NEW YORK (Reuters Health) – Initiation of highly active antiretroviral therapy (HAART) during the first year of life among infants vertically infected with HIV preserves the normal immune response to routine vaccinations, according to new research.

Writing in the April 27 early online edition of PNAS, Dr. Paolo Rossi, at University of Tor Vergata in Rome, and colleagues state, “We identified timing of HAART initiation as the major factor predicting the longevity of memory B cell responses and immune protection in vaccinated HIV-1 infected children.”

They point out that during HIV-1 infection, there is a progressive decline in memory B cells, impaired reactivity to immunization, and loss of specific antibodies despite HAART treatment, which is known to increase the absolute B cell count.

To see if timing of viral suppression “could preserve the normal development of the memory B cell compartment and responses to routine childhood vaccines,” Dr. Rossi’s team studied 70 HIV-1 perinatally infected children and 50 age-matched healthy controls.

Thirteen infected subjects received HAART before age 12 months, 6 remained treatment-na