Next-Generation Vaccine Development with Nanomaterials: Recent Advances, Possibilities, and Challenges.

Nanomaterials are becoming important tools for vaccine development owing to their tunable and adaptable nature. Unique properties of nanomaterials afford opportunities to modulate trafficking through various tissues, complement or augment adjuvant activities, and specify antigen valency and display. This versatility has enabled recent work designing nanomaterial vaccines for a broad range of diseases, including cancer, inflammatory diseases, and various infectious diseases. Recent successes of nanoparticle vaccines during the coronavirus disease 2019 (COVID-19) pandemic have fueled enthusiasm further. In this review, the most recent developments in nanovaccines for infectious disease, cancer, inflammatory diseases, allergic diseases, and nanoadjuvants are summarized. Additionally, challenges and opportunities for clinical translation of this unique class of materials are discussed.

Determinants of preventive behavior against Covid-19 in secondary school students based on Health Belief Model (HBM): a structural equations modeling (SEM).

Measures such as education, improving knowledge, attitude and taking preventive action to protect against COVID-19 are vital strategies for prevention. The aim of this study was to determine the predictability of Health Belief Model (HBM) constructs in performing preventive behaviors against COVID-19 among secondary school students in Chabahar, Iran. In this cross-sectional-analytical study, 400 secondary school students of Chabahar city were investigated by simple random sampling. The data collection tool was a questionnaire including demographic characteristics, knowledge, behavior, and Health Belief Model constructs' questions. Exploratory Factor Analysis (EFA) was used to evaluate the validity of HBM constructs, and the structural equation modeling (SEM) method was used to evaluate the direct and indirect effects of the relationship between knowledge, HBM constructs, and preventive behavior against COVID-19 based on the conceptual model. Based on the results of the structural modeling, the direct effect of knowledge on the constructs of the health belief model was positive and significant (ß = 0.34, P-value < 0.001), and on the preventive behavior of students was insignificant (ß = 0.12, P-value = 0.07) while the indirect effect of knowledge through increasing the constructs of the HBM on student behavior was positive and significant (ß = 0.30, P < 0.001). The relationship between the constructs of the HBM constructs and student behavior was also positive and significant (ß = 0.89, P-value < 0.001).Due to the fact that knowledge and HBM structures played a role in predicting the adoption of preventive behavior from COVID-19, it is possible to design appropriate interventions to increase knowledge, sensitivity, perceived severity, and self-efficacy, in order to recover from COVID-19 by adopting preventive behaviors.

Change in Nutrition and Physical Activity Practices in Early Childcare and Education Settings in Illinois During the COVID-19 Pandemic.

CONTEXT: For many young children, early childcare and education (ECE) programs are the only source of nutritious meals and physical activity (PA); however, the COVID-19 pandemic led to program closures, restrictions, and changed practices. OBJECTIVE: To examine changes in nutrition and PA-related best practices in ECE settings in Illinois from 2019, just prior to the pandemic, as compared to 2022. We also examined how changes over time varied by program type (ie, centers vs homes), Child and Adult Care Food Program (CACFP) status, and/or Head Start/Early Head Start status. DESIGN: The study design is a repeated cross-sectional survey administered in December 2019 and October 2022. SETTING: State of Illinois. PARTICIPANTS: A total of 888 and 1162 ECE providers completed initial and follow-up surveys, respectively. INTERVENTION: NA. MAIN OUTCOME MEASURE: Provider report of meeting 14 nutrition and 9 PA-related best practices. RESULTS: Overall, 9 nutrition-related best practices were maintained and 5 declined over time. Centers, CACFP, and Head Start providers reported significant declines in meeting nutrition-related practices over time. A total of 8 PA-related best practices were maintained and 1 declined over time. Centers reported a significant decline in 5 of the PA-related best practices over time, and these declines were significantly different than in homes over time. Similarly, Head Start programs reported a decline in 4 PA-related best practices over time, and the change was significantly different from non-Head Start programs in 3 of the 4 practices. CONCLUSION: The findings of this study should be considered a new baseline for ECE nutrition and PA-related best practices in Illinois and should serve as a wake-up call for advocates nationwide with regard to the provision of nutrition and PA-related best practices in centers and by CACFP and Head Start providers postpandemic.

Prospects and Challenges in Developing mRNA Vaccines for Infectious Diseases and Oncogenic Viruses.

mRNA vaccines have emerged as an optimistic technological platform for vaccine innovation in this new scientific era. mRNA vaccines have dramatically altered the domain of vaccinology by offering a versatile and rapid approach to combating infectious diseases and virus-induced cancers. Clinical trials have demonstrated efficacy rates of 94-95% in preventing COVID-19, and mRNA vaccines have been increasingly recognized as a powerful vaccine platform. Although mRNA vaccines have played an essential role in the COVID-19 pandemic, they still have several limitations; their instability and degradation affect their storage, delivery, and over-all efficiency. mRNA is typically enclosed in a transport mechanism to facilitate its entry into the target cell because it is an unstable and negatively charged molecule. For instance, mRNA that is given using lipid-nanoparticle-based vaccine delivery systems (LNPs) solely enters cells through endocytosis, establishing an endosome without damaging the cell membrane. The COVID-19 pandemic has accelerated the development of mRNA vaccine platforms used to treat and prevent several infectious diseases. This technology has the potential to change the future course of the disease by providing a safe and effective way to combat infectious diseases and cancer. A single-stranded genetic sequence found in mRNA vaccines instructs host cells to produce proteins inside ribosomes to elicit immunological responses and prepare the immune system to fight infections or cancer cells. The potential applications of mRNA vaccine technology are vast and can lead to the development of a preferred vaccine pattern. As a result, a new generation of vaccinations has gradually gained popularity and access to the general population. To adapt the design of an antigen, and even combine sequences from different variations in response to new changes in the viral genome, mRNA vaccines may be used. Current mRNA vaccines provide adequate safety and protection, but the duration of that protection can only be determined if further clinical research is conducted.

Long-term Mammography Screening Trends and Predictors of Return to Screening after the COVID-19 Pandemic: Results from a Statewide Registry.

Purpose To evaluate long-term trends in mammography screening rates and identify sociodemographic and breast cancer risk characteristics associated with return to screening after the COVID-19 pandemic. Materials and Methods In this retrospective study, statewide screening mammography data of 222 384 female individuals aged 40 years or older (mean age, 58.8 years ± 11.7 [SD]) from the Vermont Breast Cancer Surveillance System were evaluated to generate descriptive statistics and Joinpoint models to characterize screening patterns during 2000-2022. Log-binomial regression models estimated associations of sociodemographic and risk characteristics with post-COVID-19 pandemic return to screening. Results The proportion of female individuals in Vermont aged 50-74 years with a screening mammogram obtained in the previous 2 years declined from a prepandemic level of 61.3% (95% CI: 61.1%, 61.6%) in 2019 to 56.0% (95% CI: 55.7%, 56.3%) in 2021 before rebounding to 60.7% (95% CI: 60.4%, 61.0%) in 2022. Screening adherence in 2022 remained substantially lower than that observed during the 2007-2010 apex of screening adherence (66.1%-67.0%). Joinpoint models estimated an annual percent change of -1.1% (95% CI: -1.5%, -0.8%) during 2010-2022. Among the cohort of 95 644 individuals screened during January 2018-March 2020, the probability of returning to screening during 2020-2022 varied by age (eg, risk ratio [RR] = 0.94 [95% CI: 0.93, 0.95] for age 40-44 vs age 60-64 years), race and ethnicity (RR = 0.84 [95% CI: 0.78, 0.90] for Black vs White individuals), education (RR = 0.84 [95% CI: 0.81, 0.86] for less than high school degree vs college degree), and by 5-year breast cancer risk (RR = 1.06 [95% CI: 1.04, 1.08] for very high vs average risk). Conclusion Despite a rebound to near prepandemic levels, Vermont mammography screening rates have steadily declined since 2010, with certain sociodemographic groups less likely to return to screening after the pandemic. Keywords: Mammography, Breast, Health Policy and Practice, Neoplasms-Primary, Epidemiology, Screening Supplemental material is available for this article. © RSNA, 2024.

Reviewing the evidence of antimicrobial activity of glycols.

In the 1940s and 1950s, researchers seeking safe and novel ways to eliminate airborne pathogens from enclosed spaces, investigated glycol vapours as a method of disinfection. More recently, the COVID-19 pandemic highlighted the need for a non-toxic aerial disinfectant that can be used in the presence of people. This scoping review is intended to analyse the early and more recent literature on glycol disinfection, scrutinizing the methodologies used, and to determine if the use of glycols as modern-day disinfectants is justified PRISMA-ScR guidelines were used to assess the 749 articles retrieved from the Web of Science platform, with 46 articles retained after the search strategy was applied. Early studies generally demonstrated good disinfection capabilities against airborne bacteria and viruses, particularly with propylene glycol (PG) vapour. Vapour pressure, relative humidity, and glycol concentration were found to be important factors affecting the efficacy of glycol vapours. Contact times depended mainly on the glycol application method (i.e. aerosolization or liquid formulation), although information on how glycol efficacy is impacted by contact time is limited. Triethylene glycol (TEG) is deemed to have low toxicity, carcinogenicity, and mutagenicity and is registered for use in air sanitization and deodorization by the US Environmental Protection Agency. Glycols are also used in liquid formulations for their antimicrobial activity against a wide range of microorganisms, although when used as a non-active excipient in products, their contribution to antimicrobial efficacy is rarely assessed. The appropriate use of liquid glycol-containing formulations was found to positively impact the antimicrobial capabilities of disinfectants when used at temperatures <0, food preservatives, and dental medicaments. Providing modern delivery technology can accurately control environmental conditions, the use of aerosolized glycol formulations should lead to successful disinfection, aiding infection prevention, and control regimens.

COVID-19 pandemic and impact of universal face mask wear on ocular surface health and risk of infection.

Universal mask wear is an effective public health intervention to reduce SARS-Cov-2 transmission, especially in enclosed public spaces and healthcare environments. Concerns have been raised about possible transmission of the SARS-Cov-2 through ocular secretions, leading to enhanced protective measures during ophthalmic procedures. However, there is some evidence for air jets from the upper edge of the surgical mask to the ocular surface, especially when the mask is not well fit. Prolonged airflow towards the ocular surface during expiration may alter tear-film stability, leading to hyperosmolarity and ocular surface inflammation. This also raises the question of whether the ocular surface is contaminated with oral flora from airflow directed toward the eyes, thus increasing the risk of ocular infection. Herein we review the impact of patient face mask wear on the ocular surface, eyelids and risk of ocular infection, particularly during ocular surgery. There is some evidence for increased incidence of dry eye or eyelid disease during periods of mandatory face mask wear. While high daily exposure is consistent with a direct association, this should be mitigated by various cofounding factors which could also affect the ocular health during the COVID-19 pandemic. An increased risk of post-intravitreal injection endophthalmitis, possibly due to face mask wear by the patient, including culture-positive endophthalmitis, has been reported in one retrospective study. Several measures have been shown to prevent or limit the risk of developing dry eye disease or exacerbation, eyelid cyst, and ocular infection during intravitreal injections.

Physical Activity of School-Going Adolescents During the COVID-19 Pandemic: A Natural Experiment Study.

OBJECTIVE: To assess the impact of the COVID-19 pandemic associated governmental restrictions on physical activity and sedentary behavior of school-going adolescents in India and its effect on nutrition and health status. METHODS: This was a before-after natural experiment study that recorded paired data of 449 (206 boys) school-going adolescents. COVID-19 related governmental measures (March 24, 2020 till February 2021) were taken as the natural experiment. The change in proportion of adolescents who met the recommended amount of physical activity guidelines and change in sedentary and dietary behaviors and body mass index (BMI) were compared. RESULTS: The proportion of adolescents performing adequate physical activity decreased from 33.9% to 30.7% (OR 1.2,95% CI 0.9,1.6) during the pandemic. Fruit intake increased by 8.1% during the pandemic while junk food intake decreased by 17% during the pandemic. Mean (SD) BMI z-scores increased from -0.7 )1.4) to -0.5 )1.3) (P < 0.001). CONCLUSION: While there was a small decrease in the proportion of physically active adolescents during the pandemic, a shift towards healthier dietary habits was seen.

"Like not having an arm": a qualitative study of the impact of visitor restrictions on cancer care during the COVID-19 pandemic.

PURPOSE: Visitor restriction policies to prevent the spread of COVID-19 among patients and clinicians were widespread during the pandemic, resulting in the exclusion of caregivers at key points of cancer care and treatment decision-making. The aim of this study was to explore how visitor restrictions impacted cancer treatment decision-making and care from patient and physician perspectives. METHODS: Sixty-seven interviews, including 48 cancer patients and 19 cancer and palliative care physicians from four academic cancer centers in the USA between August 2020 and July 2021. RESULTS: Visitor restrictions that prevented caregivers from participating in clinic appointments and perioperative hospital care created challenges in cancer care that spanned three domains: practical, social, and informational. We identified eight themes that characterized challenges within the three domains across all three groups, and that these challenges had negative emotional and psychological consequences for both groups. Physicians perceived that patients' negative experiences due to lack of support through the physical presence of caregivers may have worsened patient outcomes. CONCLUSIONS: Our data demonstrate the tripartite structure of the therapeutic relationship in cancer care with caregivers providing critical support in the decision-making and care process to both patients and physicians. Caregiver absences led to practical, psychosocial, and informational burdens on both groups, and likely increased the risk of burnout among physicians. Our findings suggest that the quality of cancer care can be enhanced by engaging caregivers and promoting their physical presence during clinical encounters.

Video double-lumen tube for one lung ventilation: implementation and experience in 343 cases of routine clinical use during the first 20 months of the SARS-CoV-2 pandemic.

BACKGROUND: Double-lumen tubes (DLTs) are the preferred device for lung isolation. Conventional DLTs (cDLT) need a bronchoscopic position control. Visualisation of correct DLT positioning could be facilitated by the use of a video double-lumen tube (vDLT). During the SARS-CoV-2-pandemic, avoiding aerosol-generation was suggesting using this device. In a large retrospective series, we report both general and pandemic related experiences with the device. METHODS: All anesthesia records from patients aged 18 years or older undergoing surgery from April 1st, 2020 to December 31st, 2021 in the department of thoracic surgery requiring intraoperative lung isolation were analyzed retrospectively. RESULTS: During the investigation period 343 left-sided vDLTs (77.4%) and 100 left-sided cDLTs (22.6%) were used for one lung ventilation. In the vDLT group bronchoscopy could be reduced by 85.4% related to the cDLT group. Additional bronchoscopy to reach or maintain correct position was needed in 11% of the cases. Other bronchoscopy indications occured in 3.6% of the cases. With cDLT, in 1% bronchoscopy for other indications than conforming position was observed. CONCLUSIONS: The Ambu® VivaSight™ vDLT is an efficient, easy-to-use and safe airway device for the generation of one lung ventilation in patients undergoing thoracic surgery. The vDLT implementation was achieved easily with full interchangeability to the left-sided cDLT. Using the vDLT can reduce the need for aerosol-generating bronchoscopic interventions by 85.4%. Continuous video view to the carina enabling position monitoring of the DLT without need for bronchoscopy might be beneficial for both employee's and patient's safety.

Effectiveness of tailored talks between a cancer screening specialist and general practitioners to improve the uptake of colorectal cancer screening in Ancona (Italy) during the pandemic period.

BACKGROUND: Colorectal cancer (CRC) screening uptake in many countries has been low and further impacted by the COVID-19 pandemic. General Practitioners (GPs) are key facilitators, however research on their impact on organised CRC screening is still limited. OBJECTIVES: To evaluate the effectiveness of tailored talks with GPs to increase population uptake of the long-established CRC screening programme in Ancona province, Italy. METHODS: In this prospective cohort study, one-to-one tailored talks were organised in January 2020 between the GPs of one county of the province (with GPs from other counties as controls) and the screening programme physician-in-chief to discuss the deployment and effectiveness of organised screening. Data was extracted from the National Healthcare System datasets and linear regression was used to assess the potential predictors of CRC screening uptake. RESULTS: The mean CRC screening uptake remained stable from 39.9% in 2018-19 to 40.8% in 2020-21 in the 22 GPs of the intervention county, whereas it statistically significantly decreased from 38.7% to 34.7% in the 232 control GPs. In multivariate analyses, belonging to the intervention county was associated with an improved uptake compared to the control counties (+5.1%; 95% Confidence Intervals - CI: 2.0%; 8.1%). CONCLUSION: Persons cared for by GPs who received a tailored talk with a cancer screening specialist avoided a drop in CRC screening adherence, which characterised all other Italian screening programmes during the COVID-19 emergency. If future randomised trials confirm the impact of tailored talks, they may be incorporated into existing strategies to improve population CRC screening uptake.

Tailored talks on CRC screening were conducted between one cancer screening specialist and GPs.Even during the pandemic, CRC screening uptake was stable among persons cared for by GPs targeted by tailored talks.If confirmed by randomised trials, tailored talks may be employed to improve CRC screening uptake.

Effect of the COVID-19 pandemic on utilization of essential health services in Iran evidence from an interrupted time series analysis.

BACKGROUND: The COVID-19 disrupted the provision of essential health services in numerous countries, potentially leading to outbreaks of deadly diseases. This study aims to investigate the effect of the COVID-19 pandemic on the utilization of essential health services in Iran. METHODS: An analytical cross-sectional study was conducted using interrupted time series (ITS) analysis. Data about five indicators, including 'childhood vaccination, infant care, hypertension screening, diabetes screening, and breast cancer screening,' were obtained from the electronic health record System in two-time intervals: 15 months before (November 2018 to January 2020) and 15 months after (January 2020 to May 2021) the onset of the COVID-19 pandemic. The data were analyzed by utilizing ITS. In addition, a Poisson model was employed due to the usage of count data. The Durbin-Watson (DW) test was used to identify the presence of lag-1 autocorrelation in the time series data. All statistical analysis was performed using R 4.3.1 software, considering a 5% significance level. RESULTS: The ITS analysis showed that the COVID-19 pandemic significantly affected the utilization of all essential health services (P < 0.0001). The utilization of hypertension screening (RR = 0.51, p < 0.001), diabetes screening (RR = 0.884, p < 0.001), breast cancer screening (RR = 0.435, p < 0.001), childhood vaccination (IRR = 0.947, p < 0.001), and infant care (RR = 1.666, p < 0.001), exhibited a significant decrease in the short term following the pandemic (P < 0.0001). However, the long-term trend for all service utilization, except breast cancer screening (IRR = 0.952, p < 0.001), demonstrated a significant increase. CONCLUSIONS: The COVID-19 pandemic affected utilization of essential health care in Iran. It is imperative to utilize this evidence to develop policies that will be translated into targeted planning and implementation to sustain provision and utilization of essential health services during public health emergencies. It is also vital to raise awareness and public knowledge regarding the consequences of interruptions in essential health services. In addition, it is important to identify the supply- and demand-side factors contributing to these disruptions.

Influence of practice location on prescribing, diabetes care, and colorectal cancer screening among Czech general practitioners during the COVID-19 pandemic.

OBJECTIVES: The provision of primary health care was not interrupted during the coronavirus disease 2019 (COVID-19) pandemic in Czechia, although the capacity and resources of providers changed. We examined how the pandemic affected individual general practices throughout 2017-2021, focusing on differences between urban and rural practices. METHODS: We analysed data from the largest health insurance company in Czechia, which provides care to 4.5 million people (60% of the population). We evaluated the prescription volume, diabetes care procedures, and faecal immunochemical test (FIT) in preventive care and new pandemic-related procedures (remote consultations, testing, and vaccinations). For the spatial distribution of practices, we adapted the Organisation for Economic Cooperation and Development typology. RESULTS: We observed minimal declines in 2020 in the rate of prescribing (-1.0%) and diabetes care (-5.1%), with a rapid resumption in 2021, but a substantial decline in FIT (-17.8% in 2020) with slow resumption. Remote consultations were used by 94% of all practices regardless of location, with testing and vaccinations more commonly performed by rural general practitioners (GPs). CONCLUSIONS: Primary care in Czechia rose to the challenge of the COVID-19 pandemic, as shown by the finding that the volume of healthcare services provided through primary care did not decrease across most of the monitored parameters. This study also confirmed that rural GPs provide more care in-house, both in terms of prescribing and procedures performed in their practices. Future studies will need to focus on preventive care, which the pandemic has dampened in GP practices in Czechia.

Pandemic antecedents - Exploring predictivity and relationships between COVID-19 vaccine uptake and influenza, shingles, and HPV vaccination.

BACKGROUND: A wealth of extant research focuses on identifying barriers to, and predictors of, COVID-19 vaccination. In addition to treating COVID-19 vaccination and related experiences as antecedents, this study analyzes the relationships between COVID-19 vaccination experiences and intent to receive the flu, shingles, and HPV vaccines. METHOD: Analyses were performed on the responses from U.S. survey panel of 1,024 participants (n = 1,024), 530 (51.8 %) who received at least a dose of the COVID-19 vaccine and 494 (48.2 %) who had not. Descriptive and inferential statistics identify participant demographic characteristics, prior vaccination behavior, vaccination intentions, risk behavior assessment, vaccination attitudes and beliefs, and the predictivity of COVID-19 vaccination, when treated as an antecedent. RESULTS: Receiving a first dose of the COVID-19 vaccine interacted with receiving a past influenza vaccine, predicting the future intention to receive a COVID-19 vaccine or booster. Vaccine hesitancy in parents is significantly related to vaccination behaviors for themselves and their children. Analyses also showed differences between the vaccinated group (VG) and the unvaccinated group (UVG) on hesitancy, beliefs, and attitudes toward the COVID-19 vaccine. CONCLUSION: Experience with COVID-19 vaccination and the relationship of those experiences with other vaccinations provide useful insight on leveraging vaccine uptake. Healthcare professionals should improve the COVID-19 vaccination experience and use vaccination appointments to promote other vaccinations. Research should continue to compare vaccination experiences and how they may persuade or dissuade vaccination intent for other vaccinations.

How has the COVID-19 pandemic affected the delivery of preventive healthcare? An interrupted time series analysis of adults in English primary care from 2018 to 2022.

OBJECTIVE: Offering advice and support for smoking, obesity, excess alcohol, and physical inactivity is an evidence-based component of primary care. The objective was to quantify the impact of the pandemic on the rate of advice or referral for these four risk factors. METHODS: A retrospective cohort study using primary care data from 1847 practices in England and 21,191,389 patients contributing to the Oxford Clinical Informatics Digital Hub. An interrupted time series analysis was undertaken with a single change point (March 2020). Monthly trends were modelled from 1st January 2018 - 30th June 2022 using segmented linear regression. RESULTS: There was an initial step reduction in advice and referrals for smoking, obesity, excess alcohol, and physical inactivity in March 2020. By June 2022, advice on smoking (slope change -0.02 events per hundred patient years/month (EPH/month); 95% confidence interval (CI) -0.17, 0.21), obesity (0.06 EPH/month; 95% CI 0.01, 0.12), alcohol (0.02 EPH/month; 95% CI -0.01, 0.05) and physical inactivity (0.05 EPH/month; 95% CI 0.01, 0.09) had not returned to pre-pandemic levels. Similarly, smoking cessation referral remained lower (0.01 EPH/month; 95% CI -0.01, 0.09), excess alcohol referral returned to similar levels (0.0005 EPH/month; 95% CI 0.0002, 0.0008), while referral for obesity (0.14 EPH/month; 95% CI 0.10, 0.19) and physical inactivity (0.01 EPH/month; 95% CI 0.01, 0.02) increased relative to pre-pandemic rates. CONCLUSION: Advice and support for smoking, and advice for weight, excess alcohol and physical inactivity have not returned to pre-pandemic levels. Clinicians and policy makers should prioritise preventive care in COVID-19 recovery plans.

Changes in Viral Dynamics Following the Legal Relaxation of COVID-19 Mitigation Measures in Japan From Children to Adults: A Single Center Study, 2020-2023.

INTRODUCTION: Respiratory infections are an ongoing global health challenge. The COVID-19 pandemic triggered global nonpharmacological measures that reshaped public health. In Japan, the shift from legal to individual discretion in pandemic management started on May 8, 2023. However, it still unknown how the relaxation of measures affects respiratory pathogens across age groups. METHODS: We collected 16,946 samples from 13,526 patients between February 2020 and September 2023, analyzing the circulating respiratory pathogen dynamics using FilmArray respiratory panel. RESULTS: Our analysis revealed significant increases in the positivity rates of respiratory pathogens across multiple age groups after relaxation. The pathogens including adenovirus, Bordetella pertussis, parainfluenza 2 and parainfluenza 4 showed increased positivity predominantly in children aged under 10 years. Conversely, some pathogens including human metapneumovirus, rhinovirus/enterovirus, and respiratory virus (RSV) increased in broad range of age groups. SARS-CoV-2 positivity rates decreased in children under 10 years but increased in those aged over 60 years. DISCUSSION: Age-stratified analysis reveals a dynamic pattern of circulating pathogen in each age group after relaxation measures. This study provides essential epidemiologic data that can guide strategies to protect different age groups and effectively respond to respiratory infections in post-COVID-19 era.

On the impact of mass screening for SARS-CoV-2 through self-testing in Greece.

Background: Screening programs that pre-emptively and routinely test population groups for disease at a massive scale were first implemented during the COVID-19 pandemic in a handful of countries. One of these countries was Greece, which implemented a mass self-testing program during 2021. In contrast to most other non-pharmaceutical interventions (NPIs), mass self-testing programs are particularly attractive for their relatively small financial and social burden, and it is therefore important to understand their effectiveness to inform policy makers and public health officials responding to future pandemics. This study aimed to estimate the number of deaths and hospitalizations averted by the program implemented in Greece and evaluate the impact of several operational decisions. Methods: Granular data from the mass self-testing program deployed by the Greek government between April and December 2021 were obtained. The data were used to fit a novel compartmental model that was developed to describe the dynamics of the COVID-19 pandemic in Greece in the presence of self-testing. The fitted model provided estimates on the effectiveness of the program in averting deaths and hospitalizations. Sensitivity analyses were used to evaluate the impact of operational decisions, including the scale of the program, targeting of sub-populations, and sensitivity (i.e., true positive rate) of tests. Results: Conservative estimates show that the program reduced the reproduction number by 4%, hospitalizations by 25%, and deaths by 20%, translating into approximately 20,000 averted hospitalizations and 2,000 averted deaths in Greece between April and December 2021. Conclusion: Mass self-testing programs are efficient NPIs with minimal social and financial burden; therefore, they are invaluable tools to be considered in pandemic preparedness and response.