Effect of recent seasonal #influenza #vaccination on #serum #antibody responses to candidate #pandemic influenza A/ #H5N1 vaccines: A meta-analysis (Vaccine, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Vaccine. 2019 May 31. pii: S0264-410X(19)30554-7. doi: 10.1016/j.vaccine.2019.04.066. [Epub ahead of print]

Effect of recent seasonal influenza vaccination on serum antibody responses to candidate pandemic influenza A/H5N1 vaccines: A meta-analysis.

Keitel WA1, Voronca DC2, Atmar RL3, Paust S4, Hill H2, Wolff MC2, Bellamy AR2; VTEU H5N1 Vaccine Working Group.

Author information: 1 Departments of Molecular Virology & Microbiology and Medicine, Baylor College of Medicine, Houston, TX, United States. Electronic address: wkeitel@bcm.edu. 2 Emmes, Rockville, MD, United States. 3 Departments of Molecular Virology & Microbiology and Medicine, Baylor College of Medicine, Houston, TX, United States. 4 Departments of Molecular Virology & Microbiology and Medicine, Baylor College of Medicine, Houston, TX, United States; Department of Pediatrics-Center for Human Immunobiology, Texas Children’s Hospital, Houston, TX, United States.



Recent studies have suggested that among those receiving seasonal influenza vaccine (SIV), reduced immunogenicity is observed in recently vaccinated (RV; within the past season or 2) persons when compared with those not recently vaccinated (NRV). We performed a meta-analysis to assess the effect of recent immunization with SIV on serum H5 hemagglutination inhibition (HAI) antibody responses after influenza A/H5N1 vaccination using data from a series of randomized controlled trials. The primary outcome was seroconversion measured by HAI assays following receipt of 2 doses of H5N1 vaccine. The geometric mean titer (GMT) of serum HAI antibody after vaccination was the secondary outcome. Analyses were performed using propensity score (PS) matching. The PS for each individual in the meta-analysis cohort was calculated using logistic regression and covariates included age, gender, race, antigen dose, adjuvant, statin use and vaccine manufacturer. 2015 subjects enrolled in 7 clinical trials were eligible for inclusion in the meta-analysis cohort; among these, 915 (45%) were RV. 901 RV subjects were matched (1:1) with replacement to a subject who was NRV. Subjects who received SIV within the previous season were significantly less likely to seroconvert following H5N1 vaccination (adjusted odds ratio 0.76; 95%CI 0.60-0.96; p = 0.024), and the GMT was 18% higher among NRV subjects (GM ratio of HAI antibody 1.18; 95%CI 1.04-1.33; p = 0.008). Further work is needed to better define the effects of, and mechanisms contributing to, reduced immune responses to H5N1 vaccine among RV subjects.

Copyright © 2019 Elsevier Ltd. All rights reserved.

KEYWORDS: Antibody responses; H5N1; Influenza; Meta-analysis; Repeated vaccination; Vaccines

PMID: 31160101 DOI: 10.1016/j.vaccine.2019.04.066

Keywords: Seasonal Influenza; Avian Influenza; H5N1; Vaccines.


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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.