Reinfection: 0.2% with previous Covid, 1.8% with vaccines
Suspected SARS-CoV-2 Reinfections: Incidence, Predictors, and Healthcare Use among Patients at 238 U.S. Healthcare Facilities, June 1, 2020- February 28, 2021
In a retrospective cohort study, among 131,773 patients with previous COVID19, reinfection with SARS-CoV-2 was suspected in 253(0.2%) patients at 238 U.S. healthcare facilities between June 1, 2020- February 28, 2021. Women displayed a higher cumulative reinfection risk. Healthcare burden and illness severity were similar between index and reinfection encounters.
Elapsed time since BNT162b2 vaccine and risk of SARS-CoV-2 infection in a large cohort
[Preprint.] The cohort included 33,993 fully vaccinated adults, 49% women, with a mean age of 47 years (SD, 17 years), who received an RT-PCR test for SARS-CoV-2 during the study period. The median time between the second dose of the vaccine and the RT-PCR test was 146 days, interquartile range [121-167] days. 608 (1.8%) patients had positive test results. There was a significantly higher rate of positive results among patients who received their second vaccine dose at least 146 days before the RT-PCR test compared to patients who have received their vaccine less than 146 days before: odds ratio for infection was 3.00 for patients aged over 60 (95% CI 1.86-5.11); 2.29 for patients aged between 40 and 59 (95% CI 1.67-3.17); and 1.74 for patients aged between 18 and 39 (95% CI 1.27-2.37); P<0.001 in each age group. We observe a significant increase of the risk of infection in individuals who received their last vaccine dose since at least 146 days ago, particularly among patients older than 60.
Progress of the Delta variant and erosion of vaccine effectiveness, a warning from Utah
[Preprint.] We compared the proportion of cases reporting vaccination to that expected at different vaccine effectiveness (VEs), then estimated the combined daily vaccine effectiveness using a field evaluation approach. Delta has rapidly outcompeted all other variants and, as of June 20th, represents 70% of all SARS-CoV-2 viruses sequenced in Utah. If we attribute the entire change in VE to the Delta variant, the estimated vaccine effectiveness against Delta would be 82% (95% CI: 78%, 85%). We show a modest reduction in vaccine effectiveness against COVID-19 in Utah corresponding to the expansion of the Delta lineage in the state.
Presence of SARS-CoV-2 antibodies in lactating women and their infants following BNT162b2mRNA vaccine
Maternal sera and breast milk samples were obtained from 61 participated women. All maternal sera, as well as breastmilk samples, were positive for SARS-CoV-2 IgG with a median concentration of 31.7 (IQR 25.1-38.1) S/Co, and 6.3 (IQR 5.1-7.4) S/Co, respectively. There was a significant positive correlation between maternal serum levels and breastmilk levels of SARS-CoV-2 IgG (r = 0.514, P = 58 0.0001). IgG antibodies were found in the oral mucosa of three (60%) of sampled infants but not in their circulation.
Use of COVID-19 Vaccines After Reports of Adverse Events Among Adult Recipients of Janssen (Johnson & Johnson) and mRNA COVID-19 Vaccines (Pfizer-BioNTech and Moderna): Update from the Advisory Committee on Immunization Practices — United States, July 2021
On July 22, 2021, the Advisory Committee on Immunization Practices reviewed updated benefit-risk analyses after Janssen and mRNA COVID-19 vaccination and concluded that the benefits outweigh the risks for rare serious adverse events after COVID-19 vaccination. Continued COVID-19 vaccination will prevent COVID-19 morbidity and mortality far exceeding GBS, TTS, and myocarditis cases expected.