T-cell responses in children to internal influenza antigens, 1 year after immunization with pandemic H1N1 influenza vaccine, and response to revaccination with seasonal trivalent-inactivated influenza vaccine.

Abstract

BACKGROUND:

During seasonal influenza epidemics, 5-15% of the population are affected with an illness having a nontrivial mortality, morbidity and economic burden. Inactivated influenza vaccines are routinely used to prevent influenza infection, primarily by inducing humoral immunity. In addition, trivalent-inactivated influenza vaccines have previously been shown to boost influenza-specific T-cell responses in a small percentage of adults. We investigate here the influenza-specific T-cell response, in children, 1 year after pandemic H1N1 vaccination and the ability to boost the T-cell response with trivalent-inactivated influenza immunization.

METHODS:

Peripheral blood mononuclear cells (PBMCs) were isolated from children previously vaccinated with pandemic H1N1 vaccine, pre- and postseasonal 2010-2011 trivalent influenza vaccine (TIV) vaccination. Samples were analyzed by interferon-gamma enzyme-linked immunosorbent spot for reactogenicity toward internal influenza antigens (nucleoprotein, matrix protein 1 and nonstructural protein 1).

RESULTS:

Basal ex vivo T-cell responses to nucleoprotein, matrix protein 1 and nonstructural protein 1 measured by interferon-gamma enzyme-linked immunosorbent spot assay were significantly higher in those children who had previously received an AS03B-adjuvanted split virion pandemic vaccine 12 months earlier rather than a nonadjuvanted whole virion vaccine. Boosting of these responses, 21 days after 2010/2011 seasonal TIV vaccination was observed regardless of age or prior pandemic vaccination regime, although boosting was greater in those groups with the lowest initial response.

CONCLUSIONS:

We show here that children previously vaccinated with the 2009 pandemic H1N1 vaccine have measurable T-cell responses 1 year after vaccination. The magnitudes of these responses are dependent on both age of vaccine and type of pandemic H1N1 vaccine used. After 2010/2011 seasonal TIV vaccination, these T-cell responses undergo a small but significant boost.

• Authors: Teresa Lambe, Alexandra J Spencer, Caitlin E Mullarkey, Richard D Antrobus, Ly-Mee Yu, Philip de Whalley, Ben A V Thompson, Claire Jones, Jem Chalk, Simon Kerridge, Adrian V S Hill, Matthew D Snape, Andrew J Pollard, Sarah C Gilbert
• Journal: The Pediatric infectious disease journal (Pediatr Infect Dis J) Vol. 31 Issue 6 Pg. e86-91 (Jun 2012) ISSN: 1532-0987 [Electronic] United States
• PMID: 22466328 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antigens, Viral
• Influenza Vaccines
• Vaccines, Inactivated
• Interferon-gamma

Topics

• Antigens, Viral (immunology)
• Cells, Cultured
• Child
• Child, Preschool
• Female
• Humans
• Immunization, Secondary (methods)
• Infant
• Influenza A Virus, H1N1 Subtype (immunology)
• Influenza Vaccines (administration & dosage, immunology)
• Influenza, Human (prevention & control)
• Interferon-gamma (metabolism)
• Leukocytes, Mononuclear (immunology)
• Male
• Vaccines, Inactivated (administration & dosage, immunology)