J apanese Encephalitis Vaccine

1. Japanese Encephalitis Vaccine DrMonjoriMitra Associate Professor Institute of Child Health Kolkata

2. Issues to Consider • Epidemiological status • Currently Available Vaccines • New Vaccination Modalities • The Clinical Trial Currently Underway

3. Japanese Encephalitis VirusHistory • Minor epidemics of “summer encephalitis in Japan since at least 1870; large outbreak in 1924 causes 6,125 cases with 3,797 deaths • Initially called Japanese type B encephalitis to differentiate from epidemic encephalitis lethargica, type A encephalitis • Virus first isolated from the brain of a fatal case in 1935 • Isolated from Culex tritaeneorhinchus in 1938 • Now known to be the principal mosquito vector in most of the geographic distribution of the disease

4. Epidemiology • Primarily a disease of rural Asia • Vector mosquitoes proliferate in close association with birds and pigs • Birds and pigs are the major amplifying hosts • Many other mammals and reptiles infected as well, long term viremia documented in bats, others • Culex tritaeniorhynchus the principal vector but many other mosquitoes are competent and can transmit • C. pipiens • C. quinquefasciatus • Species of Aedes, Anopheles • Virus overwinters in mosquitoes as well as vertical transmission • Traditional seasonal spread (spring/summer) heavily impacted by rice paddy flooding

5. Cattle May Serve to Modulate JE Activity Photo by George Risi

6. Incidence and Prevalence • Commonest cause of encephalitis in Asia • In hyperendemic areas half of all cases occur in children under 4 years of age, nearly all before age 10 • Nearly 100% seroprevalence by adulthood in heavily infected areas • Epidemic and endemic forms • 20,000 cases and 6,000 deaths annually a gross underestimate • Mathematical modeling predicts 175,000 annual cases, 43,750 fatalities, 78,750 with disability

7. Incidence and Prevalence • Ratio of apparent to inapparent infection ranges from 1:250 in susceptible Asians to 1:63 in adult US marines, 1:18 in Torres strait outbreak • Ratio affected by age, virulence of the strain of virus, cross protective immunity from other flaviviruses (dengue) • Risk to travelers 1 case per 50,000 months of exposure

8. Epidemiology • Geographic range expanding; new areas infected by • Viremic migratory birds- Guam, Saipan • Windblown mosquitoes- Torres strait of Australia

9. Uttar Pradesh Epidemiology Bihar • July 2005 an outbreak began in northern India and Nepal; by November 10, 2005 Uttar Pradesh and Bihar had 6097 cases, 1400 deaths (23% mortality) • Outbreaks clearly related to difficulties and expense of currently available vaccine

11. Epidemiology • Japanese Encephalitis Virus is transmitted to Humans by the bite of infected Mosquito species. • Different mosquitos genera and species of mosquito serve as intermediate host and transmit JE virus. • Anopheles species: - hyrcanus, subpictus • Culex species: - tritaeniorhynchus, vishnui • Mansonia species:- annulifera, indiana • Pigs & birds are primary reservoirs wherein the virus is maintained & amplified • 30- 50,000 overt JE cases and 10,000 deaths reported annually worldwide (likely underreported). • 30% of survivors suffer from lasting damage to central nervous system • In India JE has shown increasing trend in occurrence and expansion of disease to non-endemic areas in India • In JEV endemic areas, JE is primarily a pediatric disease

12. Key risk groups Military deployed to endemic areas Travelers Expatriates in rural areas Residents of rural areas in endemic locations JEVirus –Transmission, Prevalence, Risk

13. JE Vaccination Program – Overview Map showing 112 JE vaccination campaign districts

14. The JE Mass vaccination Drives ( Campaigns ) Coverage * Based on the emergence of new cases JE/ AES and low coverage as per CES report in 9 districts 2 states , it was decided to conduct re-campaigns

15. JE vaccination campaigns - Year coverage2006 - 2011

16. JE Vaccination Campaign 2006

17. JE Vaccination Campaign 2007

18. JE Vaccination Campaign 2008

19. JE Vaccination Campaign 2009

20. JE Vaccination Campaign 2010

21. Japanese Encephalitis Disease • Incubation 6-16 days. Spectrum from mild febrile headache to severe encephalitis • Headache, fever, nausea, vomiting, drowsiness. Abdominal pain and diarrhea common in children • Progression over several days to severe disease • Dull, mask-like facies • Muscular rigidity • Cranial nerve palsies • Tremulous eye and extremity muscle movements • Generalized and localized paresis, incoordination, pathologic reflexes • Seizures frequent in children, <10% of adults Associated Press

22. Clinical Manifestations • Death in 5-40% • Some deaths after acute fulminant course, others from cardiopulmonary complications with prolonged coma • Children under 10 more likely to die or have residual neurological defects • Poor prognosis associated with • Respiratory dysfunction • Babinsky’s sign • Frequent or prolonged seizures • Prolonged fever • Albuminuria • High viral replication in the brain Source: Reuters News Agency

24. Epidemiological Data

25. Type of vaccine: 
1) Live attenuated vaccine (SA 14-14-2 strain) 
2) Inactivated, Vero cell-derived, alum-adjuvanted vaccine (SA 14-14-2 strain) 
3) Inactivated Vero cell-derived based vaccines (Beijing-1 strain) Schedule: 
1) In China, the first dose of the live attenuated vaccine is given subcutaneously at age 8 months, followed by a booster dose at 2 years of age. In some areas, an additional booster is offered at 6–7 years of age. Protection for several years may be achieved also with a single dose of this vaccine. 
2) Primary immunization of the inactivated, alum-adjuvanted vaccine consists of two intramuscular doses, 4 weeks apart 
3) The inactivated (Bejjing-1-) vaccines: three doses at days 0, 7 and 28, or two doses given preferably 4 weeks apart (0.25 ml for children <3 years, 0.5 ml for all other ages).

26. Booster: The duration of immunity is not well established for the above vaccines. 1) the live attenuated vaccine, a booster dose is recommended in some countries. 2) the Japanese vaccines, a booster is recommended after year 1, and thereafter every 3 years. 3) the inactivated, alum-adjuvanted vaccine, one booster is recommended 12–14 months after completion of the primary immunization; the possible need for further boosters to be determined. Adverse reactions: Occasional mild local or systemic reactions Before departure: The immunization series should be completed at least 1 week before potential exposure to JEV.

27. Efficacy of the SA 14-14-2 Vaccine against Japanese Encephalitis. Effectiveness of One Dose of SA 14-14-2 Vaccine against Japanese Encephalitis N Engl J Med 2009; 360:1465-1466April 2, 2009 Kumar R et al. N Engl J Med 2009;360:1465-1466.

28. Immunogenicity and efficacy of Live Attenuated SA 14-14-2 Several studies have demonstrated an excellent immune response after a single dose of SA 14-14-2 vaccine, with neutralizing antibody responses produced in 85%-100% of non-immune children. Several field trials in China have yielded protective efficacy rates above 95%. One early case control study found 80% vaccine efficacy in children receiving one dose and 98% for two doses. A more recent study in an endemic area of Nepal reported 99.3% efficacy of a single dose. One year after immunization, a follow up study in the same region reported efficacy of 98.5%.

29. GlobalAdvisoryCommittee on VaccineSafety - The SA 14-14-2 live attenuated JE vaccine GACVS has reviewed safety aspects of this vaccine at two of its meetings (twelfth, held on 9-10 June 2005, and fifteenth, held on 29-30 November 2006). GACVS reviewed data related to the safety, immunogenicity and efficacy of the vaccine, and scrutinized data on co-administration with measles vaccine. GACVS concluded that the short-term safety profile of live JE vaccine appears satisfactory and that there appears to be a high level of vaccine efficacy after the administration of a single dose. In relation to serious adverse events reported after mass vaccination campaigns in India during 2006, no direct causality has been established between the reported illnesses and the SA14-14-2 JE vaccine. Nevertheless, GACVS recommended that in future, potential vaccine-related serious adverse events should be better investigated. Furthermore, more investigations are required to assess the possible risk of low frequency adverse events (especially neurological). Since live JE vaccine is currently used in “catch-up” campaigns on many millions of children in Asian countries, the opportunity should be taken to examine whether the vaccine safety profile remains valid in large study populations.

30. Development of Vero cell-derived inactivated JE vaccine

31. Other JE Vaccine Manufacturers

32. Comparison between different JE vaccines (Mouse brain, Live (PHK) and Vero cell based ) *IXIARO

33. Collaboration with NIV & iOWH For JE Vaccine Development has collaborated with Dr. Milind Gore National Institute of Virology, Pune, India, Dr. Richard Chin, Director Dr. Raj Shankar Ghosh, Regional Director,South Asia. (now PATH)

34. Global Scenario - JE Vaccine First Generation Vaccines (Mouse Brain Derived): • BIKEN- Japan has been the largest manufacturer and international distributor,but has ceased production. • JENCEVAC- Manufactured by Green cross, South Korea. Other manufacturers are found inTaiwan, Thailand and Vietnam

35. Global Scenario - JE Vaccine Second Generation Vaccines: Vero cell derived, Purified inactivated JE vaccine: • IXIARO: Manufactured by Intercell AG, Austria. The vaccine was approved for adults. Phase III clinical trials completed in Indian children (BE collaboration). • Manufactured by Bharat Biotech International Limited. The vaccine was approved for conducting Phase-II/III clinical trial and trials completed in adults & children.

36. Thermo- stable strain Increased stability & shelf-life of the vaccine Novel inactivation process - to keep the Antigenicity increase immunogenicity Innovative aspects of BBIL JE Vaccine

37. NIV-History of JE virus seed Obtained from : NIV, Pune, India Isolation : JE infected encephalitis patient Strain : Thermostable Kolar Strain (JEV 821564 XY) Passage history : 17 times in suckling mice Original Seed titer : LD50 per mL = 107

38. Product & Production profile • Purified, inactivated Japanese encephalitis protein Not Less Than 5.0µg/0.5mL (Single Human Dose) • Robust manufacturing technology • Production facility- Fully validated commercial scale • Production capacity- 25 Million doses annually

39. Pre-clinical study

40. Pre-clinical toxicity (BBIL)Systemic toxicity Pre-Clinical studies done as per Schedule-Y

41. Pre-clinical toxicity (BBIL) Systemic toxicity • Dose schedule of the vaccine is a maximum of 2SHDs, but in this study 4SHDs were given to the rats and rabbits and no impact was found on the animal safety. • Blood samples for evaluation of serum chemistry and hematology were collected from all the animals on 0th day & 42nd day. • A terminal body weight was obtained shortly prior to necropsy and a complete gross necropsy was conducted on all animals sacrificed during the study. • There was no treatment related effects on mortality, clinical observations, body weight, food consumption, water consumption, coagulation, hematology or clinical chemistry analysis and histopathology in both rats & rabbits. Conclusion: Based on the study, Purified Inactivated Japanese Encephalitis Vaccine injection did not alter any of the above parameters in rats and rabbits in the systemic toxicity study conducted for a period of 42 days.

42. Animal Potency study

43. Day 0 1 2 3 4 5 6 7 Animal Potency study (Thailand) • Project: Study on potency of inactivated Japanese encephalitis vaccines in adult mice • Site of Study: Center for Vaccine Development, Mahidol University at Salaya (WHO approved center for JE vaccines) • Animal: Female Swiss Albino Inbred strain SPF mice, age 4 weeks Immunization dose/schedule: Vaccine 1:10 dilution 1st dose at Day 0, by I.P. route 2nd dose at Day 7, by I.P. route

44. Animal Potency study (Thailand) • Vaccines: Inactivated JE vaccine: Batch-88DP9001, Source: Bharat Biotech, India Inactivated JE vaccine: Batch-JJ 5210 3, Source: GPO, Thailand Inactivated JE vaccine: Batch 00410002 Source: Korean Green Cross, S. Korea (Nakayama), • Serum collection: Collected on day 14 post dose 1 • Serologic test: A validated Plaque Reduction Neutralization Test, 50% end point in continuous LLC- MK2 cells as per SOP using JE wild type Beijing strain as challenging virus, was used to evaluate all sera collected during the study period.

45. Animal Potency study (Thailand) Result: • To evaluate the magnitude of change in circulating neutralizing antibody titers after immunization, titers were measured in all 10 mice immunized. With 2 doses of the Bharat Biotech JE vaccine with GMT 153.55 and 100% seroconversion rate. • For GPO, GMT of PRNT was found to be 187.22. Seroconversion rate of those 10 mice being used in the study revealed 90%. • For KGC vaccine evaluation, GMT was fount to be 46.21 and 80% seroconversion rate. Conclusion: Bharat Biotech JE Vaccine, like GPO JE Vaccine confers higher GMT than the Korean Green Cross JE Vaccine. For seroconversion rate, the Bharat JE Vaccine revealed 100% seroconversion rate after 2 doses, while the other 2 vaccines could not.

46. Phase I Clinical Trial

47. Phase I Clinical Trial Protocol Title: A Phase I, Randomized, Double Blind, Placebo Controlled and Parallel Assignment Study to Evaluate the Safety, tolerability and immunogenicity of inactivated Japanese encephalitis Vaccine Produced by BBIL in healthy adult volunteers. Protocol Number: BBIL/JEV/I/2010 Study Investigator & Centre: Dr. Murali Mohan, MD-General Medicine, Professor, Dept of Medicine, Vydehi Institute of Medical Sciences, Bangalore.

48. Study Population A total of 60 healthy adult male subjects of age 18 to 50 years were participated in this study. Cohort 1: 25 vaccine and 5 placebo = 30 subjects (2 doses, day 0 & 28)* Cohort 2: 25 vaccine and 5 placebo = 30 subjects (3 doses, day 0, 7 & 28) * *Dose: As other commercially available vaccines are either 2 doses or 3 doses, hence BBIL has selected 2 & 3 dose schedule in Phase I Clinical Trial.

49. Dose and Mode of administration • Subjects received either cell culture Inactivated Japanese encephalitis vaccine containing NLT 5µg protein or placebo by intramuscular route as per randomization. • Liquid 0.5ml of vaccine/placebo is injected as two doses on day 0 and day 28+/-2 (Cohort-1) and three doses on Day 0, Day 7±1 and Day 28±2 (Cohort-2) by intramuscular route in to the deltoid region

50. Study Objectives • Primary objective: Evaluate the safety and tolerability in healthy volunteers of 18 to 50 years. • Secondary objective: Immunogenicity in healthy volunteers of 18 to 50 years.