Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) for Use of Inactivated Vero Cell Culture-derived Japanese Encephalitis Vaccine in Children
MMWR recomm. rep; 62 (45), 2023
Année de publication: 2023
Inactivated Vero cell culture-derived Japanese encephalitis vaccine (JE-VC [manufactured as IXIARO]) is the only JE vaccine licensed and available in the United States. JE-VC is manufactured by Intercell Biomedical (Livingston, United Kingdom) and distributed in the United States private market by Novartis Vaccines (Cambridge, Massachusetts). In March 2009, FDA licensed JE-VC for use in adults aged ≥17 years. ACIP recommendations for use of JE-VC in adults were approved in June 2009 and booster dose recommendations were approved in February 2011 [CDC 2010; CDC 2011].
There are no efficacy data for JE-VC. However, a JE virus 50% plaque reduction neutralization test (PRNT50) titer of ≥10 is an established immunologic correlate of protection [Markoff 2000; Hombach 2005]. JE-VC was licensed based on its ability to induce neutralizing antibodies and a non-inferiority comparison to a licensed inactivated mouse brain-derived JE vaccine (JE-MB [manufactured as JE-VAX]). Since JE-VC was licensed in 2009, >375,000 doses have been distributed in the United States for use in adults.
In May 2013, FDA approved JE-VC for use in children aged 2 months through 16 years [FDA 2013]. The FDA-approved primary series for JE-VC is two intramuscular doses administered 28 days apart. For children aged 2 months through 2 years each dose is 0.25mL and for adults and children aged ≥3 years each dose is 0.5mL.
The ACIP JE Vaccine Workgroup evaluated the evidence for use of JE-VC in children using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methods [Ahmed 2011]. The workgroup developed a policy question, identified outcomes of critical importance, performed a systematic review of the available data, and evaluated evidence of benefits, harms, values, and preferences for use of JE vaccine in U.S. children.