Polio end game strategy in india

5,006 views

Published on

1 Comment
8 Likes
Statistics
Notes
No Downloads
Views
Total views
5,006
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
351
Comments
1
Likes
8
Embeds 0
No embeds

No notes for slide

Polio end game strategy in india

  1. 1. POLIO ENDGAME STRATEGY IN INDIACONSIDERATIONS AND WAY FORWARD 1
  2. 2. WE FIRST THANK TO THE DEDICATED VOLUNTEERS, WITHOUT THEM POLIO ERADICATION IN INDIA IS NOT POSSIBLE • Each national immunization day involved: • 225,000,000 doses of polio vaccine • 172,000,000 children vaccinated • 2,500,000 vaccinators • 2,000,000 vaccine carriers • 155,000 supervisors 2
  3. 3. Content●Introduction• Poliomyelitis disease – Polio virus – Transmission, Pathogenecity – Clinical course – Diagnostic challenges – Complications• Poliomyelitis eradication – Global scenario ( Past & Current ) – Indian scenario ( Past & Current )• Poliomyelitis vaccines – Oral Polio Vaccine (OPV) – Injectable Polio Vaccine (IPV) – Comparison between OPV & IPV• End game strategy – What is the polio endgame? – Why is the world now rethinking the Polio Endgame? – What are the major elements of the New Polio Endgame?• Polio Endgame Strategy in India Considerations and Way Forward 3
  4. 4. Poliomyelitis crippled millions forcenturies is on the verge of eradication! ● Etymology – Greek word: Polio (grey) + myelos (marrow) • History – First described in 1789 in Europe – In next 100 years caused several epidemics • Impact of effective vaccines – Rapid decline in polio incidence – Only 3 countries are Polio endemic • Global polio eradication in near future! 4
  5. 5. Poliovirus is a highly pathogenic virus has3 serotypes & there is no heterotypic immunity! ● Member of Picornaviridae family – Enterovirus – Small viruses with an RNA genome – 3 serotypes (P1, P2 & P3) ♦ No heterotypic immunity • Inhabitant of GIT & stable at acidic pH • Rapidly inactivated by – Heat / Formaldehyde / Chlorine / UV light 5
  6. 6. Polio transmits via oro-fecal route!• Humans are the only reservoirs• Transmission – Fecal-oral route – No carriers• Communicability – Highly infectious for 7 - 10 days before & after onset• No seasonality 6
  7. 7. Poliovirus can cause paralysis in 10 days! 7
  8. 8. 8
  9. 9. Behind every paralytic polio case there are 100 to 1000 poliovirus infections!• Incubation period – 6 – 20 days• 95% infections – Inapparent infections• 4 – 8% – Abortive poliomyelitis● 1 – 2% – Nonparalytic meningitis• <1% – Flaccid paralysis 9
  10. 10. Paralysis is the major complication of poliomyelitis!• Complications – Spinal polio • 80% of paralytic cases • Asymmetric paralysis of legs – Bulbar polio • 2% of paralytic cases • Muscle weakness – Bulbospinal polio • 18% of cases • Mixed morbidity• Case Fatality Rate – 2 – 5% (in children ) – 15 – 30% (in adults) 10
  11. 11. Diagnosing poliomyelitis is a clinical challenge,as many diseases & conditions cause AFP!• Differential diagnosis of acute flaccid paralysis – Commonest • Gullian-Barre syndrome • Transverse myelitis – Infections • Viral - Enteroviruses & other viruses – Toxins • Bacterial (e. g. Botulinm, Tetanus) & fungal • Venoms (e. g. Ticks, spider, beetle, wasp & snake) • Organic chemicals & pesticides – Metabolic disorders • Hypokalemia & Hypophosphatemia – Traumatic neuritis (Post injection) 11
  12. 12. In 1988 the World Health Assembly passed a resolution to eradicate polio, launching the Global Polio Eradication InitiativeIn 1995,In India, 87 million children were vaccinated.
  13. 13. Global Status 1988 13
  14. 14. GLOBAL STATUS 2004 14
  15. 15. Polio Eradication : 1988 - 2012 YEAR NO.OF POLIO CASES 1988 350000 1993 1925 1988 : 1998 1934 350,000 1999 1186 cases 2000 265 > 125 2001 211 countries 2002 1919 2003 784 2004 1556 2005 1831% cases decrease: > 99% 2006 2022 2007 1387 2008 1732 2009 1783 *2012 : 299 cases (as of 9th Oct, 2012) 2010 1413 7 countries ( Endemic-3, Importation-4 ) 2011 716 2012* 299 15
  16. 16. SAW SEE Polio cases 2000 1750 1500 1250 1000 750 500 250 0 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008* 16
  17. 17. Rolling Towards the Success story * as of 13th October 2012 17
  18. 18. HOPE THIS ISLAST POLIO CASE Baby Rukhsar, Howrah 18
  19. 19. Finally, India achieved interruption of transmission for Nearly 2 Years So, India appears on track to Stop Polio 19
  20. 20. 20
  21. 21. What has been the cost towards this achievement…??? MoH: India has spent INR1200 crores towards Polio control so far International investment of over US$ 8 billion 21
  22. 22. It took 75 years of scientific efforts foreliminating polio from most part of the world! Polio Virus Jonas Salk Albert B. Sabin created first injectable Created first oral polio vaccine polio vaccine 22
  23. 23. In 1952 Prof. Salk created world’s first IPV!• Tissue Culture Era (1950 – 1951) • Cultivation in non-nervous tissue • Plaque technique to improve yield• Inactivated vaccines – 1952 - 1953 • Prof. Salk – Safety & immunogenicity in animals & humans – 1954 • Vaccine field trial by University of Michigan, US • 1,829,916 children enrolled (US, Canada & Finland) – 1955 • Trial results published – Safe & 70% effective – 6 manufacturers permitted licenses 23
  24. 24. In 1954 Prof. Sabin created world’s first OPV! –1952 ♦ Prof. Sabin identified characteristics of candidate virus for OPV ♦ Developed neurovirulence model in monkey – 1957 - WHO recommended field trials – 1958 - Singapore – 200,000 children vaccinated – 1959 - USSR – 1,500,000 children vaccinated – 1960 - > 100,000,000 children vaccinated 24
  25. 25. OPV protects the community by conferring high level of herd immunity!● Monodose (0.5 mL) in a plastic dispenser• Live attenuated strains of 3 serotypes (10:1:3)• Viruses replicate in intestine, lymph tissues• Viruses excreted in stool up to 6 wks• Herd immunity effect – Persons coming in contact with fecal material of a vaccinated child get protected 25
  26. 26. Though OPV is highly immunogenic vaccine,it is a “hit / miss” vaccine, with associated riskof VAPP!● Immunogenicity & vaccine efficacy – Highly immunogenic ♦ 1 dose - 50% recipients ♦ 3 doses - 95% recipients – Produces intestinal immunity • Prevent infection with wild virus – Provides lifelong immunity• Drawbacks – “Hit / Miss” vaccine! – Vaccine Associated Paralytic Poliomyelitis 26
  27. 27. Risk of VAPP with OPV is rare, but……………………immunodeficient children have 7000 times higherrisk! • Vaccine Associated Paralytic Poliomyelitis (VAPP) – Accounts for 95% of all cases of paralytic poliomyelitis – Type of virus • Type 3 (most cases in vaccinees) & Type 2 (most cases in contacts) – Risk of VAPP • <1/1,000,000 ) – Cause ♦ Mutation / reversion of virus (revertant) to more neurotropic form – Paralysis identical to that caused by wild virus – At risk population • Persons of > 18 years • Immunodeficient children (e.g. malnutrition) 27
  28. 28. Risks of OPV• Vaccine Associated Paralytic Poliomyelitis (VAPP),• The global burden is estimated at 250–500 cases annually• In 2000 in Hispaniola when 21 children were paralysed, first cVDPV outbreak was identified• Long term Carriers of VDPVs identified among immunodeficient (iVDPVs) reseed in general population• In the Philippines in 2001 cVDPV outbreak in 3 and in Madagascar in 2002, 4 children.• Retrospective analyses documented cVDPV circulation in Egypt 1988 -1993 30 cases• So, they all have the potential to cause Outbreaks in underimmunized populations 28
  29. 29. cVDPV Globally 5 http://www.polioeradication.org/ 29
  30. 30. Injectable Polio Vaccine● IPV (Salk) 1955● Enhanced IPV 1970’s available since 1988 in US used worldwide.● Highly immunogenic >90% protection 2 doses Murdin AD, Vaccine 1996;14., Robertson, Lancet 1998;352● 98-100%seroprotection all 3 serotypes Vidor E,Ped.Infec Dis.1997;16● Ideal vaccine for individual protection Thacker & Shendurnikar,IJP 2003;70 30
  31. 31. Risk of VAPP can be eliminated by administrating IPV prior to OPV!● Control of VAPP (Learning from US scenario) – 1996 ♦ ACIP recommended IPV followed by OPV • Production of humoral immunity against polio vaccine virus – 1998 • Fewer cases of VAPP – 2000 • Exclusive IPV vaccination form 2000 – Elimination of shedding of live vaccine virus – Elimination of VAPP 31
  32. 32. IPV administration is safe during minorillnesses, including diarrhoea & URTI!• Minor illnesses – Can be administered to a child with diarrhea – Minor illness is not contraindications• Breastfeeding – No interference • Special precautions – Severe acute illness ● Contraindication – Hypersensitivity to any vaccine component 32
  33. 33. Most IPVs use vero cell substrate for virus growth &the virus is inactivated by formaldehyde! ● Single dose prefilled syringe Cell Manufacturer Country substrate ● Administered by IM injection Novartis Italy Vero France Vero Sanofi Pasteur • Contains all 3 serotypes of virus Canada & MRC -5 GSK Belgium Vero National • Inactivated with formaldehyde Biological Sweden Vero Laboratory • 2-phenoxyethanol as Netherlands preservative Vaccine Netherlands Vero Institute • Traces of Rhesus Monkey Statens Serum neomycin, streptomycin & Denmark Kidney Institute polymyxin B & Vero 33
  34. 34. What is the polio endgame?The endgame: addressing risks due to the oral polio vaccine(OPV) after eradication ● Vaccine-Associated Paralytic Poliomyelitis (VAPP): very rare adverse event. ● very rare event; Outbreaks of circulating vaccine-derived poliovirus (cVDPV): occurs when vaccine virus regains ability to paralyze and circulate. After interruption of wild poliovirus, continued use of OPV would compromise the goal of a polio-free world. Expert Consultation on Vaccine-derived Polioviruses (VDPVs), Sept 2003, Geneva 34
  35. 35. Evolution of the Post-Eradication Timeline Last polio case OPV cessation Years 0 2 4 6 8 10 12 Certification Wild virus Certification Commission 95 eradication The endgame period World Health Wild virus Certification & VDPV elimination & Post-OPV Assembly (2008) eradication containment validation surveillance 35
  36. 36. Why is the world now rethinking the Polio Endgame? Recent developments allow a major rethink of the endgame• New bivalent vaccine (bOPV) outperforms trivalent OPV.• New diagnostics show type 2 OPV is the main problem.• New, very low cost IPV options can allow all countries to continue type 2 immunization if they want/need to. 36
  37. 37. Current Understanding of cVDPVs circulating Vaccine-Derived Type 1 (79 cases) Poliovirus Outbreaks Type 2 (450 cases) (cVDPVs) 2000-2010 Type 3 (9 cases) 37
  38. 38. Affordable IPV options in the short-term, 1/5th of 1 dose of IPV can induce a 1/5th of 1 dose of IPV could be very response in >90% of children affordable (<$0.5/dose)Response* after 1 dose IPV price(%, intradermal IPV, Cuba) ($ per dose)100 90 $3 80 70 60 50 $0.6 40 < $0.3 30 20 10 Full-dose 1/5th fractional dose 0 P1 P2 P3 Current price Expected price (low volume) (high volume**) * includes seroconversion & priming ** assumes full dose price of < US$1.5/dose at high volume 38
  39. 39. What are the major elements of the New Polio Endgame?New Polio Endgame: Guiding Principles • phased removal of Sabin/OPV viruses, beginning with highest-risk (type 2). • elimination of type 2 in parallel by switching from tOPV to bOPV for routine EPI & campaigns. • introduction of 1 IPV dose to boost immunity prior to a tOPV-bOPV switch & provide type 2 priming. 39
  40. 40. New Endgame strategy: parallel risk management Last wild polio case trivalent OPV cessation Years 0 2 4 6 8 10 12 Sequential risk Wild virus Certification & VDPV elimination & Post-OPV management eradication containment validation surveillance Parallel risk Wild virus Certification & management eradication containment VDPV2 elimination & Post-OPV validation surveillance OPV2 cessation bivalent OPV 1&3 & IPV introduction (bOPV) cessation 40
  41. 41. Advantages of the New Approach • accelerate type 1 & 3 eradication (with bOPV) • address >90% of VDPV risk while surveillance & response capacity is optimized • substantially shorten the post-eradication phase • boost routine immunization coverage (i.e. IPV at DPT3) 41
  42. 42. Polio Endgame Strategy in India Considerations and Way Forward● No WPV2 in India since 1999● tOPV used in RI and during NIDs● bOPV used in most SNIDs since Jan 2010● Areas and populations with low routine immunization coverage● All cVDPVs in India due to type 2 in setting of low immunity to type 2 42
  43. 43. Last wild poliovirus cases by type, India WPV2 24/10/1999 Aligarh (UP) WPV3 22/10/2010 Pakur (JH) WPV1 13/01/2011 Howrah (WB) 43
  44. 44. Current pattern of vaccine use-India● tOPV – EPI schedule: 6,10,14 wks Birth dose for institutional births Assessed – SIAs: 2 NIDs with tOPV each year tOPV3 coverage by CES 2009● bOPV A – Introduced in Jan 2010 – Used extensively during SNIDs in high risk states/ areas 70.4% <60 60 - 70 70 - 80 >= 80 44
  45. 45. cVDPV cases, India 2009-2011 •cVDPV cases detected in 2009-10 •100% due to type 2 Type 2 District 2009 2010 2011 Badaun 3 0 0 Bulandshahar 2 0 0 Ghaziabad 0 1 0 Meerut 2 0 0 Moradabad 2 0 0 Pilibhit 4 0 0 Shahjahanpur 2 1 0 Total 15 2 0 45
  46. 46. Low seroprevalence against poliovirus type 2 Results from different serosurveys Moradabad AFP cases UP Moradabad UP & Bihar UP & Bihar Nov 2007 Nov 08 – May 2009 Aug 2010 Aug 2011 (N=121) mid 09 (N=534) (N=1280) (N=1246) (169)Age 6-7 mo 6-11 mo 6-7 mo 6-7 mo 6-11 moType 1 78% 96.5% 99% 98% 98.5%Type 2 56% 33.7% 75% 65% 85%Type 3 69% 42.6% 49% 77% 88.2% 46
  47. 47. Evaluated OPV3 coverage by district – DLHS 3 (2007-08) and cVDPVs S ta te .s h p Uttar Pradesh D is tric t.s h p 0<- 25% 2 4 .9 225-to 9 .9 5 4 50% 550-to 4 .9 0 7 75% 7>=- 75% 5 10 0 N cVDPV type 2 W E200 0 200 400 M i le s S 10 tOPV tOPV tOPV tOPV 9 sNID NID NID sNID 8 7 Number of cases 6 5 tOPV 4 c VDPV type 2 3 2 1 0 J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D 2009 2010 2011 47
  48. 48. iVDPV & aVDPV cases, India 2009 to 2012* iVDPV aVDPV State Type 1 Type 2 Type 3 State Type 1 Type 2 Chhattisgarh 1 Assam 1 Punjab 1 Bihar 3 Tamil Nadu 1 Karnataka 1 Uttar Pradesh 1 Madhya Pradesh 1 Odisha 1 Rajasthan 1 Total 1 3 1 Uttar Pradesh 4 West Bengal 1 Total 1 11*: data as on 10 March 2012 ambiguous VDPV (aVDPV): origin uncertain e.g. single isolate from single AFP case, non-immunodeficient person 48
  49. 49. tOPV-bOPV switch in India? Considerations● Pre-switch increase in type 2 immunity● Rapidly improve routine immunization coverage● Use of IPV in conjunction with bOPV/tOPV to reduce risk of emergence and consequences of cVDPV● Availability of vaccines – IPV availability for use in routine immunization – bOPV availability for routine immunization and SIAs● Management of post-switch risks of type 2 VDPVs● cVDPV type 2 circulation stopped everywhere & switch synchronised globally 49
  50. 50. Polio Endgame Strategy-India, Possible Way Forward tOPV- bOPV switch PolioLast WPV certification case NID NID NID NID NID NID NID NID IPV Post- switch Modelling, Research, Development Sabin type 2 PQ/ licensing, stockpile risk mgt. Certification standard surveillance, improved RI coverage0 Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May 2011 2012 2013 2014 tOPV NID 50
  51. 51. ConclusionsWhile the past cannot be re-enacted, the future can certainly be redesignedSequential IPV/OPV schedules considered1st phase transition towards all IPVschedule in Routine Immunzation.The program should attend TO COUNTRY SPECIFIC NEEDSAnd Not get overawed by Global needsHope this Debate will not only generate aNation wide Debate but also create theNeed in the best interest of country. Ultimately success of the whole initiative will depend on steps being taken now to improve the economics of IPV. V Vashishtha RTC Series 2010(24) RSF India 51
  52. 52. HOPE THIS ISTHE HISTORICALLAST POLIO CASEOF INDIA 52

×