scholarly journals Impact of booster vaccination on the control of COVID-19 Delta wave in the context of waning immunity: application to France in the winter 2021/22

2022 ◽  
Vol 27 (1) ◽  
Author(s):  
Paolo Bosetti ◽  
Cécile Tran Kiem ◽  
Alessio Andronico ◽  
Juliette Paireau ◽  
Daniel Levy-Bruhl ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Booster Vaccination ◽  
Delta Wave ◽  
Transmission Rates ◽  
Waning Immunity ◽  
Protective Behaviours

Europe has experienced a large COVID-19 wave caused by the Delta variant in winter 2021/22. Using mathematical models applied to Metropolitan France, we find that boosters administered to ≥ 65, ≥ 50 or ≥ 18 year-olds may reduce the hospitalisation peak by 25%, 36% and 43% respectively, with a delay of 5 months between second and third dose. A 10% reduction in transmission rates might further reduce it by 41%, indicating that even small increases in protective behaviours may be critical to mitigate the wave.

scholarly journals Analysis of Multiple Risk Factors for Seronegative Rate of Anti-Tick-Borne Encephalitis Virus Immunization in Human Serum

Medicina ◽  
2020 ◽  
Vol 56 (5) ◽  
pp. 244
Author(s):  
Marta Janik ◽  
Sylwia Płaczkowska ◽  
Mieczysław Woźniak ◽  
Iwona Bil-Lula
Keyword(s):  
Risk Factors ◽  
Booster Vaccination ◽  
Vaccination Schedule ◽  
High Risk Group ◽  
Encephalitis Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Booster Immunization ◽  
Tick Borne Encephalitis ◽  
Waning Immunity ◽  
Tick Borne Encephalitis Virus

Background and objectives: Tick-borne encephalitis virus (TBEV) infections have been the cause of threatening outbreaks for many years. Apart from several physical and chemical methods to prevent tick bites, active vaccination of people highly exposed to infection is still the most important strategy of prevention. However, in some subjects, the lack of or low response to TBEV antigens is observed. The aim of the current study was to assess the prevalence of seronegative rate for anti-TBEV antibodies and the risk factors for waning immunity. Materials and Methods: 2315 at least primary vaccinated subjects from the high risk group for TBEV infections participated in this study. A commercial enzyme-linked immunosorbent assay (ELISA) test was used for the assessment of anti-TBEV IgG serum level. Results: Data showed that 86.2% of subjects who underwent vaccination were positive for anti-TBEV antibodies within 5 years. As much as 13.8% of subjects that underwent primary or primary and booster vaccination were barely protected after vaccination. Women and subjects under 60 years underwent more effective protection but sex and older age was not a risk factor for being a subject of waning immunity. A logistic regression showed that both a longer time since the vaccination and a lower number of booster doses constantly increased the chance of lost anti-TBEV antibodies. Conclusions: This study demonstrates that the vaccination schedule should be reevaluated. The extension of the interval of booster immunization is risky and all subjects should be surrounded by care consisting of more frequent monitoring of serum antibodies by personalized schedule to adjust the frequency of subsequent doses of booster vaccination.

scholarly journals Fall 2021 Resurgence and COVID-19 Seroprevalence in Canada: Modelling waning and boosting COVID-19 immunity in Canada, A Canadian Immunization Research Network Study

2021 ◽  
Author(s):  
David W Dick ◽  
Lauren M Childs ◽  
Zhilan Feng ◽  
Jing Li ◽  
Gergely Rost ◽  
...  
Keyword(s):  
Large Scale ◽  
Severe Disease ◽  
Booster Vaccination ◽  
Late Summer ◽  
Research Network ◽  
Canadian Population ◽  
Waning Immunity ◽  
Age Structured ◽  
Age Structured Model ◽  
Pharmaceutical Interventions

There is a threat of COVID-19 resurgence in Fall 2021 in Canada. To understand the probability and severity of this threat, quantification of the level of immunity/protection of the population is required. We use an age-structured model including infection, vaccination and waning immunity to estimate the distribution of immunity to COVID-19 in the Canadian population. By late Summer 2021, coinciding with the end of the vaccination program, we estimate that 60 - 80% of the Canadian population will have some immunity to COVID-19. Model results show that this level of immunity is not sufficient to stave off a Fall 2021 resurgence. The timing and severity of a resurgence, however, varies in magnitude given multiple factors: relaxation of non-pharmaceutical interventions such as social distancing, the rate of waning immunity, the transmissibility of variants of concern, and the protective characteristics of the vaccines against infection and severe disease. To prevent large-scale resurgence, booster vaccination and/or re-introduction of public health mitigation may be needed.

scholarly journals Pertussis booster vaccine for adolescents and young adults in São Paulo, Brazil

2011 ◽  
Vol 45 (6) ◽  
pp. 1162-1171 ◽  
Author(s):  
Angela Carvalho Freitas ◽  
Valdir Okano ◽  
Júlio Cesar Rodrigues Pereira
Keyword(s):  
Compartmental Model ◽  
Booster Vaccination ◽  
Vaccination Schedule ◽  
Sao Paulo ◽  
São Paulo ◽  
Booster Vaccine ◽  
Age Dependent ◽  
Waning Immunity ◽  
The City ◽  
Strategy I

OBJECTIVE: To develop a model to assess different strategies of pertussis booster vaccination in the city of São Paulo. METHODS: A dynamic stationary age-dependent compartmental model with waning immunity was developed. The "Who Acquires Infection from Whom" matrix was used to modeling age-dependent transmission rates. There were tested different strategies including vaccine boosters to the current vaccination schedule and three of them were reported: (i) 35% coverage at age 12, or (ii) 70% coverage at age 12, and (iii) 35% coverage at age 12 and 70% coverage at age 20 at the same time. RESULTS: The strategy (i) achieved a 59% reduction of pertussis occurrence and a 53% reduction in infants while strategy (ii) produced 76% and 63% reduction and strategy (iii) 62% and 54%, respectively. CONCLUSION: Pertussis booster vaccination at age 12 proved to be the best strategy among those tested in this study as it achieves the highest overall reduction and the greatest impact among infants who are more susceptible to pertussis complications.

scholarly journals Immunogenicity and safety of the homogenous booster shot of a recombinant fusion protein vaccine (V-01) against COVID-19 in healthy adult participants primed with a two-dose regimen

2021 ◽  
Author(s):  
Yuan Li ◽  
Xin Fang ◽  
Rongjuan Pei ◽  
Renfeng Fan ◽  
Shaomin Chen ◽  
...  
Keyword(s):  
Phase I ◽  
Booster Dose ◽  
Booster Vaccination ◽  
Protein Vaccine ◽  
Wild Type ◽  
Younger Adults ◽  
Humoral Immune ◽  
Adult Participants ◽  
Waning Immunity ◽  
Favorable Safety

Background: Rising concerns over waning immunity and reduction in neutralizing activity against variants of concern (VOCs) have contributed to deploying booster doses by different strategies to tackle the COVID-19 pandemic. Preliminary findings from Phase I and II have shown that V-01, a recombinant fusion protein vaccine against COVID-19, exhibited favorable safety and immunogenicity profiles in 1060 adult participants of both younger and senior age. Herein, we aimed to assess the immunogenicity and safety for a booster dose in participants previously primed with a two-dose 10mcg V-01 regimen (day 0, 21) from phase I trial, providing reassuring data for necessity and feasibility of a homogenous booster dose. Methods: We conducted a single-arm, open-label trial at the Guangdong Provincial Center for Disease Control and Prevention (Gaozhou, China). Forty-three eligible participants who were previously primed 4-5 months earlier with two-dose 10mcg V-01 regimen from phase I trial received booster vaccination. We primarily assessed the immunogenicity post-booster vaccination, measured by RBD-binding antibodies using ELISA and neutralizing activity against wild-type SARS-CoV-2 and emerging variants of concern (VOCs) using neutralization assays. We secondarily assessed the safety and reactogenicity of the booster vaccination. Results: The third dose of V-01 exhibited significant boosting effects of humoral immune response in participants primed with two-dose 10μg V-01 regimen regarding both wild-type SARS-CoV-2 and VOCs. We observed a 60.4-folds increase in neutralizing titres against SARS-CoV-2 of younger adults, with GMTs of 17 (95%CI: 12-23) prior to booster vaccination in comparison to 1017 (95%CI: 732-1413) at day 14 post booster vaccination; and a 53.6-folds increase in that of older adults, with GMTs of 14 (95%CI: 9-20) before booster vaccination in comparison to 729(95%CI: 397-1339) at day 14 post-booster vaccination. The neutralizing titres against SARS-CoV-2 Delta strain also demonstrated a sharp increase from the day of pre booster vaccination to day 14 post booster vaccination, with GMTs of 11 (95%CI:8-15) versus 383 (95%CI:277-531) in younger adults (35.4-folds increase), and 6.5(95%CI: 5-8) versus 300(95%CI:142-631) in older adults (46.0-folds increase), respectively. We also observed a considerable and consistent increase of pseudovirus neutralizing titres against emerging VOCs from day 28 post second vaccination to day 14 post booster vaccination, with GMTs of 206 (95%CI:163-259) versus 607 (95%CI: 478-771) for Alpha strain, 54 (95%CI:38-77) versus 329 (95%CI: 255-425) for Beta strain, 219 (95%CI:157-306) versus 647 (95%CI: 484-865) for Delta strain. Our preliminary findings indicate a homogenous booster dose of V-01 was safe and well-tolerated, with overall adverse reactions being absent or mild-to-moderate in severity, and no grade 3 or worse AEs were related to booster vaccination. Conclusions: A homogenous booster immunization in participants receiving a primary series of two-dose V-01 elicited a substantial humoral immune response against wild-type SARS-CoV-2 and emerging VOCs, along with a favorable safety and reactogenicity profile. Our study provided promising data for a homogenous prime-boost strategy using recombinant protein vaccine to tackle the ongoing pandemic, potentially providing broad protection against emerging VOCs and overcoming waning immunity.

scholarly journals Booster vaccines protect hamsters with waning immunity from Delta VOC infection, disease, and transmission

2021 ◽  
Author(s):  
Kyle G Potts ◽  
Ryan S Noyce ◽  
Chris Gafuik ◽  
Cini M John ◽  
Hayley M Todesco ◽  
...  
Keyword(s):  
Lung Inflammation ◽  
Observational Studies ◽  
Lower Respiratory Tract ◽  
Virus Transmission ◽  
Booster Vaccination ◽  
Breakthrough Infection ◽  
Increased Risk ◽  
Infection Disease ◽  
Waning Immunity ◽  
The Impact

Waning immunity to COVID-19 vaccination is associated with increased risk of breakthrough infection, especially with highly transmissible variants of concern (VOC). Booster vaccination generates rapid immune recall in humans, which real-world observational studies suggest protects against VOC infection and associated disease, and modeling studies suggest could mitigate community spread. We directly tested the impact of booster vaccination on protection against Delta VOC infection, disease, and transmission to naive cohorts in golden Syrian hamsters. Animals with waning immunity to bnt162b2 generated rapid immune recall and strong protection against upper- and lower-respiratory tract infection when boosted with bnt126b2, mRNA-1273 or AZD1222. Boosting with either mRNA vaccine generated moderate protection against lung inflammation and virus transmission to unvaccinated animals. Our data support booster vaccination as a tool to address emerging VOC in the COVID-19 pandemic.

scholarly journals Pandemic fatigue impedes mitigation of COVID-19 in Hong Kong

2021 ◽  
Author(s):  
Zhanwei Du ◽  
Lin Wang ◽  
Songwei Shan ◽  
Dickson Lam ◽  
Tim Tsang ◽  
...  
Keyword(s):  
Hong Kong ◽  
Risk Perception ◽  
Mathematical Models ◽  
Large Scale ◽  
Third Wave ◽  
Telephone Surveys ◽  
The Third ◽  
Mobility Data ◽  
Fourth Wave ◽  
Protective Behaviours

Abstract Community-wide social distancing has been a cornerstone of pandemic control prior to mass vaccinations. The extent to which pandemic fatigue is undermining adherence to such measures and accelerating transmission remains unclear. Using large-scale weekly telephone surveys and mobility data, we characterize the evolution of risk perception and protective behaviours in Hong Kong. We estimate a 1.5% to 5.5% reduction in population compliance with protective policies for the fourth wave (October 2020 to January 2021) versus the third wave (July to August 2020), inducing prolonged disease circulation with increased infections. Mathematical models incorporating population protective behaviours estimates that the fourth wave would have been 14% smaller if not for pandemic fatigue. Mitigating pandemic fatigue is essential in maintaining population protective behaviours for controlling COVID-19.

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