The impact of vaccination on COVID-19 outbreaks in the United States

Abstract Background Global vaccine development efforts have been accelerated in response to the devastating COVID-19 pandemic. We evaluated the impact of a 2-dose COVID-19 vaccination campaign on reducing incidence, hospitalizations, and deaths in the United States (US). Methods We developed an agent-based model of SARS-CoV-2 transmission and parameterized it with US demographics and age-specific COVID-19 outcomes. Healthcare workers and high-risk individuals were prioritized for vaccination, while children under 18 years of age were not vaccinated. We considered a vaccine efficacy of 95% against disease following 2 doses administered 21 days apart achieving 40% vaccine coverage of the overall population within 284 days. We varied vaccine efficacy against infection, and specified 10% pre-existing population immunity for the base-case scenario. The model was calibrated to an effective reproduction number of 1.2, accounting for current non-pharmaceutical interventions in the US. Results Vaccination reduced the overall attack rate to 4.6% (95% CrI: 4.3% - 5.0%) from 9.0% (95% CrI: 8.4% - 9.4%) without vaccination, over 300 days. The highest relative reduction (54-62%) was observed among individuals aged 65 and older. Vaccination markedly reduced adverse outcomes, with non-ICU hospitalizations, ICU hospitalizations, and deaths decreasing by 63.5% (95% CrI: 60.3% - 66.7%), 65.6% (95% CrI: 62.2% - 68.6%), and 69.3% (95% CrI: 65.5% - 73.1%), respectively, across the same period. Conclusions Our results indicate that vaccination can have a substantial impact on mitigating COVID-19 outbreaks, even with limited protection against infection. However, continued compliance with non-pharmaceutical interventions is essential to achieve this impact.

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The impact of vaccination on COVID-19 outbreaks in the United States

10.1101/2020.11.27.20240051 ◽

2020 ◽

Cited By ~ 1

Author(s):

Seyed M. Moghadas ◽

Thomas N. Vilches ◽

Kevin Zhang ◽

Chad R. Wells ◽

Affan Shoukat ◽

...

Keyword(s):

United States ◽

Vaccine Efficacy ◽

Vaccine Development ◽

The United States ◽

Adverse Outcomes ◽

Base Case ◽

Relative Reduction ◽

Substantial Impact ◽

The Impact ◽

Pharmaceutical Interventions

AbstractBackgroundGlobal vaccine development efforts have been accelerated in response to the devastating COVID-19 pandemic. We evaluated the impact of a 2-dose COVID-19 vaccination campaign on reducing incidence, hospitalizations, and deaths in the United States (US).MethodsWe developed an agent-based model of SARS-CoV-2 transmission and parameterized it with US demographics and age-specific COVID-19 outcomes. Healthcare workers and high-risk individuals were prioritized for vaccination, while children under 18 years of age were not vaccinated. We considered a vaccine efficacy of 95% against disease following 2 doses administered 21 days apart achieving 40% vaccine coverage of the overall population within 284 days. We varied vaccine efficacy against infection, and specified 10% pre-existing population immunity for the base-case scenario. The model was calibrated to an effective reproduction number of 1.2, accounting for current non-pharmaceutical interventions in the US.ResultsVaccination reduced the overall attack rate to 4.6% (95% CrI: 4.3% - 5.0%) from 9.0% (95% CrI: 8.4% - 9.4%) without vaccination, over 300 days. The highest relative reduction (54-62%) was observed among individuals aged 65 and older. Vaccination markedly reduced adverse outcomes, with non-ICU hospitalizations, ICU hospitalizations, and deaths decreasing by 63.5% (95% CrI: 60.3% - 66.7%), 65.6% (95% CrI: 62.2% - 68.6%), and 69.3% (95% CrI: 65.5% - 73.1%), respectively, across the same period.ConclusionsOur results indicate that vaccination can have a substantial impact on mitigating COVID-19 outbreaks, even with limited protection against infection. However, continued compliance with non-pharmaceutical interventions is essential to achieve this impact.Key pointsVaccination with a 95% efficacy against disease could substantially mitigate future attack rates, hospitalizations, and deaths, even if only adults are vaccinated. Non-pharmaceutical interventions remain an important part of outbreak response as vaccines are distributed over time.

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Identifying silent COVID-19 infections among children is critical for controlling the pandemic

10.1101/2021.01.06.21249349 ◽

2021 ◽

Author(s):

Seyed M. Moghadas ◽

Meagan C. Fitzpatrick ◽

Affan Shoukat ◽

Kevin Zhang ◽

Alison P. Galvani

Keyword(s):

Vaccination Coverage ◽

Vaccine Efficacy ◽

The United States ◽

Sensitivity Analyses ◽

Transmission Model ◽

Base Case ◽

Age Group ◽

One Year ◽

The Impact ◽

Targeted Approach

Importance: A significant proportion of COVID-19 transmission occurs silently during the pre-symptomatic and asymptomatic stages of infection. Children, while being important drivers of silent transmission, are not included in COVID-19 vaccination campaigns given their exclusion from clinical trials thus far. Objective: To investigate the impact of a targeted approach to identifying silent infections among children as a proxy for their vaccination. Design: This study used an age-structured disease transmission model to simulate the synergistic impact of interventions in reducing attack rates over the course of one year. Setting: A synthetic population representative of the demographics of the United States (US). Participants: Six age groups of 0-4, 5-10, 11-18, 19-49, 50-64, 65+ years old, stratified for their population size based on US census data. Exposures: Vaccination of adults, self-isolation of all symptomatic cases within 24 hours of symptom onset, and detection of silent infections. Main Outcomes and Measures: Vaccination of adults was implemented to reach a 40% coverage over the course of one year with a vaccine efficacy of 95% against symptomatic and severe COVID-19. Without vaccination of children, we determined the proportion and speed that would be required for identifying silent infections among this age group to suppress future attack rates below 5%. Results: A targeted approach that identifies 20.6% and 28.6% of silent infections among children within 2 or 3 days post-infection, respectively, would be required to bring attack rates under 5% with vaccination of adults. If silent infections among children remained undetected, achieving the same attack rates would require an unrealistically high vaccination coverage (at least 82%) of this age group, in addition to the base-case 40% vaccination coverage of adults. The results were robust in sensitivity analyses with respect to vaccine efficacy against infection and reduced susceptibility of children to infection. Conclusions and Relevance: In the absence of vaccine availability for children, a targeted approach to rapid identification of silent COVID-19 infections in this age group can significantly mitigate disease burden. Without measures to interrupt transmission chains from silent infections, vaccination of adults is unlikely to contain the outbreaks in the near term.

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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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Impact of non-pharmaceutical interventions on documented cases of COVID-19

10.1101/2020.04.16.20062141 ◽

2020 ◽

Cited By ~ 24

Author(s):

Nicolas Banholzer ◽

Eva van Weenen ◽

Bernhard Kratzwald ◽

Arne Seeliger ◽

Daniel Tschernutter ◽

...

Keyword(s):

Credible Interval ◽

The United States ◽

Current Control ◽

Relative Reduction ◽

Control Mechanisms ◽

Global Epidemic ◽

Country Analysis ◽

Cross Country ◽

The Impact ◽

Pharmaceutical Interventions

AbstractBackgroundThe novel coronavirus (SARS-CoV-2) has rapidly evolved into a global epidemic. To control its spread, countries have implemented non-pharmaceutical interventions (NPIs), such as school or border closures, while others have even enforced complete lockdowns. Here we study the impact of NPIs in reducing documented cases of COVID-19. Documented case numbers are selected because they are essential for decision-makers in the area of health-policy when monitoring and evaluating current control mechanisms.MethodsWe empirically estimate the relative reduction in the number of new cases attributed to each NPI. A cross-country analysis is performed using documented cases through April 15, 2020 from n = 20 countries (i.e., the United States, Canada, Australia, the EU-15 countries, Norway, and Switzerland).ResultsAs of April 15, venue closures were associated with a reduction in the number of new cases by 36 % (95% credible interval [CrI] 20–48 %), closely followed by gathering bans (34 %; 95% CrI 21–45 %), border closures (31 %; 95% CrI 19–42 %), and work bans on non-essential business activities (31 %; 95% CrI 16–44 %). Event bans lead to a slightly less pronounced reduction (23 %; 95% CrI 8–35 %). School closures (8 %; 95% CrI 0–23 %) and lockdowns (5 %; 95% CrI 0–14 %) appeared to be the least effective among the NPIs considered in this analysis.ConclusionsWith this cross-country analysis, we provide early estimates regarding the impact of different NPIs for controlling the COVID-19 epidemic. These findings are relevant for evaluating current health-policies.

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COViD-19: We're All in This Together – Some More Than Others

The Senior Care Pharmacist ◽

10.4140/tcp.n.2021.358 ◽

2021 ◽

Vol 36 (8) ◽

pp. 358-360

Author(s):

Chris Alderman

Keyword(s):

United States ◽

Health Care ◽

Minority Groups ◽

Premature Mortality ◽

The United States ◽

Adverse Outcomes ◽

Developed Economies ◽

Hospitalization Rates ◽

The Impact ◽

Significant Disease

It has long been apparent that gross disparities exist in health care in the United States, and, indeed, other nations with fully developed economies. All kinds of markers point to these inequities, with measures such as overall life expectancy, hospitalization rates, premature mortality, adverse outcomes associated with medical and surgical treatment, infant mortality, and the impact of many significant disease types higher and more impactful among minority groups and those of the most modest economic means. This is not new. Are there pointers to what might underpin the disparities in outcomes among the different minority groups?

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Air Pollution and Racial Disparities in Pregnancy Outcomes in the United States: A Systematic Review

10.21203/rs.3.rs-208924/v1 ◽

2021 ◽

Author(s):

Bonaventure Suiru Dzekem ◽

Briseis Aschebrook-Kilfoy ◽

Christopher O. Olopade

Keyword(s):

United States ◽

Air Pollution ◽

Birth Outcomes ◽

Pregnancy Outcomes ◽

The United States ◽

Epidemiologic Studies ◽

Adverse Pregnancy Outcomes ◽

Adverse Outcomes ◽

Adverse Pregnancy ◽

The Impact

Abstract Background Exposure to air pollutants and other environmental factors increases the risk of adverse pregnancy outcomes. There is growing evidence that adverse outcomes related to air pollution disproportionately affect racial and ethnic minorities. This paper explores the importance of race as a risk factor for air pollution-related poor pregnancy outcomes. Methods We systematically reviewed epidemiologic studies investigating the effects of exposure to air pollution on pregnancy outcomes in the United States. Results Findings across all reviewed studies show more adverse pregnancy outcomes (preterm birth, small for gestational age, low birth weight and stillbirths) due to air pollution among Blacks and Hispanics than among non-Hispanic Whites. Conclusion This paper enhances our general understanding of the impact of air pollution on birth outcomes and, specifically, of disparities in birth outcomes for infants born to Black and Hispanic mothers.

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Quantifying the impact of lifting community non-pharmaceutical interventions for COVID-19 during vaccination rollout in the United States

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab341 ◽

2021 ◽

Author(s):

Laura Matrajt ◽

Holly Janes ◽

Joshua T Schiffer ◽

Dobromir Dimitrov

Keyword(s):

United States ◽

Mathematical Model ◽

Small Proportion ◽

The United States ◽

The Us ◽

Potential Impact ◽

Nonpharmaceutical Interventions ◽

The Impact ◽

Pharmaceutical Interventions

Abstract Using a mathematical model, we estimated the potential impact in mortality and total infections of completely lifting community nonpharmaceutical interventions when only a small proportion of the population has been fully vaccinated in two states in the US. Lifting all community nonpharmaceutical interventions immediately is predicted to result in twice as many deaths over the next 6 months than a more moderate reopening allowing 70% of pre-pandemic contacts.

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