Abstract
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. <xref ref-type="sec" rid="s3">Results</xref> 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.
| Original language | English |
|---|---|
| Article number | e29249 |
| Journal | PLoS ONE |
| Volume | 6 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 22 Dec 2011 |
Bibliographical note
Funding Information:The University of Nottingham Health Protection Research Group is currently in receipt of research funds from GlaxoSmithKline (GSK). The group has recently accepted an unrestricted educational grant for influenza research from F. Hoffmann-La Roche. Research on influenza funded by an unrestricted educational grant from Astra Zeneca is also underway. The aforementioned funding received from GSK, F. Hoffmann-La Roche and Astra Zeneca did not support any aspect of this study. JSN-V-T has received funding to attend influenza related meetings, lecture and consultancy fees and research funding from several influenza antiviral drug and vaccine manufacturers. All forms of personal remuneration ceased in September 2010, but influenza-related research funding from GlaxoSmithKline, F. Hoffmann-La Roche and Astra-Zeneca remains current. He is a former employee of SmithKline Beecham plc. (now GlaxoSmithKline), Roche Products Ltd, and Aventis-Pasteur MSD (now Sanofi-Pasteur MSD), al l prior to 2005, with no outstanding pecuniary interests by way of shareholdings, share options or accrued pension rights. AZ has received fees for participating in review activities from the Global Influenza Programme, World Health Organization. JE has received consultancy fees from GSK. This does not alter our adherence to all the PLoS ONE policies on sharing data and materials.
