The Open Hydrant

School Masking Policies and Secondary SARS-CoV-2 Transmission

RESULTS
1,112,899 students and 157,069 staff attended 61 K–12 districts across 9 states that met inclusion criteria. The districts reported 40,601 primary and 3,085 secondary infections. Six districts had optional masking policies, 9 had partial masking policies, and 46 had universal masking. Districts that optionally masked throughout the study period had 3.6 times the rate of secondary transmission as universally masked districts. For every 100 community-acquired cases, universally masked districts had 7.3 predicted secondary infections, while optionally masked districts had 26.4.

CONCLUSIONS
Secondary transmission across the cohort was modest (

Safety of the BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Setting
List of authors.
Noam Barda, M.D., Noa Dagan, M.D., Yatir Ben-Shlomo, B.Sc., Eldad Kepten, Ph.D., et al.

August 25, 2021
DOI: 10.1056/NEJMoa2110475

Abstract
BACKGROUND
Preapproval trials showed that messenger RNA (mRNA)–based vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had a good safety profile, yet these trials were subject to size and patient-mix limitations. An evaluation of the safety of the BNT162b2 mRNA vaccine with respect to a broad range of potential adverse events is needed.

METHODS
We used data from the largest health care organization in Israel to evaluate the safety of the BNT162b2 mRNA vaccine. For each potential adverse event, in a population of persons with no previous diagnosis of that event, we individually matched vaccinated persons to unvaccinated persons according to sociodemographic and clinical variables. Risk ratios and risk differences at 42 days after vaccination were derived with the use of the Kaplan–Meier estimator. To place these results in context, we performed a similar analysis involving SARS-CoV-2–infected persons matched to uninfected persons. The same adverse events were studied in the vaccination and SARS-CoV-2 infection analyses.

RESULTS
In the vaccination analysis, the vaccinated and control groups each included a mean of 884,828 persons. Vaccination was most strongly associated with an elevated risk of myocarditis (risk ratio, 3.24; 95% confidence interval [CI], 1.55 to 12.44; risk difference, 2.7 events per 100,000 persons; 95% CI, 1.0 to 4.6), lymphadenopathy (risk ratio, 2.43; 95% CI, 2.05 to 2.78; risk difference, 78.4 events per 100,000 persons; 95% CI, 64.1 to 89.3), appendicitis (risk ratio, 1.40; 95% CI, 1.02 to 2.01; risk difference, 5.0 events per 100,000 persons; 95% CI, 0.3 to 9.9), and herpes zoster infection (risk ratio, 1.43; 95% CI, 1.20 to 1.73; risk difference, 15.8 events per 100,000 persons; 95% CI, 8.2 to 24.2). SARS-CoV-2 infection was associated with a substantially increased risk of myocarditis (risk ratio, 18.28; 95% CI, 3.95 to 25.12; risk difference, 11.0 events per 100,000 persons; 95% CI, 5.6 to 15.8) and of additional serious adverse events, including pericarditis, arrhythmia, deep-vein thrombosis, pulmonary embolism, myocardial infarction, intracranial hemorrhage, and thrombocytopenia.

CONCLUSIONS
In this study in a nationwide mass vaccination setting, the BNT162b2 vaccine was not associated with an elevated risk of most of the adverse events examined. The vaccine was associated with an excess risk of myocarditis (1 to 5 events per 100,000 persons). The risk of this potentially serious adverse event and of many other serious adverse events was substantially increased after SARS-CoV-2 infection. (Funded by the Ivan and Francesca Berkowitz Family Living Laboratory Collaboration at Harvard Medical School and Clalit Research Institute.)

https://www.nejm.org/doi/full/10.1056/NEJMoa2110475

Nifty website if anyone is interested. Lots of stats for almost anywhere in the US.

https://covidactnow.org/

"We examined its sensitivity to monoclonal antibodies (mAbs) and to antibodies present in sera from COVID-19 convalescent individuals or vaccine recipients, in comparison to other viral strains.

Variant Delta was resistant to neutralization by some anti-NTD and anti-RBD mAbs including Bamlanivimab, which were impaired in binding to the Spike. Sera from convalescent patients collected up to 12 months post symptoms were 4 fold less potent against variant Delta, relative to variant Alpha (B.1.1.7).

Sera from individuals having received one dose of Pfzer or AstraZeneca vaccines barely inhibited variant Delta. Administration of two doses generated a neutralizing response in 95% of individuals, with titers 3 to 5 fold lower against Delta than Alpha."

https://www.nature.com/articles/s41586-021-03777-9

Excess deaths in US up ~20%, about 522,000, for 2020 with at least 72.4% of those attributable to COVID19.

Woolf SH, Chapman DA, Sabo RT, Zimmerman EB. Excess Deaths From COVID-19 and Other Causes in the US, March 1, 2020, to January 2, 2021. JAMA. Published online April 02, 2021. doi:10.1001/jama.2021.5199

https://jamanetwork.com/journals/jama/fullarticle/2778361

Interim Public Health Recommendations for Fully Vaccinated People
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vaccinated-guidance.html

Updated Mar. 8, 2021

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Key Points

This is the first set of public health recommendations for fully vaccinated people. This guidance will be updated and expanded based on the level of community spread of SARS-CoV-2, the proportion of the population that is fully vaccinated, and the rapidly evolving science on COVID-19 vaccines.

For the purposes of this guidance, people are considered fully vaccinated for COVID-19 ≥2 weeks after they have received the second dose in a 2-dose series (Pfizer-BioNTech or Moderna), or ≥2 weeks after they have received a single-dose vaccine (Johnson and Johnson [J&J]/Janssen ).

The following recommendations apply to non-healthcare settings.

Fully vaccinated people can:

Visit with other fully vaccinated people indoors without wearing masks or physical distancing

Visit with unvaccinated people from a single household who are at low risk for severe COVID-19 disease indoors without wearing masks or physical distancing

Refrain from quarantine and testing following a known exposure if asymptomatic

For now, fully vaccinated people should continue to:

Take precautions in public like wearing a well-fitted mask and physical distancing

Wear masks, practice physical distancing, and adhere to other prevention measures when visiting with unvaccinated people who are at increased risk for severe COVID-19 disease or who have an unvaccinated household member who is at increased risk for severe COVID-19 disease

Wear masks, maintain physical distance, and practice other prevention measures when visiting with unvaccinated people from multiple households

Avoid medium- and large-sized in-person gatherings

Get tested if experiencing COVID-19 symptoms

Follow guidance issued by individual employers

Follow CDC and health department travel requirements and recommendations