A Rapid Immune Response to 2009 Influenza A(H1N1) Vaccines in Adults: A Randomized, Double‐Blind, Controlled Trial

Abstract

A double-blind, randomized, controlled trial involving 706 adults was conducted to evaluate the immunogenicity and safety of different dosages of whole-virion or split-virion H1N1 influenza vaccines with or without aluminum adjuvant. A rapid and strong immune response was induced at day 14 after the first injection. The seroprotection rates ranged from 72.7% (95% confidence interval [CI], 62.7%-81.1%) for 5-microg whole-virion aluminum formulation to 97.0% (95% CI, 90.9%-99.7%) for 30-microg split-virion nonaluminum formulation. All formulations were well tolerated. The incidences of mild, moderate, and severe reactions were 71 (10.1%), 15 (2.1%), and 1 (0.1%) of 706 reactions, respectively. The 15-microg split-virion formulation had the best immunogenicity and safety.

Non-publication and delayed publication of randomized trials on vaccines: a survey

“…In a previous analysis we found that two years after the emergence of the influenza 2009 H1N1 pandemic less than 30% of the 73 registered randomized trials on the potential vaccines had been published, representing 38% of the randomized sample size. 7 The present update showed a relevant improvement, as four years after trial completion the results of approximately 80% of the randomized participants had been published (90% including results in ClinicalTrials.gov). However, data published more than four years (or even one year) after a pandemic (and vaccine distribution) are already of little or no value.…”

“…2 31 Also, there is a substantial literature in various specialties that trials with non-significant, less favorable, or even "negative" results are more likely to be unpublished or published late compared with significant trials or trials with results that are in line with investigators' hypotheses. 7 14 16 17 19 21 23 32-37 Furthermore, half of the 16 studies on the topic documented a lower likelihood of publication for the trials sponsored by industry. 10 23 36 38-41 Vaccine trials are largely dominated by industry sponsorship.…”

“…[5][6][7] Although several studies have estimated the proportion of incomplete or selective reporting in various specialties, to our knowledge only two studies have focused on vaccines. 8 9 A first analysis evaluated the completeness of reporting of 70 randomized controlled trials of two vaccines based on the CONSORT 2010 checklist but did not assess delay to publication.…”

Influenza Vaccination for Secondary Prevention of Cardiovascular Events: A Systematic Review

“…Other trials have reported a low incidence of adverse effects (0%-3%) and no significant difference in serious adverse events between influenza vaccine and placebo. [15][16][17] Of the RCTs, FLUCAD 31 was likely the most well designed. The authors attempted to minimize bias and confounding through appropriate randomization, use of intention-to-treat analyses, and minimal loss to follow-up.…”

“…14 However, in prospective randomized trials that included CV outcomes for safety assessment, influenza vaccination was not associated with a reduction in CV events, [15][16][17][18] although these trials were limited by low event rates and potential for misclassification. 19 Both the American Heart Association/American College of Cardiology and the European Society of Cardiology recommend the influenza vaccine annually for individuals with established CVD [20][21][22] without specifically stating that the purpose is to reduce the risk of CV events.…”