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55 result(s) for "Relative vaccine efficacy"
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Safety, immunogenicity, and relative efficacy of a parenteral trivalent rotavirus subunit vaccine candidate (TV P2-VP8) in healthy Ghanaian, Malawian, and Zambian infants
While live oral rotavirus vaccines (LORVs) are effective at preventing severe rotavirus gastroenteritis (SRVGE), they perform sub-optimally in the settings with the highest burden. Parenteral rotavirus vaccines could have greater efficacy by bypassing the gut, where interference with LORVs may occur. A novel parenteral rotavirus subunit vaccine (TV P2-VP8) was evaluated in a Phase 3 study for safety, immunogenicity, and relative efficacy in healthy African infants. Participating infants were randomized at 6–8 weeks of age to receive either three doses of TV P2-VP8 intramuscularly (IM) plus oral placebo or two doses of ROTARIX® (oral) plus IM placebo. The trial was designed to enroll a total of 8200 participants in two stages separated by an interim analysis conducted upon accrual of a predetermined number of SRVGE cases. Data at interim analysis indicated a low probability of demonstrating TV P2-VP8 superiority compared to ROTARIX in prevention of SRVGE, and the study was closed early. 4055 infants were enrolled and provided safety data. TV P2-VP8 was safe and well tolerated, with no safety concerns indicated. Virus neutralizing and IgG binding antibody seroresponses to TV-P2-VP8 were detected in most participants. The crude attack rates of SRVGE in the per-protocol population (n = 3477) were 4.51 % (TV P2-VP8) and 2.57 % (ROTARIX). The relative vaccine efficacy (RVE) against SRVGE for TV P2-VP8 was −77.68 % (95 % CI, −162.38, −21.54). The RVE against SRVGE in the first and second year of life was −91.67 % (95 % CI, −199.20, −24.35) and − 31.97 % (95 % CI, −220.37, 44.49), respectively. The RVE against rotavirus gastroenteritis of any severity was −47.78 % (95 % CI, −89.63, −15.59). TV P2-VP8 provided inferior protection against SRVGE compared to ROTARIX. The vaccine candidate was safe, immunogenic, and well-tolerated by infants. Continued efforts are needed to identify alternative rotavirus vaccines with improved efficacy in LMICs. Trial Registration:NCT04010448; PACTR201907491834482. •The TV P2-VP8 vaccine candidate was safe and immunogenic.•Three doses of TV P2-VP8 were inferior to two doses of ROTARIX® in preventing severe rotavirus gastroenteritis.•Study provides insight to guide future development of rotavirus vaccine candidates.
The Cost-Effectiveness of Vaccination of Older Adults with an MF59-Adjuvanted Quadrivalent Influenza Vaccine Compared to Other Available Quadrivalent Vaccines in Germany
Enhanced quadrivalent influenza vaccines that include an adjuvant (aQIV) or a high dose of antigen (QIV-HD), which stimulate a stronger immune response in older adults than the standard vaccine (QIVe), are now approved. The objective of this research is to compare available vaccines and determine the cost-effectiveness of immunizing persons aged 65 years and above with aQIV compared to QIVe and QIV-HD in Germany. A compartmental transmission model calibrated to outpatient visits for influenza in Germany was used to predict the number of medically attended infections using the three vaccines. The rates of hospitalizations, deaths, and other economic consequences were estimated with a decision tree using German data where available. Based on meta-analysis, the rVE of −2.5% to 8.9% for aQIV versus QIV-HD, the vaccines are similar clinically, but aQIV is cost saving compared to QIV-HD (unit cost of EUR 40.55). All results were most sensitive to changes in vaccine effectiveness. aQIV may be cost-effective compared to QIVe depending on the willingness to pay for additional benefits in Germany. As aQIV and QIV-HD are similar in terms of effectiveness, aQIV is cost saving compared to QIV-HD at current unit prices.
Relative Effectiveness of Cell-Cultured and Egg-Based Influenza Vaccines Among Elderly Persons in the United States, 2017–2018
Abstract Background The low influenza vaccine effectiveness (VE) observed during the A(H3N2)-dominated 2017–2018 season may be due to vaccine virus adaptation to growth in eggs. We compared the effectiveness of cell-cultured and egg-based vaccines among Medicare beneficiaries. Methods Retrospective cohort study on Medicare beneficiaries aged ≥65 years who received an influenza vaccine (cell-cultured, egg-based quadrivalent; egg-based high-dose, adjuvanted, or standard-dose trivalent) during the 2017–2018 season. We used Poisson regression to evaluate relative VE (RVE) in preventing influenza-related hospital encounters. Results Of >13 million beneficiaries, RVE for cell-cultured vaccines relative to egg-based quadrivalent vaccines was 10% (95% confidence interval [CI], 7%–13%). In a midseason interim analysis, this estimate was 16.5% (95% CI, 10.3%–22.2%). In a 5-way comparison, cell-cultured (RVE, 11%; 95% CI, 8%–14%) and egg-based high-dose (RVE, 9%; 95% CI, 7%–11%) vaccines were more effective than egg-based quadrivalent vaccines. Conclusions The modest VE difference between cell-cultured and egg-based vaccines only partially explains the low overall VE reported by the Centers for Disease Control and Prevention, suggesting that egg adaptation was not the main contributor to the low VE found among individuals aged ≥65 years. The midseason interim analysis we performed demonstrates that our methods can be used to evaluate VE actively during the influenza season. Among >13 million Medicare beneficiaries, the cell-cultured vaccine was more effective than the comparable egg-based vaccine during the 2017–2018 season. However, the marginal difference in effectiveness observed only partially explains the overall low vaccine effectiveness reported during the season.
Comparison of the efficacy of Neethling lumpy skin disease virus and x10RM65 sheep-pox live attenuated vaccines for the prevention of lumpy skin disease – The results of a randomized controlled field study
•Neethling and RM65 vaccines are widely used to control lumpy skin disease (LSD).•This is the first study to compare their efficacy in the field.•Incidence was significantly higher among RM65 compared to Neethling vaccinated cows.•Rate of Neethling associated disease was 0.38% among Neethling vaccinated cows.•Neethling efficacy is significantly higher but it can cause mild adverse effects. Lumpy skin disease (LSD) is a viral disease of cattle and buffalo, caused by a Capripox virus. A field study was performed during an LSD epidemic which occurred in 2012–2013 in Israel, in order to assess the efficacy of two commercial vaccines for protection against LSD. Fifteen dairy herds, vaccinated 2–5 months prior to study onset with a single dose of 102.5 TCID50 of RM65 attenuated sheep-pox vaccine, and not affected previously, were enrolled in the study. 4694 cows were randomized to be either vaccinated with a 103.5 TCID50/dose of RM65 vaccine (x10RM65) or with a same dose of an attenuated Neethling LSD virus vaccine. A case of LSD was defined as the appearance of at least 5 lesions typical to LSD and a severe case was defined if this sign was accompanied by either fever (>39.5°C) or/and a 20% reduction in milk production. Deep lesion biopsies and blood samples were collected from 64.5% of the cases in an attempt to detect DNA of LSD virus by PCR and to differentiate between the wild strain and the vaccine Neethling strain. Seventy-six cows were affected by LSD in 8 herds with an incidence of 0.3–5.7%. Mantel–Haenszel relative risk (RRMH) for LSD morbidity at least 15 days after vaccination in x10RM65 vs. Neethling was 2.635 (CI95%=1.44–4.82) and 11.2 (2.3–54.7) for severe morbidity. RRMH for laboratory confirmed cases was 4.28 (1.59–11.53). An incidence of 0.38% (9/2356) of Neethling associated disease was observed among Neethling vaccinated cows while no such disease occurred in x10RM65 vaccinated cows. We conclude that the Neethling vaccine is significantly more effective than x10RM65 in preventing LSD morbidity, though it might cause a low incidence of Neethling associated disease. No transmission of the Neethling strain to non-Neethling vaccinated cows was observed in this study.
Efficacy and safety of high-dose influenza vaccine in elderly adults: A systematic review and meta-analysis
•A comparative efficacy meta-analysis of high and standard dose influenza vaccines in the elderly.•Two trials showed the high-dose vaccine was associated with lower rates of influenza infection.•No evidence for clinically-relevant outcomes (influenza-associated hospitalizations and deaths).•Pragmatic trials will be needed to determine if superiority persists in real-world settings. Older adults are prioritized for influenza vaccination but also have lowered antibody responses to the vaccine. Higher-doses of influenza antigen may increase immune response and thus be more effective. Our objectives were to compare the efficacy and safety of the high-dose influenza vaccine to the standard-dose influenza vaccine in the elderly (age>65). Data sources: Randomized trials (RCTs) from Medline (Ovid), EMBASE (Ovid), Cochrane Library (Wiley), ClinicalTrials.gov, reference lists of relevant articles, and gray literature. Study selection: Two reviewers independently identified RCTs comparing high-dose influenza vaccine (60μg of hemagglutinin per strain) to standard-dose influenza vaccine (15μg of hemagglutinin per strain) in adults over the age of 65years. Data extraction: Two reviewers independently extracted trial-level data including population characteristics, interventions, outcomes, and funding sources. Risk of bias was assessed using the Cochrane Risk of Bias tool. We included seven eligible trials; all were categorized as having a low (n=3) or unclear (n=4) risk of bias. Patients receiving the high-dose vaccine had significantly less risk of developing laboratory-confirmed influenza infections (Relative Risk 0.76, 95%CI 0.65 to 0.90; I2 0%, 2 trials, 41,141 patients). Post-vaccination geometric mean titres and seroprotection rates were also higher in high-dose vaccine recipients. There were no protocol-defined serious adverse events in the included trials in either group. In elderly adults, the high-dose influenza vaccine was well-tolerated, more immunogenic, and more efficacious in preventing influenza infections than the standard-dose vaccine. Further pragmatic trials are needed to determine if the higher efficacy translates into higher vaccine effectiveness in adults over the age of 65.
Comparative Effectiveness of Bivalent (Original/Omicron BA.4/BA.5) COVID-19 Vaccines in Adults
The emergence of Omicron variants coincided with declining vaccine-induced protection against SARS-CoV-2. Two bivalent mRNA vaccines, mRNA-1273.222 (Moderna) and BNT162b2 Bivalent (Pfizer-BioNTech), were developed to provide greater protection against the predominate circulating variants by including mRNA that encodes both the ancestral (original) strain and BA.4/BA.5. We estimated their relative vaccine effectiveness (rVE) in preventing COVID-19-related outcomes in the US using a nationwide dataset linking primary care electronic health records and pharmacy/medical claims data. The study population (aged ≥18 years) received either vaccine between 31 August 2022 and 28 February 2023. We used propensity score weighting to adjust for baseline differences between groups. We estimated the rVE against COVID-19-related hospitalizations (primary outcome) and outpatient visits (secondary) for 1,034,538 mRNA-1273.222 and 1,670,666 BNT162b2 Bivalent vaccine recipients, with an adjusted rVE of 9.8% (95% confidence interval: 2.6–16.4%) and 5.1% (95% CI: 3.2–6.9%), respectively, for mRNA-1273.222 versus BNT162b2 Bivalent. The incremental relative effectiveness was greater among adults ≥ 65; the rVE against COVID-19-related hospitalizations and outpatient visits in these patients was 13.5% (95% CI: 5.5–20.8%) and 10.7% (8.2–13.1%), respectively. Overall, we found greater effectiveness of mRNA-1273.222 compared with the BNT162b2 Bivalent vaccine in preventing COVID-19-related hospitalizations and outpatient visits, with increased benefits in older adults.
Modeling the impact of vaccination for the immunization Agenda 2030: Deaths averted due to vaccination against 14 pathogens in 194 countries from 2021 to 2030
The Immunization Agenda 2030 (IA2030) Impact Goal 1.1. aims to reduce the number of future deaths averted through immunization in the next decade. To estimate the potential impact of the aspirational coverage targets for IA2030, we developed an analytical framework and estimated the number of deaths averted due to an ambitious vaccination coverage scenario from 2021 to 2030 in 194 countries. A demographic model was used to determine annual age-specific mortality estimates associated with vaccine coverage rates. For ten pathogens (Hepatitis B virus, Haemophilus influenzae type B, human papillomavirus, Japanese encephalitis, measles, Neisseria meningitidis serogroup A, Streptococcus pneumoniae, rotavirus, rubella, yellow fever), we derived single measures of country-, age-, and pathogen-specific relative risk of deaths conditional upon coverage rates, leveraging the data from 18 modeling groups as part of the Vaccine Impact Model Consortium (VIMC) for 110 countries. We used a logistic regression model to extrapolate the relative risk estimates to countries that were not modeled by VIMC. For four pathogens (diphtheria, tetanus, pertussis and tuberculosis), we used estimates from the Global Burden of Disease 2019 study and existing literature on vaccine efficacy. A future scenario defining years of vaccine introduction and scale-up needed to reach aspirational targets was developed as an input to estimate the long-term impact of vaccination taking place from 2021 to 2030. Overall, an estimated 51.5 million (95 % CI: 44.0–63.2) deaths are expected to be averted due to vaccinations administered between the years 2021 and 2030. With immunization coverage projected to increase over 2021–2030 an average of 5.2 million per year (4.4–6.3) deaths will be averted annually, with 4.4 million (3.9–5.1) deaths be averted for the year 2021, gradually rising to 5.8 million (4.9–7.5) deaths averted in 2030. The largest proportion of deaths is attributed to Measles and Hepatitis B accounting for 18.8 million (17.8–20.0) and 14.0 million (11.5–16.9) of total deaths averted respectively. The results from this global analysis demonstrate the substantial potential mortality reductions achievable if the IA2030 targets are met by 2030. Deaths caused by vaccine preventable diseases disproportionately affect LMICs in the African region.
A real-world study evaluating the relative vaccine effectiveness of a cell-based quadrivalent influenza vaccine compared to egg-based quadrivalent influenza vaccine in the US during the 2017–18 influenza season
Cell-based influenza vaccine manufacturing reduces egg adaptations that can decrease vaccine effectiveness. We evaluated the relative vaccine effectiveness (rVE) of cell-based quadrivalent influenza vaccine (QIVc) compared to standard-dose egg-based quadrivalent influenza vaccines (QIVe-SD) against influenza-related and serious respiratory events among subjects 4–64 years of age during the 2017–18 influenza season. A retrospective cohort analysis was conducted using administrative claims data in the US (IQVIA PharMetrics Plus® database). Subjects vaccinated with QIVc or QIVe-SD from 8/2017–1/2018 were identified (date of vaccination termed the index date). Influenza-related hospitalizations/ER visits, all-cause hospitalizations and serious respiratory hospitalizations/ER visits were assessed post-vaccination. Inverse probability of treatment weighting (IPTW) and Poisson regression were used to evaluate the adjusted rVE of QIVc compared to QIVe-SD. In a subgroup analysis, rVE was assessed for several subgroups of interest (4–17, 18–64 and 50–64 years, and subjects with ≥1 high-risk condition). In a secondary economic analysis, annualized all-cause costs over the follow-up were compared using propensity score matching (PSM) and generalized estimating equation (GEE) models. The study sample comprised 555,538 QIVc recipients and 2,528,524 QIVe-SD recipients. Prior to adjustment, QIVc subjects were older and had higher total costs in the 6-months pre-index. Following IPTW-adjustment and Poisson regression, QIVc was more effective in reducing influenza-related hospitalizations/ER visits, all-cause hospitalizations, and hospitalizations/ER visits related to asthma/COPD/bronchial events and other respiratory events compared to QIVe-SD. Similar trends were generally observed in the subgroup analysis. Following PSM adjustment and GEE regression, QIVe-SD was associated with significantly higher annualized all-cause total costs compared to QIVc, driven by higher costs for outpatient medical services and inpatient hospitalizations. After adjustment for confounders and selection bias, QIVc reduced influenza-related hospitalizations/ER visits, all-cause hospitalizations, and serious respiratory hospitalizations/ER visits compared to QIVe-SD. QIVc was associated with significantly lower all-cause total costs.
Comparative effectiveness of high dose versus adjuvanted influenza vaccine: A retrospective cohort study
Adults 65 years and older (seniors) experience more complications following influenza infection than younger adults. We estimated the relative vaccine effectiveness (rVE) of a trivalent high dose (HD-IIV3) versus an adjuvanted trivalent influenza vaccine (aIIV3) in seniors for respiratory-related hospitalizations. We conducted a retrospective cohort study using claims data from Optum’s Clinformatics® Data Mart to compare outcome rates between seniors who received HD-IIV3 versus aIIV3 during the 2016/17 and 2017/18, predominantly A/H3N2 respiratory seasons. Rates were adjusted for demographic characteristics, comorbid conditions, previous influenza vaccination, and geography. We used the previous event rate ratio (PERR) approach to address bias by time-fixed unmeasured confounders. We identified 842,282 HD-IIV3 and 34,157 aIIV3 recipients for the 2016/17 season and 1,058,638 HD-IIV3 and 189,636 aIIV3 recipients for the 2017/18 season. The pooled rVE of HD-IIV3 versus aIIV3 for respiratory-related hospitalizations over both seasons was 12% (95% confidence interval: 3.3%–20%); 13% (−6.4% to 32%) for the 2016/17 season and 12% (2.1%–21%) for the 2017/18 season. Pooled over two predominantly A/H3N2 respiratory seasons, HD-IIV3 was associated with fewer respiratory hospital admissions than aIIV3 in senior members of large national managed health care company in the U.S.
Effect of Age on Relative Effectiveness of High-Dose Versus Standard-Dose Influenza Vaccines Among US Medicare Beneficiaries Aged ≥65 Years
Studies have found that the high-dose influenza vaccine has a higher relative vaccine effectiveness (RVE) versus standard-dose vaccines in some seasons. We evaluated the effect of age on the RVE of high-dose versus standard-dose influenza vaccines among Medicare beneficiaries. A 6-season retrospective cohort study from 2012 to 2018 among Medicare beneficiaries aged ≥65 years was performed. Poisson regression was used to evaluate the effect of age on the RVE of high-dose versus standard-dose influenza vaccines in preventing influenza-related hospitalizations. The study included >19 million vaccinated beneficiaries in a community pharmacy setting. The Poisson models indicated a slightly increasing trend in RVE with age in all seasons. The high-dose vaccine was more effective than standard-dose vaccines in preventing influenza-related hospital encounters (ie, influenza-related inpatient stays and emergency department visits) in the 2012-2013 (RVE, 23.1%; 95% confidence interval [CI], 17.6%-28.3%), 2013-2014 (RVE, 15.3%; 95% CI, 7.8%-22.3%), 2014-2015 (RVE, 8.9%; 95% CI, 5.6%-12.1%), and 2016-2017 (RVE, 12.6%; 95% CI, 6.3%-18.4%) seasons and was at least as effective in all other seasons. We also found that the high-dose vaccine was consistently more effective than standard-dose vaccines across all seasons for people aged ≥85 years. Similar trends were observed for influenza-related inpatient stays. The RVE of high-dose versus standard-dose influenza vaccines increases with age.