Evaluating risk factors associated with COVID-19 infections among vaccinated people early in the U.S. vaccination campaign: an observational study of five states, January-March 2021.

BACKGROUND: COVID-19 vaccines are an effective tool to prevent illness due to SARS-CoV-2 infection. However, infection after vaccination still occurs. We evaluated all infections identified among recipients of either the Pfizer-BioNTech or Moderna COVID-19 vaccine in five U.S. states during January-March 2021. METHODS: Using observational data reported to CDC, we compared the incidence of SARS-CoV-2 infection among vaccinated and unvaccinated persons, and the sex, age, and vaccine product received for individuals with vaccine breakthrough infections to those of the vaccinated population using Poisson regression models. We also compared the proportion of vaccine breakthrough cases due to a SARS-CoV-2 variant of concern to data reported to CDC's national genomic surveillance program. RESULTS: The age-adjusted incidence of reported SARS-CoV-2 infection was 97% lower among vaccinated as compared to unvaccinated persons aged ≥ 16 years (68 vs 2252 cases per 100,000 people). Vaccinated adults aged ≥ 85 years were 1.6 times (95% CI 1.3-1.9) as likely to become infected with SARS-CoV-2 than vaccinated adults aged < 65 years. Pfizer-BioNTech COVID-19 vaccine recipients were 1.4 times (95% CI 1.3-1.6) as likely to experience infection compared to Moderna COVID-19 recipients. The proportion of infections among vaccinated persons caused by SARS-CoV-2 variants of concern was similar to the proportion of circulating viruses identified as variants of concern in the five states during the same time. CONCLUSIONS: Vaccinated persons had a substantially lower incidence of SARS-CoV-2 infection compared to unvaccinated persons. Adults aged ≥ 85 years and Pfizer-BioNTech vaccine recipients had a higher risk of infection following vaccination. We provide an analytic framework for ongoing evaluation of patterns associated with SARS-CoV-2 infection among vaccinated persons using observational surveillance and immunization data. Our findings reinforce the effectiveness of COVID-19 vaccines in preventing infection in real-world settings.

Covid-19 Rates by Time since Vaccination during Delta Variant Predominance.

BACKGROUND: With the emergence of the delta variant, the United States experienced a rapid increase in Covid-19 cases in 2021. We estimated the risk of breakthrough infection and death by month of vaccination as a proxy for waning immunity during a period of delta variant predominance. METHODS: Covid-19 case and death data from 15 U.S. jurisdictions during January 3 to September 4, 2021 were used to estimate weekly hazard rates among fully vaccinated persons, stratified by age group and vaccine product. Case and death rates during August 1 to September 4, 2021 were presented across four cohorts defined by month of vaccination. Poisson models were used to estimate adjusted rate ratios comparing the earlier cohorts to July rates. RESULTS: During August 1 to September 4, 2021, case rates per 100,000 person-weeks among all vaccine recipients for the January to February, March to April, May to June, and July cohorts were 168.8 (95% confidence interval [CI], 167.5 to 170.1), 123.5 (95% CI, 122.8 to 124.1), 83.6 (95% CI, 82.9 to 84.3), and 63.1 (95% CI, 61.6 to 64.6), respectively. Similar trends were observed by age group for BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccine recipients. Rates for the Ad26.COV2.S (Janssen-Johnson & Johnson) vaccine were higher; however, trends were inconsistent. BNT162b2 vaccine recipients 65 years of age or older had higher death rates among those vaccinated earlier in the year. Protection against death was sustained for the mRNA-1273 vaccine recipients. Across age groups and vaccine types, people who were vaccinated 6 months ago or longer (January-February) were 3.44 (3.36 to 3.53) times more likely to be infected and 1.70 (1.29 to 2.23) times more likely to die from COVID-19 than people vaccinated recently in July 2021. CONCLUSIONS: Our study suggests that protection from SARS-CoV-2 infection among all ages or death among older adults waned with increasing time since vaccination during a period of delta predominance. These results add to the evidence base that supports U.S. booster recommendations, especially for older adults vaccinated with BNT162b2 and recipients of the Ad26.COV2.S vaccine. (Funded by the Centers for Disease Control and Prevention.).

Conducting Community Health Needs Assessments in the Local Public Health Department: A Comparison of Random Digit Dialing and the Community Assessment for Public Health Emergency Response.

CONTEXT: Community health needs assessments (CHNAs) are now required by the Affordable Care Act (ACA) for nonprofit hospitals and the Public Health Accreditation Board (PHAB) for local health departments that seek accreditation. Currently, various primary data collection methods exist that meet the ACA and PHAB requirements. OBJECTIVE: To compare 2 CHNA data collection methods implemented in the same geographical area from a local health department perspective. DESIGN AND SETTING: Two community surveys, one door-to-door and one telephone, in the 76706 zip code area of McLennan County, Texas. PARTICIPANTS: Adult survey respondents (Community Assessment for Public Health Emergency Response [CASPER]: N = 184; random digit dialing [RDD]: N = 133) of the 76706 zip code in McLennan County, Texas. MAIN OUTCOME MEASURES: Survey response rates, sociodemographic characteristics of survey respondents, and self-reported health behaviors from both community survey types. RESULTS: The CASPER survey had a contact rate of 36.0% and a cooperation rate of 60.5%, compared with a 10.1% response rate for the RDD survey. CASPER respondents were younger (26.6% aged 18-24 years), had lower education attainment (17.4% less than high school), and had a higher proportion of Hispanics (24.5%) than RDD respondents (4.6%, 10.5%, and 17.3%, respectively). CASPER respondents were less likely to report being overweight or obese (56.5%), to report days where no fruit or vegetables were consumed (7.1%), and to report days where no walking activity was conducted (9.8%) than RDD respondents (70.2%, 27.8%, and 21.8%, respectively). The CASPER survey cost less to conduct ($13 500) than the RDD survey ($100 000) and was logistically easier for the local health department to conduct using internally available resources. CONCLUSIONS: Local health departments use various data collection methods to conduct CHNAs for their populations and require varying levels of commitment and resources. RDD and CASPER can be used to meet ACA and PHAB requirements, collecting valuable health needs estimates and offer various strengths and weaknesses. PHAB and ACA requirements can be met using the CASPER or RDD survey to conduct CHNAs. However, local health departments may consider the CASPER survey a viable alternative to the RDD survey when time and resources are limited. The CASPER survey offers flexibility and efficiency and requires limited equipment and training.