Breakthrough SARS-CoV-2 Infections after Vaccination in North Carolina

Abstract

Importance: Real-world data are needed to assess incidence and factors associated with breakthrough SARS-CoV-2 infections following vaccination. Objective: Estimate incidence of breakthrough infections and assess associations with risk factors using self-reported data from a large NC population sample. Design: Prospective observational cohort study utilizing daily online survey data to capture information about COVID-19 symptoms, testing, and vaccination status. Setting: Six health care systems in North Carolina with data collected between January 15, 2021 and September 24, 2021. Participants: Adult study participants who reported full vaccination with a COVID-19 mRNA or J&J non-replicating viral vector vaccine (n = 16,020). Exposures: Potential community exposure to SARS-CoV-2. Main Outcome and Measures: Self-reported breakthrough infection. Results: SARS-CoV-2 infection after vaccination was self-reported in 1.9% of participants, with an incidence rate of 7.3 per 100,000 person-years. Younger age (45-64 vs. 18-44: HR (95% CI) = 0.65 (0.51-0.82); 65+ vs. 18-44: HR (95% CI) = 0.59 (0.39-0.90)), and vaccination with J&J Ad26.COV2.S were associated with a higher risk of breakthrough infection compared to vaccination with Pfizer BNT162b2 (Ad26.COV2.S vs. BNT162b2: HR (95% CI) = 2.23 (1.40-3.56)), while participants vaccinated with mRNA-1273 (mRNA-1273 vs. BNT162b2: HR (95% CI) = 0.69 (0.50-0.96) and those residing in urban counties experienced a lower rate of SARS-CoV-2 breakthrough infection compared with those from suburban (HR (95% CI) = 1.39 (1.01-1.90)) or rural (HR (95% CI) = 1.57 (1.16-2.11)) counties. There was no significant association between breakthrough infection and participant sex, race, healthcare worker status, prior COVID-19 infection, routine mask use, or overall vaccination rate in the county of residence. Conclusions and Relevance: This NC community-based observational study showed that the proportion of the cohort who self-report breakthrough SARS-CoV-2 infections was 7.3 events per 100,000 person-years. Younger adults, those vaccinated with J&J Ad26.COV2.S, and those residing in suburban or rural counties were at higher risk of breakthrough infections and should be targeted for additional risk mitigation strategies to decrease community transmission.

Imaging and Clinical Features of COVID-19 Breakthrough Infections: A Multicenter Study

“…Reported incidences of COVID-19 breakthrough infections depend on vaccine type, time elapsed after vaccination, the percentage of vaccinated people, and viral variants and range from 0.4 to 9.5% (11)(12)(13)(14)(15)(16)(17). According to a report issued by the Washington State Department of Health, the number of breakthrough infections increased up to 30% of overall newly infected patients as the total number of infected and vaccinated numbers increased (18).…”

Frequency and Clinical Characteristics of Breakthrough Cases Post COVID-19 Vaccine and Predictive Risk Factors in College Students

“…Being younger was associated with an increased risk of a breakthrough infection, also in the multivariate analysis. A higher rate of breakthrough infections in younger adults has also been observed in other cohorts (24)(25)(26)(27), after adjustment for exposure to the SARS-CoV-2 virus through their profession or environment. The risk of a breakthrough infection was significantly reduced for those having been previously infected, and for those having received a booster vaccine.…”

Are the thorax Computed Tomography findings of ICU patients diagnosed with COVID-19 pneumonia related to the duration of hospital stay and mortality?

“…COVID-19 pneumonia varies depending on the type of vaccine, the time after vaccination, the percentage of people vaccinated, and viral variants. New studies are needed because we still have limited data on how well vaccines protect against severe diseases and radiological anomalies in vaccinated patients [ [28] , [29] , [30] , [31] , [32] ].…”