Published on 25 November 2024

Novel recombinant vaccines provide improved protection against influenza in piglets

Porcine influenza A viruses cause an economically significant respiratory disease in modern pig production. Continual virus transmission between animals and progressive antigen drift are difficult to control in chronically infected pig herds.

Why is this study important?

Chronic infection of pig herds with influenza A viruses is difficult to control using commercial vaccines based on inactivated influenza viruses. This study therefore sought to compare two new candidate vaccines with inactivated influenza vaccines.

Description of the study

The vaccination study now published in the journal «npj vaccines» was conducted jointly by the Friedrich Löffler Institute (FLI) in Riems-Greifswald (Timm Harder working group), the Institute of Virology at the University of Freiburg in Breisgau (Martin Schwemmle working group) and the Institute of Virology and Immunology (IVI) in Bern/Mittelhäusern (Gert Zimmer working group). Piglets from a herd chronically infected with porcine influenza A viruses of subtype H1N2 were immunised with two novel recombinant vaccines:

  • The first vaccine was an attenuated live vaccine based on a bat influenza virus that is unable to exchange gene segments with porcine or human influenza A viruses.
  • The second vaccine is based on RNA replicon particles derived from a vesicular stomatitis virus (VSV) that is unable to replicate.

Both vaccines contained the genetic information for both the H1 and the N2 antigen of the enzootically circulating porcine influenza viruses. Stress infection of the vaccinated piglets showed that both the live vaccine and the replicon vaccine significantly reduced virus replication in the upper and lower respiratory tract. In contrast, a commercial vaccine and an autologous adjuvanted completely inactivated vaccine conferred little or no protection against porcine H1N1 viruses.

What are the main findings?

Both new vaccines can help to interrupt the continual transmission of influenza A viruses in large enzootically infected pig herds, improve the animals’ health status and reduce the risk of zoonotic transmission to humans.

Title 

«Reassortment incompetent live attenuated and replicon influenza vaccines provide improved protection against influenza in piglets»

Authors
Annika Graaf-Rau, Kathrin Schmies, Angele Breithaupt, Kevin Ciminski, Gert Zimmer, Artur Summerfield, Julia Sehl-Ewert, Kathrin Lillie-Jaschniski, Carina Helmer, Wiebke Bielenberg, Elisabeth grosse Beilage, Martin Schwemmle, Martin Beer, and Timm Harder

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