Children: Better Protection from Influenza With Improved Vaccine

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Source: http://www.sciencedaily.com/releases/2012/04/120403193735.htm

Children: Better Protection from Influenza With Improved Vaccine

ScienceDaily (Apr. 3, 2012) ? An intranasal vaccine that includes four weakened strains of influenza could do a better job in protecting children from the flu than current vaccines, Saint Louis University research shows.

Before each influenza season, scientists predict which strains of flu will be circulating and make a trivalent vaccine that includes three strains of influenza -- two of influenza A and one of influenza B.

The ability to add another strain of influenza B without compromising the vaccine's ability to protect against the other three strains will allow scientists make a better vaccine, said Robert Belshe, M.D., professor of infectious diseases at Saint Louis University School of Medicine and the corresponding author of the research article.

"The bottom line is adding another strain to make a quadrivalent vaccine improves our ability to protect against flu and doesn't reduce the body's immune response to the other strains," said Belshe, who also directs Saint Louis University's Center for Vaccine Development.

"It should bring us better protection because there's less guess work than in the standard trivalent vaccine..."

...Journal Reference:

1. Stan L. Block, Judith Falloon, Jeffrey A. Hirschfield, Leonard R. Krilov, Filip Dubovsky, Tingting Yi, Robert B. Belshe. The Immunogenicity and Safety of a Quadrivalent Live Attenuated Influenza Vaccine in Children. The Pediatric Infectious Disease Journal, 2012; : 1 DOI: 10.1097/INF.0b013e31825687b0

 

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Re: Children: Better Protection from Influenza With Improved Vaccine

Pediatr Infect Dis J. 2012 Mar 29. [Epub ahead of print]
The Immunogenicity and Safety of a Quadrivalent Live Attenuated Influenza Vaccine in Children.
Block SL, Falloon J, Hirschfield JA, Krilov LR, Dubovsky F, Yi T, Belshe RB.
Source

1 Kentucky Pediatric and Adult Research, Bardstown, Kentucky 2 MedImmune, LLC, Gaithersburg, MD 3 Score Physician Alliance, Saint Petersburg, FL 4 Children's Medical Center, Winthrop University Hospital, Mineola, NY 5 Saint Louis University School of Medicine, Saint Louis, MO.
Abstract
BACKGROUND:

Influenza B viruses from 2 lineages co-circulate annually. Because the single B strain contained in trivalent vaccines may not match the major circulating strain, adding a second B virus could enhance protection. This study compared the safety and immunogenicity of an investigational quadrivalent Ann Arbor strain live attenuated influenza vaccine (Q/LAIV) with that of 2 trivalent vaccines (T/LAIV) each containing a B strain from a different lineage.
METHODS:

This randomized, double-blind study was designed to demonstrate the immunologic noninferiority of Q/LAIV compared with T/LAIV in children 2-17 years of age by comparing post-dose geometric mean titers (GMT) of hemagglutination inhibition antibodies. Children were randomized 3:1:1 to receive Q/LAIV or 1 of 2 T/LAIV vaccines. Those subjects who were 9-17 years received 1 dose, and those 2-8 years of age received 2 doses 1 month apart. Serum immune responses were evaluated 1 month after dose 1 (dose 2 for influenza vaccine-naive subjects aged 2-8 years).
RESULTS:

Q/LAIV was noninferior to T/LAIV: upper bounds for all four 95% confidence intervals for the post-dose GMT ratios (T/LAIV ? Q/LAIV) were ≤1.5, the predefined noninferiority margin. The overall seroresponse rates (4-fold rise) were comparable between treatment groups. Safety events were comparable, except that fever was more common after dose 1 in Q/LAIV subjects (5.1%) than in T/LAIV subjects (3.1%) 2-8 years of age.
CONCLUSIONS:

The immunogenicity of Q/LAIV was noninferior to that of T/LAIV in children aged 2-17 years; safety was also comparable. Q/LAIV may broaden the protection against influenza B strains provided by current trivalent influenza vaccines.

PMID:
22466322
[PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/pubmed/22466322