Abstract
IntroductionCotton rats are a suitable model for the study of influenza disease symptoms and responses to influenza vaccination. We have previously shown that two immunizations with 15 µg whole inactivated virus (WIV) influenza vaccine could completely protect animals from infection with the H1N1pdm09 virus.MethodsTo further explore the cotton rat model, we here investigated the protective potential of a single intramuscular immunization and of prime/boost intramuscular immunizations with a low amount of antigen.ResultsA single intramuscular immunization with doses more than or equal to 0.5 µg WIV reliably evoked antibody responses and doses more than or equal to 1 µg protected the animals from virus replication in the lungs and from severe weight loss. However, clinical symptoms like an increased respiration rate were still apparent. Administration of a booster dose significantly increased the humoral immune responses but did not or only moderately improved protection from clinical symptoms.ConclusionOur data suggest that complete and partial protection by influenza vaccines can be mimicked in cotton rats by using specific vaccination regimens.
Highlights
Cotton rats are a suitable model for the study of influenza disease symptoms and responses to influenza vaccination
We demonstrate that all immunized animals developed a humoral immune response against the vaccine strain
A single immunization with a dose more than 0.5 μg antigen as well as prime/boost immunization before virus challenge resulted in reduction of lung virus titer and improved survival but had rather moderate effects on clinical symptoms
Summary
Cotton rats (Sigmodon hispidus) have been used as a small animal model for respiratory virus infections such as human parainfluenza virus, respiratory syncytial virus, measles virus, human metapneumovirus, as well as for the study of influenza virus infection and pathogenesis.[1,2,3,4,5,6,7] All these respiratory viruses can replicate in cotton rats and induce pathogenesis similar to that in humans. We have shown earlier that through intramuscular or pulmonary immunization with a high vaccine dose, 15 μg whole inactivated virus (WIV) vaccine, cotton rats can be protected completely against replication of H1N1pdm virus in the lungs and against the development of severe clinical symptoms.[18] To get more insight into the model, we here assessed the effect of vaccine dose and vaccination regimen on humoral immune responses and the protective potential in detail To this end, we immunized cotton rats once or twice with low doses of a WIV influenza vaccine derived from an H1N1pdm[09] vaccine strain and challenged the animals with a clinical isolate of H1N1pdm[09] virus. The tested vaccination regimens allow studying different scenarios as encountered in humans
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
