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Background: COVID-19 vaccines adapted to newly emerging circulating variants are necessary to better protect the population due to the evolving nature of the SARS-CoV-2 virus., Research Design and Methods: The South African population was stratified by age and risk (defined by comorbidities such as diabetes, obesity, smoking, cancer, and asthma), and HIV status. The outcomes of different vaccination strategies based on age, risk, and HIV status were estimated using a Markov-decision tree model based on age-specific inputs derived from the literature and South African surveillance data., Results: Vaccinating older adults and those with comorbidities was estimated to avert 111,179 infections 18,281 hospitalizations, and 3,868 deaths, resulting in savings of ZAR 1,260 million (USD 67 million) and ZAR 3,205 million (USD 170 million) in direct and indirect costs, respectively. Similar results were obtained when considering strategies targeting older adults and the HIV population. Expanding vaccination to 75% of the standard-risk population prevented more infections (401%), hospitalizations (167%), and deaths (67%) and increased the direct (232%) and indirect (455%) cost savings compared to the base case., Conclusions: Implementing widespread vaccination strategies that utilize a vaccine adapted to the prevailing circulating variant in South Africa would result in significant public health and economic gains.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing COVID-19 has continuously evolved, requiring the development of adapted vaccines. This study estimated the impact of the introduction and increased coverage of an Omicron-adapted bivalent booster vaccine in Thailand., Research Design and Methods: The outcomes of booster vaccination with an Omicron-adapted bivalent vaccine versus no booster vaccination were estimated using a combined cohort Markov decision tree model. The population was stratified into high- and standard-risk subpopulations. Using age-specific inputs informed by published sources, the model estimated health (case numbers, hospitalizations, and deaths) and economic (medical costs and productivity losses) outcomes in different age and risk subpopulations., Results: Booster vaccination in only the elderly and high-risk subpopulation was estimated to avert 97,596 cases 36,578 hospitalizations, 903 deaths, THB 3,119 million in direct medical costs, and THB 10,589 million in indirect medical costs. These benefits increased as vaccination was expanded to other subpopulations. Increasing the booster vaccination coverage to 75% of the standard-risk population averted more deaths (95%), hospitalizations (512%), infections (782%), direct costs (550%), and indirect costs (687%) compared to the base case., Conclusions: Broader vaccination with an Omicron-adapted bivalent booster vaccine could have significant public health and economic benefits in Thailand.

Background: The dynamic evolution of the virus causing COVID-19 necessitates the development of adapted vaccines to protect against emerging variants., Research Design and Methods: A combined Markov-decision tree model estimated the outcomes of alternative vaccination strategies. The Saudi Arabian population was stratified into standard-risk and high-risk subpopulations, defined as either the population comprising individuals aged ≥ 65 years and individuals with at least one comorbidity. The model estimated the health and economic outcomes of vaccination based on age-specific inputs taken from published sources and national surveillance data., Results: The vaccination strategy targeting the elderly and high-risk subpopulation (was estimated to prevent 156,694 cases 12,800 hospitalizations, and 2,919 deaths and result in cost savings of SAR 1,239 million in direct costs and SAR 4,145 million in indirect costs. These gains increased with the vaccination strategies additionally targeting other subpopulations. Compared to the base case (aged ≥65 and those at high-risk), expanding vaccination coverage to 75% of the standard-risk population prevented more cases (323%), hospitalizations (154%), and deaths (60%) and increased the direct (232%) and indirect (270%) cost savings., Conclusions: The adoption of broad vaccination strategies using a vaccine adapted to the dominant variant in circulation would yield substantial benefits in Saudi Arabia.

A record linkage study was done to provide comprehensive data on the epidemiologic characteristics of invasive pneumococcal disease (IPD) in Scotland. The overall incidence of IPD was 11 cases/10(5) persons and 21 cases/10(5) persons <1 year of age, 51 cases/10(5) persons 1 year of age, 45 cases/10(5) elderly persons (age > or =65 years), 176-483 cases/10(5) persons with chronic medical conditions, and 562-2031 cases/10(5) persons with severe immunosuppression. The case-fatality rate was 11% among elderly persons and ranged from 3% to 13% among persons with underlying medical conditions. The most common pneumococcal serogroups associated with IPD were 14, 9, 6, 19, 23, 8, and 4. Serogroups included in the 23-valent polysaccharide vaccine caused the majority of cases of IPD. The proportion of IPD due to the 7-, 9-, and 11-valent conjugate vaccine serogroups was lower among older people and persons with underlying medical conditions.

Vaccination against infectious disease affords direct protection from vaccine-induced immunity and additional indirect protection for unvaccinated persons. A systematic review was conducted to estimate the indirect effect of COVID-19 vaccination. From PubMed and Embase, 31 studies were included describing the impact of original wild-type COVID-19 vaccines on disease transmission or viral load. Overall, study results showed the effectiveness of COVID-19 vaccination against SARS-CoV-2 transmission (range 16–95%), regardless of vaccine type or number of doses. The effect was apparent, but less pronounced against omicron (range 24–95% for pre-omicron variants versus 16–31% for omicron). Results from viral load studies were supportive, showing SARS-CoV-2 infections in vaccinated individuals had higher Ct values, suggesting lower viral load, compared to infections among the unvaccinated. Based on these findings, well-timed vaccination programs may help reduce SARS-CoV-2 transmission—even in the omicron era. Whether better-matched vaccines can improve effectiveness against transmission in the omicron era needs further study. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) case numbers have increased following the emergence of the Omicron variant. This study estimated the impact of introducing and increasing the coverage of an Omicron-adapted bivalent booster vaccine in Malaysia. A combined cohort Markov decision tree model was used to compare booster vaccination with an Omicron-adapted bivalent COVID-19 vaccine versus no booster vaccination in Malaysia. The model utilized age-specific data from January 2021 to March 2022 derived from published sources. The outcomes of interest included case numbers, hospitalizations, deaths, medical costs, and productivity losses. The population was stratified into high-risk and standard-risk subpopulations, and the study evaluated the benefits of increased coverage in different age and risk groups. Vaccinating only high-risk individuals and those aged ≥ 65 years was estimated to avert 274,313 cases, 33229 hospitalizations, 2,434 deaths, Malaysian ringgit (MYR) 576 million in direct medical costs, and MYR 579 million in indirect costs. Expanding vaccination coverage in the standard-risk population to 75% was estimated to avert more deaths (31%), hospitalizations (155%), infections (206%), direct costs (206%), and indirect costs (281%). These findings support broader population Omicron-adapted bivalent booster vaccination in Malaysia with potential for significant health and economic gains. [ABSTRACT FROM AUTHOR]

Background: Despite several studies that have estimated the economic impact of Respiratory Syncytial Virus (RSV) in infants, limited data are available on healthcare resource use and costs attributable to RSV across age groups. The aim of this study was to quantify age-specific RSV-related healthcare resource use and costs on the US healthcare system.Methods: This retrospective case-control study identified patients aged ≥1 year with an RSV event in the Truven Health Marketscan® Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefits databases between August 31, 2012 and August 1, 2013. RSV patients were matched 1:1 with non-RSV controls for age, gender, region, healthcare plan and index date (n = 11,432 in each group). Stratified analyses for healthcare resource use and costs were conducted by age groups. RSV-attributable resource use and costs were assessed based on the incremental differences between RSV cases and controls using multivariate analysis.Results: RSV patients had a higher healthcare resource use (hospital stays, emergency room/urgent care visits, ambulatory visits and outpatient visits) than non-RSV matched controls for all age groups (all p < 0.0001), particularly in the elderly age groups with RSV (1.9 to 3 days length of stay, 0.4 to 0.5 more ER/UC visits, 0.7 to 2.7 more ambulatory visits, 12.1 to 18.6 more outpatient visits and 9.5 to 14.6 more prescriptions than elderly in the control groups). The incremental difference in adjusted mean annual costs between RSV and non-RSV controls was higher in elderly (≥65; $12,030 to $23,194) than in those aged < 65 years ($2251 to $5391). Among children, adjusted costs attributable to RSV were higher in children aged 5-17 years ($3192), than those 1-4 years ($2251 to $2521).Conclusions: Our findings showed a substantial annual RSV-attributable healthcare resource use and costs in the US across age groups, with the highest burden in those aged ≥65 years. These data can be used in cost-effectiveness analyses, and may be useful for policymakers to guide future RSV vaccination and other prevention programs. [ABSTRACT FROM AUTHOR]

Background: Five of seven serotypes in the pneumococcal conjugate vaccine, introduced for infants in the United States in 2000, are responsible for most penicillin-resistant infections. We examined the effect of this vaccine on invasive disease caused by resistant strains. Methods: We used laboratory-based data from Active Bacterial Core surveillance to measure disease caused by antibiotic-nonsusceptible pneumococci from 1996 through 2004. Cases of invasive disease, defined as disease caused by pneumococci isolated from a normally sterile site, were identified in eight surveillance areas. Isolates underwent serotyping and susceptibility testing. Results: Rates of invasive disease caused by penicillin-nonsusceptible strains and strains not susceptible to multiple antibiotics peaked in 1999 and decreased by 2004, from 6.3 to 2.7 cases per 100,000 (a decline of 57 percent; 95 percent confidence interval, 55 to 58 percent) and from 4.1 to 1.7 cases per 100,000 (a decline of 59 percent; 95 percent confidence interval, 58 to 60 percent), respectively. Among children under two years of age, disease caused by penicillin-nonsusceptible strains decreased from 70.3 to 13.1 cases per 100,000 (a decline of 81 percent; 95 percent confidence interval, 80 to 82 percent). Among persons 65 years of age or older, disease caused by penicillin-nonsusceptible strains decreased from 16.4 to 8.4 cases per 100,000 (a decline of 49 percent). Rates of resistant disease caused by vaccine serotypes fell 87 percent. An increase was seen in disease caused by serotype 19A, a serotype not included in the vaccine (from 2.0 to 8.3 per 100,000 among children under two years of age). Conclusions: The rate of antibiotic-resistant invasive pneumococcal infections decreased in young children and older persons after the introduction of the conjugate vaccine. There was an increase in infections caused by serotypes not included in the vaccine. N Engl J Med 2006;354:1455-63. [ABSTRACT FROM AUTHOR]

Background Historically, semi-closed populations have had high rates of meningococcal carriage and have experienced recurrent outbreaks. As such, these high-risk groups are recommended for targeted vaccination in many countries. Methods A systematic review of eight databases and Google Scholar forward citations was conducted to characterize serogroup-specific meningococcal carriage in university students, military personnel, and Hajj pilgrims from 2007 to 2016. Results A total of 7014 records were identified and 22 studies were included. Overall carriage ranged from 0.0% to 27.4% in Hajj pilgrims, from 1.5% to 71.1% in university students, and from 4.2% to 15.2% in military personnel. Among serogroups A, B, C, W, X, and Y, serogroup B was most prevalent in Hajj pilgrims, B and Y in university students, and B, C, and Y in military personnel. ‘Other’ serogroups were more prevalent in university students than Hajj pilgrims or military personnel. Risk factors for carriage varied by setting. Among Hajj pilgrims, a high endemicity in the country of origin increased the risk of carriage, while smoking, male sex, and frequently attending parties increased the carriage risk for university students. Similarly, smoking increased the carriage risk for professional soldiers. Data gaps remain for many regions. Conclusions Preventative vaccination policies for high-risk groups should be based on current disease data in individual countries, supplemented by carriage data. Meningococcal carriage studies and disease surveillance are critical for determining the local epidemiology, populations responsible for disease transmission, and the need for targeted vaccination. [ABSTRACT FROM AUTHOR]