Search Results (30)

COVID-19 vaccines have revolutionized prevention and clinical management by reducing disease severity and mortality. However, their long-term impact on hospitalization is unclear. This retrospective study assessed whether vaccination status, timing, and number of vaccine doses influence the risk of hospitalization and COVID-19 pneumonia in a large cohort in Italy, several years after initial vaccine rollout. From 1 October 2023, to 2 February 2024, at Humanitas Research Hospital (Milan) and two affiliates, we recorded age, sex, comorbidities, vaccination status (number of doses and time since last dose), admission type (urgent vs. elective), and pneumonia diagnosis. Baseline health was quantified by the Charlson Comorbidity Index. Among 16,034 admissions (14,874 patients), vaccination data were available for 5743 cases: 40.8% were in the emergency setting and 59.2% were elective. Patients presented with pneumonia in 6.8% of cases. Laboratory results confirmed COVID-19 pneumonia occurred in 43.7% of pneumonia cases, with a 16.9% mortality. Patients with no vaccine dose had a higher proportion of COVID-19 pneumonia, while COVID-19 pneumonia rates were lower in individuals who had received more vaccine doses. There were no significant differences in COVID-19 pneumonia risk by timing of last vaccination. Moreover, hospitalized unvaccinated patients had overall more frequent emergency admissions (57.3%), while patients with three or more doses had about a ~40% emergency admission rate. COVID-19 positivity during hospitalization was highest in unvaccinated patients (90.7%) and declined with vaccination status. Vaccinated patients, especially those with multiple doses, had significantly lower COVID-19 pneumonia rates and emergency admissions. These findings suggest a possible protective effect of vaccination in modifying the clinical presentation and severity of illness among those who are hospitalized and support continued vaccination efforts for high-risk groups to reduce severe adverse outcomes. Full article

Dengue has emerged as a significant global health threat. Despite decades of research, only two dengue vaccines—CYD-TDV (Dengvaxia) and TAK-003 (Qdenga)—have been licensed to date, with limited implementation. This paper explores and outlines strategies for integrating dengue vaccines into routine immunization programs, particularly in high-burden regions. TAK-003, a tetravalent live-attenuated vaccine, has demonstrated 61% efficacy against virologically confirmed dengue and 84% efficacy against hospitalizations in endemic settings. However, concerns remain about vaccine-enhanced disease, particularly among seronegative individuals exposed to DENV3 and DENV4. WHO recommends targeted introduction in high-transmission settings without pre-vaccination screening, while ongoing post-introduction studies will further clarify long-term safety and efficacy. Effective vaccine rollout requires a multi-pronged approach, including school-based immunization, integration with adolescent health services, and strong community engagement. Decision-making for vaccine introduction should be guided by National Immunization Technical Advisory Groups (NITAGs), local epidemiological data, and cost-effectiveness assessments. While future vaccines, including mRNA and virus-like particle candidates, are under development, optimizing the use of currently available vaccines is crucial to reducing dengue’s public health impact. Given the continued rise in cases, immediate action—combining vaccination with vector control—is essential to prevent further morbidity and mortality. Full article

Post-acute COVID-19 syndrome (PACS) is characterized by the persistence of one or more symptoms after the acute phase, leading to physical disabilities. This study aims to investigate whether the functional capacity and respiratory function 120 days post-COVID-19 differed according to the level of respiratory support needed during hospitalization in acute COVID-19 in the pre-vaccine rollout period. We followed up with 118 COVID-19 hospitalized patients in the acute phase until 120 days post-acute disease, with patients split into a Non-Invasive Oxygen Therapy Group (OTG, n = 72), Invasive Mechanical Ventilation Group (IMV, n = 12), and Room Air Group (RAG, n = 34), assessing the body composition, respiratory muscle strength, pulmonary function, functional capacity, and muscle strength at the follow-up visit. In total, 54 individuals (45.8%) were female, with a median age of 48 years old (IQR: 41–58). We found that the group with IMV was older (p < 0.001), had more admissions to the ICU (p < 0.001), and had longer hospital stays (p < 0.001). There were no statistically significant differences between groups (OTG, IMV, and RAG) for the spirometry function (p = 0.31), DASI score (p = 0.77), manovacuometry (MIP p = 0.74; MEP p = 0.23), 6MWT (p = 0.43), and handgrip (p = 0.19) outcomes. At D120, the IMV group had an important loss of body muscle mass (BMM) and a higher BMM than RAG (p = 0.02). Reduction in MIP (p = 0.01) and MEP (p = 0.02) in the IMV group and OTG group when compared to the RAG was also observed. Functional outcomes at 120 days from COVID-19 hospitalization were not found to be associated with the levels of oxygen supplementation during acute disease in this group of participants. Full article

Background: Although confirmed cases of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been declining since late 2020 due to general vaccination, little research has been performed regarding the impact of vaccines against SARS-CoV-2 in Spain in terms of hospitalizations and deaths. Objective: Our aim was to identify the reduction in severity and mortality of coronavirus disease 2019 (COVID-19) at a nationwide level due to vaccination. Methods: We designed a retrospective, population-based study to define waves of infection and to describe the characteristics of the hospitalized population. We also studied the rollout of vaccination and its relationship with the decline in hospitalizations and deaths. Finally, we developed two mathematical models to estimate non-vaccination scenarios using machine learning modeling (with the ElasticNet and RandomForest algorithms). The vaccination and non-vaccination scenarios were eventually compared to estimate the number of averted hospitalizations and deaths. Results: In total, 498,789 patients were included, with a global mortality of 14.3%. We identified six waves or epidemic outbreaks during the observed period. We established a strong relationship between the beginning of vaccination and the decline in both hospitalizations and deaths due to COVID-19 in all age groups. We also estimated that vaccination prevented 170,959 hospitalizations (CI 95% 77,844–264,075) and 24,546 deaths (CI 95% 2548–46,543) in Spain between March 2021 and December 2021. We estimated a global reduction of 9.19% in total deaths during the first year of COVID-19 vaccination. Conclusions: Demographic and clinical profiles changed over the first months of the pandemic. In Spain, patients over 80 years old and other age groups obtained clinical benefit from early vaccination. The severity of COVID-19, in terms of hospitalizations and deaths, decreased due to vaccination. Our use of machine learning models provided a detailed estimation of the averted burden of the pandemic, demonstrating the effectiveness of vaccination at a population-wide level. Full article

In January 2021, Australia initiated a national COVID-19 vaccine rollout strategy but faced setbacks, leading to negative press and media controversy, which may have diminished vaccine confidence. This study aimed to assess the factors influencing vaccine confidence in Australian adults (≥18 years of age) following the administration of a COVID-19 vaccine. Conducted at Blacktown Hospital, Sydney, a cross-sectional survey with 1053 respondents gauged vaccine confidence and influencing factors. The results showed overall high confidence (mean score 33/40). Trusted sources included the Australian Department of Health (77.8%), NSW Health (76.7%), and general practitioners (53.7%), while social media was distrusted (5.9%). The motivations for vaccination varied: university-educated individuals prioritised personal health (X² = 17.81; p < 0.001), while religious and/or older respondents (≥50 years of age) emphasised community (X² = 11.69; p < 0.001) and family protection (X² = 17.314; p < 0.001). Multivariate logistic regression revealed use of the Australian Department of Health website as a trusted source of COVID-19 information as the strongest predictor of high confidence (>30; OR 1.43; p = 0.041), while exposure to fake news decreased confidence (OR 0.71; p = 0.025). The study underscores the importance of reliable health information sources in bolstering vaccine confidence and highlights the detrimental effects of misinformation. Promoting awareness of trustworthy health channels is crucial to combat vaccine hesitancy in Australia. Full article

Background: The COVID-19 pandemic seemed to mainly involve the respiratory system, but it was realized that it could affect any organ, including the CNS. The pandemic has followed a wave-like trend, with its peaks being due to the COVID-19 different variants and the introduction of the vaccine, which led to an apparent reduction in hospitalizations but also brought about perplexities related to its adverse effects. The aim of this study was to analyze the changes in the use of head CT/contrast CT and their impacts on the onset of cerebrovascular disease in our emergency department during the COVID-19 period and the vaccine rollout. Methods: Patients ≥ 18 years old admitted to our emergency department from January 2018 to September 2021 were enrolled. The patients were divided into three groups. The COVID-19 period included patients who visited our emergency department from 1 March 2020 to 31 January 2021; the vaccine period was considered to range from 1 February 2021 to 30 September 2021. The patients who visited the emergency department from 1 January 2018 to 31 January 2020 were considered the controls. Results: We found an increase in head CT/contrast CT requests during the COVID-19 period and increase in head contrast CT during the vaccine period, without an increase in the incidence of cerebrovascular disease. Conclusions: The uncertainty regarding the possible thrombotic events associated with COVID-19 and its vaccine increased the relative use of head CT/contrast CT by about 20% compared to the control period Full article

Background: Pregnant women are at an increased risk of hospitalisation, admission to the intensive care unit, mechanical ventilation, and death from SARS-CoV-2 infection. The aim of this study is to determine the predictive factors associated with COVID-19 vaccine uptake during pregnancy over time in a population with a high background uptake of maternal influenza and pertussis vaccination. Methods: This is a population-based, cohort study of all pregnant women who gave birth in Victoria, Australia between 1 July 2021 and 30 June 2022. Data from the Victorian Perinatal Data Collection were analysed using univariable and multivariable logistic regression. Results: This study reports on 77,719 women who gave birth over a 12 month period, of whom 49,281 (63.4%) received a COVID-19 vaccine, 54,887 (70.6%) received an influenza vaccination and 63,594 (81.8%) received a pertussis vaccine by the time of delivery. Pregnant women aged >30 years (aOR 1.31 CI 1.27, 1.36), who had >=8 antenatal visits (aOR 1.08 CI 1.04, 1.12), and those who received influenza vaccine (aOR 1.23 CI 1.19, 1.28) were more likely to have received a COVID-19 vaccine. Those who smoked (aOR 0.7 CI 0.66, 0.74), were First Nations (aOR 0.83 CI 0.74, 0.93) and those who gave birth in public hospitals (aOR 0.65 CI 0.63, 0.68) were less likely to receive COVID-19 vaccine in the first 12 months of the rollout. Conclusion: Maternal age, smoking, parity and Indigenous status were factors associated with delayed and sustained lower coverage, even in a population with background maternal influenza and pertussis coverage of 70.6% and 81.8%, respectively. Full article

The early attainment of high COVID-19 vaccination rates can minimize avoidable hospitalizations/deaths. The fifth wave COVID-19 outbreak in Hong Kong caused >9000 deaths, and most of them were unvaccinated older people. This study hence investigated determinants of taking the first dose vaccination at a later phase (Phase 3: during the fifth wave outbreak, i.e., February–July 2022) versus two earlier phases (Phase 1: first six months since vaccine rollout, i.e., February–July 2021; Phase 2: six months prior to the outbreak, i.e., August 2021–January 2022) via a random telephone survey among 386 ever-vaccinated Hong Kong older people aged ≥60 (June/July 2022). A total of 27.7%, 51.1%, and 21.3% took the first dose at Phase 1, Phase 2, and Phase 3, respectively. Unfavorable perceptions related to COVID-19/vaccination, exposure to conflicting/counter-information about the suitability of older people’s vaccination from various sources, unsupportive family influences prior to the outbreak, and depressive symptoms were significantly associated with taking the first dose at Phase 3 instead of Phase 1 and Phase 2. To speed up COVID-19 vaccination and avoid unnecessary deaths, the government and health professionals should rectify misinformation, provide clear/consistent information for older people and their family members, and focus on those having depressive symptoms at an earlier stage of the pandemic. Full article

The global rollout of COVID-19 vaccines has played a critical role in reducing pandemic spread, disease severity, hospitalizations, and deaths. However, the first-generation vaccines failed to block severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and transmission, partially due to the limited induction of mucosal immunity, leading to the continuous emergence of variants of concern (VOC) and breakthrough infections. To meet the challenges from VOC, limited durability, and lack of mucosal immune response of first-generation vaccines, novel approaches are being investigated. Herein, we have discussed the current knowledge pertaining to natural and vaccine-induced immunity, and the role of the mucosal immune response in controlling SARS-CoV2 infection. We have also presented the current status of the novel approaches aimed at eliciting both mucosal and systemic immunity. Finally, we have presented a novel adjuvant-free approach to elicit effective mucosal immunity against SARS-CoV-2, which lacks the safety concerns associated with live-attenuated vaccine platforms. Full article

Mortality rates for COVID-19 have declined over time in the general population, but data in patients with hematologic malignancies are contradictory. We identified independent prognostic factors for COVID-19 severity and survival in unvaccinated patients with hematologic malignancies, compared mortality rates over time and versus non-cancer inpatients, and investigated post COVID-19 condition. Data were analyzed from 1166 consecutive, eligible patients with hematologic malignancies from the population-based HEMATO-MADRID registry, Spain, with COVID-19 prior to vaccination roll-out, stratified into early (February–June 2020; n = 769 (66%)) and later (July 2020–February 2021; n = 397 (34%)) cohorts. Propensity-score matched non-cancer patients were identified from the SEMI-COVID registry. A lower proportion of patients were hospitalized in the later waves (54.2%) compared to the earlier (88.6%), OR 0.15, 95%CI 0.11–0.20. The proportion of hospitalized patients admitted to the ICU was higher in the later cohort (103/215, 47.9%) compared with the early cohort (170/681, 25.0%, 2.77; 2.01–3.82). The reduced 30-day mortality between early and later cohorts of non-cancer inpatients (29.6% vs. 12.6%, OR 0.34; 0.22–0.53) was not paralleled in inpatients with hematologic malignancies (32.3% vs. 34.8%, OR 1.12; 0.81–1.5). Among evaluable patients, 27.3% had post COVID-19 condition. These findings will help inform evidence-based preventive and therapeutic strategies for patients with hematologic malignancies and COVID-19 diagnosis. Full article

Background: From May to December 2021, Bangladesh experienced a major surge in the Delta variant of SARS-CoV-2. The earlier rollout of several vaccines offered the opportunity to evaluate vaccine effectiveness against this variant. Methods: A prospective, test-negative case-control study was conducted in five large hospitals in Dhaka between September and December 2021. The subjects were patients of at least 18 years of age who presented themselves for care, suffering COVID-like symptoms of less than 10 days’ duration. The cases had PCR-confirmed infections with SARS-CoV-2, and up to 4 PCR test-negative controls were matched to each case, according to hospital, date of presentation, and age. Vaccine protection was assessed as being the association between the receipt of a complete course of vaccine and the occurrence of SARS-CoV-2 disease, with symptoms beginning at least 14 days after the final vaccine dose. Results: In total, 313 cases were matched to 1196 controls. The genotyping of case isolates revealed 99.6% to be the Delta variant. Receipt of any vaccine was associated with 12% (95% CI: −21 to 37, p = 0.423) protection against all episodes of SARS-CoV-2. Among the three vaccines for which protection was evaluable (Moderna (mRNA-1273); Sinopharm (Vero Cell-Inactivated); Serum Institute of India (ChAdOx1 nCoV-19)), only the Moderna vaccine was associated with significant protection (64%; 95% CI: 10 to 86, p = 0.029). Protection by the receipt of any vaccine against severe disease was 85% (95% CI: 27 to 97, p = 0.019), with protection estimates of 75% to 100% for the three vaccines. Conclusions: Vaccine protection against COVID-19 disease of any severity caused by the Delta variant was modest in magnitude and significant for only one of the three evaluable vaccines. In contrast, protection against severe disease was high in magnitude and consistent for all three vaccines. Because our findings are not in complete accord with evaluations of the same vaccines in more affluent settings, our study underscores the need for country-level COVID-19 vaccine evaluations in developing countries. Full article

Global vaccine development efforts have been accelerated in response to the devastating COVID-19 pandemic. The study aims to determine the seroprevalence of SARS-CoV-2 IgG antibodies among vaccine-naïve healthcare workers and to describe the impact of vaccination roll-out on COVID-19 antibody prevalence among the health care centers in tertiary care centers in South India. Serum samples collected from vaccinated and unvaccinated health care workers between January 2021 and April 2021were subjected to COVID-19 IgG ELISA, and adverse effects after the first and second dose of receiving the Covishield vaccine were recorded. The vaccinated group was followed for a COVID-19 breakthrough infection for a period of 6 months. Among the recruited HCW, 156 and 157 participants were from the vaccinated and unvaccinated group, respectively. The seroprevalence (COVID-19 IgG ELISA) among the vaccinated and unvaccinated Health Care Workers (HCW) was 91.7% and 38.2%, respectively, which is statistically significant. Systemic and local side-effects after Covishield vaccination occur at lower frequencies than reported in phase 3 trials. Since the COVID-19 vaccine rollout has commenced in our tertiary care hospital, seropositivity for COVID-19 IgG has risen dramatically and clearly shows trends in vaccine-induced antibodies among the health care workers. Full article

Background: The objective of this study was to assess changes in social and clinical determinants of COVID-19 outcomes associated with the first year of COVID-19 vaccination rollout in the Basque population. Methods: A retrospective study was performed using the complete database of the Basque Health Service (n = 2,343,858). We analyzed data on age, sex, socioeconomic status, the Charlson comorbidity index (CCI), hospitalization and intensive care unit (ICU) admission, and COVID-19 infection by Cox regression models and Kaplan–Meier curves. Results: Women had a higher hazard ratio (HR) of infection (1.1) and a much lower rate of hospitalization (0.7). With older age, the risk of infection fell, but the risks of hospitalization and ICU admission increased. The higher the CCI, the higher the risks of infection and hospitalization. The risk of infection was higher in high-income individuals in all periods (HR = 1.2–1.4) while their risk of hospitalization was lower in the post-vaccination period (HR = 0.451). Conclusion: Despite the lifting of many control measures during the second half of 2021, restoring human mobility patterns, the situation could not be defined as syndemic, clinical determinants seeming to have more influence than social ones on COVID-19 outcomes, both before and after vaccination program implementation. Full article

We assessed the frequency and correlates of COVID-19 vaccine hesitancy before Canada’s vaccine rollout. A cross-sectional vaccine hesitancy survey was completed by consecutive patients/family members/staff who received the influenza vaccine at McGill University affiliated hospitals. Based on the self-reported likelihood of receiving a future vaccine (scale 0–10), the following three groups were defined: non-hesitant (score 10), mildly hesitant (7.1–9.9), and significantly hesitant (0–7). Factors associated with vaccine hesitancy were assessed with multivariate logistic regression analyses and binomial logistic regression machine learning modelling. The survey was completed by 1793 people. Thirty-seven percent of participants (n = 669) were hesitant (mildly: 315 (17.6%); significantly: 354 (19.7%)). Lower education levels, opposition and uncertainty about vaccines being mandatory, feelings of not receiving enough information about COVID-19 prevention, perceived social pressure to get a future vaccine, vaccine safety concerns, uncertainty regarding the vaccine risk-benefit ratio, and distrust towards pharmaceutical companies were factors associated with vaccine hesitancy. Vaccine safety concerns and opposition to mandatory vaccinations were the strongest correlates of vaccine hesitancy in both the logistic regressions and the machine learning model. In conclusion, in this study, over a third of people immunized for influenza before the COVID-19 vaccine rollout expressed some degree of vaccine hesitancy. Effectively addressing COVID-19 vaccine safety concerns may enhance vaccine uptake. Full article