Efficacy of swine influenza A virus vaccines on transmission, viral shedding and clinical signs: Systematic review and meta-analysis
Abstract
Swine influenza A viruses (swIAV) are a major cause of respiratory disease in pigs, and vaccination remains the main control strategy. The objective of this systematic review and meta-analysis was to quantify the efficacy of swIAV vaccines in pigs, regarding viral transmission, viral shedding and clinical signs. Data were extracted from experimental studies involving vaccinated pigs subsequently challenged with swIAV. The review followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Article selection was performed using two approaches: conventional dual-reviewer screening and ASReview, an artificial intelligence-based tool for systematic reviews. A total of 163 publications met the eligibility criteria, and data were extracted from 146 studies. Meta-analyses were conducted on 11 articles for transmission, 72 for shedding, and 89 for clinical signs. Vaccination, both homologous and heterologous, significantly reduced the median transmission rate (β) and the median reproduction ratio (R) compared to unvaccinated controls. However, the median R-values remained above 1 (4.15 for heterologous and 1.44 for homologous challenges), indicating continued potential for outbreak occurrence. Vaccination also significantly reduced both mean and peak viral shedding, with standardized mean differences of –0.53 and –0.25, respectively. A generalized linear mixed model revealed a strong effect of vaccination under homologous challenge conditions. Meta-regression confirmed the influence of vaccine and challenge type on shedding outcome. No statistically significant difference in body temperature was found between vaccinated and control groups. This review highlights the need for greater harmonization in experimental study design and reporting, to improve the comparability of swIAV vaccine efficacy studies.
Related
- Combined Vaccination with Recombinant HVT-ND and Live Newcastle Disease Vaccines Accelerates Early Immunity, Limits Virus Shedding and Reduces Transmission.
- Epitope-guided optimization improves the protective efficacy of NA-based mRNA vaccines against seasonal influenza A(H3N2) virus.
- Comparative immunogenicity and relative vaccine efficacy of recombinant and cell culture-based influenza vaccines: Results from a randomized trial of adults in the United States, 2024-2025
- Immunogenicity and safety of seasonal influenza vaccine co-administered with other vaccines: a systematic review and meta-analysis.
- Efficacy of severe fever with thrombocytopenia syndrome vaccines in animal models: a systematic review and meta-analysis
BibTeX
@article{mtaallah2026efficacy,
title = {{Efficacy of swine influenza A virus vaccines on transmission, viral shedding and clinical signs: Systematic review and meta-analysis}},
author = {Oumaima Mtaallah and Evelien A. Germeraad and Gavrila Amadea Puspitarani and Bastien Bayle and Uyen H.P. Nguyen and Marina Meester and Arjan Stegeman and Andrea Apolloni and Claire Hautefeuille},
journal = {Preventive Veterinary Medicine},
year = {2026},
month = oct,
doi = {10.1016/j.prevetmed.2026.106877},
url = {https://hal.science/hal-05772947v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Efficacy of swine influenza A virus vaccines on transmission, viral shedding and clinical signs: Systematic review and meta-analysis
AU - Oumaima Mtaallah
AU - Evelien A. Germeraad
AU - Gavrila Amadea Puspitarani
AU - Bastien Bayle
AU - Uyen H.P. Nguyen
AU - Marina Meester
AU - Arjan Stegeman
AU - Andrea Apolloni
AU - Claire Hautefeuille
PY - 2026
DA - 2026/10/01
JO - Preventive Veterinary Medicine
DO - 10.1016/j.prevetmed.2026.106877
UR - https://hal.science/hal-05772947v1
AB - Swine influenza A viruses (swIAV) are a major cause of respiratory disease in pigs, and vaccination remains the main control strategy. The objective of this systematic review and meta-analysis was to quantify the efficacy of swIAV vaccines in pigs, regarding viral transmission, viral shedding and clinical signs. Data were extracted from experimental studies involving vaccinated pigs subsequently challenged with swIAV. The review followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Article selection was performed using two approaches: conventional dual-reviewer screening and ASReview, an artificial intelligence-based tool for systematic reviews. A total of 163 publications met the eligibility criteria, and data were extracted from 146 studies. Meta-analyses were conducted on 11 articles for transmission, 72 for shedding, and 89 for clinical signs. Vaccination, both homologous and heterologous, significantly reduced the median transmission rate (β) and the median reproduction ratio (R) compared to unvaccinated controls. However, the median R-values remained above 1 (4.15 for heterologous and 1.44 for homologous challenges), indicating continued potential for outbreak occurrence. Vaccination also significantly reduced both mean and peak viral shedding, with standardized mean differences of –0.53 and –0.25, respectively. A generalized linear mixed model revealed a strong effect of vaccination under homologous challenge conditions. Meta-regression confirmed the influence of vaccine and challenge type on shedding outcome. No statistically significant difference in body temperature was found between vaccinated and control groups. This review highlights the need for greater harmonization in experimental study design and reporting, to improve the comparability of swIAV vaccine efficacy studies.
SN - 0167-5877
SN - 0167-5877
ER -