Intervacc AB (publ) is first in the world to show that piglets were protected against the virulent and severe disease-causing S. suis Sequence Types 1 and 16 (serotype 2 and 9, respectively), by vaccinating sows and transferring maternal immunity to piglets. The protection was proven in two separate challenge studies.

Streptococcus suis is an important worldwide endemic swine pathogen, which causes meningitis, septicemia, arthritis, and endocarditis in weaned piglets between 4 and 10 weeks of age. Mortality rates can be as high as 20 % in some farms and the total cost of S. suis infection in pigs is estimated to more than EUR 250 million annually in Europe alone. As of today, there are no approved vaccines available against S. suis infection in pigs.

Protection against a broad spectrum of S. Suis strains

The experimental infection model involved the intravenous administration of a high dose of the virulent serotype 9 strain of S. suis (ST16) to induce systemic disease. The study showed that vaccination of pregnant sows was safe and provided statistically significant protection (total clinical score; p = 0,017) to piglets compared with piglets from an unvaccinated control group. The vaccine has previously conferred statistically significant protection to piglets against a virulent serotype 2 strain (ST1). The vaccine is administered to pregnant sows by intramuscular injection making it simple and cost-effective for pig farmers to use.

The subunit vaccine, which is based on Intervacc's platform using recombinant fusion proteins, is designed to give protection against a wide range of S. suis strain types, using conserved, immunogenic, and virulence-associated proteins from S. suis.

S. suis serotype 2 strains are the most common global cause of severe disease in piglets. Serotype 9 is currently less prevalent than serotype 2 but is increasingly responsible for severe pig diseases in Europe. Protection from a vaccine against multiple S. suis serotypes has been sought after by the pig farming industry for many years. Intervacc is the first company to show that a vaccine protected piglets against the highly virulent serotypes 2 (ST1) and 9 (ST16). This is a major breakthrough since the strains used in the studies are not closely related and the vaccine was only administered to pregnant sows with subsequent transfer of maternal immunity to their piglets.

Reduced need for antibiotics and improved profitability for pig farmers

It is estimated that S. suis accounts for one-third of the total antibiotic usage in weaner pigs. A safe and efficacious vaccine against S. suis would reduce the need for antibiotics and the global threat from antimicrobial resistance, play a significant role in improving animal welfare, and improve the profitability of the pig farming industry.

A game-changing breakthrough

"The significant levels of protection provided to piglets against these virulent and severe disease-causing types of S. suis, after the vaccination of pregnant sows, is novel and very encouraging" says Dr. Andrew Waller, Chief Scientific Officer at Intervacc. "These data underline the strengths of our technology platform, which generate broad immune responses that target multiple virulence pathways required by complex bacterial pathogens".

"This breakthrough is a game-changer in the fight to protect pigs from the severe disease-causing strains of S. suis and merit its further development into a commercial vaccine" says Carl-Johan Dalsgaard CEO of Intervacc.

Intervacc will continue advancing the vaccine and prepare for GMP manufacturing and pivotal clinical studies.

For more information please contact:  

Carl-Johan Dalsgaard, CEO

Tel: +46 (0)8 120 10 600

Email: carl-johan.dalsgaard@intervacc.se

This information is information that Intervacc AB (publ) is obliged to make public pursuant to the EU Market Abuse Regulation. The information was submitted for immediate publication, through the agency of the contact person set out above on March 19, 2026.

About Intervacc

Intervacc AB is an animal health group that develops vaccines for animals. The company's vaccines and vaccine candidates are based on many years of research at the Karolinska Institute and the Swedish University of Agricultural Sciences. The Intervacc share (Nasdaq: IVACC) is listed on the Nasdaq First North Growth Market. For more information, see intervacc.se

About the study

The latest study is part of a project co-funded by the Eurostars 3 program, which is part of the European Union's framework program for research and innovation, and was conducted in collaboration with Moredun Scientific in the UK.

About Moredun Scientific

Moredun Scientific is a contract research organisation specialising in animal health and biosafety testing of biopharmaceuticals enabling companies to develop, register and commercialize their products. Their expert staff work with a global client base to ensure on time delivery of studies to the required quality standards. For more information, see www.moredun.org.uk

Contact information for Certified Adviser

Eminova Fondkommission AB

E-mail: adviser@eminova.se, Phone: +46 (0)8 - 684 211 10