. .

[2]
Date: 27 Mar 2001
From: Stephen M Apatow <s.m.apatow@humanitarian.net>
Source: Rationale for Vaccination: A Review of the Scientific Literature
<www.sheepdrove.com/why_vaccinate.htm>

[It is reasonable for the people to want to vaccinate and protect the  animals. However, it seems they do not know vaccinated animals will later  be killed. ­ Mod.TG]

The European policy of non-vaccination has the objective of creating a European herd without evidence of antibodies to FMD virus, since this might  indicate animals that carry infection after exposure.

Since antibodies also arise from vaccination, very considerable effort has been made in the 1990s to develop tests [that] distinguish between vaccination antibodies and infection antibodies. At least 5 different tests have been developed and validated (an entire European Union-funded Concerted Action was devoted to this, research summarized in over 15 papers in the supplement of the Vet Quarterly, 1998, 20, suppl 2) and these now transform our ability to identify vaccinated animals that have not been infected. They can also identify the important category of animals that have been vaccinated in an emergency situation and [that] subsequently become infected upon severe virus challenge.

Developing international recognition ("standardization") of these tests for the purposes of trade is [in progress], and DG-SANCO of the European Commission is revising its recommendations on the use of vaccination to incorporate these technical advances. This committee is due to report shortly. Since it is likely they will recognize the use of these tests in 
clean herds after vaccination, that policy will change to allow FMD-free status to be regained after surveillance for infection in vaccinated animals (Panina and Ahl, 1998, ref above) after a much shorter waiting period than is currently necessary.

Examples of peer reviewed papers [on the subject]: 

Bergmann IE, et al. Improvement of a sero-diagnostic strategy for FMD virus surveillance in cattle under systematic vaccination. Arch Virol 2000; 145(3): 473-89.

Sorensen KJ, et al. Differentiation of infection from vaccination in foot-and-mouth (shortened title). 
Arch Virol 1998; 148(8): 1461-76.

In other words, if DG-SANCO (and later the Office Internationale des Epizooties in Paris (OIE)) were to decide tomorrow that these tests could be used in herd surveillance after vaccination, then vaccinated herds would not need culling unless they were shown to be infected. This decision could well be made in the next few weeks and would completely change the economic 
arguments (effect on livestock trade) against vaccination.

-- 
Stephen M Apatow
Humanitarian Resource Institute
Emerging Infectious Disease Network
<s.m.apatow@humanitarian.net>

[This possible change in policy seems long overdue. We will certainly be hoping the decision to use tests to distinguish between the antibodies will shortly be put into place. - Mod.TG]
..................................tg/pg/sh
 

Additional Information/Research

John B. Belfrage, DVM, MPH; Barbara A. Corso, DVM, MS; Dianne Norden, DVM, MS;Terry Disney, PhD; Mark A. Schoenbaum, DVM, PhD.
Foot-and Mouth Disease Vaccine Use Model
Previous outbreaks of FMD in the United States have been eliminated by destroying the affected herds and burying the carcasses (stamping out). In today's political climate and environmental awareness, this kind of activity may not be easily accomplished especially if there are massive numbers of animals affected. Economically, stamping out may not be the best control or elimination method. New trade agreements allow for sectioning off portions of countries into affected and non-affected regions. Therefore, at the request of the North American Foot-and-Mouth Disease Vaccine Bank, we have examined the costs and benefits of vaccine use in comparison to stamping out without vaccine use.

Peer Reviewed Papers

I. E. Bergmann, V. Malirat, E. Neitzert, E. Beck, N. Panizzutti, C. Sánchez, A. Falczuk:
Improvement of a serodiagnostic strategy for foot-and-mouth disease virus surveillance in cattle under systematic vaccination: a combined system of an indirect ELISA-3ABC with an enzyme-linked immunoelectrotransfer blot assay  Arch. Virol. 145 (2000) 3, 473-489 

K. J. Sørensen, K. G. Madsen, E. S. Madsen, J. S. Salt, J. Nqindi, D. K. J. Mackay:
Differentiation of infection from vaccination in foot-and-mouth disease by the detection of antibodies to the non-structural proteins 3D, 3AB and 3ABC in ELISA using antigens expressed in baculovirus Arch. Virol. 143 (1998) 8, 1461-1476

International Model: FMD  Free Countries with Vaccination

OIE FMD free countries with vaccination:  Brazil, Paraguay being FMD free countries where vaccination is practised, according to the provisions of Chapter 2.1.1 of the International Animal Health Code1: 

Through its Pan American Foot-and-Mouth Disease Center (PANAFTOSA), PAHO has created one of the world’s most sensitive and practical epidemiological surveillance systems, which provides information on the occurrence of cases of this disease to all categories of livestock breeders. The system—and timely dissemination of the data it generates—made it possible in 1998 to monitor in detail the trends in foot-and-mouth disease and allowed the International Office of Epizootics (OIE) to maintain certification of Chile and Uruguay as dis-ease-free areas.

In 1998, the OIE conferred disease-free status on the region com-prising the Brazilian states of Rio Grande do Sul and Santa Catarina, in which livestock is vaccinated against foot-and-mouth disease. The sur-veillance system also verified that non-Amazonian Brazil, i.e., the states of São Paulo, Minas Gerais, Espírito Santo, Paraná, Mato Grosso, Goiás, and the Federal District, has marked over two years without any case occurrences.

The strategies promoted by PAHO include involving breeders in the hemispheric plan and in running local programs, setting up local veteri-nary health committees, applying vaccine in oil suspension, improving diagnostic techniques for the vesicular disease, and upgrading the information system for surveillance of the disease. Thanks to these strategies, over two million cattle herds—equivalent to 164.6 million head of cattle (or 42.4% of South America’s total herd)—are free of
foot-and-mouth disease.

Note: The advent of ELISA technology has made sero-monitoring a practical reality for vaccination monitoring. The Pan-African Rinderpest Campaign (PARC) sero-monitoring network coordinated by the Joint FAO/IAEA Division is the most extensive sero-monitoring network in the world. The crucial elements of this network are the application of the ELISA technique using standardized and highly specific reagents, standardized equipment and computer software, supported by a well-controlled quality-assurance programme for the reagents and techniques by consistent technical advice from FAO/IAEA personnel and the scientist responsible for developing and standardizing the technique. A standardized training programme is also included for all individuals responsible for the national testing programme. It is now FAO policy to extend the approach to other parts of the world involved in GREP. A similar scheme is being developed by the Joint FAO/IAEA Division to monitor the effectiveness of FMD and brucellosis control programmes in South America. FAO strategy for international animal health Vaccines: http://www.fao.org/WAICENT/FAOINFO/AGRICULT/AGa/AGAP/WAR/warall/V8180b/v8180b0d.htm

• F.Shen, P.D.Chen, A.M. Walfield, J.Ye, J. House, F.Brown, C.Y. Wang  Differentiation of convalescent animals from those vaccinated against foot and mouth disease by a peptide ELISA  Vaccine 17 (1999) 3039-3049