A leptospirosis vaccine holds the promise of immunity from acquiring leptospirosis. However, as of present, scientists are still looking for the perfect vaccine for leptospirosis, one that can provide longer lasting immunity and will be effective regardless of the serotypes present in an area.

Leptospirosis is a disease caused by infection with Leptospira bacteria. It is commonly transmitted to the victim when unhealed wounds, the eyes, or the mucous membranes come into contact with objects or environment that has been contaminated with the infected animals’ urine.

The most common types of vaccines for the prevention of leptospirosis that we see now are made from attenuated bacteria. This and the fact that there are countless of Leptospires serotypes in existence prove to be the Achiles’ heel of the available leptospirosis vaccines today. Attenuated vaccines do not last long and they are only useful for certain serotypes. Dr. Sharon Villanueva of the Kyushu University (KU) Department of Bacteriology explained, â€œInactivated or attenuated vaccines in one country cannot be used in another because the prevailing Leptospira serovars is different from each country.”

To solve the problems in the existing leptospirosis vaccines, Dr. Villanueva and other researchers started the study, Pathogenicity Studies of Four Leptospira Isolates from the Philippines and Cocktail DNA Vaccination Trial Using Golden Syrian Hamster. Under the collaborative support of the Philippine Council for Health Research and Development of the Department of Science and Technology (PCHRD-DOST), Japan International Cooperation Agency (JICA), World Health Organization (WHO), University of the Philippines Manila (UPM), and KU, the research experimented with Golden Syrian Hamsters using proteins that have been suspected as virulence factors of leptospirosis.

Dr. Villanueva said, â€œThe challenge now is to develop a safe vaccine that will elicit longer lasting immunity, a vaccine that is effective against multiple Leptospira serotypes. Our study aims to develop a universal vaccine, so to speak.