Administration of G-CSF from day +6 post-allogeneic hematopoietic stem cell transplantation in children and adolescents accelerates neutrophil engraftment but does not appear to have an impact on cost savings.

G-CSF post-allogeneic HSCT accelerates neutrophil engraftment, but evidence that it impacts on cost-related outcomes is lacking. We performed a retrospective child and adolescent single-center cohort study examining G-CSF administration from Day +6 of allogeneic HSCT vs. ad hoc G-CSF use where clinically indicated. Forty consecutive children and adolescents undergoing allogeneic HSCT were included. End-points were as follows: time to engraftment; incidence of acute and chronic GvHD; number of patients alive at Day +100; 180-day TRM; post-transplant days in hospital; and cost of antimicrobials, TPN, and G-CSF usage. Neutrophil engraftment occurred earlier in the group that received G-CSF from Day +6. There was no difference between groups in any of the other end-points with the following exception: the cost of GCSF was significantly higher in the D + 6 G-CSF group. However, median G-CSF cost in this group amounted to only €280. There was a trend towards reduced cost of antimicrobials in the D + 6 G-CSF group, although this did not reach significance (p = 0.13). The median cost per patient of antimicrobial agents between groups differed by €1116. This study demonstrated the administration of G-CSF on Day +6 in pediatric HSCT to be safe. A further study using a larger cohort of patients is warranted to ascertain its true clinico-economic value.

HIV virological suppression influences response to the AS03-adjuvanted monovalent pandemic influenza A H1N1 vaccine in HIV-infected children.

DESIGN: Children with HIV are especially susceptible to complications from influenza infection, and effective vaccines are central to reducing disease burden in this population. We undertook a prospective, observational study to investigate the safety and immunogenicity of the inactivated split-virion AS03-adjuvanted pandemic H1N1(2009) vaccine in children with HIV. SETTING: National referral centre for Paediatric HIV in Ireland. SAMPLE: Twenty four children with HIV were recruited consecutively and received two doses of the vaccine. The serological response was measured before each vaccine dose (Day 0 and Day 28) and 2 months after the booster dose. Antibody titres were measured using a haemagglutination inhibition (HAI) assay. Seroprotection was defined as a HAI titre ≥ 1:40; seroconversion was defined as a ≥ fourfold increase in antibody titre and a postvaccination titre ≥ 1:40. MAIN OUTCOME MEASURES: The seroconversion rates after prime and booster doses were 75% and 71%, respectively. HIV virological suppression at the time of immunization was associated with a significantly increased seroconversion rate (P = 0·009), magnitude of serological response (P = 0·02) and presence of seroprotective HAI titres (P = 0·017) two months after the booster dose. No other factor was significantly associated with the seroconversion/seroprotection rate. No serious adverse effects were reported. Vaccination had no impact on HIV disease progression. The AS03-adjuvanted pandemic H1N1 vaccine appears to be safe and immunogenic among HIV-infected children. A robust serological response appears to be optimized by adherence to a HAART regimen delivering virological suppression.

Does vaccine dose predict response to the monovalent pandemic H1N1 influenza a vaccine in children with acute lymphoblastic leukemia? A single-centre study.

BACKGROUND: Vaccination against influenza is an important strategy in preventing severe infection among children with acute lymphoblastic leukemia (ALL). Successful vaccination depends on both vaccine and host-related factors. We conducted a study on factors predicting the immunogenicity of the monovalent pandemic H1N1 (pH1N1) influenza A vaccine in children with ALL. METHODS: Children with ALL in our hospital were recruited and received two doses of the inactivated split-virion AS03-adjuvanted vaccine. The serological response was measured before each vaccine dose (Day 0 and 28) and 3 months after the second dose. Antibody titres were measured using a hemagglutination-inhibition assay. Seroconversion was defined as a ≥fourfold increase in antibody titre and a post-vaccination titre ≥1:40. RESULTS: Pre and post-vaccination titres were available from 45 children with ALL after one dose of the vaccine and 39 children after two doses. The seroconversion rate was 11.1% after one dose and 25.6% after the second dose. Univariate analysis demonstrated a significantly higher (P = 0.01) seroconversion rate among children who received the adult dose (0.5 ml) of the vaccine and a trend towards increased seroconversion (P = 0.07) by multivariate analysis. Factors including age, gender, lymphocyte count, treatment phase and regimen did not significantly affect the seroconversion rate. Children who received the adult dose demonstrated a significantly greater magnitude of serological response after both one dose (P = 0.04) and two doses (P = 0.001). CONCLUSIONS: These data suggest that the immunogenicity of the pH1N1 vaccine among children with ALL is improved by repeated and adult doses of the vaccine.