The study of the effect of the data collected during vaccination period on the prediction of the number of Covid-19 cases

2021 ◽  
Author(s):  
Amir Ahmad ◽  
Santosh Kumar Ray ◽  
Ch. Aswani Kumar ◽  
Apurva Anand ◽  
Muhsin Jabbar Cheratta
Keyword(s):  
Vaccination Period

scholarly journals The Impact of an Inactivated Hepatitis A Vaccine with One Dose in Brazil: A Retrospective Time-Series

Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 407
Author(s):  
Ana Luiza Bierrenbach ◽  
Yoonyoung Choi ◽  
Paula de Mendonça Batista ◽  
Fernando Brandão Serra ◽  
Cintia Irene Parellada ◽  
...  
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Hepatitis A ◽  
National Level ◽  
Age Groups ◽  
High Rate ◽  
Series Analysis ◽  
Annual Reduction ◽  
The Impact ◽  
Vaccination Period

Background: In 2014, a recommended one-dose of inactivated hepatitis A vaccine was included in the Brazilian National Immunization Program targeting children 12–24 months. This decision addressed the low to intermediate endemicity status of hepatitis A across Brazil and the high rate of infection in children and adolescents between 5 and 19 years old. The aim of the study was to conduct a time-series analysis on hepatitis A incidence across age groups and to assess the hepatitis A distribution throughout Brazilian geographic regions. Methods: An interrupted time-series analysis was performed to assess hepatitis A incidence rates before (2010–2013) and after (2015–2018) hepatitis A vaccine program implementation. The time-series analysis was stratified by age groups while a secondary analysis examined geographic distribution of hepatitis A cases. Results: Overall incidence of hepatitis A decreased from 3.19/100.000 in the pre-vaccine period to 0.87/100.000 (p = 0.022) post-vaccine introduction. Incidence rate reduction was higher among children aged 1-4 years old, with an annual reduction of 67.6% in the post-vaccination period against a 7.7% annual reduction in the pre-vaccination period (p < 0.001). Between 2015 and 2018, the vaccination program prevented 14,468 hepatitis A cases. Conclusion: Our study highlighted the positive impact of a recommended one-dose inactivated hepatitis A vaccine for 1–4-years-old in controlling hepatitis A at national level.

Risk factors for susceptibility to varicella in newly arrived adult migrants in Canada

2013 ◽  
Vol 142 (8) ◽  
pp. 1695-1707 ◽  
Author(s):  
C. GREENAWAY ◽  
J. F. BOIVIN ◽  
S. CNOSSEN ◽  
C. ROSSI ◽  
B. TAPIERO ◽  
...  
Keyword(s):  
Risk Factors ◽  
Varicella Vaccination ◽  
Cold Climates ◽  
Community Size ◽  
Tropical Country ◽  
Younger Age ◽  
Recent Arrival ◽  
Household Crowding ◽  
Source Countries ◽  
Vaccination Period

SUMMARYVaricella occurs at an older age in tropical compared to cold climates. Migrants from tropical countries provide the opportunity to gain insights into observed global differences in varicella epidemiology. Severity of varicella increases with age thus, description of risk factors for varicella susceptibility will identify those who would benefit most from vaccination. A total of 1480 migrants, with a mean age of 32 years, were recruited in the pre-vaccination period (2002–2004) in Montreal, Canada. A questionnaire was administered and serum varicella antibodies were measured. Overall 6% were susceptible and ranged from 0·8% to 14·1% in subgroups. Risk factors for susceptibility were younger age, recent arrival, and originating from a tropical country. This could be modified by conditions that increased the probability of person-to-person spread of varicella through direct contact in source countries such as larger community size or household crowding. Many new young adult migrants would benefit from targeted varicella vaccination programmes.

scholarly journals A MEAN FIELD GAME ANALYSIS OF SIR DYNAMICS WITH VACCINATION

2020 ◽  
pp. 1-18
Author(s):  
Josu Doncel ◽  
Nicolas Gast ◽  
Bruno Gaujal
Keyword(s):  
Mean Field ◽  
Vaccination Strategy ◽  
Game Analysis ◽  
Total Cost ◽  
Mean Field Game ◽  
Vaccination Behavior ◽  
Switching Curve ◽  
The One ◽  
The Cost ◽  
Vaccination Period

We analyze a mean field game model of SIR dynamics (Susceptible, Infected, and Recovered) where players choose when to vaccinate. We show that this game admits a unique mean field equilibrium (MFE) that consists in vaccinating at a maximal rate until a given time and then not vaccinating. The vaccination strategy that minimizes the total cost has the same structure as the MFE. We prove that the vaccination period of the MFE is always smaller than the one minimizing the total cost. This implies that, to encourage optimal vaccination behavior, vaccination should always be subsidized. Finally, we provide numerical experiments to study the convergence of the equilibrium when the system is composed by a finite number of agents ( $N$ ) to the MFE. These experiments show that the convergence rate of the cost is $1/N$ and the convergence of the switching curve is monotone.

scholarly journals Preparing to introduce the varicella vaccine into the Italian immunisation programme: varicella-related hospitalisations in Tuscany, 2004–2012

2016 ◽  
Vol 21 (24) ◽  
Author(s):  
Sara Boccalini ◽  
Paolo Bonanni ◽  
Angela Bechini
Keyword(s):  
National Level ◽  
Varicella Vaccine ◽  
Age Groups ◽  
Immunisation Programme ◽  
Significant Decline ◽  
Hospitalisation Rate ◽  
High Coverage ◽  
The Impact ◽  
Risk Ratios ◽  
Vaccination Period

A universal immunisation programme against varicella in the form of the measles-mumps-rubella-varicella (MMRV) vaccine for toddlers aged 13–15 months was introduced in Tuscany in July 2008. An assessment of the impact of this programme on varicella-related hospitalisations 4 years after its introduction could further support its adoption at a national level. The hospitalisation data were analysed in two periods: pre-vaccination (2004–2007) and vaccination period (2009–2012). The high coverage of the vaccines (84% in 2012) resulted in a significant decline in notifications, from 33,114 (2004–2007) to 13,184 cases (2009–2012), and also of hospitalisations, from 584 (pre-vaccination period) to 325 (vaccination period). The hospitalisation rate was 4.1 per 100,000 (95% confidence intervals (CI): 3.4–4.7) before the introduction of vaccination, which dropped to 2.2 per 100,000 (95% CI: 1.7–2.7) in the vaccination period (hospitalisation risk ratios: 0.54; 95% CI:  0.472–0.619). The reduction was most significant in the youngest age groups. The introduction of universal vaccination has already led to a significant decline in hospitalisations due to varicella after just 4 years of implementation. Hospitalisation rates fell noticeably among younger individuals involved in the vaccination programme. The decrease in hospitalisation rate in the older age groups suggests a possible indirect protection.

scholarly journals The resurgence risk of COVID-19 in the presence of immunity waning and ADE effect: a mathematical modelling study

2021 ◽  
Author(s):  
Weike Zhou ◽  
Biao Tang ◽  
Yao Bai ◽  
Yiming Shao ◽  
Yanni Xiao ◽  
...  
Keyword(s):  
Mainland China ◽  
Population Level ◽  
Mass Vaccination ◽  
Low Risk ◽  
Vaccination Program ◽  
Post Vaccination ◽  
Catching Up ◽  
Vaccination Period ◽  
Transmission Ability

Since the end of 2020, the mass vaccination has been actively promoted and seemed to be effective to bring the COVID-19 pandemic under control. However, the fact of immunity waning and the possible existence of antibody-dependent enhancement (ADE) make the situation uncertain. We developed a dynamic model of COVID-19 incorporating vaccination and immunity waning, which was calibrated by using the data of accumulative vaccine doses administered and the COVID-19 epidemic in 2020 in mainland China. We explored how long the current vaccination program can prevent China in a low risk of resurgence, and how ADE affects the long-term trajectory of COVID-19 epidemics. The prediction suggests that the vaccination coverage with at least one dose reach 95.87%, and with two-doses reach 77.92% on August 31, 2021. However, even with the mass vaccination, randomly introducing infected cases in the post-vaccination period can result in large outbreaks quickly in the presence of immunity waning, particularly for SARS-CoV-2 variants with higher transmission ability. The results showed that with the current vaccination program and a proportion of 50% population wearing masks, mainland China can be protected in a low risk of resurgence till 2023/01/18. However, ADE effect and higher transmission ability for variants would significantly shorten the protective period for more than 1 year. Furthermore, intermittent outbreaks can occur while the peak values of the subsequential outbreaks are decreasing, meaning that subsequential outbreaks boosted the immunity in the population level, which further indicating that catching-up vaccination program can help to mitigate the possible outbreaks, even avoid the outbreaks. The findings reveal that integrated effects of multiple factors, including immunity waning, ADE, relaxed interventions, and higher transmission ability of variants, make the control of COVID-19 much more difficult. We should get ready for a long struggle with COVID-19, and should not totally rely on COVID-19 vaccine.

scholarly journals Assessment of the timeliness of vaccination against pertussis in children of the first year of life and the reasons for the violation of the vaccination schedule

2021 ◽  
Vol 13 (2) ◽  
pp. 79-86
Author(s):  
T. M. Chernova ◽  
V. N. Timchenko ◽  
A. I. Pedash ◽  
M. D. Subbotina ◽  
O. I. Bulina ◽  
...  
Keyword(s):  
Young Children ◽  
Whooping Cough ◽  
Vaccination Schedule ◽  
Severe Form ◽  
Recombinant Interferon ◽  
Post Vaccination ◽  
Ifn Alpha ◽  
Vaccination History ◽  
Acute Respiratory Viral Infection ◽  
Vaccination Period

The maximum incidence of pertussis in young children confirms the importance of their timely immunization.The goal is – to study the timeliness of vaccination against whooping cough, causes of violation of the vaccination schedule in young children, the effect of recombinant interferon-a on the post-vaccination period.Materials and methods: the vaccination history and data on the course of the post-vaccination period after immunization with DPT and DaPT vaccines of 469 children at the age of 3–24 months were studied.Results. The analysis showed that 14,9% of the observed children were not vaccinated against whooping cough in a timely manner. Of these: 34,3% had a written refusal to vaccinate (5.1% of the total number of observed children), in 32,8% of cases, the vaccination schedule was violated due to late arrival of parents, 32,9% of children by the start of immunization had medical challenges, and only half of them had justified contraindications. Non-serious side effects associated with immunization were observed in 11.3% of cases, statistically more often with DTP (22,0%) compared with DaPT (5.,5%). General and local reactions, in general, were recorded on DPT (6,9% and 15,1%, respectively) and less often developed with the use of DaPT (1,0% and 4,5%, respectively). Within 1 month after immunization, 16,2% of the observed children had an acute respiratory viral infection of varying severity. Those who did not receive antiviral therapy more often carried the disease in a moderate and severe form, which in all cases led to the postponement of the administration of the second and third doses of the vaccine.Conclusion. To increase the timeliness of vaccination of children against whooping cough, medical professionals should persistently remind parents about the timing of turnout for the next vaccination, when making medical withdrawals, be guided by modern methodological documents and instructions for vaccines. The use of antiviral and immunomodulatory effects of IFN-alpha drugs allows us to comply with the recommended schedule for vaccination of children with a high risk of SARS in the post-vaccination period.

scholarly journals Uncovering the First Atypical DS-1-like G1P[8] Rotavirus Strains That Circulated during Pre-Rotavirus Vaccine Introduction Era in South Africa

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 391 ◽  
Author(s):  
Peter N. Mwangi ◽  
Milton T. Mogotsi ◽  
Sebotsana P. Rasebotsa ◽  
Mapaseka L. Seheri ◽  
M. Jeffrey Mphahlele ◽  
...  
Keyword(s):  
South Africa ◽  
South African ◽  
Whole Genome ◽  
Evolutionary Mechanisms ◽  
Vaccine Introduction ◽  
Rotavirus Vaccination ◽  
African Strain ◽  
Group A ◽  
First Time ◽  
Vaccination Period

Emergence of DS-1-like G1P[8] group A rotavirus (RVA) strains during post-rotavirus vaccination period has recently been reported in several countries. This study demonstrates, for the first time, rare atypical DS-1-like G1P[8] RVA strains that circulated in 2008 during pre-vaccine era in South Africa. Rotavirus positive samples were subjected to whole-genome sequencing. Two G1P[8] strains (RVA/Human-wt/ZAF/UFS-NGS-MRC-DPRU1971/2008/G1P[8] and RVA/Human-wt/ZAF/UFS-NGS-MRC-DPRU1973/2008/G1P[8]) possessed a DS-1-like genome constellation background (I2-R2-C2-M2-A2-N2-T2-E2-H2). The outer VP4 and VP7 capsid genes of the two South African G1P[8] strains had the highest nucleotide (amino acid) nt (aa) identities of 99.6–99.9% (99.1–100%) with the VP4 and the VP7 genes of a locally circulating South African strain, RVA/Human-wt/ZAF/MRC-DPRU1039/2008/G1P[8]. All the internal backbone genes (VP1–VP3, VP6, and NSP1-NSP5) had the highest nt (aa) identities with cognate internal genes of another locally circulating South African strain, RVA/Human-wt/ZAF/MRC-DPRU2344/2008/G2P[6]. The two study strains emerged through reassortment mechanism involving locally circulating South African strains, as they were distinctly unrelated to other reported atypical G1P[8] strains. The identification of these G1P[8] double-gene reassortants during the pre-vaccination period strongly supports natural RVA evolutionary mechanisms of the RVA genome. There is a need to maintain long-term whole-genome surveillance to monitor such atypical strains.

scholarly journals Challenges of the Pandemic Response in Primary Care during Pre-Vaccination Period: A Qualitative Study

2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Marina Kunin ◽  
Dan Engelhard ◽  
Shane Thomas ◽  
Mark Ashworth ◽  
Leon Piterman
Keyword(s):  
Primary Care ◽  
Qualitative Study ◽  
Pandemic Response ◽  
Vaccination Period

EVIDENCE FOR A FRACTAL STOCHASTIC PROCESS UNDERLYING MEASLES EPIDEMICS IN BRITAIN

Fractals ◽  
2000 ◽  
Vol 08 (01) ◽  
pp. 29-34 ◽  
Author(s):  
WAYNE S. KENDAL
Keyword(s):  
Stochastic Process ◽  
Time Series ◽  
Spectral Density ◽  
Geometric Distribution ◽  
Fano Factor ◽  
Distribution Histogram ◽  
Power Spectral ◽  
Allan Factor ◽  
Measles Incidence ◽  
Vaccination Period

The variability in measles incidence during the pre-vaccination period of 1944 to 1966, as recorded from 366 communities in England and Wales, was examined for properties of fractal stochastic processes. The power spectral density, Fano factor, and Allan factor were computed from the incidence time-series, and all revealed power-law scaling. As well, the distribution histogram for the weekly incidence approximated a geometric distribution. These features constituted evidence for a fractal stochastic process with underlying geometric statistics at play in the development and resolution of measles epidemics.

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