{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,20]],"date-time":"2026-03-20T07:20:19Z","timestamp":1773991219619,"version":"3.50.1"},"reference-count":23,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2024,10,17]],"date-time":"2024-10-17T00:00:00Z","timestamp":1729123200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>(1) Background: The effect of varicella emergency vaccination (EV) has not been fully evaluated. (2) Methods: This was a cohort study. Participants were categorized into five groups based on their immune status: unvaccinated group, first dose as EV group, one dose no EV group, second dose as EV group, and two doses no EV group. A Cox proportional hazards model was employed to examine the association between the EV measures and the varicella incidence rate in this outbreak. (3) Results: Demographic characteristics, vaccination details, and disease onset information were 100% (918\/918) collected. The crude attack rate was 44% (11\/25), 8% (3\/36), 11% (24\/215), 3% (6\/176), and 2% (8\/466) among the unvaccinated group, first dose as EV group, one dose no EV group, second dose as EV group and two doses no EV group, respectively. Compared to the unvaccinated group and the one dose no EV group, the first dose varicella vaccine as EV and the second dose as EV demonstrated an incremental effectiveness of 90% (95% CI 65\u201397%) and 79% (95% CI 47\u201392%), respectively. (4) Conclusions: Both the first dose and the second dose as EV contributed to reducing the incidence rates of varicella and offered incremental vaccine effectiveness in an outbreak setting. Our study underscores the importance and benefits of initiating emergency varicella vaccination early to reduce the disease incidence rate in an elementary school setting where there was no complete coverage of the two doses of varicella vaccine and an outbreak occurred.<\/jats:p>","DOI":"10.3390\/vaccines12101184","type":"journal-article","created":{"date-parts":[[2024,10,17]],"date-time":"2024-10-17T11:19:18Z","timestamp":1729163958000},"page":"1184","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Incremental Effectiveness of Emergency Vaccination Against a Varicella Outbreak at an Elementary School in Beijing, China, 2019: An Observational Cohort Study"],"prefix":"10.3390","volume":"12","author":[{"given":"Zhiqiang","family":"Cao","sequence":"first","affiliation":[{"name":"Department of Eexpanded Programme on Immunization, Beijing Center for Disease Prevention and Control, Beijing 100013, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dan","family":"Zhao","sequence":"additional","affiliation":[{"name":"Department of Eexpanded Programme on Immunization, Beijing Center for Disease Prevention and Control, Beijing 100013, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rujing","family":"Shi","sequence":"additional","affiliation":[{"name":"Department of Eexpanded Programme on Immunization, Haidian Center for Disease Prevention and Control, Beijing 100080, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanhong","family":"Zhao","sequence":"additional","affiliation":[{"name":"Department of Eexpanded Programme on Immunization, Haidian Center for Disease Prevention and Control, Beijing 100080, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaojing","family":"Wen","sequence":"additional","affiliation":[{"name":"Department of Eexpanded Programme on Immunization, Beijing Center for Disease Prevention and Control, Beijing 100013, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ying","family":"Ma","sequence":"additional","affiliation":[{"name":"Department of Eexpanded Programme on Immunization, Beijing Center for Disease Prevention and Control, Beijing 100013, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaomei","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Eexpanded Programme on Immunization, Beijing Center for Disease Prevention and Control, Beijing 100013, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luodan","family":"Suo","sequence":"additional","affiliation":[{"name":"Department of Eexpanded Programme on Immunization, Beijing Center for Disease Prevention and Control, Beijing 100013, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,10,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1128\/CMR.9.3.361","article-title":"Varicella-zoster virus","volume":"9","author":"Arvin","year":"1996","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/S1473-3099(18)30716-3","article-title":"Protection against varicella with two doses of combined measles-mumps-rubella-varicella vaccine or one dose of monovalent varicella vaccine: 10-year follow-up of a phase 3 multicentre, observer-blind, randomised, controlled trial","volume":"19","author":"Povey","year":"2019","journal-title":"Lancet Infect. Dis."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"S392","DOI":"10.1093\/infdis\/jiac221","article-title":"Monitoring Varicella Vaccine Impact on Varicella Incidence in the United States: Surveillance Challenges and Changing Epidemiology, 1995\u20132019","volume":"226","author":"Marin","year":"2022","journal-title":"J. Infect. Dis."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3384","DOI":"10.1016\/j.vaccine.2024.04.021","article-title":"Low vaccine coverage and varicella outbreaks in Brazil\u20142019\u20132022","volume":"42","author":"Fujita","year":"2024","journal-title":"Vaccine"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Liu, X., Li, Q., Du, X., Zhao, X., and Yin, Z. (2022). Vaccine Coverage and Effectiveness in a School-Based Varicella Outbreak in Jinan Prefecture, Shandong Province. Vaccines, 10.","DOI":"10.3390\/vaccines10081225"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"311","DOI":"10.46234\/ccdcw2021.085","article-title":"Effect of Earlier Vaccination and a Two-Dose Varicella Vaccine Schedule on Varicella Incidence\u2014Beijing Municipality, 2007\u20132018","volume":"3","author":"Zhao","year":"2021","journal-title":"China CDC Wkly."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1016\/j.jinf.2018.11.009","article-title":"Varicella vaccine effectiveness over 10 years in Australia; moderate protection from 1-dose program","volume":"78","author":"Quinn","year":"2019","journal-title":"J. Infect."},{"key":"ref_8","first-page":"1","article-title":"Prevention of varicella: Recommendations of the Advisory Committee on Immunization Practices (ACIP)","volume":"56","author":"Marin","year":"2007","journal-title":"MMWR Recomm. Rep."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"5316","DOI":"10.1080\/21645515.2021.2009729","article-title":"Effectiveness of varicella vaccine as post-exposure prophylaxis: A meta-analysis","volume":"17","author":"Chen","year":"2021","journal-title":"Hum. Vaccines Immunother."},{"key":"ref_10","first-page":"CD001833","article-title":"Vaccines for post-exposure prophylaxis against varicella (chickenpox) in children and adults","volume":"2014","author":"Macartney","year":"2014","journal-title":"Cochrane Database Syst. Rev."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"101016","DOI":"10.1016\/j.pmedr.2019.101016","article-title":"Varicella-zoster virus post-exposure management and prophylaxis: A review","volume":"16","author":"Lachiewicz","year":"2019","journal-title":"Prev. Med. Rep."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"5094","DOI":"10.1016\/j.vaccine.2012.05.072","article-title":"A varicella outbreak in a school with high one-dose vaccination coverage, Beijing, China","volume":"30","author":"Lu","year":"2012","journal-title":"Vaccine"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3690","DOI":"10.1016\/j.vaccine.2020.01.087","article-title":"Impact of a 2-dose voluntary vaccination strategy on varicella epidemiology in Beijing, 2011\u20132017","volume":"38","author":"Suo","year":"2020","journal-title":"Vaccine"},{"key":"ref_14","first-page":"559","article-title":"Effectiveness on post-exposure vaccination of varicella and its influencing factors in elementary schools in Beijing","volume":"30","author":"Ma","year":"2009","journal-title":"Chin. J. Epidemiol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1542\/peds.61.4.550","article-title":"Studies with live varicella vaccine and inactivated skin test antigen: Protective effect of the vaccine and clinical application of the skin test","volume":"61","author":"Baba","year":"1978","journal-title":"Pediatrics"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1093\/infdis\/172.1.217","article-title":"Safety and cellular and humoral immune responses of a booster dose of varicella vaccine 6 years after primary immunization","volume":"172","author":"Watson","year":"1995","journal-title":"J. Infect. Dis."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"685","DOI":"10.1097\/INF.0b013e3181d9f657","article-title":"Incremental effectiveness of second dose varicella vaccination for outbreak control at an elementary school in Philadelphia, Pennsylvania, 2006","volume":"29","author":"Nguyen","year":"2010","journal-title":"Pediatr. Infect. Dis. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1093\/oxfordjournals.epirev.a036023","article-title":"Assessing vaccine efficacy in the field. Further observations","volume":"10","author":"Orenstein","year":"1988","journal-title":"Epidemiol. Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"872","DOI":"10.1016\/j.cmi.2018.11.013","article-title":"Effectiveness of second-dose varicella vaccination as post-exposure prophylaxis: A prospective cohort study","volume":"25","author":"Wu","year":"2019","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.ijid.2017.10.016","article-title":"Effectiveness of varicella vaccine as post-exposure prophylaxis during a varicella outbreak in Shanghai, China","volume":"66","author":"Wu","year":"2018","journal-title":"Int. J. Infect. Dis."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"5754","DOI":"10.1016\/j.vaccine.2018.08.004","article-title":"Effectiveness of post-exposure prophylaxis during varicella outbreaks among primary and middle school students in Shanghai: An analysis of three-year surveillance data","volume":"36","author":"Cao","year":"2018","journal-title":"Vaccine"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"7043","DOI":"10.1016\/j.vaccine.2014.10.076","article-title":"Varicella vaccination coverage inverse correlation with varicella hospitalizations in Spain","volume":"32","year":"2014","journal-title":"Vaccine"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"World Health Organization (2016). Varicella and herpes zoster vaccines: WHO position paper, June 2014\u2014Recommendations. Vaccine, 34, 198\u2013199.","DOI":"10.1016\/j.vaccine.2014.07.068"}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/12\/10\/1184\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:15:33Z","timestamp":1760112933000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/12\/10\/1184"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,10,17]]},"references-count":23,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2024,10]]}},"alternative-id":["vaccines12101184"],"URL":"https:\/\/doi.org\/10.3390\/vaccines12101184","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,10,17]]}}}