Effect of influenza virus vaccine on the expression of human immunodeficiency virus co-receptor CCR5

Influenza vaccination for immunocompromised patients: systematic review and meta-analysis from a public health policy perspective

BACKGROUND

Immunocompromised patients are vulnerable to severe or complicated influenza infection. Vaccination is widely recommended for this group. This systematic review and meta-analysis assesses influenza vaccination for immunocompromised patients in terms of preventing influenza-like illness and laboratory confirmed influenza, serological response and adverse events.

METHODOLOGY/PRINCIPAL FINDINGS

Electronic databases and grey literature were searched and records were screened against eligibility criteria. Data extraction and risk of bias assessments were performed in duplicate. Results were synthesised narratively and meta-analyses were conducted where feasible. Heterogeneity was assessed using I(2) and publication bias was assessed using Begg's funnel plot and Egger's regression test. Many of the 209 eligible studies included an unclear or high risk of bias. Meta-analyses showed a significant effect of preventing influenza-like illness (odds ratio [OR]=0.23; 95% confidence interval [CI]=0.16-0.34; p<0.001) and laboratory confirmed influenza infection (OR=0.15; 95% CI=0.03-0.63; p=0.01) through vaccinating immunocompromised patie nts compared to placebo or unvaccinated controls. We found no difference in the odds of influenza-like illness compared to vaccinated immunocompetent controls. The pooled odds of seroconversion were lower in vaccinated patients compared to immunocompetent controls for seasonal influenza A(H1N1), A(H3N2) and B. A similar trend was identified for seroprotection. Meta-analyses of seroconversion showed higher odds in vaccinated patients compared to placebo or unvaccinated controls, although this reached significance for influenza B only. Publication bias was not detected and narrative synthesis supported our findings. No consistent evidence of safety concerns was identified.

CONCLUSIONS/SIGNIFICANCE

Infection prevention and control strategies should recommend vaccinating immunocompromised patients. Potential for bias and confounding and the presence of heterogeneity mean the evidence reviewed is generally weak, although the directions of effects are consistent. Areas for further research are identified.

Short communication: immunogenicity of an inactivated influenza vaccine and postvaccination influenza surveillance in HIV-infected and noninfected children and adolescents

Individuals infected with HIV are at higher risk for severe cases of seasonal influenza infection and should receive annual doses of vaccine. Our objectives were to evaluate the immunogenicity of an influenza vaccine in 37 HIV-infected patients (HIV group) compared to 29 uninfected individuals (control group) and to carry out a clinical and virological surveillance of influenza during a 6-month follow-up. Both groups received the vaccine recommended for the southern hemisphere in 2008. Antibody responses to antigens H1N1, H3N2, and B were measured in blood samples at vaccination (T0) and after 1 month (T1). Influenza surveillance was performed by weekly telephone calls for a follow-up period of 6 months. Nasal washes were taken from subjects with respiratory symptoms. The direct immunofluorescence assay in house polymerase chain reaction (PCR) and real-time PCR were used for the detection of different respiratory viruses. The median age of the participants was 13.3 years (sd = 2.2) and 12.1 years (sd = 1.3) for the HIV group and control group, respectively. One month after vaccination (T1), both groups showed significant increases in the antibody geometric mean titers (GMTs) for all antigens. However, healthy controls showed higher values for antigens A/H1N1 and A/H3N2 (p = 0.002 and 0.001, respectively). There was a higher increase in the percentage of HIV-uninfected subjects with protective A/H1N1 antibodies (96.6%) compared to HIV-infected vaccinees (67.6%) at T1 (p = 0.004). Rhinovirus (27.7%) and coronavirus (22.5%) were the most prevalent agents identified in HIV-infected individuals. In the control group, the viruses most frequently found were rhinovirus (24.2%) and adenovirus (21.2%). The seroprotection rate for the H1N1 antigen was higher in the control group, which also showed a greater increase in GMTs for H1N1 and H3N2 antigens after immunization. Viral agents were identified in 39/60 (65%) episodes of respiratory infections from the HIV-infected group and in 17/32 episodes (53.1%) from the control group (p = 0.273).