Comparison of the effectiveness of Neethling LSD and ... · Neethling LSD and 10xRM65 sheeppox...
Transcript of Comparison of the effectiveness of Neethling LSD and ... · Neethling LSD and 10xRM65 sheeppox...
Comparison of the effectiveness of Neethling LSD and 10xRM65
sheeppox attenuated vaccines - The results of a randomized
controlled field study Koret School of Veterinary Medicine
Israel Veterinary services Kimron Veterinary Institute
Hachaklait Presented by Prof. Eyal Klement - Koret School of Veterinary Medicine 1
…Before we start…
• RM65 vaccine – an attenuated sheep-pox vaccine manufactured by ABIC® and JOVAC®
• Each dose contains a minimum of 102.5 TCID50 of freeze dried live attenuated sheep-pox vaccine
• 1 ml administered S.C.
2
…Before we start…
• Neethling vaccine – an attenuated lumpy skin disease vaccine manufactured by OBP
• Virus titer dose - 103.5 TCID50*
• 2 ml administered S.C.
3
*According to registration file
Background • A large LSD outbreak spreading mostly in the north of Israel
from July 2012. • Initially, only beef herds were affected. • On October, first cases began to appear among intensive zero-
grazing high producing Holstein dairy cattle herds. • Vaccination with attenuated RM65 sheep-pox vaccine did not
seem to affect outbreak progression.
4
Previous Israeli experience with RM65 vaccine
• Large outbreaks in RM-65 vaccinated herds in Israel:
5
Data regarding Neethling and 10XRM65 vaccines
• No controlled clinical trial evaluating the effectiveness of these vaccines
• Anecdotal data pointing of possible effectiveness of the Neethling disease for controlling LSD in South Africa
• Anecdotal data stating the RM65 vaccine in a x10 dose is more effective than the regular dose
6
Study aim
• To compare the field effectiveness of 10XRM65 and Neethling attenuated vaccines for prevention of LSD
7
Vaccine preparation
• Neethling – According to manufacturer instructions. 2 ml injected S.C.
• 10xRM65 – Use 1/5 of the diluent recommended by the manufacturer and inject 2 ml S.C.
8
Study population
• 15 dairy cattle herds located in the north of Israel
• 4694 cows and 3756 calves and heifers
• All herds vaccinated 3-5 months previously with an RM65 attenuated vaccine
9
Study design
• Cows randomized according to skin number: – Even – Neethling – Odd – 10xRM65
• In 7 farms all calves were vaccinated with the Neethling vaccine
• In 8 farms all calves were vaccinated with 10XRM65 vaccine
10
Surveillance
• All cattle in the herds were monitored daily by the herdsmen for any sign of LSD or other illness
• Suspected illness was examined by the herd veterinarian twice weekly and informed immediately to the study veterinarian
• When possible, the study veterinarian collected blood and skin specimen biopsies from affected animals
11
Case definitions
• LSD case – a cow/calve with at least one typical LSD nodule
• Severe case - typical skin nodules accompanied by fever (>39.5 oC) or by a decrease in milk yield of over 20%
• Laboratory confirmed case – identification of wild strain by PCR from either skin biopsy or blood (Menasherow S et al. J Virol Methods, 2014)
12
Results
• 82 cases occurred in 8 herds which included 5546 vaccinated cows and calves (incidence = 1.5%)
• Among cows only the incidence was 76/3077 (2.5%)
13
Crude effectiveness (cows only) • In 5 herds – higher morbidity in 10xRM65 vaccinees. • In 2 herds – Higher morbidity in Neethling vaccinees • In 1 herd – Equal morbidity • RRMH = 1.49 (0.92-2.41) • P-value for heterogeneity = 0.122
14
Crude effectiveness – severe cases
• Only cows - RRMH = 3.65 (1.59-8.35) • No significant heterogeneity
15
Accumulation of cases in time
16
Accumulation of severe cases in time
17
Effectiveness (cows)- >14 days post vaccination
• 42 cases among 10xRM65 vaccinated cows (incidence=2.7%) vs. 13 cases among Neethling vaccinated cows (0.84%): RRMH=2.64 (1.44-4.82)
• 20 cases among 10xRM65 vaccinated cows (incidence=1.3%) vs. 1 case among Neethling vaccinated cows (0.06%): RRMH=11.2 (2.3-54.7)
18
Effectiveness (cows)- Isolation of wild strain
• 22 cases among 10xRM65 vaccinated cows (incidence=1.4%) vs. 6 cases among Neethling vaccinated cows (0.84%): RRMH=4.28 (1.59-11.53)
19
Neethling’s disease
• 9 confirmed cases out of 2356 vaccinated cows (incidence= 0.4%). Of these 1 severe case
• All occurring within 14 days from vaccination • No Isolation of Neethling strain from a non-
Neethling vaccinated cow
20
Final conclusions • Relative effectiveness
– Neethling vaccine is significantly more effective in preventing LSD.
– Relative effectiveness for preventing LSD in cows when full immunity is anticipated (i.e. >14 p.v.) = 62%
– Relative effectiveness for preventing severe LSD = 91%
– Relative effectiveness for preventing confirmed LSD = 77%
21
…However…
• Neethling’s disease: – 0.4% incidence of Neethling’s disease durig the 14 days
post vaccination. – Mostly non-severe disease – … though no evidence of transmission of the Neethling
strain to non-Neethling vaccinated cows
• Outbreak control – Outbreak was fully controlled with extensive use of both
vaccines. – Therefore it is conceivable that 10xRM65 is also effective
in preventing LSD 22
So...
• Which vaccine is better?
• It depends on… – Risk assessment – Epidemiological condition
23
Thanks • Prof. Nahum Shpigel – Study initiation, design and
conduction • Dr. Nadav Galon and veterinary services – study
support, and vaccination performance • Dr. Yonatan Ben-Gera – Study conduction and data
coordination • Dr. Yevegeny Chinitz and Dr. Yehuda Stram – virus
isolation and identification • Dr. Benny Sharir, Hachaklait veterinarians –
vaccination and clinical surveillance • Herdsmen
24