Combating H3N2 influenza viruses of humans and swine by heterologous prime-boost vaccination strategies: studies in the pig model

Chepkwony, Sharon
Faculteit Diergeneeskunde
Vakgroep Virologie, Parasitologie en Immunologie
Sharon Cherotich Chepkwony completed her secondary education from Alliance Girls High School, in Kiambu, Kenya in 2003. She obtained her Bachelor of Education (Science) degree from Kenyatta University in Nairobi, Kenya, in 2010. In her Bachelor’s degree, she had a major in biology and a minor in chemistry. She enrolled for a Master of Science degree in immunology at the same university in 2011. Her Master thesis focused on herpesvirus studies in olive baboons. It aimed to investigate the distribution of herpesvirus papio 2 in wild caught olive baboons and identify the circulating strains in Kenya. The Masters research was conducted at the Institute of Primate Research in Nairobi, Kenya. In 2016, Sharon joined the Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, as a PhD student. Her research focused on vaccination studies with human and swine H3N2 influenza viruses in pigs, with emphasis on heterologous prime-boost vaccination. During her research, Sharon also carried out surveillance of swine influenza viruses in order to determine the evolutionary dynamics of these viruses. She has published a number of first-author and co-author papers in international peer-reviewed journals and given presentations in both national and international conferences.
Academische graad
Doctor in de diergeneeskundige wetenschappen
Taal proefschrift
Prof. Dr. Kristien Van Reeth, Faculty of Veterinary Medicine, Ghent University, Belgium - Prof. Dr. Eric Cox, Faculty of Veterinary Medicine, Ghent University, Belgium
Prof. Dr. Bart Pardon, Chair of the examination committee, Faculty of Veterinary Medicine, Ghent University - Prof. Dr. Timm Harder, Friedrich Loeffler Institute, Germany - Prof. Dr. Xavier Saelens, VIB, Ghent University Dr Sebastiaan Theuns, Pathosense Laboratory, Ghent University - Dr. Annebel De Vleeschauwer, Faculty of Veterinary Medicine, Ghent University - Dr. Mieke Steensels, Sciensano, Brussels

Korte beschrijving

This doctoral research examines the efficacy of heterologous prime-boost vaccination regimes against drifted H3N2 influenza A viruses of both humans and swine. All studies were performed in the pig model of influenza, with experimental whole inactivated influenza virus vaccines (WIV). The vaccines were based on various H3N2 strains of swine and humans and combined with an oil adjuvant. In previous research in the lab, we had obtained promising results by vaccinating pigs with a European H3N2 swine influenza A virus (swIAV) strain (A/swine/Gent/2008, swG08) followed one month later by an antigenically distinct North American H3N2 swIAV strain (A/swine/Pennsylvania/2010, swPA10). The serum antibodies induced by this strategy cross-reacted with 80% of a panel of 15 antigenically distinct H3N2 influenza viruses of humans and swine in virus neutralization assays. Like most experimental heterologous prime-boost studies, our previous study had been conducted in influenza naïve animals. This hampers extrapolation of the findings to humans, who have almost invariably been infected with one or several H3N2 influenza virus strains before the first administration of inactivated flu vaccine. In a first study of the doctoral research, we used pigs with pre-existing infection immunity against a historical human H3N2 virus strain, A/Nanchang/1995, to examine the efficacy of heterologous prime-boost vaccination with WIV based on swG08 and swPA10. We observed even higher and more cross-reactive serum antibody responses than in the previous study in naïve pigs. A novel and highly interesting finding was that boosting infection-immune pigs with WIV led to a recall of antibody secreting cell (ASC) responses in nasal mucosa and tracheobronchial lymph nodes.


Donderdag 25 februari 2021, 14:00
Diergeneeskunde, Salisburylaan 133, 9820 Merelbeke

Due to the current measurements against covid-19 the defence can only be followed by live stream. If you would like to participate in this video conference, please send an email to to receive a personal invitation.