Evaluation of the stability of the vaccine against Contagious Bovine Nodular Dermatitis, “DERMAPOX,” under accelerated conditions, produced by the Central Veterinary Laboratory of Bamako (Mali)

Lumpy Skin Disease (LSD) still remains a major health problem in livestock farms in Mali. Among the means of combating this disease, vaccination remains the only solution envisaged for developing countries. The present study is part of the regulatory framework (Implementing Regulation N°007/2009/COM/UEMOA) of the West African Economic and Monetary Union (WAEMU), relating to the eligibility criteria for immunological medicinal products for obtaining marketing authorization (MA) community. Also the Central Veterinary Laboratory (CVL) vaccine producer needs scientific data concerning the accelerated conditions for the stability of the vaccine called DERMAPOX against LSD one of the sine qua non conditions to obtain the quality label in accordance with the World Organization for Animal Health (OMSA). So to determine the stability and degradation of the vaccine against lumpy skin disease (LSD), three successive batches of DERMAPOX vaccine were produced by the Central Veterinary Laboratory (CVL) in Bamako and then exposed and titrated under accelerated at +37 °C +40 °C and +45 °C. The production and quality control methods and procedures for the culture media, solutions, semi-finished products, and finished products were carried out in accordance with the CVL's vaccine production protocol and quality control manual, and in compliance with the Pan-African Vaccine Quality Control Centre (PANVAC) vaccine quality control manual. The three DERMAPOX batches were exposed to +37 °C, +40 °C, and +45 °C for two weeks. The initial titers of these vaccine batches were determined before exposure to the different temperatures. These batches of DERMAPOX have obtained the quality label compliant with sterility, vacuum, titer (≥102.5 DICT50), residual moisture content (≤ 3%), and safety standards. The initial titers of the DERMAPOX batches before undergoing the stability study were 103.36/dose, 103.43/dose, and 103.63/dose for DERMAPOX batch No. Pox 001, DERMAPOX batch No. Pox 002, and DERMAPOX batch No. Pox 003, respectively. At +37 °C on the 14th day of exposure, the titers of the samples from DERMAPOX batch No. Pox 001, DERMAPOX batch No. Pox 002, and DERMAPOX batch No. Pox 003 were 101.00/dose, 100.70/dose, and 101.25/dose, respectively, with titer loss rates of less than 30% for all three DERMAPOX batches from time T0 to time T-7 of exposure, beyond which the rates of Securities losses ranged from 40% to over 70%. At +40°C on the 12th day of exposure, the titers of the samples from batches of DERMAPOX No. Pox 001, DERMAPOX No. Pox 002, and DERMAPOX No. Pox 003 were respectively 100.90/dose, 100.90/dose, and 101.00/dose, with titer loss rates of less than 30% for all three batches of DERMAPOX from time T0 to time T-3 of exposure, beyond which, the titer loss rates varied from 35% to 100%. At +45°C on the 5th day of exposure, the titers of samples from batches DERMAPOX No. Pox 001, DERMAPOX No. Pox 002, and DERMAPOX No. Pox 003 were 101.70/dose, 101.60/dose, and 102.10/dose, respectively, with titer loss rates of less than 30% for all three DERMAPOX batches from time T0 to time T-2 of exposure beyond which, the titer loss rates varied from 34% to 100%. These data will allow for improvements to the DERMAPOX package insert and labeling, which will be included in the application for amendments to obtain Marketing Authorization (MA). They will also contribute to minimizing vaccination failures and improving disease control.