Efficacy of trivalent inactivated influenza vaccines in the cotton rat Sigmodon hispidus model.

Abstract

Annually adjusted inactivated influenza vaccines can prevent infection and limit the spread of seasonal influenza when vaccine strain closely matches circulating strain. For the years when the match is difficult to achieve, a rapid screening of a larger repertoire of vaccines may be required but is difficult to accomplish due to the lack of a convenient small animal model of seasonal influenza vaccines. The goal of this work was to determine whether the cotton rat Sigmodon hispidus, a small laboratory animal susceptible to infection with unadapted influenza viruses, may become such a model. Cotton rats were immunized with a trivalent inactivated vaccine (TIV) FluLaval (2006/2007) and vaccine immunogenicity and antiviral efficacy was evaluated against the homologous H1N1 and a heterologous H3N2 challenge. FluLaval induced a strong virus-specific IgG and neutralizing antibody response against homologous virus, elicited sterilizing immunity in the lungs and significantly reduced viral replication in the nose of infected animals. FluLaval was efficacious in cotton rats as either a single-time or a double immunization, although higher level of protection of the upper respiratory tract was achieved following two doses of vaccine. Antibodies against a heterologous influenza strain were induced in FluLaval-vaccinated animals, but vaccine lacked antiviral efficacy and did not reduce replication of a heterologous virus. Similarity of these findings to human TIV data suggests that the cotton rat may prove to be a reliable small animal model of human influenza vaccines.

• Authors: Kevin Yim, Brian Miles, Rachel Zinsou, Gregory Prince, Marina Boukhvalova
• Journal: Vaccine (Vaccine) Vol. 30 Issue 7 Pg. 1291-6 (Feb 08 2012) ISSN: 1873-2518 [Electronic] Netherlands
• PMID: 22210139 (Publication Type: Journal Article)
• Copyright: Copyright © 2011 Elsevier Ltd. All rights reserved.

Chemical References

• Antibodies, Neutralizing
• Antibodies, Viral
• FluLaval
• Immunoglobulin G
• Influenza Vaccines
• Vaccines, Inactivated

Topics

• Animals
• Antibodies, Neutralizing (biosynthesis, immunology)
• Antibodies, Viral (biosynthesis, immunology)
• Disease Models, Animal
• Immunoglobulin G (biosynthesis, immunology)
• Influenza A Virus, H1N1 Subtype (drug effects, immunology, pathogenicity)
• Influenza A Virus, H3N2 Subtype (drug effects, immunology, pathogenicity)
• Influenza Vaccines (immunology)
• Lung (drug effects, immunology, virology)
• Nose (drug effects, immunology, virology)
• Orthomyxoviridae Infections (immunology, prevention & control, virology)
• Sigmodontinae
• Vaccination
• Vaccines, Inactivated (immunology)
• Viral Load (drug effects, immunology)
• Virus Replication (drug effects)