Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Mar 3;16(3):499-505.
doi: 10.1080/21645515.2019.1663121. Epub 2019 Oct 23.

Varicella vaccine dose depended effectiveness and waning among preschool children in Hong Kong

Yung-Wai Desmond Chan  1   2 , W John Edmunds  2 , Hong-Lam Chan  1 , Miu-Ling Wong  1 , Ka-Wing Albert Au  1 , Shuk-Kwan Chuang  1 , Albert Jan van Hoek  2 , Stefan Flasche  2
Affiliations

Varicella vaccine dose depended effectiveness and waning among preschool children in Hong Kong

Yung-Wai Desmond Chan et al. Hum Vaccin Immunother. .

Abstract

In Hong Kong, universal varicella vaccination was introduced in July 2014 with a two-dose schedule but the vaccines had been available in the private market since 1996. With data from varicella notification and surveys on immunization coverage, we used the screening method to estimate dose-specific varicella vaccine effectiveness (VE) among preschool children in Hong Kong before universal vaccination. We estimated the VE of one- and two-dose varicella vaccination against all notified varicella as 69.4% (95% confidence interval (95% CI) 69.5-71.2) and 93.4% (95% CI 91.7-94.7), respectively. We found that VE did not decrease with time since receipt. Varicella vaccine was more effective against complications (85.4% [95% CI 48.8-95.8] for one dose and 100% [95% CI -Inf to 100] for two doses) and against hospital admission (75.2% [95% CI 53.4-86.8] for one dose and 93.1% [95% CI 47.1-99.1] for two doses). Lower protection of one-dose varicella vaccine resulted in breakthrough varicella. Under universal vaccination, second-dose varicella vaccine (given as combined measles, mumps, rubella and varicella vaccine) was first scheduled for children when they reach primary one (about 6 years of age) and was recently advanced to 18 months of age. Shortening the interval between the first dose and second dose of varicella vaccination should reduce breakthrough varicella and outbreaks in preschool.

Keywords: Chickenpox; chickenpox vaccine; immunity; vaccine effectiveness.

PubMed Disclaimer

References

    1. The Department of Health HKSAR Government. Press release - Chickenpox vaccine to incorporate into DH Childhood Immunisation Programme on July 2. Available at: https://www.info.gov.hk/gia/general/201406/24/P201406240290.htm. Last accessed on 12 Jan 2019.
    1. Chan DYW, Edmunds WJ, Chan HL, Chan V, Lam YCK, Thomas SL, van Hoek AJ, Flasche S.. The changing epidemiology of varicella and herpes zoster in Hong Kong before universal varicella vaccination in 2014. Epidemiol Infect. 2018;146(6):723–734. doi:10.1017/S0950268818000444. - DOI - PMC - PubMed
    1. Greshon AA, Takahashi M, Seward JF. Varicella vaccine. In: Plotkin S, Orenstein WA, Offit PA, editors. Vaccines. Amsterdam (Netherlands): Elsevier; 2013. p. 837–869.
    1. White CJ, Kuter BJ, Ngai A, Hildebrand CS, Isganitis KL, Patterson CM, Capra A, Miller WJ, Krah DL, Provost PJ. Modified cases of chickenpox after varicella vaccination: correlation of protection with antibody response. Pediatr Infect Dis J. 1992;11:19–23. doi:10.1097/00006454-199201000-00006. - DOI - PubMed
    1. Tugwell BD, Lee LE, Gillette H, Lorber EM, Hedberg K, Cieslak PR. Chickenpox outbreak in a highly vaccinated school population. Pediatrics. 2004;113:455–59. doi:10.1542/peds.113.3.455. - DOI - PubMed

Publication types