Develop and Commercialize Thermo-stable PPR Vaccine

Thermal-Stable PPR Vaccine Research Activity

Research Centre: Veterinary Science Research Institute (VSRI) - Muguga

Principal Researcher: Dr. Duncan Ithinji

Research Background:

Peste des petits ruminants (PPR), caused by a virus similar to rinderpest is a widespread, virulent, and devastating sheep and goat infection with significant economic, food security, and livelihood impacts. The disease was first confirmed in Kenya and formally reported to the World Organisation for Animal Health (WOAH, founded as OIE) in 2007.

The disease is controlled mainly by vaccination using live attenuated vaccines. However, the vaccine currently available is heat labile requiring cold chain handling which is a challenge in ASALs due to the vastness and remoteness of these areas and high temperatures. Scientists in ASAL APRP used the technique of the Xerovac vaccine dehydration process to prepare a thermostable PPR vaccine that can be stored at ambient temperatures for long periods of time (up to 30 days) without significant loss of potency at room temperature (22-25oC). At 37oC the vaccine was viable for 15 days while at 42oC it was viable for only one day.

Efficacy tests in sheep and goats both on-station and on selected government farms showed good immune response with antibodies detectable up to six months onthe station. Similar observations were made under field conditions up to three months following vaccination. KALRO has supported the follow-up of these studies that require further funding to complete the proof of concept at one year post-vaccination. Further studies are required to provide data for the dossier needed to register the vaccine product. The following sub-activities are being implemented.

Research Objectives:

  1. Conclude vaccination trials (monitor vaccine efficacy one-year post-vaccination).
  2. Production of a test batch by KEVEVAPI (KEVEVAPI as co-applicant undertook the PPR vaccine development through a direct award).
  3. Registration and release of the product.

Achievements:

The vaccine was tested for routine vaccine tests. i.e., sterility, potency, vacuum and moisture This vaccine passed on these parameters. However, result from PANVAC lab in Ethiopia indicated that vaccine candidate did not pas test for thermostability. Therefore, the test is being repeated with adjustments in the methodology as advised by veterinary stakeholders.