scholarly journals Comparison between one and two dose SARS-CoV-2 vaccine prioritisation for a fixed number of vaccine doses

2021 ◽  
Author(s):  
Edward M. Hill ◽  
Matt J. Keeling
Keyword(s):  
Phase 1 ◽  
Vaccine Dose ◽  
Risk Groups ◽  
Vaccination Schedule ◽  
Careful Consideration ◽  
Fixed Number ◽  
Optimal Timing ◽  
Vaccination Rates ◽  
Risk Of Mortality ◽  
Optimal Mix

AbstractBackgroundThe swift development of vaccines targeting SARS-CoV-2, which have been shown to generate significant immune responses and offer considerable protection against disease, has been met with worldwide commendation. However, in the context of an ongoing pandemic there is an interplay between infection and vaccination. While infection can grow exponentially, potentially overwhelming healthcare resources, vaccination rates are generally limited by both supply and logistics. With the first SARS-CoV-2 vaccines receiving medical approval requiring two doses, there has been scrutiny on the spacing between doses; an elongated period between doses would allow more of the population to receive a first vaccine dose in the short-term generating wide-spread partial immunity.MethodsFocusing on data from England, we investigated prioritisation of a one dose or two dose vaccination schedule given a fixed number of vaccine doses and with respect to a measure of maximising averted deaths. We optimised outcomes for two different estimates of population size and relative risk of mortality for at-risk groups within the Phase 1 vaccine priority order in England, for different amounts of available vaccine and for different vaccine efficacies.FindingsWe find that vaccines offering relatively high protection from the first dose (compared to the efficacy derived from two doses) favour strategies that prioritise giving more people one dose rather than a smaller number two. The optimal mix of one and two doses between the defined priority groups of Phase 1 shows a pattern of returning to give second doses to the highest risk groups as the number of available doses increases.DiscussionWhile this work highlights that an optimal timing of first and second doses between the Phase 1 priority groups can substantially reduce the overall mortality risk to the population, there also needs to be careful consideration of the precise timing between first and second doses as well as the logistics of vaccine delivery.

scholarly journals Comparison between one and two dose SARS-CoV-2 vaccine prioritization for a fixed number of vaccine doses

2021 ◽  
Vol 18 (182) ◽  
pp. 20210214
Author(s):  
Edward M. Hill ◽  
Matt J. Keeling
Keyword(s):  
Phase 1 ◽  
Vaccine Dose ◽  
Optimal Dose ◽  
Risk Groups ◽  
Vaccination Schedule ◽  
Careful Consideration ◽  
Fixed Number ◽  
Vaccination Rates ◽  
Risk Of Mortality ◽  
Priority Order

The swift development of SARS-CoV-2 vaccines has been met with worldwide commendation. However, in the context of an ongoing pandemic there is an interplay between infection and vaccination. While infection can grow exponentially, vaccination rates are generally limited by supply and logistics. With the first SARS-CoV-2 vaccines receiving medical approval requiring two doses, there has been scrutiny on the spacing between doses; an elongated period between doses allows more of the population to receive a first vaccine dose in the short-term generating wide-spread partial immunity. Focusing on data from England, we investigated prioritization of a one dose or two dose vaccination schedule given a fixed number of vaccine doses and with respect to a measure of maximizing averted deaths. We optimized outcomes for two different estimates of population size and relative risk of mortality for at-risk groups within the Phase 1 vaccine priority order. Vaccines offering relatively high protection from the first dose favour strategies that prioritize giving more people one dose, although with increasing vaccine supply eventually those eligible and accepting vaccination will receive two doses. While optimal dose timing can substantially reduce the overall mortality risk, there needs to be careful consideration of the logistics of vaccine delivery.

scholarly journals Predicting the impact of COVID-19 vaccination campaigns - a flexible age-dependent, spatially-stratified predictive model, accounting for multiple viral variants and vaccines

2022 ◽  
Author(s):  
Kristan Alexander Schneider ◽  
Henri Christian Junior Tsoungui Obama ◽  
Nessma Adil Mahmoud Yousif ◽  
Pierre Marie Ngougoue Ngougoue
Keyword(s):  
Herd Immunity ◽  
Risk Groups ◽  
Vaccination Schedule ◽  
Dimensional System ◽  
Vaccination Rates ◽  
Low Incidence ◽  
Mandatory Vaccination ◽  
Vaccination Campaigns ◽  
Low Coverage ◽  
The Impact

Background: After COVID-19 vaccines received approval, vaccination campaigns were launched worldwide. Initially, these were characterized by a shortage of vaccine supply, and specific risk groups were prioritized. Once supply was guaranteed and vaccination coverage saturated, the focus shifted from risk groups to anti-vaxxers, the underaged population, and regions of low coverage. At the same time, hopes to reach herd immunity by vaccination campaigns were put into perspective by the emergence and spread of more contagious and aggressive viral variants. Particularly, concerns were raised that not all vaccines protect against the new-emerging variants. Methods and findings: A model designed to predict the effect of vaccination campaigns on the spread of viral variants is introduced. The model is a comprehensive extension of the model underlying the pandemic preparedness tool CovidSim 2.0 (http://covidsim.eu/). The model is age and spatially stratified, incorporates a finite (but arbitrary) number of different viral variants, and incorporates different vaccine products. The vaccines are allowed to differ in their vaccination schedule, vaccination rates, the onset of vaccination campaigns, and their effectiveness. These factors are also age and/or location dependent. Moreover, the effectiveness and the immunizing effect of vaccines are assumed to depend on the interaction of a given vaccine and viral variant. Importantly, vaccines are not assumed to immunize perfectly. Individuals can be immunized completely, only partially, or fail to be immunized against one or many viral variants. Not all individuals in the population are vaccinable. The model is formulated as a high-dimensional system of differential equations, which is implemented efficiently in the programming language Julia. As an example, the model was parameterized to reflect the epidemic situation in Germany until November 2021 and predicted the future dynamics of the epidemic under different interventions. In particular, without tightening contact reductions, a strong epidemic wave is predicted. At the current state, mandatory vaccination would be too late to have a strong effect on reducing the number of infections. However, it would reduce mortality. An emergency brake, i.e., an incidence-based stepwise lockdown would be efficient to reduce the number of infections and mortality. Furthermore, to specifically account for mobility between regions, the model was applied to two German provinces of particular interest: Saxony, which currently has the lowest vaccine rollout in Germany and high incidence, and Schleswig-Holstein, which has high vaccine rollout and low incidence. Conclusions: A highly sophisticated and flexible but easy-to-parameterize model for the ongoing COVID-19 pandemic is introduced. The model is capable of providing useful predictions for the COVID-19 pandemic, and hence provides a relevant tool for epidemic decision-making. The model can be adjusted to any country, to derive the demand for hospital and ICU capacities as well as economic collateral damages.

scholarly journals Evaluation of health system readiness and coverage of intermittent preventive treatment of malaria in infants (IPTi) in Kambia district to inform national scale-up in Sierra Leone

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Maria Lahuerta ◽  
Roberta Sutton ◽  
Anthony Mansaray ◽  
Oliver Eleeza ◽  
Brigette Gleason ◽  
...  
Keyword(s):  
Sierra Leone ◽  
Phase 1 ◽  
Scale Up ◽  
Intermittent Preventive Treatment ◽  
Vaccine Dose ◽  
Preventive Treatment ◽  
Household Survey ◽  
Register Data ◽  
Phase 2 ◽  
Pentavalent Vaccine

Abstract Background Intermittent preventive treatment of malaria in infants (IPTi) with sulfadoxine-pyrimethamine (SP) is a proven strategy to protect infants against malaria. Sierra Leone is the first country to implement IPTi nationwide. IPTi implementation was evaluated in Kambia, one of two initial pilot districts, to assess quality and coverage of IPTi services. Methods This mixed-methods evaluation had two phases, conducted 3 (phase 1) and 15–17 months (phase 2) after IPTi implementation. Methods included: assessments of 18 health facilities (HF), including register data abstraction (phases 1 and 2); a knowledge, attitudes and practices survey with 20 health workers (HWs) in phase 1; second-generation sequencing of SP resistance markers (pre-IPTi and phase 2); and a cluster-sample household survey among caregivers of children aged 3–15 months (phase 2). IPTi and vaccination coverage from the household survey were calculated from child health cards and maternal recall and weighted for the complex sampling design. Interrupted time series analysis using a Poisson regression model was used to assess changes in malaria cases at HF before and after IPTi implementation. Results Most HWs (19/20) interviewed had been trained on IPTi; 16/19 reported feeling well prepared to administer it. Nearly all HFs (17/18 in phase 1; 18/18 in phase 2) had SP for IPTi in stock. The proportion of parasite alleles with dhps K540E mutations increased but remained below the 50% WHO-recommended threshold for IPTi (4.1% pre-IPTi [95%CI 2–7%]; 11% post-IPTi [95%CI 8–15%], p < 0.01). From the household survey, 299/459 (67.4%) children ≥ 10 weeks old received the first dose of IPTi (versus 80.4% for second pentavalent vaccine, given simultaneously); 274/444 (62.5%) children ≥ 14 weeks old received the second IPTi dose (versus 65.4% for third pentavalent vaccine); and 83/217 (36.4%) children ≥ 9 months old received the third IPTi dose (versus 52.2% for first measles vaccine dose). HF register data indicated no change in confirmed malaria cases among infants after IPTi implementation. Conclusions Kambia district was able to scale up IPTi swiftly and provide necessary health systems support. The gaps between IPTi and childhood vaccine coverage need to be further investigated and addressed to optimize the success of the national IPTi programme.

scholarly journals Influenza and Pneumococcal Vaccination in Non-Infected Cardiometabolic Patients from the Americas during the COVID-19 Pandemic. A Sub-Analysis of the CorCOVID-LATAM Study

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 123
Author(s):  
Álvaro Sosa Liprandi ◽  
Ezequiel José Zaidel ◽  
Ricardo Lopez Santi ◽  
John Jairo Araujo ◽  
Manuel Alfonso Baños González ◽  
...  
Keyword(s):  
Pneumococcal Vaccination ◽  
Risk Groups ◽  
Southern Cone ◽  
Multivariate Model ◽  
Immunization Rate ◽  
Tropical Regions ◽  
Vaccination Rates ◽  
Cardiometabolic Diseases ◽  
Ambulatory Patients ◽  
Artery Disease

Background: Influenza vaccination (IV) and Pneumococcus vaccination (PV) are recommended for patients with cardiometabolic diseases. This study aimed to evaluate the immunization rate of ambulatory cardiometabolic patients during the COVID-19 pandemic in the Americas. Methods: Electronic surveys were collected from 13 Spanish speaking countries between 15 June and 15 July 2020. Results: 4216 patients were analyzed. Mean age 60 (±15) years and 49% females. Global IV rate was 46.5% and PV 24.6%. Vaccinated patients were older (IV = 63 vs. 58 years; PV = 68 vs. 59, p < 0.01) but without gender difference. Vaccination rates were greater in higher-risk groups (65+, diabetics, heart failure), but not in coronary artery disease patients. In the Southern cone, the rate of IV and PV was approximately double that in the tropical regions of the Americas. In a multivariate model, geographic zone (IV = OR 2.02, PV = OR 2.42, p < 0.001), age (IV = OR 1.023, PV = OR 1.035, p < 0.001), and incomes (IV = OR 1.28, PV = OR 1.58, p < 0.001) were predictors for vaccination. Conclusions: During the COVID-19 pandemic, ambulatory patients with cardiometabolic diseases from the Americas with no evidence of COVID-19 infection had lower-than-expected rates of IV and PV. Geographic, social, and cultural differences were found, and they should be explored in depth.

scholarly journals PIN41 INFLUENZA VACCINATION RATES AMONG HIGH RISK GROUPS IN THE UNITED STATES

2011 ◽  
Vol 14 (3) ◽  
pp. A121
Author(s):  
M. DiBonaventura ◽  
J.S. Wagner ◽  
A. Goren
Keyword(s):  
United States ◽  
High Risk ◽  
Influenza Vaccination ◽  
Risk Groups ◽  
The United States ◽  
Vaccination Rates

scholarly journals Are radiomics features universally applicable to different organs?

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Seung-Hak Lee ◽  
Hwan-ho Cho ◽  
Junmo Kwon ◽  
Ho Yun Lee ◽  
Hyunjin Park
Keyword(s):  
Risk Groups ◽  
Careful Consideration ◽  
Distinct Pattern ◽  
Common Category ◽  
Independent Test ◽  
Organ Specific ◽  
Tumor Region ◽  
Organ Level ◽  
Test Sets ◽  
Feature Selection Approach

Abstract Background Many studies have successfully identified radiomics features reflecting macroscale tumor features and tumor microenvironment for various organs. There is an increased interest in applying these radiomics features found in a given organ to other organs. Here, we explored whether common radiomics features could be identified over target organs in vastly different environments. Methods Four datasets of three organs were analyzed. One radiomics model was constructed from the training set (lungs, n = 401), and was further evaluated in three independent test sets spanning three organs (lungs, n = 59; kidneys, n = 48; and brains, n = 43). Intensity histograms derived from the whole organ were compared to establish organ-level differences. We constructed a radiomics score based on selected features using training lung data over the tumor region. A total of 143 features were computed for each tumor. We adopted a feature selection approach that favored stable features, which can also capture survival. The radiomics score was applied to three independent test data from lung, kidney, and brain tumors, and whether the score could be used to separate high- and low-risk groups, was evaluated. Results Each organ showed a distinct pattern in the histogram and the derived parameters (mean and median) at the organ-level. The radiomics score trained from the lung data of the tumor region included seven features, and the score was only effective in stratifying survival for other lung data, not in other organs such as the kidney and brain. Eliminating the lung-specific feature (2.5 percentile) from the radiomics score led to similar results. There were no common features between training and test sets, but a common category of features (texture category) was identified. Conclusion Although the possibility of a generally applicable model cannot be excluded, we suggest that radiomics score models for survival were mostly specific for a given organ; applying them to other organs would require careful consideration of organ-specific properties.

scholarly journals Coronavirus Infection and BCG Vaccination: Facts and Possibilities

2020 ◽  
Vol 19 (5) ◽  
pp. 18-24
Author(s):  
B. V. Karalnik ◽  
B. I. Alimbekova ◽  
L. T. Eralieva
Keyword(s):  
Innate Immunity ◽  
Risk Groups ◽  
Optimal Timing ◽  
Scientific Publications ◽  
Bcg Vaccination ◽  
Outbreak Period ◽  
Vaccine Prophylaxis ◽  
Scientific Facts

Relevance. The relevance of protection against SARS-Cov-19 by means of BCG vaccination is important not only with respect to coronavirus infections. That issue should be considered in light of overall biological and immunological pillars (innate immunity system).Aims. To consider the role of the lipid components and certain vaccines in stimulation of the innate immunity system, in particular, in induction of the heterogenous immune response and protection against various pathogens, including Covid-19, based on analysis of known scientific facts.Conclusions. The relevant database has been analyzed (51 scientific publications), including studies with application of various methods from immunological tests (in vitro and in vivo) to epidemiological trials. The analysis revealed the meaningful potential of heterogenous protection against various infections by means of BCG immunization, and according to some data, measles vaccine capacity. Simultaneously on the basis of performed analysis, the following issues that so far remained unclear have been identified: what is the duration of heterogenous protection; what is the optimal timing for BCG administration as related to the outbreak period of dangerous infection for the sake of decrease of its harm. The analyzed materials of that review substantiate the rationale for further continuation of the scientific studies and possibility for application of already accumulated data in order to protect, primarily the risk groups, against dangerous infections, especially in the timeframe when no relevant vaccines are available. Besides, the conducted review serves as the leverage for expected development of the new preventive medicine dimension – the systemic vaccine prophylaxis.

Phase 1 Clinical Trial of a Conditionally Replication-Defective Human Cytomegalovirus (CMV) Vaccine in CMV-Seronegative Subjects

2019 ◽  
Vol 220 (3) ◽  
pp. 411-419 ◽  
Author(s):  
Stuart P Adler ◽  
Nicole Lewis ◽  
Anthony Conlon ◽  
Mark P Christiansen ◽  
Mohamed Al-Ibrahim ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Injection Site ◽  
Human Cytomegalovirus ◽  
Neutralizing Antibodies ◽  
De Novo ◽  
Phase 1 ◽  
Vaccine Dose ◽  
Genetically Engineered ◽  
Clinical Trial Registration ◽  
Viral Shedding

Abstract Background A conditionally replication-defective human cytomegalovirus (CMV) vaccine (V160) derived from AD169 and genetically engineered to express CMV pentameric complex (gH/gL/pUL128/pUL130/pUL131) was developed and evaluated for phase 1 vaccine safety and immunogenicity in CMV-seronegative and CMV-seropositive adults. Methods Subjects received 3 doses of V160 or placebo on day 1, month 1, and month 6. Four vaccine dose levels, formulated with or without aluminum phosphate adjuvant, were evaluated. Injection-site and systemic adverse events (AEs) and vaccine viral shedding were monitored. CMV-specific cellular and humoral responses were measured by interferon-gamma ELISPOT and virus neutralization assay up to 12 months after last dose. Results V160 was generally well-tolerated, with no serious AEs observed. Transient, mild-to-moderate injection-site and systemic AEs were reported more frequently in vaccinated subjects than placebo. Vaccine viral shedding was not detected in any subject, confirming the nonreplicating feature of V160. Robust neutralizing antibody titers were elicited and maintained through 12 months postvaccination. Cellular responses to structural and nonstructural viral proteins were observed, indicating de novo expression of viral genes postvaccination. Conclusions V160 displayed an acceptable safety profile. Levels of neutralizing antibodies and T-cell responses in CMV-seronegative subjects were within ranges observed following natural CMV infection. Clinical Trial Registration . NCT01986010.

scholarly journals Multifunctional Antibodies Are Induced by the RTS,S Malaria Vaccine and Associated With Protection in a Phase 1/2a Trial

2020 ◽  
Author(s):  
Liriye Kurtovic ◽  
Tanmaya Atre ◽  
Gaoqian Feng ◽  
Bruce D Wines ◽  
Jo-Anne Chan ◽  
...  
Keyword(s):  
Malaria Vaccine ◽  
Protective Efficacy ◽  
Phase 1 ◽  
Vaccine Dose ◽  
Effector Functions ◽  
Malaria Vaccines ◽  
Multiple Regions ◽  
Protective Antibodies ◽  
Falciparum Sporozoite ◽  
Functional Antibodies

Abstract Background RTS,S is the leading malaria vaccine candidate but only confers partial efficacy against malaria in children. RTS,S is based on the major Plasmodium falciparum sporozoite surface antigen, circumsporozoite protein (CSP). The induction of anti-CSP antibodies is important for protection; however, it is unclear how these protective antibodies function. Methods We quantified the induction of functional anti-CSP antibody responses in healthy malaria-naive adults (N = 45) vaccinated with RTS,S/AS01. This included the ability to mediate effector functions via the fragment crystallizable (Fc) region, such as interacting with human complement proteins and Fcγ-receptors (FcγRs) that are expressed on immune cells, which promote various immunological functions. Results Our major findings were (1) RTS,S-induced antibodies mediated Fc-dependent effector functions, (2) functional antibodies were generally highest after the second vaccine dose, (3) functional antibodies targeted multiple regions of CSP, (4) participants with higher levels of functional antibodies had a reduced probability of developing parasitemia following homologous challenge (P &lt; .05), and (5) nonprotected subjects had higher levels of anti-CSP IgM. Conclusions Our data suggest a role for Fc-dependent antibody effector functions in RTS,S-induced immunity. Enhancing the induction of these functional activities may be a strategy to improve the protective efficacy of RTS,S or other malaria vaccines. Clinical Trials Registration NCT00075049

scholarly journals Immunization aganist hepatitis B in children from endemic zone: evaluation of the antibody response against the DNA recombinant vaccine (Engerix B-20 mcg)

1993 ◽  
Vol 35 (1) ◽  
pp. 89-92 ◽  
Author(s):  
C.R.B. Ferreira ◽  
C.F.T. Yoshida ◽  
L.A.C. Mercadante ◽  
D.F. Gomes ◽  
J.M. Oliveira ◽  
...  
Keyword(s):  
Hepatitis B ◽  
Antibody Response ◽  
Recombinant Dna ◽  
Hepatitis B Surface Antigen ◽  
Vaccine Dose ◽  
Vaccination Schedule ◽  
Hepatitis B Vaccine ◽  
Recombinant Hepatitis ◽  
The Third ◽  
Rural Zone

A previous seroepidemiological study in the rural zone of Vargem Alta (ES) SouthEast of Brazil, showed a prevalence of up to 9% of hepatitis B surface antigen (HBsAg) in some areas. One hundred susceptible children aging 1 to 5 years old were selected and immunized with a recombinant DNA hepatitis B vaccine (Smith-Kline 20 mcg) using the 0-1-6 months vaccination schedule. Blood samples were collected at the time of the first vaccine dose (month 0) in order to confirm susceptible individuals and 1,3,6 and 8 months after the first dose , to evaluate the antibody response. Our results showed that two and five months after the second dose, 79% and 88% of children seroconverted respectively, reaching 97% after the third dose. The levels of anti-HBs were calculated in milli International Units/ml (mIU/ml) and demonstrated the markedly increase of protective levels of antibodies after the third dose. These data showed a good immunogenicity of the DNA recombinant hepatitis B vaccine when administered in children of endemic areas.

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