Effect of vaccine storage temperatures and dose rate on antibody responses to foot and mouth disease vaccination in Cambodia

Abstract

A field study investigated the effects of foot and mouth disease vaccine storage temperature for 7 days (frozen, refrigerated or held at ambient temperature) and dose (half or full dose) on the serological response to vaccination. It utilised a complete factorial design replicated on 18 smallholder cattle farms in three villages in Pursat province, Cambodia. Antibody responses from the 108 cattle involved were assessed by serological examination of blood samples collected at primary vaccination (day 0), at booster vaccination (day 30) and finally at 60 days post primary vaccination. Vaccination responses to the inactivated vaccine were assessed by testing for antibodies directed against FMD structural proteins in a liquid‐phase blocking ELISA (LPBE test) and differentiated from responses to natural infection by examining antibody titres against non‐structural viral proteins (NSPE test). LPBE results indicated that the mean log10 LPBE antibody titres of all experimental cattle increased from below protective levels at day 0 to protective levels at 30 days post primary vaccination, and increased further at 60 days post primary vaccination. Storage at ambient temperature for 1 week had no effect on antibody response to vaccination. However, freezing the vaccine for a week or use of a half dose resulted in significant reduction in titres at day 60 (P = 0.04 and P = 0.02, respectively). The results of this study reinforce the need to store FMD vaccines within the range recommended by the manufacturers and to adhere to the specified dosage instructions.

Virulence-determinants and antibiotic-resistance genes of MDR-E. coli isolated from secondary infections following FMD-outbreak in cattle

“…A previous study in Cambodia reported the occurrence of FMD-vaccination failure in more than 50% of the vaccinated animals. The vaccination failure is mainly attributed to improper technique, insufficient dose, immunological factors, and vaccine cold-chain miscarriage 36 . Several causes are implicated in the existence of E. coli secondary infection, including; bad sanitation, intensive-breeding management, bad environmental conditions, stress, and weak animal immunity 18 .…”

Targeted Modification of the Foot-And-Mouth Disease Virus Genome for Quick Cell Culture Adaptation

“…The examination of the virus particle integrity revealed only low amounts of intact 146S particles in comparison to the original Asia-1 Shamir isolate. FMDV is naturally highly sensitive to even mildly acidic pH [38] and the maintenance of the cold chain is of high importance for FMDV vaccines [39]. It was therefore examined if the adapted strains are more sensitive against changes in pH or temperature than the original Asia-1 Shamir isolate, but we found no difference in the impact of pH or temperature on virus particle instability for the adapted virus strains.…”

Constraints and opportunities to improve livestock production and health, and reduce zoonotic risks in small-scale native chicken, cattle and small ruminant farms in the Central Dry Zone of Myanmar

“…• Some farmers in this research seemed to have had negative experiences with vaccinations, and potentially, the 'potency' of these vaccines could have played a role. Expiry dates of the vaccines and perhaps also quality of vaccines produced in other South-East Asian countries need to be considered (Garland 1999, Sakamoto, Morioka et al 2016, Sieng, Walkden-Brown et al 2018, Solyom, Fazekas et al 1980).…”