http://www.fao.org/ag/againfo/programmes/en/rinderpest/home.html http://www-data.fao.org/ag/againfo/programmes/en/empres/event_200116.html Presentation made during the international meeting titled “Maintaining global freedom from rinderpest” held in FAO-HQ from 20 to 22 January 2016.

1. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Molecular tools: needs post-eradicationMolecular tools: needs post-eradication
Michael D BaronMichael D Baron
Scientific ConsultantScientific Consultant
FAO/AGAHFAO/AGAH

2. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Abstract
In 2011, ten years after the last reported outbreak, the eradication of rinderpest was declared. However, as rinderpest virus stocks still
exist, there remains a risk of rinderpest re-introduction.
A semi-quantitative risk assessment was conducted to assess this risk, which was defined as the probability of at least one host becoming
infected and infectious outside a laboratory anywhere in the world within a one-year period. Pathways leading to rinderpest re-
introduction were: deliberate or accidental use of virus in laboratories, deliberate or accidental use of vaccines, host exposure to an
environmental source of virus, and use of virus for anti-animal biological warfare. The probability of each pathway step occurring was
estimated through expert opinion elicitation.
The risk estimate was associated with a high degree of uncertainty. It was estimated to range from negligible to high, with the median
being very low. The accidental use of laboratory virus stocks was the highest risk pathway. Reducing the number of virus stocks and
restricting their use, as well as upgrading the laboratories to a higher biosafety level, would effectively decrease the maximum and median
risks. Likewise, ensuring that remaining vaccine stocks are not used and are instead destroyed or relocated to a limited number of regional
repositories would also have a major effect on these estimates. However, these measures are unlikely to eliminate the risk of rinderpest
re-introduction so that maintaining response preparedness is essential.
The accidental use of laboratory virus stocks was the highest risk pathway.
…as rinderpest virus stocks still exist, there remains a risk
of rinderpest re-introduction.

3. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Keeping a watch for rinderpest
Active surveillance:
not warranted for v rare disease
Passive/clinical surveillance:
Low cost Low sensitivity
Differential diagnosis not perfect:
e.g. mild rinderpest vs MCF, IBR or mucosal disease
Syndromic surveillance should be identifying suspect cases

4. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Threats to rinderpest detection
1 Loss of skills/knowledge
How many vets still know what rinderpest looks like?
1 Political sensitivity
No one wants to be the first to even suspect rinderpest
1 Rinderpest eradication!
No-one is testing for
rinderpest, even if syndromic
positive

5. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Threats to diagnosis
1 Loss of skills/techniques
Partially replaced by PPRV diagnostic skills
1 Absence of reagents
No one re-ordering PCR primers, etc., ELISA kit reagents out of date
1 Restrictions on materials
RPV-containing materials restricted and kits no longer available

6. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Available tests
• Test for virus – RT-PCR (primers available)
• Test for virus – RT-qPCR (primers/probe available)
• Test for virus – immunocapture ELISA
• Test for virus – pen-side test (no longer made)
• Test for virus/antibody – AGID (serum available)
• Test for antibody – cELISA (not allowed to send out kit)

7. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
New reagents/tests required
• Non-virus control for RT-PCR/RT-qPCR
– E.g. armoured RNA
PCR target
RPV target
PCR target
Transcribed
RNA

8. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
New reagents/tests required
• Non-virus control for RT-PCR/RT-qPCR
– E.g. armoured RNA
• Non-virus control for antigen for ELISA/AGID
– E.g. pseudotyped virus, bacterially expressed antigen, helper-
dependent virus, inactivated vaccine virus

9. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
New reagents/tests required
• Non-virus control for RT-PCR/RT-qPCR
– E.g. armoured RNA
• Non-virus control for antigen for ELISA/AGID
– E.g. pseudotyped virus, bacterially expressed antigen, helper-
dependent virus, inactivated vaccine virus
• Sequence database
– Full genome sequencing now relatively easy

10. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
New reagents/tests required
• Non-virus control for RT-PCR/RT-qPCR
– E.g. armoured RNA
• Non-virus control for antigen for ELISA/AGID
– E.g. pseudotyped virus, bacterially expressed antigen, helper-
dependent virus, inactivated vaccine virus
• Sequence database
– Full genome sequencing now relatively easy
– Any virus can be remade (if required) from the genome

11. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Production of recombinant RP viruses
Live virus
Initiator
plasmids
Copy of any
genome in a
plasmid
N
L
P

12. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Need for sequence database
• Identification of outbreak virus
a) Where did it come from?
b) Is it a release or an escape?
• Preparing for the future
a) How did RPV spread through Africa?
b) Are we ready for the next bovine morbillivirus?

13. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Appearance of novel paramyxoviruses

14. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy

15. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Alternative vaccines
• Recombinant vaccinia?
• Recombinant Lumpy Skin Disease virus?
• Effective, but not widely acceptable (GMOs)
• Expressed RPV protein?
• Does not work
• Other morbillivirus, e.g. PPRV
• Had not been tested, but RPV protects against PPR in goats

16. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
PPRV as a vaccine against RP
RPV vaccine No vaccine
PPRV Sungri/96
vaccine
PPRV Ivory Coast/89
(wild type)
PPRV Nigeria/75/1
vaccine
Challenge with RPV Saudi/81
4 Weeks

17. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Summary
• There is a low but not negligible risk of RPV reappearance
• This virus may come from laboratory escape or deliberate
release
• Passive surveillance/awareness should be turning up
occasional suspect cases
• Diagnostic laboratories should maintain capability (or good
links to lab with capability)
• We need to develop alternate (nonviral) controls for diagnosis
• We need to be prepared for the next bovine morbillivirus

18. Maintaining Global Freedom from Rinderpest International Meeting • 20-22 January 2016 • Rome, Italy
Questions ?