Sustained Responses to Measles Revaccination at 24 Months in HIV-infected Children on Antiretroviral Therapy in Kenya

Abstract

Background There are limited data on whether HIV-infected children in resource-limited countries who are receiving antiretroviral therapy (ART) are able to produce sustained, protective levels of measles antibody after multiple measles vaccinations. Methods We administered an additional measles vaccine to HIV-infected children 15 months to 12 years of age receiving ART in Nairobi, Kenya. Measles antibody concentrations were determined by enzyme-linked immunosorbent assay (ELISA) at enrollment, one month, 12 months, and 24 months post revaccination. Results At enrollment, 125 (54%) of 232 study participants had protective concentrations of measles antibody. Measles seropositivity increased to 98% of all children at one month post revaccination, but decreased to 71% at 12 months, and 60% at 24 months post revaccination. Measles seroconversion and sustained measles seropositivity among those who were measles seronegative at enrollment was 25% at 24 months post revaccination. In this group, 39% of children with <50 copies/mL plasma HIV RNA measles seroconverted compared with 4% of children with plasma HIV RNA ≥1,000 copies/mL (p=0.018). Conclusions Measles revaccination can result in a sustained antibody response in a subset of HIV-infected children receiving ART, especially among those with HIV suppression.

Safety and Immunogenicity of Measles Vaccination in HIV-Infected and HIV-Exposed Uninfected Children: A Systematic Review and Meta-Analysis

“…Seventy-one studies fulfilled the eligibility criteria (Supplementary data 4). Twenty-eight studies reported on safety [24], [25], [29], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47], [48], [49], [50], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61] and 62 reported on immunogenicity [23], [24], [25], [29], [30], [33], [34], [35], [36], [37], [39], [40], [41], [43], [44], [45], [47], [48], [50], [51], [53], [55], [56], [57], [59], [60], [61], [62], [63], [64], [65], [66], [67], [68], [69], [70], [71], [72], [73], [74], [75], [76], [77], [78], [79], [80], [81], [82], [83], [84], [85], [86], [87], …”

Measles Vaccine

“…With time, MeV-specific Abs and CD4 + T cells induced by vaccine decrease (22,24,71,108), and secondary vaccine failure rates are estimated to be *5% 10-15 years after immunization (2,89). Lack of a sustained protective response is a particular problem in HIV-infected children (45,98,104,112). Attempts to boost immunity with repeated immunization have generally led to only transient improvements in either levels of neutralizing Ab or MeV-specific T cell responses (42) and raise the possibility that new vaccine approaches may be required for measles control in the future (54).…”

Prevalence and risk factors of measles seronegativity in a cohort of HIV‐positive subjects: a retrospective study

“…Vertically infected subjects represented a large proportion (36.2%) of seronegative subjects, although the majority of those subjects had evidence of previous MMR vaccination, with a median of 2 doses. Following MMR vaccination, HIV‐infected children have a lower rate of seroconversion and antibody persistence compared with HIV‐uninfected children . A study performed in a US cohort in which the majority of children had received two doses of MMR vaccine found a seroprotection rate of only 52% .…”

“…Importantly, studies showed that revaccination of HIV‐infected children with an additional dose of the MMR vaccine allowed seroconversion and persistence of anti‐measles IgG. Being on cART and having an undetectable viral load have been shown to be critical factors associated with prolonged protective immune responses after revaccination of HIV‐infected children . Accordingly, the Pediatric European Network for the Treatment of AIDS (PENTA) recommends testing of HIV‐infected children and revaccination of seronegative children with an additional dose of the MMR vaccine every 3–5 years .…”