Post-vaccination herd immunity against peste des petits ruminants and inter-vaccination population turnover in small ruminant flocks in northwest Ethiopia

Serosurvey for Assessment of Peste des Petits Ruminants Virus Antibodies Status in Sheep and Goats in the Rural System of Odisha State, India

“…Hence, the observed 64% prevalence of PPRV antibodies in the population indicates the population immunity level. The observed seropositivity level was concurrent to what has expected from post-vaccination evaluation status in Odisha, however, as the area is PPR endemic and risk zone, and animals are constantly being challenged with the virus either through natural infection or vaccination as reported earlier in northwest Ethiopia (Yirga et al, 2020). Therefore, seropositive animals and presumably many of the animals will be protected against future PPR outbreaks, though sporadic outbreaks are being reported in Odisha state.…”

“…January 2022 | Volume 10 | Issue 1 | Page 2 (Balamurugan et al, 2021). The disease poses a serious threat to small ruminant production in Africa, Asia, and the Middle East, where the disease is widespread and endemic; hence the disease outbreak on small ruminants has a huge socio-economic impact on all the developing countries (Balamurugan et al, 2014(Balamurugan et al, , 2021OIE and FAO, 2015;Yirga et al, 2020). Because of its increasing spread, it becomes a main constraint in augmenting the productivity of small ruminants in endemic countries.…”

“…The proportion of immune animals which confer protection due to population immunity may vary depending on the contact structure of the population and transmissibility of the agent. The prevalence studies after PPR vaccination in small ruminants has been reported from different endemic countries in the world including India (Balamurugan et al, 2018(Balamurugan et al, , 2020bYirga et al, 2020).…”

“…In general, the difficulty of maintaining an effective cold chain in remote rural areas and poor vaccine delivery can compromise the development of sufficient herd immunity in the vaccinated population (Yirga et al, 2020). Moreover, small ruminant populations are characterized by rapid turnover due to lambing/kidding, fecundity of animals, slaughter and sales of animals, etc., and this dynamic population turnover including the appearance of newborns animals may rapidly reduce the herd immunity acquired from vaccination programs upsetting efforts at controlling the disease.…”

A Preliminary Investigation on a Commercial Ovine Pasteurellosis Vaccine Using Clinical and Pathological Endpoints

“…First, food or production animals have a rapid population turnover (eg small ruminants) staying for a relatively short period of time in the flock due to market and household consumption making the task of animal follow-up postvaccination impractical. 32 Second, there are no national or district vaccine safety monitoring systems in place to report adverse events after vaccination in Ethiopia. Third, animals in Ethiopia are mainly managed in an extensive farming system 33 , 34 with no proper documentation and recording which makes it difficult to determine the type of vaccines and time of administration in a given flock.…”