Fig 1. Study design and enrollment numbers.
The flow diagram indicates maternal and infant participation at the stages of study enrollment, delivery, vaccination, and biannual infant follow-up.
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.