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.
Inclusion criteria for index cases and household contacts in South Korea, June 25, 2021 to January 22, 2022. a)Alpha: 15 index cases, 43 household contacts; Beta: 2 index cases, 5 household contacts. b)Viral-vector: 831 index cases, 1,574 household contacts; mixed: 294 index cases, 579 household contacts.
VS, vaccination status.
