Background:  The Advisory Committee on Immunization Practices (ACIP) recommends that HIV⁺ children to be given a yearly influenza vaccine. Standard practice has been to use inactivated influenza vaccine (TIV) annually; however, few data are available with regard to safety and immunogenicity of the recently licensed live attenuated influenza vaccine (LAIV) in this population.

Methods:  In the fall of 2004, prior to the onset of the 2004-2005 influenza season, we enrolled 3 groups of HIV⁺ children 5£18 years of age (stratified by prior and current CD4%) who had received prior priming with TIV. Only children with current viral load <60,000 and CD4 >15% were enrolled. Subjects were randomized (1:1) to receive either TIV or LAIV. Safety and nasal surveillance for viral shedding (LAIV recipients only) occurred at day 3, 14, and 28. Subjects with a history of reactive airway disease were enrolled if there was no recent exacerbation of disease. Adverse events occurring until day 28 were reviewed for causality.

Results:  We enrolled 243 HIV⁺ children, comparing LAIV vs TIV. In each group, 53% were male; the majority were black (59% and 68%) and Hispanic (22% and 21%), mean age was 11.4 and 11.9; mean CD4% was 33% and 34%, and mean viral load was 2.9 in both groups. There were no changes in CD4% or viral load related to study vaccine administration. Among LAIV recipients, influenza shedding was detected in 31 (27%) of 115 subjects at day 3 (n = 19 type A, 6 type B, and 6 both A and B), in 3 (2.5%) of 119 subjects at day 14 (n = 1 type A and 2 B), and in 1 (0.9%) of 115 subjects at day 28 (type A). A follow-up culture in this subject at day 56 was negative. There were 73 grade ≥2 signs and symptoms and 32 diagnoses that occurred within 28 days from the vaccination (LAIV 61, TIV 44) but only 6 grade ≥3 signs and symptoms occurring within 28 days of vaccination. Of all 105 events, 14 could have been treatment-related, 5 to TIV and 9 to LAIV. Events related to LAIV included:  fever and malaise, conjunctivitis (2), acute otitis media, sinusitis, pharyngitis and lower respiratory tract illness (2, one of whom was hospitalized). The 5 events related to TIV were acute otitis media (2), pharyngitis (2), and injection-site swelling (1). One patient receiving LAIV had 2 events (fever and malaise). 

Conclusions:  There were no unexpected toxicities or serious adverse events associated with administration of either LAIV or TIV in HIV⁺ children in this study. Prolonged shedding of vaccine virus was not observed. LAIV appears to be safe and well tolerated in HIV⁺ children with CD4% >15%.