Modeling the use of SARS-CoV-2 vaccination to safely relax non-pharmaceutical interventions

AbstractIn response to the COVID-19 pandemic, widespread non-pharmaceutical interventions (NPIs), including physical distancing, mask wearing, and enhanced hygiene, have been implemented. As of March 2021, three effective vaccines have been approved for emergency use in the United States, with several other vaccines in the pipeline. We use a transmission model to study when and how NPIs could be relaxed in the United States with relative safety as vaccination becomes more widespread. We compare different relaxation scenarios where NPIs begin to relax 0-9 months after vaccination begins for both a one dose and two dose strategy, with historical levels of social interactions being reached within 1 month to 1 year. In our model, vaccination can allow widespread relaxation of NPIs to begin safely within 2 to 9 months, greatly reducing deaths and peak health system burden compared to relaxing NPIs without vaccination. Vaccinated individuals can safely begin to relax NPIs sooner than unvaccinated individuals. The extent of delay needed to safely reopen depends primarily on the rate of vaccine rollout, with the degree of protection against asymptomatic infection playing a secondary role. If a vaccination rate of 3 million doses/day can be achieved, similar to the typical rollout speed of seasonal influenza vaccination, NPIs could begin to be safely relaxed in 2-3 months. With a vaccination rate of 1 million doses/day, a 6–9-month delay is needed. A one dose strategy is preferred if relative efficacy is similar to a two-dose series, but the relative benefit of this strategy is minimal when vaccine rollout is fast. Due to the urgent need to pursue strategies that enable safe relaxation of NPIs, we recommend a two-dose strategy with an initial delay of at least 3 months in relaxing restrictions further, and that the speed of vaccine rollout be given immediate priority.

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Effect of specific non-pharmaceutical intervention policies on SARS-CoV-2 transmission in the counties of the United States

Nature Communications ◽

10.1038/s41467-021-23865-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Bingyi Yang ◽

Angkana T. Huang ◽

Bernardo Garcia-Carreras ◽

William E. Hart ◽

Andrea Staid ◽

...

Keyword(s):

United States ◽

Home Visiting ◽

Leisure Activities ◽

The United States ◽

Causal Effects ◽

Basic Reproductive Number ◽

Reproductive Number ◽

County Level ◽

Metapopulation Model ◽

Pharmaceutical Interventions

AbstractNon-pharmaceutical interventions (NPIs) remain the only widely available tool for controlling the ongoing SARS-CoV-2 pandemic. We estimated weekly values of the effective basic reproductive number (Reff) using a mechanistic metapopulation model and associated these with county-level characteristics and NPIs in the United States (US). Interventions that included school and leisure activities closure and nursing home visiting bans were all associated with a median Reff below 1 when combined with either stay at home orders (median Reff 0.97, 95% confidence interval (CI) 0.58–1.39) or face masks (median Reff 0.97, 95% CI 0.58–1.39). While direct causal effects of interventions remain unclear, our results suggest that relaxation of some NPIs will need to be counterbalanced by continuation and/or implementation of others.

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Impact of the COVID-19 Vaccine on Asymptomatic Infection Among Patients Undergoing Pre-Procedural COVID-19 Molecular Screening

Clinical Infectious Diseases ◽

10.1093/cid/ciab229 ◽

2021 ◽

Cited By ~ 4

Author(s):

Aaron J Tande ◽

Benjamin D Pollock ◽

Nilay D Shah ◽

Gianrico Farrugia ◽

Abinash Virk ◽

...

Keyword(s):

United States ◽

Relative Risk ◽

Healthcare System ◽

The United States ◽

Asymptomatic Infection ◽

Screening Tests ◽

Molecular Screening ◽

Molecular Tests ◽

Asymptomatic Individuals ◽

The Impact

Abstract Background Several vaccines are now clinically available under emergency use authorization in the United States and have demonstrated efficacy against symptomatic COVID-19. The impact of vaccines on asymptomatic SARS-CoV-2 infection is largely unknown. Methods We conducted a retrospective cohort study of consecutive, asymptomatic adult patients (n = 39,156) within a large United States healthcare system who underwent 48,333 pre-procedural SARS-CoV-2 molecular screening tests between December 17, 2020 and February 8, 2021. The primary exposure of interest was vaccination with at least one dose of an mRNA COVID-19 vaccine. The primary outcome was relative risk of a positive SARS-CoV-2 molecular test among those asymptomatic persons who had received at least one dose of vaccine, as compared to persons who had not received vaccine during the same time period. Relative risk was adjusted for age, sex, race/ethnicity, patient residence relative to the hospital (local vs. non-local), healthcare system regions, and repeated screenings among patients using mixed effects log-binomial regression. Results Positive molecular tests in asymptomatic individuals were reported in 42 (1.4%) of 3,006 tests performed on vaccinated patients and 1,436 (3.2%) of 45,327 tests performed on unvaccinated patients (RR=0.44 95% CI: 0.33-0.60; p<.0001). Compared to unvaccinated patients, the risk of asymptomatic SARS-CoV-2 infection was lower among those >10 days after 1 st dose (RR=0.21; 95% CI: 0.12-0.37; p<.0001) and >0 days after 2 nd dose (RR=0.20; 95% CI: 0.09-0.44; p<.0001) in the adjusted analysis. Conclusions COVID-19 vaccination with an mRNA-based vaccine showed a significant association with a reduced risk of asymptomatic SARS-CoV-2 infection as measured during pre-procedural molecular screening. The results of this study demonstrate the impact of the vaccines on reduction in asymptomatic infections supplementing the randomized trial results on symptomatic patients.

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Estimated transmissibility and impact of SARS-CoV-2 lineage B.1.1.7 in England

Science ◽

10.1126/science.abg3055 ◽

2021 ◽

Vol 372 (6538) ◽

pp. eabg3055 ◽

Cited By ~ 82

Author(s):

Nicholas G. Davies ◽

Sam Abbott ◽

Rosanna C. Barnard ◽

Christopher I. Jarvis ◽

Adam J. Kucharski ◽

...

Keyword(s):

United States ◽

Severe Acute Respiratory Syndrome ◽

Reproduction Number ◽

The United States ◽

Control Measures ◽

Transmission Model ◽

Educational Institutions ◽

Stringent Control ◽

Dynamic Transmission Model ◽

Credible Intervals

A severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, VOC 202012/01 (lineage B.1.1.7), emerged in southeast England in September 2020 and is rapidly spreading toward fixation. Using a variety of statistical and dynamic modeling approaches, we estimate that this variant has a 43 to 90% (range of 95% credible intervals, 38 to 130%) higher reproduction number than preexisting variants. A fitted two-strain dynamic transmission model shows that VOC 202012/01 will lead to large resurgences of COVID-19 cases. Without stringent control measures, including limited closure of educational institutions and a greatly accelerated vaccine rollout, COVID-19 hospitalizations and deaths across England in the first 6 months of 2021 were projected to exceed those in 2020. VOC 202012/01 has spread globally and exhibits a similar transmission increase (59 to 74%) in Denmark, Switzerland, and the United States.

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Investing for Growth and Security

Fiscal Therapy ◽

10.1093/oso/9780190645410.003.0011 ◽

2019 ◽

pp. 193-206

Author(s):

William G. Gale

Keyword(s):

United States ◽

Research And Development ◽

Interest Rates ◽

Federal Government ◽

The United States ◽

Federal Spending ◽

President Obama ◽

Transit Systems ◽

Historical Levels

Besides its investment in people, the federal government makes critical investments in infrastructure and research and development. Because federal spending in these areas has fallen significantly in recent years and interest rates are low relative to historical levels, this chapter proposes sizable increases for both categories. The increases in infrastructure spending will provide the resources needed to restore and update aging roads, bridges, and public transit systems, while the increases in research and development will help the United States to explore cutting-edge technologies. Policymakers should also fund the military’s long-term plans through 2032, as outlined by President Obama, and let spending grow modestly afterward. That would allow for a continuing presence overseas. If a new war broke out, policymakers presumably would provide the additional temporary funds to ensure that America achieved its mission and emerged victorious.

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Cost-effectiveness of HPV vaccination for adults through age 45 years in the United States: Estimates from a simplified transmission model

Vaccine ◽

10.1016/j.vaccine.2020.10.019 ◽

2020 ◽

Vol 38 (50) ◽

pp. 8032-8039 ◽

Cited By ~ 1

Author(s):

Harrell W. Chesson ◽

Elissa Meites ◽

Donatus U. Ekwueme ◽

Mona Saraiya ◽

Lauri E. Markowitz

Keyword(s):

United States ◽

Cost Effectiveness ◽

Hpv Vaccination ◽

The United States ◽

Transmission Model

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Differential effects of intervention timing on COVID-19 spread in the United States

Science Advances ◽

10.1126/sciadv.abd6370 ◽

2020 ◽

Vol 6 (49) ◽

pp. eabd6370 ◽

Cited By ~ 4

Author(s):

Sen Pei ◽

Sasikiran Kandula ◽

Jeffrey Shaman

Keyword(s):

United States ◽

Disease Transmission ◽

Human Mobility ◽

The United States ◽

Control Measures ◽

Basic Reproductive Number ◽

Transmission Model ◽

Reproductive Number ◽

Mobility Data ◽

Nonpharmaceutical Interventions

Assessing the effects of early nonpharmaceutical interventions on coronavirus disease 2019 (COVID-19) spread is crucial for understanding and planning future control measures to combat the pandemic. We use observations of reported infections and deaths, human mobility data, and a metapopulation transmission model to quantify changes in disease transmission rates in U.S. counties from 15 March to 3 May 2020. We find that marked, asynchronous reductions of the basic reproductive number occurred throughout the United States in association with social distancing and other control measures. Counterfactual simulations indicate that, had these same measures been implemented 1 to 2 weeks earlier, substantial cases and deaths could have been averted and that delayed responses to future increased incidence will facilitate a stronger rebound of infections and death. Our findings underscore the importance of early intervention and aggressive control in combatting the COVID-19 pandemic.

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Estimating data-driven COVID-19 mitigation strategies for safe university reopening

10.1101/2021.08.13.21261983 ◽

2021 ◽

Author(s):

Qihui Yang ◽

Don M. Gruenbacher ◽

Caterina M. Scoglio

Keyword(s):

Extreme Events ◽

Social Contact ◽

The United States ◽

Vaccination Rate ◽

Mitigation Strategies ◽

Contact Patterns ◽

University Population ◽

The University ◽

University Settings ◽

Pharmaceutical Interventions

AbstractAfter one pandemic year of remote or hybrid instructional modes, universities in the United States are now planning for an in-person fall semester in 2021. However, it is uncertain what the vaccination rate will look like after students, faculty, and staff return to campus. To help inform university-reopening policies, we collected survey data on social contact patterns and developed an agent-based model to simulate the spread of COVID-19 in university settings. In this paper, we aim to identify the immunity threshold that, if exceeded, would lead to a relatively safe on-campus experience for the university population. With relaxed non-pharmaceutical interventions, we estimated that immunity in at least 60% of the university population is needed for safe university reopening. Still, attention needs to be paid to extreme events that could lead to huge infection size spikes. At an immune level of 60%, continuing non-pharmaceutical interventions, such as wearing masks, could lead to an 89% reduction in the maximum cumulative infection, which reflects the possible non-negligible infection size from extreme events.

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Optimizing antiviral treatment for seasonal influenza in the United States: A Mathematical Modeling Analysis

10.1101/2020.07.28.20163741 ◽

2020 ◽

Author(s):

Matan Yechezkel ◽

Martial Ndeffo-Mba ◽

Dan Yamin

Keyword(s):

United States ◽

High Risk ◽

Seasonal Influenza ◽

Antiviral Treatment ◽

Social Contact ◽

Population Level ◽

The United States ◽

Transmission Model ◽

High Risk Patients ◽

Risk Patients

Seasonal influenza remains a major health burden in the United States. Despite recommendations of early antiviral treatment of high-risk patients, the effective treatment coverage remains very low. We developed an influenza transmission model that incorporates data on infectious viral load, social contact, and healthcare-seeking behavior, to evaluate the population-level impact of increasing antiviral treatment timeliness and coverage among high-risk patients in the US. We found that increasing the rate of early treatment among high-risk patients who received treatment more than 48 hours after symptoms onset, would substantially avert infections and influenza-induced hospitalizations. We found that treatment of the elderly has the highest impact on reducing hospitalizations, whereas treating high-risk individuals aged 5-19 years old has the highest impact on transmission. The population-level impact of increased timeliness and coverage of treatment among high-risk patients was observed regardless of seasonal influenza vaccination coverage and the severity of the influenza season.

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Non-pharmaceutical interventions and inoculation rate shape SARS-COV-2 vaccination campaign success

10.1101/2021.02.22.21252240 ◽

2021 ◽

Author(s):

Marta Galanti ◽

Sen Pei ◽

Teresa K. Yamana ◽

Frederick J. Angulo ◽

Apostolos Charos ◽

...

Keyword(s):

Vaccination Campaign ◽

The United States ◽

Vaccination Rate ◽

Vaccine Administration ◽

Number Of Factors ◽

Uptake Rates ◽

One Year ◽

Inference Methods ◽

Vaccination Campaigns ◽

Pharmaceutical Interventions

AbstractNearly one year into the COVID-19 pandemic, the first SARS-COV-2 vaccines received emergency use authorization and vaccination campaigns began. A number of factors can reduce the averted burden of cases and deaths due to vaccination. Here, we use a dynamic model, parametrized with Bayesian inference methods, to assess the effects of non-pharmaceutical interventions, and vaccine administration and uptake rates on infections and deaths averted in the United States. We estimate that high compliance with non-pharmaceutical interventions could avert more than 60% of infections and 70% of deaths during the period of vaccine administration, and that increasing the vaccination rate from 5 to 11 million people per week could increase the averted burden by more than one third. These findings underscore the importance of maintaining non-pharmaceutical interventions and increasing vaccine administration rates.

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Impact of non-pharmaceutical interventions for SARS-CoV-2 on norovirus outbreaks: an analysis of outbreaks reported by 9 US States

10.1101/2020.11.25.20237115 ◽

2020 ◽

Author(s):

Alicia N.M. Kraay ◽

Peichun Han ◽

Anita K. Kambhampati ◽

Mary E. Wikswo ◽

Sara A. Mirza ◽

...

Keyword(s):

United States ◽

South Carolina ◽

The United States ◽

Respiratory Pathogen ◽

Secondary Outcome ◽

Interrupted Time Series Analysis ◽

Official Position ◽

The Impact ◽

Pharmaceutical Interventions ◽

Outbreak Size

AbstractImportanceThe impact of non-pharmaceutical interventions (NPIs) in response to the SARS-CoV-2 pandemic on incidence of other infectious diseases is still being assessed.ObjectiveTo determine if the observed change in reported norovirus outbreaks in the United States was best explained by underreporting, seasonal trends, or reduced exposure due to NPIs. We also aimed to assess if the change in reported norovirus outbreaks varied by setting.DesignAn ecologic, interrupted time series analysis of norovirus outbreaks from nine states reported to the National Outbreak Reporting System (NORS) from July 2012–July 2020.SettingSurveillance data from Massachusetts, Michigan, Minnesota, Ohio, Oregon, South Carolina, Tennessee, Virginia, and Wisconsin were included in the analysis.Participants9,226 reports of acute gastroenteritis outbreaks with norovirus as an epidemiologically suspected or laboratory-confirmed etiology were included in the analysis, resulting in more than 8 years of follow up. Outbreak reports from states that participated in NoroSTAT for at least 4 years were included in the analysis (range: 4–8 years).ExposureThe main exposure of interest was time period: before (July 2012–February 2020) or after (April 2020–July 2020) the start of NPIs in the United StatesMain outcomeThe main outcome of interest was monthly rate of reported norovirus outbreaks. As a secondary outcome, we also examined the average outbreak size.ResultsWe found that the decline in norovirus outbreak reports was significant for all 9 states considered (pooled incidence rate ratio (IRR) comparing April 2020-July 2020 vs. all pre-COVID months for each state= 0.14, 95% CI: 0.098, 0.21; P=<0.0001), even after accounting for typical seasonal decline in incidence during the summer months. These patterns were similar across a variety of settings, including nursing homes, child daycares, healthcare settings, and schools. The average outbreak size was also reduced by 61% (95% CI: 56%, 42.7%; P=<0.0001), suggesting that the decline does not reflect a tendency to report only more severe outbreaks due to strained surveillance systems, but instead reflects a decline in incidence.Conclusions and relevanceWhile NPIs implemented during the spring and summer of 2020 were intended to reduce transmission of SARS-CoV-2, these changes also appear to have impacted the incidence of norovirus, a non-respiratory pathogen. These results suggest that NPIs may provide benefit for preventing transmission of other human pathogens, reducing strain to health systems during the continued SARS-CoV-2 pandemic.DisclaimerThe findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the US Centers for Disease Control and Prevention (CDC).

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