Preservation of vaccines, viruses and other biologicals is one of the onerous tasks in maintaining the quality of the products from manufacture until they reach the end users. Live-attenuated viral vaccines, serum immunoglobulins, plasma fractions and clinical samples, including tissues and body fluids, are all materials that usually require cold-chain maintenance during storage and distribution. A number of stabilizers are currently used to help retain the quality of these materials, in particular vaccines, during transit. Deuterium oxide (heavy water; D(2)O) has previously been reported to have a protective effect on biomolecules (proteins and nucleic acids), cells and simple multicellular organisms against thermal shock. Of late, the potential of D(2)O has been demonstrated in stabilization of the oral polio and yellow fever 17D vaccines. This review is the outcome of a thorough search and scan of the literature in a quest to explore the potential use of heavy water in the stabilization of veterinary biologicals. The literature search revealed this potential of heavy water as exemplified by successful stabilization of oral polio and yellow fever vaccines. Through this review, the authors wish to inform animal health researchers and disseminate their knowledge on the use of heavy water in biomolecule stabilization and its potential application in the stabilization of veterinary vaccines and other biologicals.
10 May 2009 in Tropical Animal Health and Production
A mixed infection with peste des petits ruminants virus (PPRV) and bluetongue virus (BTV) occurred in goats which exhibited symptoms characteristic of PPR. A number of samples were collected from ailing or dead goats for labrotory diagnosis. Antibody to BTV and PPRV was detected in sera samples by competitive ELISA. No PPRV antigen was detected in tissue samples like lung and spleen, however, presence of PPRV antigen in some sera samples was confirmed by sandwich ELISA. All the blood samples collected from the ailing animals were found positive for BTV antigen by a sandwich ELISA. BTV- and PPRV nucleic acids were amplified from the pooled blood and tissue samples respectively by RT-PCR assays. The identity of the amplicons was confirmed by cloning and sequencing. All these tests confirm that the goats were infected with PPRV and BTV simultaneously. Isolation of viruses from the clinical samples is underway.
The present study deals with the co-ordination of cytokine (IL-4 and IFN-γ) expression and kinetics of peste des petits ruminants (PPR) virus antigen and antibody in PPRV infected and vaccinated goats. The infected animals exhibited mixed cytokine (both TH1 and TH2) responses in the initial phase of the disease. The infected and dead goats had increased IFN-γ response before their death; while IL-4 remained at the base level. The cytokine expression in recovered animals was almost similar to that of vaccinated ones, where a unique biphasic response of IL-4 expression was observed with an up-regulation of IFN-γ on 7th days post vaccination (dpv). Analysis of PPR virus antigen and antibody kinetics in different components of blood from infected and vaccinated animals revealed that the PPR virus antigen load was highest in plasma followed by serum and blood of the infected animals, whereas vaccinated animals showed only marginal positivity on 9th dpv. The antibody titer was high in serum followed by plasma and blood in both vaccinated and infected animals. Therefore, it is inferred that the presence of antigen and antibody were significant with the expression of cytokine, and that a decreased response of IL-4 was noticed during intermediate phase of the disease i.e., 7 to 12th days post infection (dpi). This indicates the ability to mount a functional TH2 response after 14th dpi could be a critical determinant in deciding the survival of the PPR infected animal.
A pilot study was carried out to find out the seroprevalence of Porcine circovirus 2 (PCV2), classical swine fever virus (CSFV), and Porcine respiratory and reproductive syndrome virus (PRRS) in pig population of Meghalaya