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Author Spotlight: Studying Host-Virus Interactions with Pseudotyped Viruses
Published on: November 21, 2023
Primary and Secondary Attack Rates by Vaccination Status after a SARS-CoV-2 B.1.617.2 (Delta) Variant Outbreak at a
Julia M Baker1,2, Melisa M Shah1,2, Michelle O'Hegarty1
1CDC COVID-19 Response Team, Atlanta, Georgia, USA.
Abstract:
Children are capable of initiating COVID-19 transmission into households, but many questions remain about the impact of vaccination on transmission. Data from a COVID-19 Delta variant outbreak at an overnight camp in Texas during June 23-27, 2021, were analyzed. The camp had 451 attendees, including 364 youths aged < 18 years and 87 adults. Detailed interviews were conducted with 92 (20.4%) of consenting attendees and 117 household members of interviewed attendees with COVID-19. Among 450 attendees with known case status, the attack rate was 41%, including 42% among youths; attack rates were lower among vaccinated (13%) than among unvaccinated youths (48%). The secondary attack rate was 51% among 115 household contacts of 55 interviewed index patients. Secondary infections occurred in 67% of unvaccinated household members and 33% of fully or partially vaccinated household members. Analyses suggested that household member vaccination and camp attendee masking at home protected against household transmission.
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