Towards a population-based threshold of protection for COVID-19 vaccines.
Ontology highlight
ABSTRACT:
SUBMITTER: Goldblatt D
PROVIDER: S-EPMC8673730 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2) infection, the causative agent of COVID-19, now represents the sixth Public Health Emergency of International Concern (PHEIC)-as declared by the World Health Organization (WHO) since 2009. Considering that SARS-CoV-2 is mainly transmitted via the mucosal route, a therapy administered by this same route may represent a desirable approach to fight SARS-CoV-2 infection. It is now widely accepted that genetically modified microorganisms, including probiotics, represent attractive vehicles for oral or nasal mucosal delivery of therapeutic molecules. Previous studies have shown that the mucosal administration of therapeutic molecules is able to induce an immune response mediated by specific serum IgG and mucosal IgA antibodies along with mucosal cell-mediated immune responses, which effectively concur to neutralize and eradicate infections. Therefore, advances in the modulation of mucosal immune responses, and in particular the use of probiotics as live delivery vectors, may encourage prospective studies to assess the effectiveness of genetically modified probiotics for SARS-CoV-2 infection. Emerging trends in the ever-progressing field of vaccine development re-emphasize the contribution of adjuvants, along with optimization of codon usage (when designing a synthetic gene), expression level, and inoculation dose to elicit specific and potent protective immune responses. In this review, we will highlight the existing pre-clinical and clinical information on the use of genetically modified microorganisms in control strategies against respiratory and non-respiratory viruses. In addition, we will discuss some controversial aspects of the use of genetically modified probiotics in modulating the cross-talk between mucosal delivery of therapeutics and immune system modulation.
| S-EPMC8148110 | biostudies-literature
Project description:In the current context of the pandemic triggered by SARS-COV-2, the immunization of the population through vaccination is recognized as a public health priority. In the case of SARS‑COV‑2, the genetic sequencing was done quickly, in one month. Since then, worldwide research has focused on obtaining a vaccine. This has a major economic impact because new technological platforms and advanced genetic engineering procedures are required to obtain a COVID‑19 vaccine. The most difficult scientific challenge for this future vaccine obtained in the laboratory is the proof of clinical safety and efficacy. The biggest challenge of manufacturing is the construction and validation of production platforms capable of making the vaccine on a large scale.
| S-EPMC7255458 | biostudies-literature
Project description:BackgroundEstimates of COVID-19 vaccine effectiveness under real-world conditions, and understanding of barriers to uptake, are necessary to inform vaccine rollout.MethodsWe enrolled cases (testing positive) and controls (testing negative) from among the population whose SARS-CoV-2 molecular diagnostic test results from 24 February-29 April 2021 were reported to the California Department of Public Health. Participants were matched on age, sex, and geographic region. We assessed participants' self-reported history of mRNA-based COVID-19 vaccine receipt (BNT162b2 and mRNA-1273). Participants were considered fully vaccinated two weeks after second dose receipt. Among unvaccinated participants, we assessed willingness to receive vaccination. We measured vaccine effectiveness (VE) via the matched odds ratio of prior vaccination, comparing cases with controls.ResultsWe enrolled 1023 eligible participants aged ≥18 years. Among 525 cases, 71 (13.5%) received BNT162b2 or mRNA-1273; 20 (3.8%) were fully vaccinated with either product. Among 498 controls, 185 (37.1%) received BNT162b2 or mRNA-1273; 86 (16.3%) were fully vaccinated with either product. Two weeks after second dose receipt, VE was 87.0% (95% confidence interval: 68.6-94.6%) and 86.2% (68.4-93.9%) for BNT162b2 and mRNA-1273, respectively. Fully vaccinated participants receiving either product experienced 91.3% (79.3-96.3%) and 68.3% (27.9-85.7%) VE against symptomatic and asymptomatic infection, respectively. Among unvaccinated participants, 42.4% (159/375) residing in rural regions and 23.8% (67/281) residing in urban regions reported hesitancy to receive COVID-19 vaccination.ConclusionsAuthorized mRNA-based vaccines are effective at reducing documented SARS-CoV-2 infections within the general population of California. Vaccine hesitancy presents a barrier to reaching coverage levels needed for herd immunity.
| S-EPMC8406879 | biostudies-literature
Project description:BackgroundVaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), have been used since December 2020 in the United Kingdom. Real-world data have shown the vaccines to be highly effective against Covid-19 and related severe disease and death. Vaccine effectiveness may wane over time since the receipt of the second dose of the ChAdOx1-S (ChAdOx1 nCoV-19) and BNT162b2 vaccines.MethodsWe used a test-negative case-control design to estimate vaccine effectiveness against symptomatic Covid-19 and related hospitalization and death in England. Effectiveness of the ChAdOx1-S and BNT162b2 vaccines was assessed according to participant age and status with regard to coexisting conditions and over time since receipt of the second vaccine dose to investigate waning of effectiveness separately for the B.1.1.7 (alpha) and B.1.617.2 (delta) variants.ResultsVaccine effectiveness against symptomatic Covid-19 with the delta variant peaked in the early weeks after receipt of the second dose and then decreased by 20 weeks to 44.3% (95% confidence interval [CI], 43.2 to 45.4) with the ChAdOx1-S vaccine and to 66.3% (95% CI, 65.7 to 66.9) with the BNT162b2 vaccine. Waning of vaccine effectiveness was greater in persons 65 years of age or older than in those 40 to 64 years of age. At 20 weeks or more after vaccination, vaccine effectiveness decreased less against both hospitalization, to 80.0% (95% CI, 76.8 to 82.7) with the ChAdOx1-S vaccine and 91.7% (95% CI, 90.2 to 93.0) with the BNT162b2 vaccine, and death, to 84.8% (95% CI, 76.2 to 90.3) and 91.9% (95% CI, 88.5 to 94.3), respectively. Greater waning in vaccine effectiveness against hospitalization was observed in persons 65 years of age or older in a clinically extremely vulnerable group and in persons 40 to 64 years of age with underlying medical conditions than in healthy adults.ConclusionsWe observed limited waning in vaccine effectiveness against Covid-19-related hospitalization and death at 20 weeks or more after vaccination with two doses of the ChAdOx1-S or BNT162b2 vaccine. Waning was greater in older adults and in those in a clinical risk group.
| S-EPMC8781262 | biostudies-literature
Project description:BackgroundHerd immunity through vaccination is the target of public health interventions against COVID-19, but vaccine refusal or hesitancy is one of the global threats that make achievement of community immunity very difficult. The aim of this study was to determine negative attitudes and intentions and their predictors towards COVID-19 vaccines.MethodsThis was cross sectional survey, that targeted 1011 Egyptians aged 18 years and above, from 24 governorates, during the period from 7 January 2021, to 30 March 2021. Using a convenient sampling technique, the data were collected through an online self-administered, structured questionnaire, which was composed of two main sections, that involved sociodemographic and health related factors, intentions, and attitudes towards COVID-19 vaccines.ResultsThe mean age of participants was 29.35 ± 10.78 years, (16.6 %) of them had COVID-19. (54%) of respondents, reported COVID-19 vaccine hesitancy and 21% of them reported vaccine non-acceptance while (27.1%) of participants preferred receiving Pfizer vaccine. (51.8%) of the respondents expressed strong worries about unforeseen effects of the vaccine which was associated with younger age groups, married, females, absence of history of allergy to food or drugs, perceived susceptibility to COVID 19 and never having flu vaccination. Vaccine hesitancy was associated with female sex, urban residence, university/post graduate, married respondents, those never had flu vaccine, and those did not have confidence in the ability of health system to control the epidemic. Female sex, urban residence and having concerns about unforeseen effects were predictors for vaccine hesitancy and vaccine non-acceptance.ConclusionThe observed high level of worries about unforeseen effects of COVID-19 vaccines and widespread vaccine hesitancy amongst Egyptians and its predictors should be considered during implementation of public health intervention campaigns to change negative attitudes and improve acceptance and uptake of COVID-19 vaccines in Egypt.
| S-EPMC8253692 | biostudies-literature
Project description:COVID-19 is a pandemic of unprecedented proportions in recent human history. Less than 18 months since the onset of the pandemic, there are close to two hundred million confirmed cases and four million deaths worldwide. There have also been massive efforts geared towards finding safe and effective vaccines. By July 2021 there were 184 COVID-19 vaccine candidates in pre-clinical development, 105 in clinical development, and 18 vaccines approved for emergency use by at least one regulatory authority. These vaccines include whole virus live attenuated or inactivated, protein-based, viral vector, and nucleic acid vaccines. By mid-2021 three billion doses of COVID-19 vaccine have been administered around the world, mostly in high-income countries. COVID-19 vaccination provides hope for an end to the pandemic, if and only if there would be equal access and optimal uptake in all countries around the world.
| S-EPMC8272971 | biostudies-literature
Project description:Synopsis This manuscript is a narrative review of the rapidly moving COVID-19 vaccine field with an emphasis on clinical efficacy established in both randomized trials and post-marketing surveillance of clinically available vaccines. We review the major clinical trials that supported authorization for general use of the Janssen (Ad.26.CoV2), Pfizer-BioNTech (BNT162b2), and Moderna (mRNA-1273) vaccines and the publicly available post-marketing information with the goal of providing a broad, clinically relevant comparison of efficacy and safety. This review is primarily focused on the United States (US) market.
| S-EPMC8802612 | biostudies-literature
Project description:BackgroundCoronavirus disease 2019 (COVID-19) vaccination is necessary to reach herd immunity and essential for mitigating the spread of the pandemic. In May 2021, the US FDA and the EU have expanded the emergency use authorization for a COVID-19 vaccine to children aged 12 to 15. The aim of this study was to investigate parental acceptability of COVID-19 vaccination for their children, factors affecting their acceptability, and children's perceptions of COVID-19 vaccines in Republic of Korea.MethodsWe conducted a questionnaire survey at two tertiary hospitals from May 25, 2021 to June 3, 2021. Subjects were parents having children under 18 years and children aged 10-18 years.ResultsTwo hundred twenty-six parents and 117 children aged 10-18 years were included in the final analysis. Overall, 76.5% and 64.2% of parents intended to get vaccinated against COVID-19 and intended to have their children vaccinated, respectively. However, only 49.6% of children responded that they would get COVID-19 vaccination. In the multivariate analysis, high confidence in the safety of COVID-19 vaccines (adjusted odds ratio [AOR], 4.87; 95% confidence interval [CI], 1.32-24.12), parents' willingness to vaccinate themselves (AOR, 19.42; 95% CI, 6.85-64.00), and awareness of the need to vaccinate children against COVID-19 (AOR, 13.15; 95% CI, 4.77-41.27) were associated with positive factors intention to vaccinate their children.ConclusionThis study provides insight into how parents think about the COVID-19 vaccine for their children in South Korea. Our findings could be referenced in establishing a policy for childhood COVID-19 vaccination in the future.
| S-EPMC8352785 | biostudies-literature
Project description:BackgroundSince the beginning of the COVID-19 outbreak, many pharmaceutical companies have been racing to develop a safe and effective COVID-19 vaccine. Simultaneously, rumors and misinformation about COVID-19 are still widely spreading. Therefore, this study aimed to investigate the prevalence of COVID-19 misinformation among the Yemeni population and its association with vaccine acceptance and perceptions.MethodsA cross-sectional online survey was conducted in four major cities in Yemen. The constructed questionnaire consisted of four main sections (sociodemographic data, misinformation, perceptions (perceived susceptibility, severity, and worry), and vaccination acceptance evaluation). Subject recruitment and data collection were conducted online utilizing social websites and using the snowball sampling technique. Descriptive and inferential analyses were performed using SPSS version 27.ResultsThe total number of respondents was 484. Over 60% of them were males and had a university education. More than half had less than 100$ monthly income and were khat chewers, while only 18% were smokers. Misinformation prevalence ranged from 8.9% to 38.9%, depending on the statement being asked. Men, university education, higher income, employment, and living in urban areas were associated with a lower misinformation level (p <0.05). Statistically significant association (p <0.05) between university education, living in urban areas, and being employed with perceived susceptibility were observed. The acceptance rate was 61.2% for free vaccines, but it decreased to 43% if they had to purchase it. Females, respondents with lower monthly income, and those who believed that pharmaceutical companies made the virus for financial gains were more likely to reject the vaccination (p <0.05).ConclusionThe study revealed that the acceptance rate to take a vaccine was suboptimal and significantly affected by gender, misinformation, cost, and income. Furthermore, being female, non-university educated, low-income, and living in rural areas were associated with higher susceptibility to misinformation about COVID-19. These findings show a clear link between misinformation susceptibility and willingness to vaccinate. Focused awareness campaigns to decrease misinformation and emphasize the vaccination's safety and efficacy might be fundamental before initiating any mass vaccination in Yemen.
| S-EPMC8555792 | biostudies-literature
Project description:Since the emergence of COVID-19, caused by the SARS-CoV-2 virus at the end of 2019, there has been an explosion of vaccine development. By 24 September 2020, a staggering number of vaccines (more than 200) had started preclinical development, of which 43 had entered clinical trials, including some approaches that have not previously been licensed for human vaccines. Vaccines have been widely considered as part of the exit strategy to enable the return to previous patterns of working, schooling and socializing. Importantly, to effectively control the COVID-19 pandemic, production needs to be scaled-up from a small number of preclinical doses to enough filled vials to immunize the world's population, which requires close engagement with manufacturers and regulators. It will require a global effort to control the virus, necessitating equitable access for all countries to effective vaccines. This review explores the immune responses required to protect against SARS-CoV-2 and the potential for vaccine-induced immunopathology. We describe the profile of the different platforms and the advantages and disadvantages of each approach. The review also addresses the critical steps between promising preclinical leads and manufacturing at scale. The issues faced during this pandemic and the platforms being developed to address it will be invaluable for future outbreak control. Nine months after the outbreak began we are at a point where preclinical and early clinical data are being generated for the vaccines; an overview of this important area will help our understanding of the next phases.
| S-EPMC7597597 | biostudies-literature