SARS-CoV-2 infection and COVID-19 vaccination rates in pregnant women in Scotland

Population-level data on COVID-19 vaccine uptake in pregnancy and SARS-CoV-2 infection outcomes are lacking. We describe COVID-19 vaccine uptake and SARS-CoV-2 infection in pregnant women in Scotland, using whole-population data from a national, prospective cohort. Between the start of a COVID-19 vaccine program in Scotland, on 8 December 2020 and 31 October 2021, 25,917 COVID-19 vaccinations were given to 18,457 pregnant women. Vaccine coverage was substantially lower in pregnant women than in the general female population of 18−44 years; 32.3% of women giving birth in October 2021 had two doses of vaccine compared to 77.4% in all women. The extended perinatal mortality rate for women who gave birth within 28 d of a COVID-19 diagnosis was 22.6 per 1,000 births (95% CI 12.9−38.5; pandemic background rate 5.6 per 1,000 births; 452 out of 80,456; 95% CI 5.1−6.2). Overall, 77.4% (3,833 out of 4,950; 95% CI 76.2−78.6) of SARS-CoV-2 infections, 90.9% (748 out of 823; 95% CI 88.7−92.7) of SARS-CoV-2 associated with hospital admission and 98% (102 out of 104; 95% CI 92.5−99.7) of SARS-CoV-2 associated with critical care admission, as well as all baby deaths, occurred in pregnant women who were unvaccinated at the time of COVID-19 diagnosis. Addressing low vaccine uptake rates in pregnant women is imperative to protect the health of women and babies in the ongoing pandemic.

Age-Stratified Risk of Cerebral Venous Sinus Thrombosis After SARS-CoV-2 Vaccination

Background and ObjectivesCerebral Venous Sinus Thrombosis (CVST) as a part of the thrombosis and thrombocytopenia syndrome is a rare adverse drug reaction of SARS-CoV-2 vaccination. Estimated background rate of CVST with thrombocytopenia is 0.1 per million per month. We assessed the age-stratified risk of CVST with and without thrombocytopenia after SARS-CoV-2 vaccination.MethodsWe estimated the absolute risk of CVST with and without thrombocytopenia within 28 days of first dose of four SARS-CoV-2 vaccinations, using data from the European Medicines Agency’s EudraVigilance database (until 13 June 2021). As a denominator, we used data on vaccine delivery from 31 European countries. For 22.8 million adults from 25 countries, we estimated the absolute risk of CVST after the first dose of ChAdOx1 nCov-19 per age category.ResultsThe absolute risk of CVST within 28 days of first dose vaccination was 7.5 (95%CI 6.9-8.3), 0.7 (95%CI 0.2-2.4), 0.6 (95%CI 0.5-0.7) and 0.6 (95%CI 0.3-1.1) per million of first doses of ChAdOx1 nCov-19, Ad26.COV2.S, BNT162b2 and mRNA-1273, respectively. The absolute risk of CVST with thrombocytopenia within 28 days of first dose vaccination was 4.4 (95%CI 3.9-4.9), 0.7 (95%CI 0.2-2.4), 0.0 (95%CI 0.0-0.1) and 0.0 (95%CI 0.0-0.2) per million of first doses of ChAdOx1 nCov-19, Ad26.COV2.S, BNT162b2 and mRNA-1273, respectively. In recipients of ChAdOx1 nCov-19, the absolute risk of CVST, both with and without thrombocytopenia, was the highest in the 18-24 years age group (7.3 per million, 95%CI 2.8-18.8 and 3.7 per million, 95%CI 1.0-13.3, respectively). The risk of CVST with thrombocytopenia in ChAdOx1 nCov-19 recipients was the lowest in the age group≥70 years (0.2, 95%CI 0.0-1.3). Age <60 compared to ≥60 was a predictor for CVST with thrombocytopenia (incidence rate ratio 5.79; 95%CI 2.98-11.24, p<0.001).DiscussionThe risk of CVST with thrombocytopenia within 28 days of first dose vaccination with ChAdOx1 nCov-19 was higher in younger age groups. The risk of CVST with thrombocytopenia was slightly increased in patients receiving Ad26.COV2.S, compared with the estimated background risk. The risk of CVST with thrombocytopenia was not increased in recipients of SARS-CoV-2 mRNA vaccines.

Forecasting COVID-19 infection trends in the EU-27 countries, the UK and Switzerland due to SARS-CoV-2 Variant of Concern Omicron

Background: On November 26, 2021, WHO designated the variant B.1.1.529 as a new SARS-CoV-2 variant of concern (VoC), named Omicron, originally identified in South Africa. Several mutations in Omicron indicate that it may have an impact on how it spreads, resistance to vaccination, or the severity of illness it causes. Methods: We used our previous modelling algorithms to forecast the spread of Omicron aggregated in the EU-27 countries, the United Kingdom and Switzerland, and report trends in daily cases with a 7-day moving average. We followed EQUATOR TRIPOD guidance for multivariable prediction models. Modelling included a third-degree polynomial curve in existing epidemiological trends on the spread of Omicron in South Africa, a five-parameter logistic (5PL) asymmetrical sigmoidal curve following a parametric growth in Europe, and a new Gaussian curve to estimate a downward trend after a peak. Results: Up to January 15, 2022, we estimated a background rate projection in EU-27 countries, the UK and Switzerland of about 145,000 COVID-19 daily cases without Omicron, which increases up to 440,000 COVID-19 daily cases in the worst scenario of Omicron spread, and 375,000 in the best scenario. Therefore, Omicron might represent a relative increase from the background daily rates of COVID-19 infection in Europe of 1.03-fold or 2.03-fold, that is up to a 200% increase. Conclusion: This warning pandemic surge due to Omicron is calling for further reinforcing of COVID-19 universal hygiene interventions (indoor ventilation, social distance, and face masks), and anticipating the need of new lockdowns in Europe.

Comparisons of the risk of myopericarditis between COVID-19 patients and individuals receiving COVID-19 vaccines: a population-based study

Background: Both COVID-19 infection and COVID-19 vaccines have been associated with the development of myopericarditis. The objective of this study is to 1) analyze the rates of myopericarditis after COVID-19 infection and COVID-19 vaccination in Hong Kong and 2) compare to the background rates, and 3) compare the rates of myopericarditis after COVID-19 vaccination to those reported in other countries. Methods: This was a population-based cohort study from Hong Kong, China. Patients with positive RT-PCR test for COVID-19 between 1st January 2020 and 30th June 2021 or individuals who received COVID-19 vaccination until 31st August were included. The main exposures were COVID-19 positivity or COVID-19 vaccination. The primary outcome was myopericarditis. Results: This study included 11441 COVID-19 patients from Hong Kong, of whom four suffered from myopericarditis (rate per million: 350; 95% confidence interval [CI]: 140-900). The rate was higher than the pre-COVID-19 background rate in 2020 (rate per million: 61, 95% CI: 55-67) with a rate ratio of 5.73 (95% CI: 2.23-14.73. Compared to background rates, the rate of myopericarditis among vaccinated subjects in Hong Kong was substantially lower (rate per million: 8.6; 95% CI: 6.4-11.6) with a rate ratio of 0.14 (95% CI: 0.10-0.19). The rates of myocarditis after vaccination in Hong Kong are comparable to those vaccinated in the United States, Israel, and the United Kingdom. Conclusions: COVID-19 infection is associated with a higher rate of myopericarditis whereas COVID-19 vaccination is associated with a lower rate of myopericarditis compared to the background.

Guillain-Barré Syndrome after COVID-19 Vaccination in the Vaccine Safety Datalink

ImportancePost-authorization monitoring of vaccines in a large population can detect rare adverse events not identified in clinical trials including Guillain-Barré syndrome (GBS). GBS has a background rate of 1-2 per 100,000 person-years.ObjectiveTo 1) describe cases and incidence of GBS following COVID-19 vaccination, and 2) assess the risk of GBS after vaccination for Ad.26.COV2.S (Janssen) and mRNA vaccines.DesignInterim analysis of surveillance data from the Vaccine Safety Datalink.SettingEight participating integrated healthcare systems in the United States.Participants10,158,003 individuals aged ≥12 years.ExposuresReceipt of Ad.26.COV2.S, BNT162b2 (Pfizer-BioNTech), or mRNA-1273 (Moderna) COVID-19 vaccine.Main Outcomes and MeasuresGBS with symptom onset in the 1-84 days after vaccination as confirmed by medical record review and adjudication. Descriptive characteristics of confirmed cases, GBS incidence rates during postvaccination risk intervals after each type of vaccine compared to the background rate, rate ratios (RRs) comparing GBS incidence in the 1-21 vs. 22-42 days postvaccination, and RRs directly comparing risk of GBS after Ad.26.COV2.S vs. mRNA vaccination, using Poisson regression adjusted for age, sex, race/ethnicity, site, and calendar day.ResultsFrom December 13, 2020 through November 13, 2021, 14,723,318 doses of COVID-19 vaccines were administered, including 467,126 Ad.26.COV2.S, 8,573,823 BNT162b2, and 5,682,369 mRNA-1273 doses. Eleven cases of GBS after Ad.26.COV2.S were confirmed. The unadjusted incidence rate of confirmed cases of GBS per 100,000 person-years in the 1-21 days after Ad.26.COV2.S was 34.6 (95% confidence interval [CI]: 15.8-65.7), significantly higher than the background rate, and the adjusted RR in the 1-21 vs. 22-42 days following Ad.26.COV2.S was 6.03 (95% CI: 0.79-147.79). Thirty-four cases of GBS after mRNA vaccines were confirmed. The unadjusted incidence rate of confirmed cases per 100,000 person-years in the 1-21 days after mRNA vaccines was 1.4 (95% CI: 0.7-2.5) and the adjusted RR in the 1-21 vs. 22-42 days following mRNA vaccines was 0.56 (95% CI: 0.21-1.48). In a head-to-head comparison of Ad.26.COV2.S vs. mRNA vaccines, the adjusted RR was 20.56 (95% CI: 6.94-64.66).Conclusions and RelevanceIn this interim analysis of surveillance data of COVID-19 vaccines, the incidence of GBS was elevated after Ad.26.COV2.S. Surveillance is ongoing.

Bias, Precision and Timeliness of Historical (Background) Rate Comparison Methods for Vaccine Safety Monitoring: An Empirical Multi-Database Analysis

Using real-world data and past vaccination data, we conducted a large-scale experiment to quantify bias, precision and timeliness of different study designs to estimate historical background (expected) compared to post-vaccination (observed) rates of safety events for several vaccines. We used negative (not causally related) and positive control outcomes. The latter were synthetically generated true safety signals with incident rate ratios ranging from 1.5 to 4. Observed vs. expected analysis using within-database historical background rates is a sensitive but unspecific method for the identification of potential vaccine safety signals. Despite good discrimination, most analyses showed a tendency to overestimate risks, with 20%-100% type 1 error, but low (0% to 20%) type 2 error in the large databases included in our study. Efforts to improve the comparability of background and post-vaccine rates, including age-sex adjustment and anchoring background rates around a visit, reduced type 1 error and improved precision but residual systematic error persisted. Additionally, empirical calibration dramatically reduced type 1 to nominal but came at the cost of increasing type 2 error.

COVID-19 vaccination rates and SARS-CoV-2 infection in pregnant women in Scotland

We describe SARS-CoV-2 infection and COVID-19 vaccine uptake in Scotland in a prospective cohort of all pregnant women in Scotland drawn from national databases. As of mid-October 2021, the Covid-19 in pregnancy in Scotland (COPS) cohort included linked data on a total of 139,136 pregnancies in 126,749 women. Up to September 30, 2021, a total of 22,779 COVID-19 vaccinations had been administered to 16,229 pregnant women. Vaccine coverage was substantially lower in pregnant women than in the general female population of reproductive age (23.7% of women giving birth in September 2021 were fully vaccinated compared to 74.9 % in women 18-44 years). Of the 4,274 cases of COVID-19 in pregnancy (confirmed by SARS-CoV-2 viral reverse transcriptase polymerase chain reaction) between December 2020 (the month the COVID-19 vaccination programme started in Scotland) and September 2021 inclusive, 629 women (14.7%) were admitted to hospital and 89 (2.1%) were admitted to critical care. Of the COVID-19 cases occurring in pregnant women, 81.7% (3,491/4,274; 95% CI 80.5-82.8) were in unvaccinated women. Of the COVID-19 associated hospital admissions, 93.0% (585/629; 95% CI 90.7-94.8) were in women who were unvaccinated at the time of COVID-19 diagnosis. Of the COVID-19 associated critical care admissions 98.9% (88/89; 95% CI 93.9-100) were in women who were unvaccinated at the time of COVID-19 diagnosis. The extended perinatal mortality rate for women who gave birth within 28 days of COVID-19 diagnosis was 15.9 per 1000 births (95% CI 7.8 to 31.0; background rate in 2020 6.3 per 1,000 total births [95% CI 5.7-7.1]; background rate 2019 5.7 per 1,000 total births [95% CI 5.0-6.4]). All baby deaths occurred after pregnancies in women who were unvaccinated at the time of COVID-19 diagnosis. Addressing low vaccine uptake rates in pregnant women is imperative to protect the health of women and babies.

Performance of a triple-GEM demonstrator in pp collisions at the CMS detector

After the Phase-2 high-luminosity upgrade to the Large Hadron Collider (LHC), the collision rate and therefore the background rate will significantly increase, particularly in the high η region. To improve both the tracking and triggering of muons, the Compact Muon Solenoid (CMS) Collaboration plans to install triple-layer Gas Electron Multiplier (GEM) detectors in the CMS muon endcaps. Demonstrator GEM detectors were installed in CMS during 2017 to gain operational experience and perform a preliminary investigation of detector performance. We present the results of triple-GEM detector performance studies performed in situ during normal CMS and LHC operations in 2018. The distribution of cluster size and the efficiency to reconstruct high pT muons in proton-proton collisions are presented as well as the measurement of the environmental background rate to produce hits in the GEM detector.

Glider Observations of Thermohaline Staircases in the Tropical North Atlantic Using an Automated Classifier

Thermohaline staircases are stepped structures of alternating thick mixed layers and thin high gradient interfaces. These structures can be up to several tens of metres thick and are associated with double-diffusive mixing. Thermohaline staircases occur across broad swathes of the Arctic and tropical/subtropical oceans and can increase rates of diapycnal mixing by up to five times the background rate, driving substantial nutrient fluxes to the upper ocean. In this study, we present an improved classification algorithm to detect thermohaline staircases in ocean glider profiles. We use a dataset of 1162 glider profiles from the tropical North Atlantic collected in early 2020 at the edge of a known thermohaline staircase region. The algorithm identifies thermohaline staircases in 97.7 % of profiles that extend deeper than 300 m. We validate our algorithm against previous results obtained from algorithmic classification of Argo float profiles. Using fine resolution temperature data from a fast-response thermistor on one of the gliders, we explore the effect of varying vertical bin sizes on detected thermohaline staircases. Our algorithm builds on previous work with improved flexibility and the ability to classify staircases from profiles with poor salinity data. Using our results, we propose that the incidence of thermohaline staircases is limited by strong background vertical gradients in conservative temperature and absolute salinity.