Clinical Report: Assessment of Varicella Vaccine Efficacy Amidst an Outbreak
Overview
This study evaluates the vaccine effectiveness of single-dose and two-dose varicella vaccines among senior high school students during a varicella outbreak in China.
Background
Varicella, caused by the varicella-zoster virus, is a highly contagious disease that can lead to severe complications. Vaccination is the most effective preventive measure, yet single-dose vaccination has shown declining effectiveness over time. Understanding the efficacy of different vaccination strategies is crucial for controlling outbreaks, particularly in school settings.
Data Highlights
Group
Attack Rate
Vaccine Effectiveness (VE)
Unvaccinated
-
-
1-Dose
6.29%
32.14% (−54.37%-70.17%)
2-Dose
6.29%
94.74% (88.62%-97.57%)
Key Findings
The overall varicella attack rate among students was 6.29%.
Single-dose varicella vaccine coverage was 28.24%, while two-dose coverage was 66.23%.
Vaccine effectiveness for 1-dose recipients was 32.14%, compared to 94.74% for 2-dose recipients.
Post-exposure vaccination showed a VE of 90.15% among unvaccinated students.
Male students had a higher risk of varicella infection compared to female students.
Clinical Implications
The findings indicate that timely post-exposure vaccination can significantly reduce the risk of infection among unvaccinated individuals.
Conclusion
The study provides insights into the effectiveness of single-dose and two-dose varicella vaccination regimens during an outbreak.
Federal prosecutors allege that a Florida physician and research staff fabricated clinical trial records that were submitted into database systems used to evaluate investigational drugs.
