Exploratory analyses to assess the impact of a CMV infection on the immunogenicity of a flu vaccine

Abstract

Introduction: Influenza virus infection, caused by influenza viruses, is a worldwide, highly contagious respiratory disease that is self-limiting in immunocompetent persons but life-threatening in immunocompromised subjects as well as in the older population. Of interest to the public health are H1N1 and H3N2 and the B strains of the virus. Research has shown that younger subjects respond better to influenza vaccines than the elderly. There are speculations that pathogens like the cytomegalovirus (CMV) may influence the response to influenza vaccine. The objective of this study is to investigate the relationship between the CMV status and response to the influenza vaccines; and to assess whether the response varies from one treatment group to another. Data and method: The data contains measurements for hemagglutinin inhibition serological tests based on ELISA technique to determine the CMV. Measurements of the response to the vaccine were based on seroconversion, seroprotection and Geometric Mean Titers (GMT). Exploratory analyses were carried out using test statistics, graphical techniques, Linear mixed models and Logistic regression. Result: Exploratory analyses with test statistics and graphical techniques revealed a potential difference between CMV seropositive and seronegative subjects in the response to influenza vaccine. Logistic regression models based on seroconversion provided evidence of an association between the CMV status and the response to influenza vaccine for strains H1N1 and B. Results from the linear mixed models provided evidence that the response to influenza vaccine varies between the treatment groups. Conclusion: CMV seronegative subjects respond better to influenza vaccines than CMV seropositive subjects for strains H1N1 and B based on the seroconversion seroresponse. Response to the influenza vaccine varies between treatment groups based on the GMT seroresponse.