Project description:In the last two years, the coronavirus disease 19 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a scientific and social challenge worldwide. Vaccines have been the most effective intervention for reducing virus transmission and disease severity. However, virus genetic variants are still circulating among vaccinated individuals with different symptomatology disease cases. Understanding the protective or disease associated mechanisms in vaccinated individuals is relevant to advance in vaccine development and implementation. To address this objective, serum protein profiles were characterized by quantitative proteomics and data analysis algorithms in four cohorts of vaccinated individuals uninfected and SARS-CoV-2 infected with asymptomatic, nonsevere and severe disease symptomatology. The results showed that immunoglobulins were the most overrepresented proteins in infected cohorts when compared to PCR-negative individuals. The immunoglobulin profile varied between different infected cohorts and correlated with protective or disease associated capacity. Overrepresented immunoglobulins in PCR-positive individuals correlated with protective response against SARS-CoV-2, other viruses, and thrombosis in asymptomatic cases. In nonsevere cases, correlates of protection against SARS-CoV-2 and HBV together with risk of myasthenia gravis and allergy and autoantibodies were observed. Patients with severe symptoms presented risk for allergy, chronic idiopathic thrombocytopenic purpura, and autoantibodies. The analysis of underrepresented immunoglobulins in PCR-positive compared to PCR-negative individuals identified vaccine-induced protective epitopes in various coronavirus proteins including the Spike receptor-binding domain RBD. Non-immunoglobulin proteins were associated with COVID-19 symptoms and biological processes. These results evidence host-associated differences in response to vaccination and the possibility of improving vaccine efficacy against SARS-CoV-2.
Project description:The SARS-CoV-2 Delta (B.1.617.2) variant is capable of infecting vaccinated persons. An open question remains as to whether deficiencies in specific vaccine-elicited immune responses result in susceptibility to vaccine breakthrough infection. We investigated 55 vaccine breakthrough infection cases (mostly Delta) in Singapore, comparing them against 86 vaccinated close contacts who did not contract infection. Vaccine breakthrough cases showed lower memory B cell frequencies against SARS-CoV-2 receptor binding domain (RBD). Compared to plasma antibodies, antibodies secreted by memory B cells retained a higher fraction of neutralizing properties against the Delta variant. Inflammatory cytokines including IL-1β and TNF were lower in vaccine breakthrough infections than primary infection of similar disease severity, underscoring the usefulness of vaccination in preventing inflammation. This report highlights the importance of memory B cells against vaccine breakthrough, and suggests that lower memory B cell levels may be a correlate of risk for Delta vaccine breakthrough infection.
Project description:Blood collected from adults pre vaccination and post vaccination to study the immune effects of COVID-19 vaccination and how they relate to antibody and T-cell responses.
Project description:Background and objectivesThe Food and Drug Administration expanded Emergency Use Authorization for use of Pfizer-BioNTech (BNT-162b2) coronavirus disease 2019 vaccine to include people ages 12 years and older on May 10, 2021. We describe adverse events observed during the first full year of the US coronavirus disease 2019 vaccination program for adolescents ages 12 to 17 years.MethodsWe conducted descriptive analyses using data from 2 complementary US vaccine safety monitoring systems: v-safe, a voluntary smartphone-based system that monitors reactions and health impacts, and the Vaccine Adverse Event Reporting System (VAERS), the national spontaneous reporting system. We reviewed reports and calculated adverse event reporting rates using vaccine administration data.ResultsAmong 172 032 adolescents ages 12 to 17 years enrolled in v-safe, most reported reactions following BNT-162b2 were mild to moderate, most frequently reported on the day after vaccination, and more common after dose 2. VAERS received 20 240 adverse event reports; 91.5% were nonserious. Among adverse events of interest, we verified 40 cases of multisystem inflammation syndrome in children (1.2 cases per million vaccinations), 34 (85%) of which had evidence of prior severe acute respiratory syndrome coronavirus 2 infection; and 570 cases of myocarditis (17.7 cases per million vaccinations), most of whom (77%) reported symptom resolution at the time of report.ConclusionsDuring the first year BNT-162b2 was administered to adolescents ages 12 to 17 years, most reported adverse events were mild and appeared self-limited. Rates of myocarditis were lower than earlier reports. No new serious safety concerns were identified.
Project description:BackgroundEarly clinical data from studies of the NVX-CoV2373 vaccine (Novavax), a recombinant nanoparticle vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that contains the full-length spike glycoprotein of the prototype strain plus Matrix-M adjuvant, showed that the vaccine was safe and associated with a robust immune response in healthy adult participants. Additional data were needed regarding the efficacy, immunogenicity, and safety of this vaccine in a larger population.MethodsIn this phase 3, randomized, observer-blinded, placebo-controlled trial conducted at 33 sites in the United Kingdom, we assigned adults between the ages of 18 and 84 years in a 1:1 ratio to receive two intramuscular 5-μg doses of NVX-CoV2373 or placebo administered 21 days apart. The primary efficacy end point was virologically confirmed mild, moderate, or severe SARS-CoV-2 infection with an onset at least 7 days after the second injection in participants who were serologically negative at baseline.ResultsA total of 15,187 participants underwent randomization, and 14,039 were included in the per-protocol efficacy population. Of the participants, 27.9% were 65 years of age or older, and 44.6% had coexisting illnesses. Infections were reported in 10 participants in the vaccine group and in 96 in the placebo group, with a symptom onset of at least 7 days after the second injection, for a vaccine efficacy of 89.7% (95% confidence interval [CI], 80.2 to 94.6). No hospitalizations or deaths were reported among the 10 cases in the vaccine group. Five cases of severe infection were reported, all of which were in the placebo group. A post hoc analysis showed an efficacy of 86.3% (95% CI, 71.3 to 93.5) against the B.1.1.7 (or alpha) variant and 96.4% (95% CI, 73.8 to 99.5) against non-B.1.1.7 variants. Reactogenicity was generally mild and transient. The incidence of serious adverse events was low and similar in the two groups.ConclusionsA two-dose regimen of the NVX-CoV2373 vaccine administered to adult participants conferred 89.7% protection against SARS-CoV-2 infection and showed high efficacy against the B.1.1.7 variant. (Funded by Novavax; EudraCT number, 2020-004123-16.).
Project description:BackgroundThere is debate on the necessity of booster doses of COVID-19 vaccination, especially in countries with limited resources.MethodsThis cross-sectional study was conducted in a referral laboratory in Tehran, Iran. The level of COVID-19 antibodies was measured and compared between individuals regarding the number of COVID-19 vaccine shots.ResultsIn this study, 176 individuals with a mean age of 36.3 (±11.7) years participated. A total of 112 individuals received two doses of the COVID-19 vaccine, and 64 individuals received three doses. Level of all antibodies was higher in those who received three doses than in those who received two doses of the COVID-19 vaccine. Considering the SARS-CoV-2 Spike IgG, the difference was not statistically significant but for the SARS-CoV-2 RBD IgG and SARS-CoV-2 NAB the difference was statistically significant. Regarding to the background variables, receiving influenza vaccine in the past year, history of autoimmune diseases and past medical history of chicken pox showed a significant association with the number of vaccine doses received. Their effects on the outcome variables assessed with multivariate logistic regression analysis.ConclusionThe results of our study show that a booster dose of the COVID-19 vaccine enhances the antibody response.
Project description:The promise of efficacious vaccines against SARS-CoV-2 is fulfilled and vaccination campaigns have started worldwide. However, the fight against the pandemic is far from over. Here, we propose an age-structured compartmental model to study the interplay of disease transmission, vaccines rollout, and behavioural dynamics. We investigate, via in-silico simulations, individual and societal behavioural changes, possibly induced by the start of the vaccination campaigns, and manifested as a relaxation in the adoption of non-pharmaceutical interventions. We explore different vaccination rollout speeds, prioritization strategies, vaccine efficacy, as well as multiple behavioural responses. We apply our model to six countries worldwide (Egypt, Peru, Serbia, Ukraine, Canada, and Italy), selected to sample diverse socio-demographic and socio-economic contexts. To isolate the effects of age-structures and contacts patterns from the particular pandemic history of each location, we first study the model considering the same hypothetical initial epidemic scenario in all countries. We then calibrate the model using real epidemiological and mobility data for the different countries. Our findings suggest that early relaxation of safe behaviours can jeopardize the benefits brought by the vaccine in the short term: a fast vaccine distribution and policies aimed at keeping high compliance of individual safe behaviours are key to mitigate disease resurgence.
Project description:ObjectiveThis study examines employee perceptions of safety and health climates for well-being during the COVID-19 pandemic in a sample of small businesses.MethodsWe evaluated changes to employees' work and home life resulting from COVID-19 and perceptions of safety and health climates. Cross-sectional relationships were assessed using multivariable linear regression models for a sample of 491 employees from 30 small businesses in Colorado in May 2020.ResultsEmployee perceptions of safety and health climates were significantly related to their self-reported well-being during the first wave of COVID-19, even when there were changes to childcare, the ability to work, and limited social contacts.ConclusionSafety and health climates may influence employee well-being even when other disruptions occur, suggesting that during emergencies, small businesses with strong climates may be better prepared to maintain employee well-being.
Project description:Background and objectivesCovid-19 vaccines approved by the EU, UK and USA have been found to be safe and effective. The cost effectiveness of these vaccines depends upon a number of factors. The aim of this paper is to explore the cost effectiveness of a COVID-19 vaccine and to analyse how the price of the vaccine and the cost of administrating it influence its cost effectiveness.MethodsWe considered an epidemiological model developed by an expert group within 'Statens Serum Institut', which is a unit under the auspices of the Danish Ministry of Health. The model allowed us to differentiate between two population groups, those aged ≥60 years and those aged <60 years. We used the model to consider four scenarios: (i) vaccination of 25% of the total population (corresponding to approximately 1.5 million persons) but targeting vaccines towards the population aged ≥60 years, (ii) vaccination of 25% of the total population, targeting vaccines only towards the population aged <60 years, (iii) vaccination of 40% of the total population where 15% are aged <60 years and 25% are aged ≥60 years (corresponding approximately to the full Danish population aged >60 years), and (iv) 40% of the total population is vaccinated but vaccines are targeted solely towards those aged <60 years. The time horizon of the analysis was six months, and the perspective was that of the Danish healthcare sector.ResultsThe results show that inclusion of the elderly population aged ≥60 years was more cost effective than a vaccination strategy that targeted a population aged <60 years old only, when productivity losses were not included. Furthermore, the results show that an extension of the target group from the elderly population only, to also include the younger population comes with an increasing cost per life-year gained. The incremental cost-effectiveness ratio depends on the price of the vaccine, hereunder also the administration costs, and the discount rate used for the estimation of life-years or quality-adjusted life-years gained from a vaccine. Furthermore, inclusion of productivity losses in the analyses influenced the cost effectiveness of vaccination of the population aged <60 years of age.ConclusionThe cost effectiveness of a COVID-19 vaccine is sensitive to whether or not productivity losses are included in the analyses. Without productivity losses, the elderly population should always be part of the target group for a COVID-19 vaccination programme. Taking productivity losses into account, at least in the case of low vaccine prices, vaccinating the younger population first can actually be cost effective.