Extract: our system has sufficient sensitivity and specificity to detect evidence of infection in vaccinated herds (e.g., potentially infectious carrier animals if they truly exist) while distinguishing the antibody response to infection from the response to vaccination. (United BiomedicalAlicia Eykyn from the FMD Forum asked for clarification from UBI about diagnostic tests for FMD:
-----Original Message----- From: am.eykyn [SMTP:email@example.com]
Sent: Thursday, April 04, 2002 11:42 AM
Subject: FMD Tests
I very much look forward to hearing from you regarding the up-to-date situation of your FMD tests. I am very keen to get as much information as I can on the progress (if any!) towards international validation of both yours and any comparison that you have with others in the field.
We are at present in the throes of a number of inquiries, one in the EU and others in Britain, into the way FMD was handled and what should be done in the future. I am off to the EU in Strasburg on Sunday and am trying to put to together as much latest information as I can muster to take with me.
As you may or may not be aware, at the International Conference on Foot and Mouth in Brussels in December, which I attended as a DEFRA delegate in the British contingency, Brinkhorst of Belgium made a rousing speech. The point he made was the urgent necessity of concentrating resources, on getting internationally validated, the EXISTING tests for showing the difference between vaccinated animals and those naturally infected.
Thus allowing the OIE rules on the 'carrier' state no validity and putting a whole new and welcome light on the use of vaccination
I am very much looking forward to hearing from you. kind regards Alicia Eykyn
The reply: ....
To quickly summarize for you:
UBI has four types of diagnostic tests for FMDV.
1. The UBI FMDV NS EIA is an enzyme-linked immunoassay based on a peptide taken from the sequence for the 3B non-structural (NS) protein. The 3B peptide is used as the solid-phase antigen for the capture and detection of antibody associated with FMDV infection. It is intended for use as a screening test on both vaccinated and unvaccinated herds for detection of antibodies that result from exposure to FMDV. It is a differential diagnostic test because it does not detect antibodies that result from vaccination. NS viral proteins are conserved across FMDV serotypes so that a single NS-based test will detect the antibody response against all FMDV serotypes. Separate NS kits are made for use on swine and ruminants.
Specificity on unvaccinated populations approaches 100%, and is somewhat less for vaccinated populations insomuch as some FMD vaccines contain small amounts of NS proteins. We manufacture two confirmatory tests for animals that are scored as positive on the NS screening test.
2. The UBI FMDV NS 3B Neutralization Buffer test is a confirmatory competitive inhibition test for the UBI FMDV NS EIA. It is based on a soluble 3B NS antigen that is used to inhibit presumptive anti-3B antibody from binding to the solid-phase antigen of the UBI FMDV NS EIA.
3. The UBI FMDV 3A NS EIA is an additional confirmatory test for samples that are positive on the UBI FMDV NS EIA . This test is an enzyme-linked immunoassay that uses a synthetic peptide antigen taken from the 3A NS protein of the virus, as the solid-phase antigen. There are separate versions for swine and ruminants.
The complete UBI NS test system has a specificity approaching 100% on vaccinated livestock. We believe that our system has sufficient sensitivity and specificity to detect evidence of infection in vaccinated herds (e.g., potentially infectious carrier animals if they truly exist) while distinguishing the antibody response to infection from the response to vaccination.
4. The UBI FMDV VP1 EIA is an enzyme-immunoassay that uses a synthetic peptide taken from VP1 structural protein of FMDV for detection of antibody response to vaccination. It is intended for applications that monitor the effectiveness of vaccination programmes. The VP1 protein is serotype-specific so that VP1 EIAs must have peptide antigen tailored for the serotypes used in a vaccine.
All UBI diagnostic tests are especially appropriate for use with our synthetic-peptide based vaccines that are still in development because the peptide vaccines are "antigenic marker vaccines" that cannot result in false positives when animals are screened by the UBI FMDV NS EIA.
All UBI FMDV diagnostic products are based on synthetic peptide antigens. These are chemically-defined entities produced by controlled chemical syntheses. UBI has a strong platform technology in synthetic peptide chemistry and can manufacture these test kits on an industrial scale. The process does not involve difficult and dangerous virus culture. Also, the synthesis of peptide antigens is simple compared to the complicated, expensive, and often non-reproducible processes involved in the production and purification of recombinant antigens from genetically engineered organisms.
UBI has is going through a licensure process with the US Dept. of Agriculture, for the UBI FMDV NS EIA . While this process is ongoing, we are permitted to export the kits from our Hauppauge facility for research use only, and have done so with Material Transfer Agreements that call for the sharing of data. Such studies can help us with the validation of our kits. Incidentally, we have a European partner that is seeking to register the UBI FMDV NS EIA in an EU member state. The identities of that partner and the EU state are confidential.
I am attaching Scott's slides and two of our publications for your information. (The two publications won't fit into this transmission, I will attach them to a separate email.) <
> Thank you for your interest and I hope this has helped. Regards,
-Alan Alan M. Walfield, Ph.D. Senior Scientist United Biomedical Inc.
25 Davids Drive Hauppauge, NY 11788
U.S.A. ph 631 273-2828 fax 631 273-1717
email firstname.lastname@example.org internet www.unitedbiomedical.com