Assessment of Immune Responses to a Trivalent Pichinde Virus-Vectored Vaccine Expressing Hemagglutinin Genes from Three Co-Circulating Influenza A Virus Subtypes in Pigs

• Published in: Vaccines (Basel) Vol. 11; no. 12; p. 1806
• Main Authors: Kumari, Sushmita, Chaudhari, Jayeshbhai, Huang, Qinfeng, Gauger, Phillip, De Almeida, Marcelo Nunes, Ly, Hinh, Liang, Yuying, Vu, Hiep L X
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 02-12-2023; MDPI
• Subjects: Adenoviruses; Analysis; Animal species; Antibodies; Antigens; Bronchus; Diseases; DNA testing; Evaluation; Genes; Genetic aspects; Hemagglutination inhibition; Hemagglutinins; Homology; Immune response; Immunization; Immunogenicity; Infections; Influenza; Influenza A; Influenza vaccines; Influenza viruses; Lavage; Neutralizing; Pichinde virus; Plasmids; Proteins; Respiratory diseases; Ribonucleic acid; RNA; RNA polymerase; Swine; swine influenza virus; vaccine platform; Vaccines; Vectors (Biology); viral vector vaccine; Viruses; United States; Iowa; Minnesota; Grand Island; United States > US; vaccine platform; swine influenza virus; viral vector vaccine; Pichinde virus
• ISSN: 2076-393X; 2076-393X
• DOI: 10.3390/vaccines11121806

Pichinde virus (PICV) can infect several animal species and has been developed as a safe and effective vaccine vector. Our previous study showed that pigs vaccinated with a recombinant PICV-vectored vaccine expressing the hemagglutinin (HA) gene of an H3N2 influenza A virus of swine (IAV-S) developed virus-neutralizing antibodies and were protected against infection by the homologous H3N2 strain. The objective of the current study was to evaluate the immunogenicity and protective efficacy of a trivalent PICV-vectored vaccine expressing HA antigens from the three co-circulating IAV-S subtypes: H1N1, H1N2, and H3N2. Pigs immunized with the trivalent PICV vaccine developed virus-neutralizing (VN) and hemagglutination inhibition (HI) antibodies against all three matching IAV-S. Following challenge infection with the H1N1 strain, five of the six pigs vaccinated with the trivalent vaccine had no evidence of IAV-S RNA genomes in nasal swabs and bronchoalveolar lavage fluid, while all non-vaccinated control pigs showed high number of copies of IAV-S genomic RNA in these two types of samples. Overall, our results demonstrate that the trivalent PICV-vectored vaccine elicits antibody responses against the three targeted IAV-S strains and provides protection against homologous virus challenges in pigs. Therefore, PICV exhibits the potential to be explored as a viral vector for delivering multiple vaccine antigens in swine.