OBJECTIVE: A previous measles outbreak investigation in a high school in Quebec, Canada identified 2-dose vaccine effectiveness of 94%. The risk of measles in 2-dose recipients was significantly higher (2-4 times) when measles vaccine was first administered at 12 versus ≥ 15 months of age, with no significant effect of the age at second dose. Generalizability of this association was also assessed in the expanded provincial data set of notified cases. METHODS: This matched case-control study included only 2-dose recipients. All confirmed (laboratory or epidemiologically linked) cases in patients aged 5 to 17 years were included. Each case was matched to 5 controls. RESULTS: A total of 102 cases and 510 controls were included; 89% of cases were in patients 13 to 17 years old. When the first dose was administered at 12 to 13 months compared with ≥ 15 months of age, the risk of measles in participants outside the outbreak school was 6 times higher (95% confidence interval, 1.33-29.3) and was 5.2 times higher (95% confidence interval, 1.91-14.3) in the pooled estimate (participants from the outbreak school + outside that school). CONCLUSIONS: A significantly greater risk of measles among 2-dose recipients whose first dose was given at 12 to 13 months rather than ≥ 15 months of age is confirmed in the larger Quebec data set. The mechanism remains unknown, but vaccine failures in 2-dose recipients could have substantial implications for measles elimination efforts through 2-dose vaccination. The optimal age at first dose may warrant additional evaluation.
OBJECTIVE: A previous measles outbreak investigation in a high school in Quebec, Canada identified 2-dose vaccine effectiveness of 94%. The risk of measles in 2-dose recipients was significantly higher (2-4 times) when measles vaccine was first administered at 12 versus ≥ 15 months of age, with no significant effect of the age at second dose. Generalizability of this association was also assessed in the expanded provincial data set of notified cases. METHODS: This matched case-control study included only 2-dose recipients. All confirmed (laboratory or epidemiologically linked) cases in patients aged 5 to 17 years were included. Each case was matched to 5 controls. RESULTS: A total of 102 cases and 510 controls were included; 89% of cases were in patients 13 to 17 years old. When the first dose was administered at 12 to 13 months compared with ≥ 15 months of age, the risk of measles in participants outside the outbreak school was 6 times higher (95% confidence interval, 1.33-29.3) and was 5.2 times higher (95% confidence interval, 1.91-14.3) in the pooled estimate (participants from the outbreak school + outside that school). CONCLUSIONS: A significantly greater risk of measles among 2-dose recipients whose first dose was given at 12 to 13 months rather than ≥ 15 months of age is confirmed in the larger Quebec data set. The mechanism remains unknown, but vaccine failures in 2-dose recipients could have substantial implications for measles elimination efforts through 2-dose vaccination. The optimal age at first dose may warrant additional evaluation.
Authors: Emily A Voigt; Inna G Ovsyannikova; Iana H Haralambieva; Richard B Kennedy; Beth R Larrabee; Daniel J Schaid; Gregory A Poland Journal: Vaccine Date: 2016-08-30 Impact factor: 3.641
Authors: Iana H Haralambieva; Richard B Kennedy; Inna G Ovsyannikova; Jennifer A Whitaker; Gregory A Poland Journal: Trends Mol Med Date: 2015-11-18 Impact factor: 11.951
Authors: Xiaoqin Wang; Mei Ma; Zhaozhao Hui; Paul D Terry; Yue Zhang; Rui Su; Mingxu Wang; Wei Gu; Ling Li Journal: Int J Environ Res Public Health Date: 2017-06-06 Impact factor: 3.390
Authors: Anna Bednarek; Małgorzata Bartkowiak-Emeryk; Robert Klepacz; Barbara Ślusarska; Danuta Zarzycka; Andrzej Emeryk Journal: Med Sci Monit Date: 2018-07-23