The Friedrich-Loeffler-Institut (FLI) reports improved protection of pigs against influenza viruses. The study "Novel recombinant vaccines provide improved protection against influenza in piglets" has now been published in the journal "npj vaccines". It was carried out jointly by the FLI on the island of Riems-Greifswald (Timm Harder group), the Institute of Virology at the University of Freiburg (Martin Schwemmle group) and the Institute of Virology and Immunology (IVI) in Bern/Mittelhäusern (Gert Zimmer group).
Influenza A viruses cause an economically important respiratory disease in modern pig production. This can lead to continuous virus transmission between animals, which is difficult to control. Conventional vaccines based on inactivated influenza viruses, which are almost exclusively used in sows, cannot completely solve the problem. The aim of this study was to test new vaccine candidates that could also be used directly in piglets.
To this end, piglets from an affected herd were immunised with two novel recombinant vaccines. The first vaccine was a live attenuated vaccine based on a bat influenza virus that is unable to exchange gene segments with pig or human influenza A viruses. The other vaccine was based on RNA replicon particles derived from a vesicular stomatitis virus (VSV) that is unable to replicate. Both vaccines contained the genetic information for proteins of a swine influenza virus against which protective immunity was to be induced. In stress infections of the animals with a swine influenza virus, the new recombinant vaccines provided clearly improved protection compared to two conventional vaccines.
The two new vaccine candidates could help to interrupt the continuous transmission of influenza A viruses in pig herds. This would improve the health status of the animals and also reduce the risk of transmission of swine influenza viruses to humans.
This study was funded by the European ICRAD project "PIGIE" (number 2821ERA24), the Swiss National Fund (grant number IZCOZO_189903) and the German Research Foundation (grant number DFG-434507207).
Publication
Graaf-Rau, A., Schmies, K., Breithaupt, A. et al. Reassortment incompetent live attenuated and replicon influenza vaccines provide improved protection against influenza in piglets. npj Vaccines 9, 127 (2024).
DOI: 10.1038/s41541-024-00916-x
