Assessment of the Immunogenicity and Safety of Japanese Encephalitis Live Attenuated SA 14-14-2 Vaccine in Children in Sri Lanka
Overview
- Phase
- Phase 4
- Intervention
- Not specified
- Conditions
- Japanese Encephalitis
- Sponsor
- PATH
- Enrollment
- 278
- Locations
- 3
- Primary Endpoint
- Number and Percentage of Subjects With Demonstrated Seropositivity for Japanese Encephalitis (JE) Neutralizing Antibodies
- Status
- Completed
- Last Updated
- 7 years ago
Overview
Brief Summary
To facilitate introduction of live attenuated SA 14-14-2 Japanese encephalitis vaccine (LJEV) into the National Immunization Programme of Sri Lanka, we evaluated the safety and immunogenicity of co-administration of LJEV and measles vaccine at 9 months of age. The primary hypothesis was that the seropositivity rate at 28 days post vaccination in Japanese Encephalitis (JE) and measles concomitantly vaccinated subjects 9 months of age is greater than 80% for JE and greater than 90% for measles.
Detailed Description
JE virus is an arbovirus that causes a devastating neurological disease resulting in high rates of mortality orneurologic sequelae. The severity of sequelae, together with the volume of cases, makes JE an important cause of encephalitis. The disease is endemic across temperate and tropical zones of Asia,and because of its zoonotic cycle, eradicating JE from the environment is unrealistic. Universal childhood vaccination is essential for disease control. In Sri Lanka, immunization against JE began in 1988. By 2006, two types of JE vaccines were available for use in Sri Lanka-inactivated mouse brain-derived vaccine and live attenuated SA-14-14-2 JE vaccine (LJEV). Only the inactivated vaccine was being used in the country's public-sector immunization program. Concern in Japan over a rare but potentially dangerous adverse event associated with a mouse brain-derived vaccine led the manufacturer in Japan to discontinue production in 2005, thus limiting global supply of inactivated JE vaccines and raising costs for remaining inactivated vaccines. In August of 2006, the World Health Organization stated in its position paper on Japanese encephalitis vaccines that the mouse brain-derived vaccine should be replaced by a new generation of JE vaccines. For Sri Lanka, switching to the less expensive LJEV was estimated in 2006 to save the National Immunization Programme (NIP) between US$8.6 and $8.9 million annually in direct vaccine costs alone. To generate local immunogenicity and safety data to guide policy for potential use of LJEV in Sri Lanka's NIP, the Ministry of Healthcare and Nutrition, in cooperation with PATH, initiated the study. The study was conducted in three peri-urban health divisions of low JE endemicity in the District of Colombo.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Healthy child 9 months (±2 weeks) of age at the enrollment visit.
- •Subject was a full-term infant.
- •Subject's parent or legal guardian is literate and willing to provide written informed consent.
- •Subject is up-to-date for all vaccinations recommended in the Sri Lankan childhood immunization schedule.
Exclusion Criteria
- •Enrolled in another clinical trial involving any therapy.
- •Subject and/or parent(s) or guardian(s) are unable to attend the scheduled visits or comply with the study procedures.
- •Received any non-study vaccine within 2 weeks prior to enrolment or refusal to postpone receipt of such vaccines until 28 days after study entry.
- •Prior or anticipated receipt of immune globulin or other blood products, or injected or oral corticosteroids or other immune modulator therapy except routine vaccines within 6 weeks of administration of study vaccine. Individuals on a tapering dose schedule of oral steroids lasting \<7 days may be included in the trial as long as they have not received more than one course within the last 2 weeks prior to enrolment.
- •History of documented or suspected encephalitis, encephalopathy, or meningitis.
- •History of measles.
- •History of Japanese encephalitis.
- •Serious adverse event related (i.e., possible, probably, definite) to previous receipt of any JE vaccine, if applicable.
- •Persistent inconsolable crying (\>3 hours) observed after previous receipt of any JE vaccine, if applicable.
- •Hypotonic - hyporesponsiveness after past receipt of any JE vaccine, if applicable.
Outcomes
Primary Outcomes
Number and Percentage of Subjects With Demonstrated Seropositivity for Japanese Encephalitis (JE) Neutralizing Antibodies
Time Frame: 1 year
Blood serum was collected immediately before administration (Day 0), Day 28, six months post-administration, and 1 year later. Serum neutralizing antibodies to the Beijing-1 JE strain were measured by plaque reduction neutralization test (PRNT) where the neutralizing titer was measured as the inverse dilution at which plaque counts were reduced by 50%. Seropositivity was defined as a titer of ≥1:10.
Number and Percentage of Subjects With Demonstrated Seropositivity for Anti-measles Immunoglobulin G (IgG): Manufacturer Definition
Time Frame: 1 year
Blood serum was collected immediately before administration (Day 0), Day 28, six months post-administration, and 1 year later. Serum anti-measles immunoglobulin class G (IgG) antibodies were measured by enzyme-linked immunosorbent assay (ELISA) (Serion ELISA classic Measles Virus IgG, Serion GmbH, Würzburg,Germany). For anti-measles IgG, two definitions of seropositivity were used: per manufacturer's instruction (concentration of\>200 mIU/mL, this table) and when including those with "borderline" results (≥150 mIU/mL).
Number and Percentage of Subjects With Demonstrated Seropositivity for Anti-measles Immunoglobulin G (IgG): Including Borderline Subjects
Time Frame: 1 year
Blood serum was collected immediately before administration (Day 0), Day 28, six months post-administration, and 1 year later. Serum anti-measles immunoglobulin class G (IgG) antibodies were measured by enzyme-linked immunosorbent assay (ELISA) (Serion ELISA classic Measles Virus IgG, Serion GmbH, Würzburg,Germany). For anti-measles IgG, two definitions of seropositivity were used: per manufacturer's instruction (concentration of\>200 mIU/mL) and when including those with "borderline" results (≥150 mIU/mL, this table).
Secondary Outcomes
- Geometric Mean Titer (GMT) of Anti-measles Immunoglobulin G (IgG)(1 year)
- Number and Percentage of Subjects With Immediate Reactions, Local and Systemic Reactions, and Unsolicited Adverse Events (AE)(1 year)
- Number of Solicited Local Reactions to LJEV: Days 4-7(4 days)
- Geometric Mean Titer (GMT) of Japanese Encephalitis (JE) Neutralizing Antibodies(1 year)
- Number of Solicited Local Reactions to LJEV: Days 0-3(3 days)
- Number of Solicited Local Reactions to Measles Vaccine: Days 4-7(4 days)
- Number of Solicited Local Reactions to Measles Vaccine: Days 0-3(3 days)
- Number of Solicited Systemic Reactions: Days 0-3(3 days)
- Number of Solicited Systemic Reactions: Days 4-7(4 days)