Foot-and-mouth disease (FMD) is one of the most devastating livestock diseases due to its high infection rate (ease of spread) and its effect on livestock movement and trade. An outbreak of FMD will have a devastating effect on a country’s food security with direct impact on national and international trade. The confirmatory diagnosis of FMD and its effective control through prophylactic, quarantine or slaughter-out procedures are therefore of paramount importance. Vaccination with inactivated FMD virus is undertaken to control FMD in endemic countries or countries at risk. Vaccines, which are widely available but should match (i.e. should be of homologous serotype and strain isolate) with virulent FMD viruses circulating in the region of vaccine use, are of variable quality, not from the homologous outbreak serotype/strain isolate, and are often stored under inadequate temperature conditions and therefore might be not as effective in the field as determined in animal experiments. This Coordinated Research Project (CRP) investigated methods and provided internationally acceptable guidelines for procedures which test a vaccine’s ability to induce the production of protective antibodies in cattle without the need for animal challenge experiments.
The CRP involved countries and laboratories both from endemic regions as well as those free from FMD. The participating laboratories have different levels of expertise ranging from internationally acclaimed research facilities with numerous global collaborations to laboratories that presently cannot perform diagnostic assays due to various reasons. One aspect of the CRP was to make the expertise available to those laboratories that are in need, to set up the links and build their capacity.? Participants were strongly encouraged to contact the agreement and contract holders for research inputs and other needs.
The CRP made it clear that vaccines and vaccination are not properly controlled in some countries.? Therefore, the need to perform post vaccine monitoring is of high priority to provide feedback to producers and decision makers on the efficiency of the vaccines.? Countries should be encouraged to ensure they use vaccines applicable to their epidemiological situation, which antigenically match the viruses circulating in their region. In addition, if they produce their own vaccine, they should perform the necessary quality tests prior to releasing the vaccine in the field.? All vaccination campaigns should be monitored using sero-surveys regardless of the product used, as several aspects could impact the level of sero-conversion in the field.
The CRP covered many aspects related to vaccines and post vaccination monitoring. Through the CRP, an attenuated Asia-1 vaccine strain was developed that can be used in the existing production facilities using currently accepted technologies, but which will not cause outbreaks should the virus accidentally escape from the facility. Since it is based on using the registered international techniques for FMD vaccine production, application and uptake was rapid. This technology is furthermore applicable to any other FMD strain; therefore it potentially has an important global impact.
The use of P1 amino acid sequences together with virus neutralization titration (VNT), structural data and mathematical modelling, was employed to characterize FMD-SAT type viruses in order to predict antigenic matching. This was an important step to replace animal challenges, therefore addressing animal ethics standards. The methodology relies on using only the sequence data once a new virus emerges, applying the sequence to the CRP developed model to determine whether the current vaccine strains will provide protection. Since sequence data can be generated rapidly once a new virus is detected, this method significantly shortens the period between detection and decision on vaccine strains. This complements the approach in South America where experts are optimizing the VNT results to predict protection against the vaccine strains used in the region. One laboratory has established a multiplex PCR based diagnostic assay that both confirms disease and provides information on the serotype. More than 200 peer reviewed research papers emanated from this CRP, with 50 SOPs developed and disseminated, which are now being distributed to all IAEA Member States.
For more information, please see the CRP description:
http://www.dgdingfa.net/projects/crp/d32028
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