Table 2.
Varicella vaccination uptake and age of vaccination in preschool children surveyed and preschool children with varicella reported in Hong Kong, 2009, 2012, and 2015.
| Varicella vaccination among preschool children surveyed | |||||||
|---|---|---|---|---|---|---|---|
| At least 1 dose |
1st dose |
2nd dose |
|||||
| Survey year | Age (years)/cohort |
Number surveyed | Number received (%) | Number received (%) | Median age (months) at 1st dose (IQR) | Number received (%) | Median age (months) at 2nd dose (IQR) |
| 2009 | 5/2003 | 1666 | 397 (23.8) | 375 (22.5) | 25.5 (16.7–34.5) | 7 (0.4) | 40.0 (38.7–64.1) |
| 4/2004 | 1726 | 509 (29.5) | 405 (23.5) | 24.9 (16.5–32.4) | 9 (0.5) | 40.7 (35.9–49.7) | |
| 3/2005 | 1819 | 613 (33.7) | 526 (28.9) | 23.0 (15.6–28.8) | 6 (0.3) | 37.0 (35.2–37.4) | |
| 2012 | 5/2006 | 1596 | 430 (26.9) | 375 (23.5) | 20.6 (14.7–29.5) | 24 (1.5) | 62.0 (39.3–65.5) |
| 4/2007 | 1834 | 614 (33.5) | 546 (29.8) | 19.0 (14.2–27.9) | 22 (1.2) | 48.7 (36.6–51.7) | |
| 3/2008 | 1815 | 612 (33.7) | 575 (31.7) | 18.4 (14.1–25.9) | 20 (1.1) | 35.4 (27.0–40.9) | |
| 2015 | 5/2009 | 2276 | 1034 (45.4) | 924 (40.6) | 19.2 (14.3–27.4) | 110 (4.8) | 51.0 (39.9–59.2) |
| 4/2010 | 2488 | 1216 (48.9) | 1046 (42.0) | 16.3 (14.0–23.5) | 170 (6.8) | 34.9 (24.6–50.4) | |
| |
3/2011 |
2831 |
1443 (51.0) |
1172 (41.4) |
15.6 (13.5–21.9) |
271 (9.6) |
22.6 (17.2–30.4) |
| Varicella vaccination among cases reported to the DH | |||||||
| At least 1 dose |
1st dose |
2nd dose |
|||||
| Notification year |
Age (years) |
Number reported |
Number received (%) |
Number received (%) |
Median age (year) at 1st dose (IQR) |
Number received (%) |
Median age (month) at 2nd dose (IQR) |
| 20094 | 5 | 684 | 130 (19.0) | 130 (19.0) | 2.0 (1.0–3.0) | – | – |
| 4 | 751 | 121 (16.1) | 121 (16.1) | 2.0 (1.0–2.0) | – | – | |
| 3 | 653 | 95 (14.5) | 95 (14.5) | 1.0 (1.0–2.0) | – | – | |
| 2012 | 5 | 861 | 177 (20.6) | 147 (17.1) | 1.0 (1.0–2.0) | 6 (0.7) | 3.0 (2.5–3.0) |
| 4 | 951 | 182 (19.1) | 146 (15.4) | 2.0 (1.0–2.0) | 7 (0.7) | 3.0 (2.0–3.0) | |
| 3 | 727 | 126 (17.3) | 105 (14.4) | 1.0 (1.0–2.0) | 3 (0.4) | 1.0 (1.0–1.5) | |
| 2015 | 5 | 838 | 171 (20.4) | 136 (16.2) | 1.0 (1.0–2.0) | 15 (1.8) | 2.0 (2.0–5.0) |
| 4 | 866 | 189 (21.8) | 143 (16.5) | 1.0 (1.0–2.0) | 20 (2.3) | 2.0 (1.0–2.0) | |
| 3 | 675 | 110 (16.3) | 89 (13.2) | 1.0 (1.0–1.3) | 11 (1.6) | 2.0 (1.0–2.0) | |
Note:
(1) Survey respondents and reported cases aged three to five were included in this study.
(2) Survey respondents and reported cases with missing vaccination information were not included in the above table. Those who were vaccinated with unknown dose was not shown.
(3) Number and the proportion (%) of children received varicella vaccine for different doses was presented in the above table. Proportion was computed by the number of children received the vaccine divided by the number surveyed/ reported in each stratum.
(4) Number of varicella vaccine received was not collected for cases reported in 2009. In view of low second-dose uptake for children surveyed in 2009, all vaccinated varicella cases reported in 2009 were assumed to have received only one dose.
(5) Age of vaccination for survey respondents was computed by subtracting date of vaccination with date of birth. Median and interquartile range (IQR) of the age of vaccination was presented in the above table to indicate timeliness of vaccination.
(6) Age of vaccination for varicella cases was collected by a standardized questionnaire for which the precision is up to year only.