LJUBLJANA, SLOVENIA – A “surprisingly low” prevalence of protective antibodies against measles is present in adolescents and adults living with HIV infection despite their prior vaccination against the resurgent disease, Raquel M. Simakawa, MD, reported at the annual meeting of the European Society for Paediatric Infectious Diseases.
“With the present concern about the global reemergence of measles, we should consider measuring measles antibodies in people living with HIV, especially those who acquired the infection vertically, and then revaccinating those with low titers,” said Dr. Simakawa of the Federal University of São Paolo.
She presented interim findings of an ongoing study of the measles immunologic status of persons living with HIV, which for this analysis included 57 patients who acquired HIV from their mother via vertical transmission and 24 with horizontally acquired HIV. The vertical-transmission group was significantly younger, with a median age of 20 years, compared with 31 years in the horizontal group, who were diagnosed with HIV infection at an average age of 24 years. The vast majority of subjects were on combination antiretroviral therapy. No detectable HIV viral load had been present for a median of 70 months in the vertical group and 25 months in the horizontal group.
Only a mere 7% of the vertical transmission group had protective levels of measles IgG antibodies as measured by enzyme-linked immunosorbent assay, as did 29% of the horizontal group. The likely explanation for the higher rate of protection in the horizontal group, she said, is that they received their routine measles vaccination before they acquired HIV infection, and some of them didn’t lose their protective antibodies during their immune system’s fight against HIV infection.
Session chair, of Franciscus Hospital in Rotterdam, the Netherlands, posed a question: Given the sky-high rate of measles seronegativity status among the vertically transmitted HIV-positive group – the patient population pediatricians focus on – why bother to measure their measles antibody level? Why not just give them all a measles booster?
Dr. Simakawa replied that that’s worth considering in routine clinical practice now that her study has shown that this group is more vulnerable to measles because of their poor response to immunization. But the study is ongoing, with larger numbers of patients to be enrolled. Also, in the second phase of the study, which will include a control group, measles IgG antibodies will be remeasured 1 month after administration of a new dose of measles vaccine.
She reported having no financial conflicts regarding this study, conducted free of commercial support.