, 2, and 3 in 95 Zimbabwean children 2 months to 2 years of age, born to HIV-infected mothers, who received OPV according to the national schedule. RESULTS: HIV-infected children had significantly lower rates of seroconversion to all 3 poliovirus serotypes than HIV-uninfected children (60%, 67%, and 47% vs. 96%, 100%, and 82%, P = 0.001, 0.0003, and 0.015 for serotypes 1, 2, and 3 in HIV-infected and uninfected children, respectively, after ≥3 OPV doses). Among poliovirus seroconverters, HIV-infected children also had significantly lower geometric mean titers against serotypes 1 and 2 than HIV-uninfected children (geometric mean titers: 198 and 317 vs. 1193 and 1056, P = 0.032 and 0.050, for serotypes 1 and 2, respectively, after ≥3 OPV doses). In addition, HIV-infected children had significantly higher levels of total IgG and significantly lower CD4% and mean weight than HIV-uninfected children. Of note, none of the HIV-infected children were receiving antiretroviral therapy, and 71% had a CD4% indicating severe immunodeficiency. CONCLUSIONS: Pediatric HIV infection is associated with a poor serologic response to OPV, which could pose an obstacle to global polio eradication.