Post on 03-Feb-2017
transcript
Towards vaccine selection guidelines for each regional
virus pool
Can vaccine strains tailored to cover the needs of particular regions be identified and provide better, more targeted, regionalised
vaccine recommendations?
WRLFMD Vaccine recommendations (National & European antigen banks)
O ManisaO BFS or CamposA24 CruzeiroA22 Iraq Asia 1 ShamirSAT 2 Saudi Arabia (or equivalent)
A Argentina 01A Iran 96A Iran 99A EritreaA Iran 87 or A Saudi Arabia 23/86 (or equivalent)A Malaysia 97 (or Thai equivalent such as A/NPT/TAI/86)O Taiwan 97 (pig-adapted strain or Philippine equivalent)SAT 1 South AfricaSAT 2 Zimbabwe
A15 Bangkok related strainA KenyaA87 Argentina related strainSAT 1 KenyaSAT 2 KenyaSAT 3 ZimbabweC Noville Within category: not in order of importance
HIGHPRIORITY
MEDIUMPRIORITY
LOWPRIORITY
Lanzhou Meeting, China, Sept 15-18
Regional/National
Reference Centres Reference Laboratories and
Collaborating Centres
Additional
Reference Centres
Intermediate, sporadic
Endemic
FMD-free. Virus present in game parks Free with vaccination
Countries with multiples zones
Source: Annual OIE/FAO FMD Reference Laboratory Network Report, 2007
Pool 1
O, A, Asia 1
Pool 2
O, A, Asia 1
Pool 3
O, A, Asia 1
Pool 6
SAT 1, 2, 3
Pool 4
A, O, SAT 1, 2, 3Pool 5
O, A, SAT 1, 2Pool 7
O, A
Regional Differences in FMDV
FMD-free
Pool 1: East and South-East Asia
Panel members: China, Thailand, Japan.
Position of watershed:• Main weight of infection in SE Asia• Malaysia and all of Vietnam should be included in the region of Pool 1• Variable vaccine cover
Local and international vaccine seed viruses:• China – O 1999 (equivalent to O Manisa), A 1972 (equivalent to A22 Iraq),
Asia1 2005 (equivalent to Asia1 Shamir). • Thailand – O 189/87 (equivalent to O Manisa), A 118/87 (equivalent to A15
Bangkok and A Malaysia 97), and Asia 1 2005.• Japan – Emergency vaccines such as O Manisa, A Malaysia 97
Priority Vaccines: O Manisa-like, O Cathay-like, A Malaysia 97-like, A22 Iraq-like, Asia1 Shamir-like
Improvement in Priority Setting: Improving communication between countries especially over border areas. Better surveillance in some areas, e.g. Myanmar
Pool 2: Indian Sub-Continent
Panel members: Russia, India, Belgium.
Position of watershed: Separation of Pools 2 and 3 reflects differences in A types
Vaccine seed viruses – standardised throughout India:• Type A. Genotype VII replaced Genotype VI after co-existence (1999-2003). A
Iran 05 occurs sporadically and not in Genotype VII. IND 40/2000 (Genotype VII) will replace IND 17/1982 (Genotype VI) in the vaccine (Dec 2008)
• Type O. Manisa related O/IND R2 75 replaced by O PanAsia 1 strain (better r1values). O PanAsia 2 may be introduced as vaccine.
• Type Asia 1. IND/ 63/72 still provides good protection though genetically distant. Asia1 Shamir vaccine might protect but there is no field information on use.
Priority Vaccines:• O PanAsia (O Manisa or equivalent for now), A IND 40/2000, Asia 1/IND/ 63/72
– theoretically Asia 1 Shamir.
Improvement in Priority Setting: The criteria for replacing a strain in a vaccine are laboratory and field data on match/efficacy and whether the strain is widespread and persistent in field (more than 1 year).
Pool 3: EurasiaPanel Members: Russia, India, Belgium.
Position of watershed: Separation of Pools 2 and 3 reflects differences in A types
Russian vaccine seed viruses:• Type A. A22 550/USSR/65 replaced in 90s by A Armenia 98 (A Iran 96 strain)
until 2006/7, and will be replaced by A Iran 2005 (A/Turkey/1 2006) for Transcaucasia. The vaccine for the Far East still contains A22 or a bivalent vaccine with Iran 05.
• Type O. Manisa related O 1618 replaced by O PanAsia 1 strain due to better r1values. In future O PanAsia 2 vaccine might be introduced.
• Type Asia 1. Old Asia 1-48/RUS still protects against currently strains though genetically different.
Other local vaccine seeds: Turkey, IranWRL recommendations for W. Europe
Priority Vaccines:• Could use same type O and Asia 1 vaccine strains in Pools 2 and 3.• The priority vaccines - O PanAsia (O Manisa or equivalent for now), A Iran 05
type (or A22 Iraq for now), various Asia1 strains – theoretically Asia 1 Shamir.
Improvement in Priority Setting: Better surveillance in Central Asian countries and bordering pool 2
Pool 4-6: AfricaPanl members: South Africa, Botswana, WRL
Position of watersheds:• Kruger National Park in South Africa should be in Pool 6 • Insufficient data on central Africa to define border between Pools 4 and 5.
Vaccine seed viruses:• Strains developed for use elsewhere e.g. O Manisa• Historic strains from e.g. Nigeria, Kenya• SAT strains from BVI and OVI
Priority Vaccines:• Historic strains often not available• Uncertainty over suitability of limited selection available
Improvement in Priority Setting:• Need to survey the FMD vaccine strains available/in production in Africa. • Need a systematic analysis of the viruses circulating and their r1 values with
respect to current vaccines. • Increased demand could stimulate supply • Difficulty in adapting some SAT strains
Pool 7: South America
Panel members: USA, PANAFTOSA, Argentina
Position of watershed: Agreed
Vaccine seed viruses:• Different matching requirements for prophylactic and emergency
vaccination. • Vaccine strains in current use - O Campos, A24 Cruziero, C3 Indaial and A
2001. • Depending on the countries needs bi-, tri- or tetra-valent vaccines are used.
Priority Vaccines:• As above. • Preferential use of high quality vaccines including broad antigenic strains
over use of multiple strains that give an exact match. • Strong emphasis on batch quality control. • Many countries implement surveillance strategies to evaluate the efficiency
of the vaccination programmes.
Improvement in Priority Setting: some difficulties with field isolate supply
Conclusions
• Decision makers want impartial advice, but sometimes have difficulty interpreting WRLFMD’s general recommendations – regional advice would be useful, but sometimes conflicts of interest
• Watershed concept useful, but overlaps and uncertainties exist
• Continuing and in places improved surveillance needed
• Variable harmonisation of vaccine strains at national and regional level
• Vaccine matching requirements differ for emergency use and prophylaxis –exact match versus generic broadly reactive strains
• Vaccines held in reserves of FMD-free countries often differ from those used in endemic countries
• More thorough antigenic characterisation of available isolates is required, but not clear if public sector has responsibility to select new vaccines
• Some areas have no tailored vaccine supply and few measures to control suitability – related to low demand and public identification of need versus private supply
• Affordability and quality control of vaccines are separate but very important issues
Recommendations• Map the watersheds better through enhanced and targeted surveillance
(action check list?)
• Border areas between pools
• Blind spots and neighbouring areas plus Facilitate reporting and sample shipment
• Incentives (vaccine/training) for samples
• Simplify sample submission
• Foster regional projects involving local labs and vet services to study prevalence and virus types
• Establish new regional labs (e.g. W Africa - OIE twinning model)
• Survey vaccine strains more fully – availability, use
• More systematic antigenic matching studies to provide confidence in available strains and to develop new ones
• Improve collaboration and clarify roles between reference laboratories and vaccine producers
• Provide regional advice on vaccine selection in future Ref Lab Network reports