TABLE 4. Seroprotection rates and geometric mean titers among adults at intervals after first dose of a 2-dose primary series of inactivated Vero cell culture–derived Japanese encephalitis vaccine, by tickborne encephalitis vaccination status.
| Measure | 6
mos |
12
mos |
24
mos |
60
mos |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Seroprotection rate*
|
Total
|
No.
seroprotected
|
(%)
|
Total
|
No.
seroprotected
|
(%)
|
Total
|
No.
seroprotected
|
(%)
|
Total
|
No.
seroprotected
|
(%)
|
| TBE
vaccine† |
89
|
86 |
(97) |
89
|
82 |
(92)§ |
86
|
78 |
(91)§ |
78
|
67 |
(86)§ |
| No TBE
vaccine |
92
|
86 |
(93) |
92
|
69 |
(75) |
78
|
53 |
(68) |
47
|
30 |
(64) |
|
GMT
|
GMT
|
GMT
|
GMT
|
GMT
|
||||||||
| TBE
vaccine† |
96 |
48 |
56 |
45 |
||||||||
| No TBE vaccine | 73 |
35 |
33 |
29 |
||||||||
Sources: Dubischar-Kastner K. New clinical data for IXIARO Japanese encephalitis vaccine, inactivated, adsorbed. Presentation to Advisory Committee on Immunization Practices (ACIP), February 24, 2016. Atlanta, GA: US Department of Health and Human Services, CDC; 2016. https://stacks.cdc.gov/view/cdc/60592; Taucher C, Kollaritsch H, Dubischar KL. Persistence of the immune response after vaccination with the Japanese encephalitis vaccine, IXIARO® in healthy adults: A five year follow-up study. Vaccine 2019;37:2529–31.
Abbreviations: GMT = geometric mean titer; TBE = tickborne encephalitis.
* Proportion with 50% plaque reduction neutralization test titer ≥10.
† TBE vaccine received before or after Vero cell culture–derived Japanese encephalitis vaccine.
§ Nonoverlapping 95% confidence intervals (calculated according to the method recommended by Altman, developed by Wilson) for seroprotection rates for TBE and no TBE vaccine groups.