scholarly journals Measles Outbreak in Complex Emergency: Estimating Vaccine Effectiveness and Evaluation of the Vaccination Campaign in Borno State, Nigeria, 2019

2021 ◽  
Author(s):  
Anne Eudes Jean Baptiste ◽  
John Wagai ◽  
Richard Ray Luce ◽  
Balcha Girma Masresha ◽  
Don Klinkenberg ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Screening Method ◽  
Population Level ◽  
Vaccine Effectiveness ◽  
Sensitivity Analyses ◽  
Outbreak Response ◽  
Internally Displaced ◽  
Health Authorities ◽  
Campaign Coverage ◽  
Measles Outbreaks

Abstract Background: From January to May 2019, large measles outbreaks affected Nigeria. Borno state was the most affected, recording 15,237 suspected cases with the state capital of Maiduguri having 1,125 cases investigated and line-listed by March 2019. In Borno state, 22 of the 27 Local Government Areas (LGAs or Districts), including 37 internally displaced persons (IDPs) camps were affected. In response to the situation, an outbreak response immunization (ORI) campaign was conducted in the 13 most affected LGAs. In addition to conventional vaccination teams, special teams were deployed in security compromised areas, areas with migrants, and for nomadic and IDPs. Here we describe the outbreak and the ORI campaign. We also assess the measles-containing vaccine (MCV) coverage and vaccine effectiveness (VE) in order to quantify the population-level impactMethods: We reviewed the ORI activities, and conducted an analysis of the surveillance and the outbreak investigation reports. We assessed VE of MCV by applying the screening-method. Sensitivity analyses were also conducted to assess the effect of final classification of cases on the VE of MCV. The MCV coverage was assessed by a post-campaign coverage survey (PCCS) after completion of the ORI through a quantitative survey in the 12 LGAs that were accessible. Results: Of the total 15,237 reported measles cases, 2,002 cases were line-listed and investigated, and 737 were confirmed for measles by week 9 of 2019. Of the investigated cases 67.3% (n = 1,348) were between 9 and 59 months of age. Among the 737 confirmed cases, only 9% (n = 64) stated being vaccinated with at least 1 dose of MCV. The overall VE for MCV was 98.4 % (95%CI: 97.8 – 98.8). No significant differences were observed in the VE estimates of lab-confirmed and epi-linked cases when compared to the original estimates. The aggregated weighted vaccination coverage was 85.7% (95% CI: 79.6 – 90.1).Conclusion: The experience in Borno demonstrates that adequate VE can be obtained in conflict-affected areas. In complex emergencies affected by measles outbreaks, health authorities may consider integration with other health strategies and the engagement of security personnel as part of the ORI activities.

scholarly journals Measles outbreak in complex emergency: estimating vaccine effectiveness and evaluation of the vaccination campaign in Borno State, Nigeria, 2019

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Anne Eudes Jean Baptiste ◽  
John Wagai ◽  
Richard Luce ◽  
Balcha Masresha ◽  
Don Klinkenberg ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Screening Method ◽  
Population Level ◽  
Vaccine Effectiveness ◽  
Sensitivity Analyses ◽  
Outbreak Response ◽  
Internally Displaced ◽  
Health Authorities ◽  
Campaign Coverage ◽  
Measles Outbreaks

Abstract Background From January to May 2019, large measles outbreaks affected Nigeria. Borno state was the most affected, recording 15,237 suspected cases with the state capital of Maiduguri having 1125 cases investigated and line-listed by March 2019. In Borno state, 22 of the 27 Local Government Areas (LGAs or Districts), including 37 internally displaced persons (IDPs) camps were affected. In response to the situation, an outbreak response immunization (ORI) campaign was conducted in the 13 most affected LGAs. In addition to conventional vaccination teams, special teams were deployed in security compromised areas, areas with migrants, and for nomadic and IDPs. Here we describe the outbreak and the ORI campaign. We also assess the measles-containing vaccine (MCV) coverage and vaccine effectiveness (VE) in order to quantify the population-level impact. Methods We reviewed the ORI activities, and conducted an analysis of the surveillance and the outbreak investigation reports. We assessed VE of MCV by applying the screening-method. Sensitivity analyses were also conducted to assess the effect of final classification of cases on the VE of MCV. The MCV coverage was assessed by a post-campaign coverage survey after completion of the ORI through a quantitative survey in the 12 LGAs that were accessible. Results Of the total 15,237 reported measles cases, 2002 cases were line-listed and investigated, and 737 were confirmed for measles by week 9 of 2019. Of the investigated cases 67.3% (n = 1348) were between 9 and 59 months of age. Among the 737 confirmed cases, only 9% (n = 64) stated being vaccinated with at least 1 dose of MCV. The overall VE for MCV was 98.4% (95%CI: 97.8–98.8). No significant differences were observed in the VE estimates of lab-confirmed and epi-linked cases when compared to the original estimates. The aggregated weighted vaccination coverage was 85.7% (95% CI: 79.6–90.1). Conclusion The experience in Borno demonstrates that adequate VE can be obtained in conflict-affected areas. In complex emergencies affected by measles outbreaks, health authorities may consider integration with other health strategies and the engagement of security personnel as part of the ORI activities.

scholarly journals Measles Outbreak in Complex Emergency: Estimating Vaccine Effectiveness and Evaluation of the Vaccination Campaign in Borno State, Nigeria, 2019

2020 ◽  
Author(s):  
Anne Eudes Jean Baptiste ◽  
John Wagai ◽  
Richard Ray Luce ◽  
Balcha Girma Masresha ◽  
Don Klinkenberg ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Screening Method ◽  
Population Level ◽  
Vaccine Effectiveness ◽  
Sensitivity Analyses ◽  
Outbreak Response ◽  
Internally Displaced ◽  
Complex Emergency ◽  
Campaign Coverage ◽  
Measles Outbreaks

Abstract Background: From January to May 2019, large measles outbreaks affected Nigeria. Borno state was the most affected, recording 15,237 suspected cases with the state capital of Maiduguri having 1,125 cases investigated and line-listed by March 2019. In Borno state, 22 of the 27 Local Government Areas (LGAs or Districts), including 37 internally displaced persons (IDPs) camps were affected. In response to the situation, an outbreak response immunization (ORI) campaign was conducted in the 13 most affected LGAs. In addition to conventional vaccination teams, special teams were deployed in security compromised areas, areas with migrants, and for nomadic and IDPs. Here we describe the outbreak and the ORI campaign. We also assess the measles-containing vaccine (MCV) coverage and vaccine effectiveness (VE) in order to quantify the population-level impactMethods: We reviewed the ORI activities, and conducted an analysis of the surveillance and the outbreak investigation reports. We assessed VE of MCV by applying the screening-method. Sensitivity analyses were also conducted to assess the effect of final classification of cases on the VE of MCV. The MCV coverage was assessed by a post-campaign coverage survey (PCCS) after completion of the ORI through a quantitative survey in the 12 LGAs that were accessible. . Results: Of the total 15,237 reported measles cases, 2,002 cases were line-listed and investigated, and 737 were confirmed for measles by week 9 of 2019. Of the investigated cases 67.3% (n = 1,348) were between 9 and 59 months of age. Among the 737 confirmed cases, only 9% (n = 64) stated being vaccinated with at least 1 dose of MCV. The overall VE for MCV was 98.4 (95%CI: 97.8 – 98.8). No significant differences were observed in the VE estimates of lab-confirmed and epi-linked cases when compared to the original estimates. The aggregated weighted vaccination coverage was 85.7% (95% CI: 79.6 – 90.1).Conclusion: The experience in Borno demonstrates that adequate VE can be obtained in conflict-affected areas. In complex emergency affected by measles outbreaks, health authorities may consider integration with other health strategies and the engagement of security personnel as part of the ORI activities.

scholarly journals Measles Outbreak in Complex Emergency: Estimating Vaccine Effectiveness and Evaluation of the Vaccination Response in Borno State, Nigeria, 2019

2020 ◽  
Author(s):  
Anne Eudes Jean Baptiste ◽  
John Wagai ◽  
Richard Ray Luce ◽  
Balcha Girma Masresha ◽  
Don Klinkenberg ◽  
...  
Keyword(s):  
Vaccination Coverage ◽  
Vaccination Campaign ◽  
Screening Method ◽  
Population Level ◽  
Vaccine Effectiveness ◽  
Outbreak Response ◽  
Internally Displaced ◽  
Measles Outbreak ◽  
Complex Emergency ◽  
Measles Outbreaks

Abstract Background: From January to May 2019, large measles outbreaks affected all states in Nigeria and the Federal Capital Territory. Borno state was the most affected by the measles outbreak recording 15,237 suspected cases with the state capital of Maiduguri having 1,125 confirmed cases by March 2019. Twenty-two Local Government Areas (LGAs or Districts) and 37 internally displaced persons (IDPs) camps had been affected. In response to the situation, outbreak response immunization (ORI) was conducted. In addition to conventional vaccination teams, special teams were deployed in security compromised areas, areas with migrants, and for nomadic and IDPs. Here we describe the ORI and estimated the vaccine effectiveness (VE) for measles-containing vaccine (MCV) to assess the population-level impact. A post-campaign coverage survey (PCCS) was also carried out to assess the vaccination coverage.Methods: We reviewed the outbreak response-associated immunization activities, and conducted an analysis of the surveillance and the outbreak investigation reports. We evaluated VE of MCV by applying the screening-method using data from the measles outbreak and the latest mass vaccination campaign. The PCCS was conducted after completion of the ORI through a quantitative survey assessment in 1,800 households in 12 LGAs involved in the response.Results: Of the total 15,237 reported measles cases, 2,002 cases were line-listed and investigated, and 737 were confirmed for measles as at epidemiological week 9. Of the investigated cases 67.3% (n = 1,348) were between 9 and 59 months of age. Among the 737 confirmed cases, only 9% (n = 64) stated being vaccinated with at least 1 dose of MCV. The median VE for MCV is 96.7% (95%CI: 94.7 – 98.1), and 87.3% (95%CI: 71.0 – 95.2) when vaccine was received at 9 – 11. The aggregated weighted vaccination coverage is 85.7% (95%CI: 79.6 – 90.1).Conclusion: The experience in Borno demonstrates that adequate VE can be obtained in conflict-affected areas. In complex emergency affected by measles outbreaks, health authorities may consider integration with other health strategies and the engagement of security personnel as part of the ORI activities.

scholarly journals Exploring the time to intervene with a reactive mass vaccination campaign in measles epidemics

2006 ◽  
Vol 134 (4) ◽  
pp. 845-849 ◽  
Author(s):  
R. F. GRAIS ◽  
X. DE RADIGUÈS ◽  
C. DUBRAY ◽  
F. FERMON ◽  
P. J. GUERIN
Keyword(s):  
Urban Areas ◽  
Vaccine Coverage ◽  
Vaccination Campaign ◽  
Epidemic Spread ◽  
Outbreak Response ◽  
Poor Countries ◽  
Mass Vaccination Campaign ◽  
Measles Outbreaks ◽  
Vaccination Campaigns ◽  
Reactive Vaccination

The current WHO policy during measles outbreaks focuses on case management rather than reactive vaccination campaigns in urban areas of resource-poor countries having low vaccine coverage. Vaccination campaigns may be costly, or not timely enough to impact significantly on morbidity and mortality. We explored the time available for intervention during two recent epidemics. Our analysis suggests that the spread of measles in African urban settings may not be as fast as expected. Examining measles epidemic spread in Kinshasa (DRC), and Niamey (Niger) reveals a progression of smaller epidemics. Intervening with a mass campaign or in areas where cases have not yet been reported could slow the epidemic spread. The results of this preliminary analysis illustrate the importance of revisiting outbreak response plans.

scholarly journals Modelling the impact of delaying vaccination against SARS-CoV-2 assuming unlimited vaccine supply

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Marcos Amaku ◽  
Dimas Tadeu Covas ◽  
Francisco Antonio Bezerra Coutinho ◽  
Raymundo Soares Azevedo ◽  
Eduardo Massad
Keyword(s):  
Mathematical Model ◽  
Vaccination Campaign ◽  
Vaccination Rate ◽  
Sao Paulo ◽  
The State ◽  
São Paulo ◽  
Health Authorities ◽  
The World ◽  
The Moment ◽  
The Impact

Abstract Background At the moment we have more than 177 million cases and 3.8 million deaths (as of June 2021) around the world and vaccination represents the only hope to control the pandemic. Imperfections in planning vaccine acquisition and difficulties in implementing distribution among the population, however, have hampered the control of the virus so far. Methods We propose a new mathematical model to estimate the impact of vaccination delay against the 2019 coronavirus disease (COVID-19) on the number of cases and deaths due to the disease in Brazil. We apply the model to Brazil as a whole and to the State of Sao Paulo, the most affected by COVID-19 in Brazil. We simulated the model for the populations of the State of Sao Paulo and Brazil as a whole, varying the scenarios related to vaccine efficacy and compliance from the populations. Results The model projects that, in the absence of vaccination, almost 170 thousand deaths and more than 350 thousand deaths will occur by the end of 2021 for Sao Paulo and Brazil, respectively. If in contrast, Sao Paulo and Brazil had enough vaccine supply and so started a vaccination campaign in January with the maximum vaccination rate, compliance and efficacy, they could have averted more than 112 thousand deaths and 127 thousand deaths, respectively. In addition, for each month of delay the number of deaths increases monotonically in a logarithmic fashion, for both the State of Sao Paulo and Brazil as a whole. Conclusions Our model shows that the current delay in the vaccination schedules that is observed in many countries has serious consequences in terms of mortality by the disease and should serve as an alert to health authorities to speed the process up such that the highest number of people to be immunized is reached in the shortest period of time.

Influenza vaccine effectiveness: best practice and current limitations of the screening method and their implications for the clinic

2014 ◽  
Vol 13 (8) ◽  
pp. 1039-1048 ◽  
Author(s):  
Laëtitia Minodier ◽  
Thierry Blanchon ◽  
Cecile Souty ◽  
Clement Turbelin ◽  
Frederic Leccia ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Best Practice ◽  
Screening Method ◽  
Vaccine Effectiveness

scholarly journals Measles Outbreak Associated With Low Vaccine Effectiveness Among Adults in Pohnpei State, Federated States of Micronesia, 2014

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Craig M. Hales ◽  
Eliaser Johnson ◽  
Louisa Helgenberger ◽  
Mark J. Papania ◽  
Maribeth Larzelere ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Vaccination Campaign ◽  
Vaccine Effectiveness ◽  
Mass Vaccination ◽  
Cold Chain ◽  
Primary Case ◽  
Federated States Of Micronesia ◽  
Measles Outbreak ◽  
Mass Vaccination Campaign ◽  
Vaccination Campaigns

Abstract Background.  A measles outbreak in Pohnpei State, Federated States of Micronesia in 2014 affected many persons who had received ≥1 dose of measles-containing vaccine (MCV). A mass vaccination campaign targeted persons aged 6 months to 49 years, regardless of prior vaccination. Methods.  We evaluated vaccine effectiveness (VE) of MCV by comparing secondary attack rates among vaccinated and unvaccinated contacts after household exposure to measles. Results.  Among 318 contacts, VE for precampaign MCV was 23.1% (95% confidence interval [CI], −425 to 87.3) for 1 dose, 63.4% (95% CI, −103 to 90.6) for 2 doses, and 95.9% (95% CI, 45.0 to 100) for 3 doses. Vaccine effectiveness was 78.7% (95% CI, 10.1 to 97.7) for campaign doses received ≥5 days before rash onset in the primary case and 50.4% (95% CI, −52.1 to 87.9) for doses received 4 days before to 3 days after rash onset in the primary case. Vaccine effectiveness for most recent doses received before 2010 ranged from 51% to 57%, but it increased to 84% for second doses received in 2010 or later. Conclusions.  Low VE was a major source of measles susceptibility in this outbreak; potential reasons include historical cold chain inadequacies or waning of immunity. Vaccine effectiveness of campaign doses supports rapid implementation of vaccination campaigns in outbreak settings.

scholarly journals The Public Health Impact of Delaying a Second Dose of the BNT162b2 or mRNA-1273 COVID-19 Vaccine

2021 ◽  
Author(s):  
Santiago Romero-Brufau ◽  
Ayush Chopra ◽  
Alex J Ryu ◽  
Esma Gel ◽  
Ramesh Raskar ◽  
...  
Keyword(s):  
Vaccination Strategy ◽  
Population Level ◽  
Health Impact ◽  
Vaccination Rate ◽  
Agent Based Modeling ◽  
Sensitivity Analyses ◽  
Agent Based ◽  
Cumulative Mortality ◽  
Vaccination Rates ◽  
The Public

AbstractObjectivesTo estimate population health outcomes under delayedsecond dose versus standard schedule SARS-CoV-2 mRNA vaccination.DesignAgent-based modeling on a simulated population of 100,000 based on a real-world US county. The simulation runs were replicated 10 times. To test the robustness of these findings, simulations were performed under different estimates for single-dose efficacy and vaccine administration rates, and under the possibility that a vaccine prevents only symptoms but not asymptomatic spread.Settingpopulation level simulation.Participants100,000 agents are included in the simulation, with a representative distribution of demographics and occupations. Networks of contacts are established to simulate potentially infectious interactions though occupation, household, and random interactionsInterventionswe simulate standard Covid-19 vaccination, versus delayed-second-dose vaccination prioritizing first dose. Sensitivity analyses include first-dose vaccine efficacy of 70%, 80% and 90% after day 12 post-vaccination; vaccination rate of 0.1%, 0.3%, and 1% of population per day; assuming the vaccine prevents only symptoms but not asymptomatic spread; and an alternative vaccination strategy that implements delayed-second-dose only for those under 65 years of age.Main outcome measurescumulative Covid-19 mortality over 180 days, cumulative infections and hospitalizations.ResultsOver all simulation replications, the median cumulative mortality per 100,000 for standard versus delayed second dose was 226 vs 179; 233 vs 207; and 235 vs 236; for 90%, 80% and 70% first-dose efficacy, respectively. The delayed-second-dose strategy was optimal for vaccine efficacies at or above 80%, and vaccination rates at or below 0.3% population per day, both under sterilizing and non-sterilizing vaccine assumptions, resulting in absolute cumulative mortality reductions between 26 and 47 per 100,000. The delayed-second-dose for those under 65 performed consistently well under all vaccination rates tested.ConclusionsA delayed-second-dose vaccination strategy, at least for those under 65, could result in reduced cumulative mortality under certain conditions.

scholarly journals The Delta Variant Had Negligible Impact on COVID-19 Vaccine Effectiveness in the USA

2021 ◽  
Author(s):  
Ben Blaiszik ◽  
Carlo Graziani ◽  
James L. Olds ◽  
Ian Foster
Keyword(s):  
Age Distribution ◽  
Vaccine Effectiveness ◽  
Vaccination Status ◽  
Rt Pcr ◽  
Factors Affecting ◽  
A Value ◽  
Health Authorities ◽  
Public Health Authorities ◽  
The Usa ◽  
Zero Baseline

The SARS-CoV-2 Delta variant (B.1.617.2) was initially identified in India in December 2020. Due to its high transmissibility, its prevalence in the U.S.A. grew from a near-zero baseline in early May 2021 to nearly 100% by late August 2021, according to CDC tracking. We accessed openly available data sources from the public health authorities of seven U.S. states, five U.S. counties, and the District of Columbia on RT-PCR COVID-19 tests split by the COVID-19 vaccination status of individuals tested during this period. Together, these time series enable estimation and tracking of COVID-19 vaccine effectiveness (VE∗) (against RT-PCR diagnosed infection) concurrently with the growth of Delta variant prevalence in those locations. Our analyses reveal that in each locality the VE∗ for the combined set of all three US vaccines remained relatively stable and quite well-performing, despite the dramatic concurrent rise of Delta variant prevalence. We conclude that the Delta variant does not significantly evade vaccine-induced immunity. The variations in our measured VE∗ appear to be driven by demographic factors affecting the composition of the vaccinated cohorts, particularly as pertains to age distribution. We report that the measured VE∗, aggregated across the collected sites, began at a value of about 0.9 in mid-May, declined to about 0.76 by mid-July, and recovered to about 0.9 by mid-September.SummaryWe estimated local COVID-19 vaccine effectiveness using RT-PCR COVID-19 test data broken out by vaccination status from select localities in the U.S.A. between 15 May and 15 September 2021 while the SARS-CoV-2 Delta variant (B.1.617.2) was ascending from essentially zero prevalence to total dominance of the genome, and showed that the rise of the Delta variant had negligible effect on vaccine effectiveness.

scholarly journals Ensuring COVID-19 Vaccines for Migrant and Immigrant Farmworkers

2021 ◽  
Author(s):  
Christine M. Thomas ◽  
Amy K. Liebman ◽  
Alma Galván ◽  
Jonathan D. Kirsch ◽  
William M. Stauffer
Keyword(s):  
Public Health ◽  
Disease Burden ◽  
Vaccination Campaign ◽  
Geographic Location ◽  
The United States ◽  
Health Centers ◽  
Coordination Of Care ◽  
Faith Based ◽  
Food And Agriculture ◽  
Health Authorities

Migrant and immigrant farmworkers are cornerstones to food security and production in many nations. In the United States, farmworkers have been disproportionately impacted by COVID-19. Because they are considered essential workers, vaccines may be made imminently available to them and offer an opportunity to reduce these COVID-19–related impacts. It is essential for a successful vaccination campaign to address the unique challenges arising from this workforce’s inherently mobile nature and limited access to healthcare. Proposed strategies to overcome these challenges include ensuring farmworkers are prioritized in vaccine allocation and provided cost-free vaccines at convenient locations through partnerships among health authorities, community- and faith-based groups, and health centers with trusted community relationships. Further, a portable immunization record should be used, and coordination of care continued when a farmworker moves to a new geographic location. If implemented well, vaccinating farmworkers can reduce the COVID-19 disease burden among these essential workers, improve public health, and protect food and agriculture production.

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