Several studies have demonstrated that immune activation caused by vaccination may result in elevation of HIV viral load. Additionally, poor immunization responses are common in HIV-infected children. We therefore studied serologic responses to influenza vaccination and resulting changes in HIV bDNA (Chiron Inc.) in HIV-infected children. Because vitamin A supplementation may enhance immunization responses in vitamin A deficient children, we also determined vitamin A status in the patients, who were then randomized to receive either vitamin A (2 successive daily oral dosages of 200,000 IU) or placebo 2 weeks before vaccination in a double blind study.
Fifty nine children living in Chicago were enrolled (median age 81 mos., range 25-209; CDC immunologic stages 1: n=12, 2: n=25, 3: n=22). There were no differences between vitamin A and placebo supplemented groups at baseline.
Adequate serologic responses to vaccination were demonstrated: influenza strain H1N1 geometric mean titer at vaccination was 13.43±1.19 and 1 mo. later 33.11±1.23 (p<0.001); for strain H3N2 16.98±1.19 and 49.43±1.22, respectively (p<0.001). More severely immunocompromised patients (CDC stage 3) had significantly worse responses to strain H1N1 when compared to less immunocompromised children (p=0.04), but not to strain H3N2 (p=0.08). Vaccination did not result in a change in plasma bDNA: mean logbDNA at vaccination was 3.98±1.01, 2 wks. later 3.93±0.14 (p=0.89), 4 wks. later 3.92±0.15 (p=0.86). Plasma vitamin A levels were normal (>20mg/dL) in the majority (n=47, 79%) and low in 12 patients (21%); median level was 25.1 mg/dL, range 11-150. No difference in influenza vaccination response was demonstrated between vitamin A and placebo supplemented groups (H1N1: p=0.151, H3N2: p=0.706).
We conclude that serologic response to influenza vaccination was adequate in our cohort of HIV-infected children. Worse serologic responses were demonstrated in more immunocompromised children. Influenza vaccination did not result in change in HIV viral load. Vitamin A supplementation did not enhance serologic response to vaccination. However, this finding may be explained by adequate vitamin A status in our cohort; the role of vitamin A supplementation in vitamin A deficient HIV-infected children should be studied further.
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Infectious Disease Clinics of North America (2001)