Recently one cohort study conducted by Choi et al published in Human vaccines & immunotherapeutics demonstrated that the incidence rate of varicella decreased 67% after universal one-dose varicella vaccination in South Korea.Citation1 Another cohort study by Cheng et al demonstrated that the incidence rate of varicella decreased 82.8% after universal one-dose varicella vaccination in Taiwan.Citation2 Some points needs to be discussed. First, Choi et al demonstrated that the incidence of varicella decreased from 5.7 per 1000 person-years before universal one-dose varicella vaccination to 1.87 per1000 person-years after universal one-dose varicella vaccination. The absolute risk reduction was about 0.383%, which resulted in the number needed to treat of 261. Although the number needed to treat is high, from a view of primary prevention, universal vaccination remains to be required. Second, one meta-analysis demonstrated that two-dose varicella vaccination may reduce the incidence rate of varicella by 92%, and two-dose varicella vaccination may provide 10% or more protection than one-dose varicella vaccination.Citation3 However, not all countries can afford to the expense of universal two-dose varicella vaccination. Cheng et al noted that breakthrough varicella-related hospitalizations were only 0.024% after one-dose varicella vaccination. Therefore, the cost-benefit effect between one-dose and two-dose varicella vaccination should be balanced. If the country budget is able to cover the expense of universal two-dose varicella vaccination, the two-dose policy is better from a view of public health. Finally, I appreciate Choi et al’ efforts to investigate the efficacy of universal one-dose varicella vaccine.
Disclosure of potential conflicts of interest
No potential conflicts of interest were disclosed.
Authorship statement
Shih-Wei Lai contributed to the conception of the article, initiated the draft of the article, and has approved the final draft submitted.
References
- Choi JK, Park SH, Park S, Choi SM, Kim SH, Lee DG, Yoo J-H, Choi J-H, Kang JH. Trends in varicella and herpes zoster epidemiology before and after the implementation of universal one-dose varicella vaccination over one decade in South Korea, 2003-2015. Hum Vaccin Immunother. 2019:1–7. doi:10.1080/21645515.2019.1603985.
- Cheng HY, Chang LY, Lu CY, Huang LM. Epidemiology of breakthrough varicella after the implementation of a universal varicella vaccination program in Taiwan, 2004-2014. Sci Rep. 2018;8:018–35451. doi:10.1038/s41598-018-35451-y.
- Marin M, Marti M, Kambhampati A, Jeram SM, Seward JF. Global varicella vaccine effectiveness: a meta-analysis. Pediatrics. 2016;137:e20153741. doi:10.1542/peds.2015-3741.