Table 3. Geometric mean virus neutralization (VN) titers of the sera collected from the yearlings one month after the second dose of the primary vaccination course.
| Indicator viruses | Groupsa) | ||
|---|---|---|---|
| NN (n=13) | ON (n=13) | OO (n=9) | |
| A/equine/Yokohama/aq13/2010 | 27.3 | 35.6 | 34.6 |
| A/equine/Ayrshire/1/2013 | 41.8 | 39.6 | NDb) |
| A/equine/Carlow/2011 | 16.9 | 5.0d) | 6.3c,d) |
| A/equine/Devon/1/2011 | 19.8 | 9.4d) | 8.0c,d) |
a) NN or OO indicates the group of yearlings was vaccinated twice one month apart with the new updated vaccine or the old vaccine, respectively. ON indicates the group of yearlings was vaccinated twice one month a part with the old vaccine and new updated vaccine sequentially. b) Not determined. c) These data were cited from our previous study [21]. d) Statistical significance between the VN titer against A/equine/Yokohama/aq13/2010 and the other two (OO) or three (NN and ON) Fc2 viruses in each column (Friedman’s test with Dunn’s multiple comparison tests, P<0.05).