Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Mean estimated influenza vaccine effectiveness (VE) from 1000 simulations of a cohort study (open circles) and a test-negative (filled circles) study at different values of true VE assuming RT-PCR sensitivity and specificity; the dashed line shows perfect agreement between true and estimated VE.
