SAN FRANCISCO — The live attenuated influenza vaccine known as FluMist is as safe as an inactivated virus vaccine for children with HIV who have CD4 percentages of 15% or greater, according to the findings of a randomized, controlled trial.
Investigators recorded similar toxicity profiles for FluMist and the trivalent inactivated virus (TIV) vaccine that is standard for this population, Dr. Sharon Nachman reported at the annual meeting of the Pediatric Academic Societies.
Prolonged shedding, a major concern, was not observed in either arm of the phase I-II trial, according to Dr. Nachman, chief of pediatric infectious diseases, department of pediatrics, State University of New York at Stony Brook.
“There were no unexpected toxicities or adverse events associated with administration of LAIV [live attenuated influenza virus] or TIV in HIV-positive children in this study,” she said, summarizing 6 months of follow-up on behalf of the Pediatric AIDS Clinical Trials Group.
The investigators randomized 243 HIV-positive children aged 5–18 years at the start of the 2004–2005 flu season: 122 to intranasal LAIV and 121 to injected TIV. The LAIV arm received the FluMist formulation that is currently approved for healthy children and adults aged 5–49 years.
Entry criteria included a current viral load below 60,000 copies/mL. All participants had at least 16 weeks of stable antiretroviral therapy with three different antiretroviral agents from at least two therapeutic classes. All had been vaccinated with TIV in at least one of the two previous years as well.
“Ethnicity looks exactly like [the] demographic of perinatally infected children across the United States,” Dr. Nachman said. The study arms were evenly matched with respect to mean age (11.4–11.9 years), CD4 percentage (33%–34%), and viral load (2.9 copies/mL in both groups).
Vaccine administration did not lead to clinically significant changes in CD4 count, viral load, or changes in antiretroviral therapy during the study.
Investigators detected influenza shedding in 31 of 115 LAIV recipients (27%) 3 days after they received the vaccine. By day 28 only one of 119 subjects (0.9%) was shedding virus, and the results of a follow-up culture on day 56 were negative.
During the first 28 days, eight children in the LAIV arm had nine events that may have been related to FluMist administration, including fever, conjunctivitis, sinusitis, and pharyngitis.
One child was hospitalized and recovered with antibiotic therapy, Dr. Nachman reported at the meeting, sponsored by the American Pediatric Society, Society for Pediatric Research, Ambulatory Pediatric Association, and American Academy of Pediatrics.
A coinvestigator on the study is an employee of MedImmune Inc., manufacturer of FluMist.