Pre-vaccination Period Research Articles

Differences in SARS-CoV-2 antibody prevalence at the end of the pre-vaccination period between age groups: A cross-sectional analysis of the multi-ethnic population-based HELIUS study.

During the first waves of the COVID-19 pandemic, SARS-CoV-2 antibody prevalence (seroprevalence) was lower in older compared to younger adults. We studied age group differences in SARS-CoV-2 seroprevalence, across ethnic groups, and assessed the explanatory value of factors that increase the exposure to the virus, and factors related to susceptibility, given the level of exposure. We analysed cross-sectional data from 2,064 participants from the multi-ethnic HELIUS study (Amsterdam, The Netherlands). SARS-CoV-2 seroprevalence at the second wave of infections was compared between age groups (<40, 40-54, and ≥55 years), within ethnic groups, using Poisson regression with robust standard errors. To determine whether age group differences were explained by differences in exposure and in susceptibility, we sequentially adjusted for exposure (job setting, occupation level, health literacy, household size, household member with suspected infection), education level, and susceptibility (vitamin D intake, BMI, systolic blood pressure, haemoglobin level, number of comorbidities). SARS-CoV-2 seroprevalence did not statistically differ across age groups (p>0.05), but age patterns varied across ethnic groups. Age group differences in SARS-CoV-2 seroprevalence were most pronounced in the Dutch majority group, with the highest prevalence ratio in the youngest group (2.55, 95%CI 0.93-6.97) and the lowest in the oldest group (0.53, 95%CI 0.16-1.74), compared to the middle-aged group. In ethnic minority groups, age group differences were smaller. In all groups, patterns did not substantially change after adjustments for exposure and susceptibility variables. We found no evidence of age group differences in SARS-CoV-2 seroprevalence, particularly for ethnic minority groups, even when accounting for exposure and susceptibility. While early prevention strategies particularly aimed at protecting older adults against SARS-CoV-2 infections, seroprevalence was similar across age groups in ethnic minority groups. Thus, older adults in ethnic minority groups may pose a target group for additional prevention strategies for future infectious disease outbreaks.

Salivary assessment of the immune/inflammatory responses and oxidative stress in older adults vaccinated with CoronaVac or ChadOx-1

BackgroundAlthough important information concerning COVID-19 vaccination is available, the effects of the CoronaVac and ChadOx-1 vaccines on immunity and the redox balance in the upper airway mucosa of the aged population are not fully understood. Therefore, the aim of this study was to investigate the impacts of two doses of the CoronaVac or ChadOx-1 vaccine on immune/inflammatory responses and oxidative stress in the airway mucosa of older adults.MethodsSeventy-six older adults of both sexes, with a mean age of 75.1 ± 6.4 years, were separated according to vaccination status into the CoronaVac (n = 52) and ChadOx-1 (n = 24) groups. Saliva samples were collected before (pre) and 30 days after (post) the administration of the second dose of the CoronaVac or ChadOx-1 vaccine to assess the levels of antibodies (sIgA and IgG), antimicrobial peptides, cytokines, and oxidant/antioxidant agents.ResultsThe immunogenicity in the ChadOx-1 group was 37.5% for sIgA and 25% for IgG, while that in the CoronaVac group was 18.9% for sIgA and 13.2% for IgG. Intergroup analysis revealed that (1) lower levels of IFN-α, IFN-γ, and IL-10 and a greater IFN-γ/IL-10 ratio, in addition to a greater IL-6/IL-10 ratio, were found in both the pre- and postvaccination periods, and (2) lower levels of total sIgA, IL-12p70, IL-17A, TNF-α, and the IL-12p70/IL-10 ratio, in addition to higher levels of specific sIgA for SARS-CoV-2 antigens and lysozyme, were observed only in the postvaccination period in the ChadOx-1 group than in the CoronaVac group. Intragroup analysis revealed (1) a significant increase in the salivary levels of total peroxides in the postvaccination period compared to those in the prevaccination period in both volunteer groups; (2) a decrease in the levels of lysozyme and the ratio between total antioxidant capacity (TAC) and total peroxides in the postvaccination period in the CoronaVac group compared with those in the prevaccination period; and (3) decreases in the TNF-α, IL-6, and IL-12p70 levels, and the IL-12p70/IL-10 ratio in the ChadoX-1 group, as well as a higher lactoferrin concentration in the postvaccination period than in the prevaccination period. Several positive and negative correlations between the parameters assessed here were found.ConclusionsIn general, the ChadOx-1 group exhibited improvements in both immune/inflammatory responses and redox balance and greater immunogenicity than did the CoronaVac group.

Inborn errors of immunity are associated with increased COVID-19-related hospitalization and intensive care compared to the general population

BackgroundIt is thought that patients with inborn errors of immunity (IEI) are more susceptible to severe Covid-19 than the general population, but a quantification of this potential risk is largely missing. ObjectiveTo assess the impact of Covid-19 on patients with IEI. MethodsA nationwide cohort study was performed to estimate the relative risk (RR) for hospitalization, intensive care, and death within 30 days after a positive SARS-CoV-2 test in an IEI population (n=2392) compared to the general population (n=8,270,705) using data from Swedish national registries. Three time-periods were studied: Pre-vaccination, Alpha/Delta, and Omicron. Adjustment was made for demographics, income, comorbidities, and vaccination status. ResultsDuring the Pre-vaccination period 25.2% of the IEI population were hospitalized, compared to 17.5% and 5.2% during the Alpha/Delta and Omicron periods, respectively. For the three time periods the adjusted RR for hospitalization in the IEI population compared to the general population was 3.1 [95% CI 2.1–4.2], 3.5 [2.4–4.8], and 4.3 [2.5–6.7], respectively. The adjusted RR for intensive care after Covid-19 were 5.6 [2.6–10.8], 4.7 [1.7–10.1], and 4.7 [1.7–10.1] for the three periods. Five patients (0.6%) in the IEI population died within 30 days of a positive PCR test compared to 18,773 (0.2%) in the general population during the three study periods. ConclusionPatients with IEI had 3-4 times higher risk for hospitalization and 5 times higher risk for intensive care during Covid-19, compared to the general population.

Pediatric Varicella-related Hospitalization in Turkey Between 2008 and 2018: Impact of Universal Single Dose Varicella Vaccine (VARICOMP Study).

A single-dose varicella vaccine at 12 months of age was introduced to the National Immunization Program in February 2013 in Turkey. This study aimed to evaluate varicella-related hospitalization in children and the impact of a single-dose live attenuated varicella vaccine over the first 5.5 years of introducing a universal varicella vaccination. We analyzed data collected from the medical records of children <18 years old who required hospitalization due to varicella in 17 cities representing 50% of the childhood population in Turkey between 2008 and 2018. We calculated the rate of hospitalization for varicella per 100,000 children during the study period. The main objective of this study was to determine the yearly rate of hospitalization due to varicella and to compare these rates in the pre-vaccine and post-vaccine periods. The secondary objective was to compare demographic features, varicella-related complications, and outcomes between the pre-vaccine and post-vaccine periods. A total of 4373 children (2458 boys and 1915 girls; 72.3% previously healthy) were hospitalized for varicella over a 10-year period, including 2139 children during the pre-vaccine period and 2234 children during the post-vaccine period. Overall, varicella hospitalization rates decreased significantly after the introduction of varicella vaccination [pre-vaccine vs. post-vaccine period; 3.79 vs. 2.87 per 100,000 per year; P < 0.001; odds ratio 0.75; 95% confidence interval 0.64-0.88]. The incidence of varicella-related hospitalization among children between 1 and 5 years of age was significantly lower in the post-vaccine era than in the pre-vaccine era, with a 60.2% decrease in hospitalizations (2.43 vs. 6.12 per 100,000 children; P < 0.001, odds ratio 0.39; 95% confidence interval 0.34-0.46). In both the <1-year and 6- to 10-year age groups, the incidence of varicella-related hospitalizations was similar in the pre-vaccine and post-vaccine periods. The incidence of varicella-related hospitalization was higher in the post-vaccine era among 11-15 years and >15-year-old groups (P < 0.01 and P < 0.05). The mean age was higher during the post-vaccine period than during the pre-vaccine period (P < 0.001). The absolute number of secondary bacterial infections (P < 0.01), respiratory complications (P < 0.01), and neurological complications (P < 0.001) was significantly lower during the post-vaccine period. The incidence of severe varicella was lower during the post-vaccine period than during the pre-vaccine period (P < 0.001). After 5.5 years of routine single-dose varicella vaccine use, we observed the impact of varicella vaccination on the incidence of varicella-related hospitalizations, especially in the target age group. However, we did not observe herd protection in the other age groups. The implementation of a second dose of the varicella vaccine in the National Immunization Program would help control disease activity.

Seroprevalence trends of anti-SARS-CoV-2 antibodies in the adult population of the São Paulo Municipality, Brazil: Results from seven serosurveys from June 2020 to April 2022. The SoroEpi MSP Study.

Sequential population-based household serosurveys of SARS-CoV-2 covering the COVID-19 pre- and post-vaccination periods are scarce in Brazil. This study investigated seropositivity trends in the municipality of São Paulo. We conducted seven cross-sectional surveys of adult population-representative samples between June 2020 and April 2022. The study design included probabilistic sampling, test for SARS-CoV-2 antibodies using the Roche Elecsys anti-nucleocapsid assay, and statistical adjustments for population demographics and non-response. The weighted seroprevalences with 95% confidence intervals (CI) were estimated by sex, age group, race, schooling, and mean income study strata. Time trends in seropositivity were assessed using the Joinpoint model. We compared infection-induced seroprevalences with COVID-19 reported cases in the pre-vaccination period. The study sample comprised 8,134 adults. The overall SARS-CoV-2 seroprevalence increased from 11.4% (95%CI: 9.2-13.6) in June 2020 to 24.9% (95%CI: 21.0-28.7) in January 2021; from 38.1% (95%CI: 34.3-41.9) in April 2021 to 77.7% (95%CI: 74.4-81.0) in April 2022. The prevalence over time was higher in the subgroup 18-39 years old than in the older groups from Survey 3 onwards. The self-declared Black or mixed (Pardo) group showed a higher prevalence in all surveys compared to the White group. Monthly prevalence rose steeply from January 2021 onwards, particularly among those aged 60 years or older. The infection-to-case ratios ranged from 8.9 in June 2020 to 4.3 in January 2021. The overall seroprevalence rose significantly over time and with age and race subgroup variations. Increases in the 60 years or older age and the White groups were faster than in younger ages and Black or mixed (Pardo) race groups in the post-vaccination period. Our data may add to the understanding of the complex and changing population dynamics of the SARS-CoV-2 infection, including the impact of vaccination strategies and the modelling of future epidemiological scenarios.

Long-term impact of rotavirus vaccination on all-cause and rotavirus-specific gastroenteritis and strain distribution in Central Kenya: An 11-year interrupted time-series analysis

Background: Kenya introduced a monovalent rotavirus vaccine administered orally at 6 and 10 weeks of age into her National Immunization Program in July 2014. The study evaluated the long-term impact of the vaccine on hospitalization for all-cause and rotavirus-specific acute gastroenteritis (AGE) and strain epidemiology in Kenya. Methods: Data on all-cause and rotavirus-specific AGE and strain distribution were derived from an eleven-year hospital-based surveillance of AGE among children aged <5 years at Kiambu County Teaching and Referral Hospital (KCTRH) in Central Kenya between 2009 and 2020. Fecal samples were screened for group A rotavirus using ELISA and genotyped using multiplex semi-nested RT-PCR. Trends in all-cause and rotavirus-related AGE and strain distribution were compared between the pre-vaccine (July 2009–June 2014), early post-vaccine (July 2014–June 2016) and late post-vaccine (February 2019–October 2020) periods. Results: Rotavirus-specific AGE was detected at 27.5% (429/1546, 95% CI: 25.5–30.1%) in the pre-vaccine period; 13.8% (91/658, 95% CI: 11.3–16.6%) in the early post-vaccine period (July 2014–June 2016); and 12.0% (229/1916, 95% CI: 10.6–13.5%) in the late post-vaccine period (February 2019–October 2020). This amounted to a decline of 49.8% (95% CI: 34.6%–63.7%) in rotavirus-specific AGE in the early post-vaccine period and 53.4% (95% CI: 41.5–70.3%) in the late post-vaccine period when compared to the pre-vaccine period. All-cause AGE hospitalizations declined by 40.2% (95% CI: 30.8%–50.2%) and 75.3% (95% CI: 65.9–83.1%) in the early post-vaccine and late post-vaccine periods, respectively, when compared to the pre-vaccine period. G3P [8] was the predominant strain in the late post-vaccine period, replacing G1P[8] which had predominated in the pre-vaccine and early post-vaccine periods. Additionally, we detected considerable proportions of uncommon strains G3P[6] (4.8%) and G12P[6] (3.5%) in the post-vaccine era. Conclusion: Rotavirus vaccination has resulted in a significant decline in all-cause and rotavirus-specific AGE, and thus, provides strong evidence for public health policy makers in Kenya to support the sustained use of the rotavirus vaccine in routine immunization. However, the shift in strain dominance and age distribution of rotavirus AGE in the post-vaccine era underscores the need for continued surveillance to assess any possible vaccine-induced selective pressure that could diminish the vaccine effectiveness over time.

Assessing marginal effects of non-pharmaceutical interventions on the transmission of SARS-CoV-2 across Africa: a hybrid modeling study.

Since 2019, a new strain of coronavirus has challenged global health systems. Due its fragile healthcare systems, Africa was predicted to be the most affected continent. However, past experiences of African countries with epidemics and other factors, including actions taken by governments, have contributed to reducing the spread of SARS-CoV-2. This study aims to assess the marginal impact of non-pharmaceutical interventions in fifteen African countries during the pre-vaccination period. To describe the transmission dynamics and control of SARS-CoV-2 spread, an extended time-dependent SEIR model was used. The transmission rate of each infectious stage was obtained using a logistic model with NPI intensity as a covariate. The results revealed that the effects of NPIs varied between countries. Overall, restrictive measures related to assembly had, in most countries, the largest reducing effects on the pre-symptomatic and mild transmission, while the transmission by severe individuals is influenced by privacy measures (more than $10\%$). Countries should develop efficient alternatives to assembly restrictions to preserve the economic sector. This involves e.g. training in digital tools and strengthening digital infrastructures.

Comparative analysis of COVID-19-associated venous thromboembolism outcomes: evolution from 2020 to 2021-2022.

Patients with COVID-19 are at an increased risk for venous thromboembolism (VTE). With the advent of vaccinations and novel treatments from 2020 through 2022, the landscape of COVID-19 has evolved. Notably, the effects of such interventions on the outcomes of COVID-19-associated VTE have not been thoroughly examined. Data from the RIETE registry were analyzed to evaluate 90-day VTE-related outcomes (all-cause mortality, major bleeding, and VTE recurrences) in patients with COVID-19-associated VTE. We compared the periods before and after the widespread introduction of COVID-19 vaccines: March to December 2020 (pre-vaccine period) and March 2021 to December 2022 (post-vaccine period). Statistical analysis included mixed-effects parametric survival-time models. Among 1,620 patients with COVID-19-associated VTE, most (74.1%) were identified during 2020 period. The analysis revealed a more than two-fold increase in the risk of death within 90days (adjusted hazard ratio [HR]: 2.27; 95% confidence interval, CI: 1.18-4.38) and major bleeding (adjusted HR: 2.91; 95%CI: 1.08-7.84) for patients from the 2020 period compared to those from the 2021-2022 period. Inpatient subgroup analysis confirmed the observed mortality differences. The frequency of recurrent VTE was low (1.1 vs. 0.7%, respectively), and did not show significant variation between the two periods. Our research provides a comparative perspective on the clinical outcomes of COVID-19-associated VTE before and after the introduction of vaccines. Our findings reveal a significant decrease in the incidence of 90-day mortality and major bleeding in patients with COVID-19-associated VTE in the 2021-2022 period.

Demographic changes in COVID-19 mortality during the pandemic: analysis of trends in disparities among workers using California’s mortality surveillance system

BackgroundThere is limited information on the extent and patterns of disparities in COVID-19 mortality throughout the pandemic. We aimed to examine trends in disparities by demographics over variants in the pre- and post-vaccine availability period among Californian workers using a social determinants of health lens.MethodsUsing death certificates, we identified all COVID-19 deaths that occurred between January 2020 and May 2022 among workers aged 18–64 years in California (CA). We derived estimates for at-risk worker populations using the Current Population Survey. The waves of COVID-19 mortality in the pre-vaccine availability period were March 2020-June 2020 (wave 1), and July 2020-November 2020 (wave 2), and in the post-vaccine availability period: December 2020-May 2021 (wave 3), June 2021-January 2022 (wave 4), and February 2022-May 2022 (wave 5). Poisson regression models with robust standard errors were used to determine wave-specific mortality rate ratios (MRRs). We examined the change in MRR across waves by including an interaction term between each demographic characteristic and wave period in different models. The role of potential misclassification of Race/ethnicity on death certificates was examined using probabilistic quantitative bias analysis as sensitivity analysis.ResultsAmong the 24.1 million working age CA population included in the study, there were 26,068 COVID-19 deaths in the period between January 2020 and May 2022. Compared with their respective reference groups, workers who were 50–64 years old, male, Native Hawaiian, Latino, or African American, foreign-born; individuals who had lower education; and unmarried were disproportionately affected by COVID-19 mortality. While disparities by sex, race/ethnicity and foreign-born status narrowed in later waves (post-vaccine availability), disparities by age, education level and marital status did not change substantially across waves.ConclusionDemographic disparities in COVID-19 mortality narrowed in the post-vaccine availability waves. However, the existence of disparities across all waves of the pandemic, even in an era of widespread vaccine coverage, could indicate remaining gaps in prevention and differential vulnerability. Addressing the underlying social, structural, and occupational factors that contribute to these disparities is critical for achieving health equity.

Incidence of adverse events of the Covid-19 vaccine in a population of kidney transplant recipients

Introducción: Early published series suggest that most renal transplant recipients remain at high risk of SARS-CoV-2 infection due to poor humoral response after vaccination. The aim was to study the occurrence of adverse events after two doses of mRNA-1273 vaccine in a population of renal transplant recipients.Material and Method: Analytical, observational, and prospective study. Subjects were injected with two doses of mRNA-1273 vaccine against SARS-CoV-2 according to the schedule established by the laboratory. After injection of each dose, and up to 72 hours later, participants recorded local and/or systemic symptoms and their intensity.Results: 187 patients were included. Eighteen percent of them became infected with SARS-CoV-2 in the pre-vaccination period or between the 1st and 2nd dose. The incidence of adverse events was 91.2%. Of these, the incidence of local (62%) was higher than that of systemic (55%). Past infection was a risk factor for the occurrence of local adverse events after vaccination (OR= 2.4; p=0.045). The same association was detected for systemic adverse events, which were more frequent among those who had passed the disease (OR=3.83; p=0.003).Conclusions: The mRNA-1273 vaccine does not appear to cause serious side effects. The incidence of local and systemic adverse events was higher in those patients with past disease.

Temporal Trends in SARS-CoV-2 Antibody Levels Among COVID-19 Patients in Kerala During the First Wave and Pre-vaccination Period.

The SARS-CoV-2 virus interacts with host cells through the S1 domain of its spike protein. This study measures the IgG immune response to this domain in COVID-19 patients from Kerala, India, and explores its association with various health factors. A cohort of 258 COVID-19 patients was analyzed for IgG antibodies targeting the S1 spike protein domain. The temporal pattern of the IgG response and its correlation with hospitalization needs, intensive care, and pre-existing conditions such as diabetes, hypertension, and coronary artery disease were assessed. A significant IgG response (76.4%) was detected, indicating robust immune activation post-infection. The IgG levels peaked between two tofour and four to eight weeks post-infection, with a notable increase at 12 weeks, hinting at possible secondary exposure or an immune memory response. No correlation was found between IgG levels and the presence of diabetes mellitus, hypertension, or coronary artery disease. However, higher IgG responses correlated with the severity of the infection, as seen in patients requiring hospitalization or intensive care. The IgG response to the S1 spike protein domain serves as a potential marker of immune activation in COVID-19. It reflects the body's defense mechanism against the virus and may predict disease severity and outcomes. The findings suggest that IgG levels could be indicative of the viral load, inflammatory response, and possibly the likelihood of protection against reinfection.

Long term impact of COVID-19 pandemic on mammographic breast cancer screening.

1597 Background: The impact of COVID19 pandemic on patient health beliefs and healthcare systems has adversely affected mammographic breast cancer screening (MBCS) during the initial stages of the pandemic. The aims of our study were to determine whether the initial decrease in MBCS rates persisted or if there was a rebound in later stages and to quantify the impact on urban and rural populations. Methods: This retrospective observational study analyzed data from March 2017 to March 2023 to assess whether eligible women received annual MBCS during this timeframe. We included women aged 40-75 years, drawn from the integrated Mayo Clinic system, encompassing nearly 60 primary care practices in Arizona, Florida, Iowa, Minnesota, and Wisconsin, representing a broad cross-section of the United States (US) population. US census data was utilized to classify a county as urban or rural. We divided the study period into 4 categories:1) pre-COVID-19 pandemic (March 1, 2017-March 10, 2020), 2) early pandemic (March 11, 2020-March 10, 2021; pre-vaccination period), 3) mid- pandemic (March 11, 2021-March 10, 2022; delta and omicron variant dominant period), and 4) late pandemic (March 11, 2022-March 1, 2023; recovery period). Utilizing the Poisson regression model, we compared the incidence rate ratio (IRR) for rates of MBCS across the 4 predefined time periods. Multivariable modeling was performed to assess the significance of MBCS rates with urbanicity while controlling for the year (2017-2022) and age. Results: By race and ethnicity, the women in this cohort were White (92%), Black (3.1%), Asian (3%) and other (1.9%). The median age was 57 years and the cohort included 239, 804 women aged 40-75 years. MBCS rates was 49.2% in 2017, 47.1% in 2018, 46.4% in 2019, and decreased to 42.1% in 2020 and improved to 44.7% in 2021 and 43.8% in 2022. Compared with the pre-COVID-19 pandemic period, there was a significant decrease in MBCS rate in the early pandemic (IRR= 0.886, 95% CI 0.879, 0.892, p&lt;0.001). Though the MBCS rate improved in the mid-pandemic period, it remained below the pre-pandemic level (IRR=0.941, 95% CI 0.934, 0.948, p&lt;0.001). Similarly, during the late stage of the pandemic, the MBCS rate remained lower than the pre-pandemic level (IRR=0.922, 95% CI 0.915, 0.928, p&lt;0.001). Rural counties had a lower MBCS rate compared with urban counties (IRR = 0.936, 95% CI 0.931, 0.941, p&lt;0.001). Conclusions: This study confirms the negative impact of the early COVID-19 pandemic on MBCS, and it revealed its persistent effect, as the current MBCS rate remains below the pre-pandemic rate. These findings were more evident in rural counties. Factors contributing to the long-lasting impact are being analyzed with the intent to develop and implement targeted solutions to improve the MBCS rate.

Estimates of SARS-CoV-2 Hospitalization and Fatality Rates in the Prevaccination Period, United States.

Few precise estimates of hospitalization and fatality rates from COVID-19 exist for naive populations, especially within demographic subgroups. We estimated rates among persons with SARS-CoV-2 infection in the United States during May 1-December 1, 2020, before vaccines became available. Both rates generally increased with age; fatality rates were highest for persons >85 years of age (24%) and lowest for children 1-14 years of age (0.01%). Age-adjusted case hospitalization rates were highest for African American or Black, not Hispanic persons (14%), and case-fatality rates were highest for Asian or Pacific Islander, not Hispanic persons (4.4%). Eighteen percent of hospitalized patients and 44.2% of those admitted to an intensive care unit died. Male patients had higher hospitalization (6.2% vs. 5.2%) and fatality rates (1.9% vs. 1.5%) than female patients. These findings highlight the importance of collecting surveillance data to devise appropriate control measures for persons in underserved racial/ethnic groups and older adults.

Rotavirus strains in children less than 5 years of age: A case control study

BackgroundGlobally, rotavirus A (RV) is a leading cause of acute gastroenteritis (AGE) in young children under 5 years. The main aim of this study was to describe the prevalence of RV in children with and without diarrhea whose age ranged from 3 months to 5 years from two different hospitals of Nepal. We also described the diversity of rotavirus circulating during the pre-vaccination period in Nepal between 2006–2009. Materials and methodsA total of 2400 stool samples collected from children's years with diarrhea (cases, N = 1200) and without diarrhea (controls, N = 1200) were tested for the presence of RV by both enzyme-linked immunosorbent assay and real-time reverse transcription polymerase chain reaction (RT-PCR). All samples positive for RT PCR and/or ELISA were further characterized for G and P genotypes by conventional RT-PCR. ResultsIn total, 500 of the 2398 (20.8 %) samples (424 cases and 76 controls), were positive for RV. The most frequently detected G-types were G12, G1, and G9 and P-types were P[8] and P[6]. The predominant genotypes G12P[6], G12P[8], G1P[8] and G9P[8] were identified in 27.8 %, 24.2 %, 11.8 % and 10.8 % of the samples, respectively. ConclusionThis study observed high prevalence of G12P[6] rotavirus circulating in Nepal before vaccine introduction and they may pose an emerging challenge to current and future vaccine. Therefore, continuous molecular surveillance of circulating genotypes and emerging rotavirus strain should be carried out to better understand the effectiveness of vaccination program.

Serotype diversity of &lt;i&gt;Streptococcus pneumoniae&lt;/i&gt; in children with chronic bronchopulmonary pathology in the pre-vaccination and post-vaccination periods

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Analysis of the fight against the COVID-19 pandemic in long-term care facilities in the pre-vaccination period

IntroductionThe COVID-19 pandemic has disproportionately affected individuals residing in Long-Term Care Facilities (LTCFs), necessitating tailored strategies to manage outbreaks. This study examines the outcomes of the ILPI BH project, a collaborative effort between the Municipal Health Department and the Hospital das Clínicas of the Federal University of Minas Gerais, designed to mitigate COVID-19 spread within LTCFs. MethodsProspective cohort of secondary data: 1,794 old residents in 99 long-term care facilities of Belo Horizonte, Brazil, were followed from May 2020 to January 2021. The study analyzed the prevention strategies, residents’ clinical data, and the characteristics of the long-term care facilities, correlating these variables with the number of infections, hospitalizations, and deaths from COVID-19. It checked absolute numbers and rates of incidence, hospitalization, mortality, and lethality. ResultsThere have been 58 COVID-19 outbreaks in long-term care facilities. There were 399 cases among residents, 96 hospitalizations for COVID-19 and 48 deaths from COVID-19 (2.7 % of the cohort), with a case fatality rate of 12 %. After multivariate analysis, the intrinsic variables to residents associated with higher mortality risk were higher degree of frailty (OR=1.08; p = 0.004) and the fact of living in a long-term care facility with a considerable proportion of residents’ coverage by health plans (OR = 1.01; p = 0.028). Early geriatric follow-up showed an association with a reduction in the number of hospitalizations due to COVID-19. ConclusionThe correct classification of the degree of frailty of institutionalized older people seems to have been relevant for predicting mortality from COVID-19. The extensive assistance by private health plans, contrary to what is supposed, did not result in better health protection. Early geriatric follow-up was beneficial and may be an attractive strategy in the face of health emergencies that affect long-term care facilities to reduce hospital admissions.

Monitoring HPV Prevalence and Risk Cofactors for Abnormal Cytology in the Post-Vaccination Period among Croatian Women.

The incidence and mortality rate of cervical cancer in Croatia remains a health challenge despite screening efforts. Besides the persistent infection with HPV, the development of cancer is also associated with some cofactors. The goal of this study was to assess circulating HPV genotypes and risk factors for the development of cervical precancer after almost 16 years from the onset of HPV vaccination in Croatia. In this study, a total of 321 women attending gynecological care were evaluated. Relevant medical and demographic information, including cytology, were collected. HPV genotyping was performed by PCR. Comparing the HPV types found in circulation in the pre-vaccination (1999-2015) and post-vaccination periods (2020-2023), a statistically significant reduction in HPV 31 was noted, while the overall prevalence increased in the post-vaccination period. Besides the expected HPV positivity as a risk factor, the history of smoking was associated with LSIL or worse cytology at enrollment. For the first time, this population study revealed a statistically significant shift in the HPV genotype in the post-vaccination period, as well as the confirmation of risk factors for the development of abnormal cytology among Croatian women.

Vaccine Safety and Immunogenicity in Patients With Multiple Sclerosis Treated With Natalizumab

Vaccination in patients with highly active multiple sclerosis (MS) requiring prompt treatment initiation may result in impaired vaccine responses and/or treatment delay. To assess the immunogenicity and safety of inactivated vaccines administered during natalizumab treatment. This self-controlled, prospective cohort study followed adult patients with MS from 1 study center in Spain from September 2016 to February 2022. Eligible participants included adults with MS who completed immunization for hepatitis B virus (HBV), hepatitis A virus (HAV), and COVID-19 during natalizumab therapy. Data analysis was conducted from November 2022 to February 2023. Patients were categorized according to their time receiving natalizumab treatment at the time of vaccine administration as short-term (≤1 year) or long-term (>1 year). Demographic, clinical, and radiological characteristics were collected during the year before vaccination (prevaccination period) and the year after vaccination (postvaccination period). Seroprotection rates and postvaccination immunoglobulin G titers were determined for each vaccine within both periods. Additionally, differences in annualized relapse rate (ARR), new T2 lesions (NT2L), Expanded Disability Status Scale (EDSS) scores, and John Cunningham virus (JCV) serostatus between the 2 periods were assessed. Sixty patients with MS (mean [SD] age, 43.2 [9.4] years; 44 female [73.3%]; 16 male [26.7%]; mean [SD] disease duration, 17.0 [8.7] years) completed HBV, HAV, and mRNA COVID-19 immunization during natalizumab treatment, with 12 patients in the short-term group and 48 patients in the long-term group. The global seroprotection rate was 93% (95% CI, 86%-98%), with individual vaccine rates of 92% for HAV (95% CI, 73%-99%), 93% for HBV (95% CI, 76%-99%), and 100% for the COVID-19 messenger RNA vaccine (95% CI, 84%-100%). Between the prevaccination and postvaccination periods there was a significant reduction in the mean (SD) ARR (0.28 [0.66] vs 0.01 [0.12]; P = .004) and median (IQR) NT2L (5.00 [2.00-10.00] vs 0.81 [0.00-0.50]; P = .01). No changes in disability accumulation were detected (median [IQR] EDSS score 3.5 [2.0-6.0] vs 3.5 [2.0-6.0]; P = .62). No differences in safety and immunogenicity were observed for all vaccines concerning the duration of natalizumab treatment. The findings of this cohort study suggest that immunization with inactivated vaccines during natalizumab therapy was both safe and immunogenic, regardless of the treatment duration. Natalizumab may be a valuable option for proper immunization, averting treatment delays in patients with highly active MS; however, this strategy needs to be formally evaluated.

Sustained Decline in Hospitalisations for Anogenital Warts in Australia: Analysis of National Hospital Morbidity Data 2003-2020.

In Australia, school-based human papillomavirus (HPV) vaccination was introduced initially for girls in 2007, and then also for boys in 2013. While studies have shown declines in the incidence of anogenital warts, there is a paucity of recent data analysis assessing the impact of vaccination on more severe disease. The National Hospital Morbidity Database of the Australian Institute of Health and Welfare (AIHW) hospitalisation admission data that included ICD-10-AM code A63.0 ('anogenital warts') as the diagnoses, for the years 2003-2020, were analysed to estimate hospitalisation rates per 100,000 mid-year population. The annual average hospitalisation rates per 100,000 population for anogenital warts in both genders combined in the age groups 10-19 years, 20-29 years, and 30-39 years decreased, respectively, from 16.9, 49.6, and 23.6 in 2003-2007 (pre-vaccine period) to 2.6, 15.2, and 14.6 in 2008-2020 (post-vaccine period), equating to declines of 84.7%, 69.4%, and 38.2%, respectively. Following the introduction of the boy's vaccination, hospitalisation rates decreased further in the respective age bands from 4.3, 22.8, and 18.4 in 2008-2013 (early post-vaccine period) to 1.1, 9.3, and 11.7 in 2014-2020 (late post-vaccine period), equating to respective declines of 73.4%, 59.3%, and 36.4%. This analysis confirms that there is a substantial incremental decline in anogenital warts hospitalisations among Australians aged 10-39 years.

Аналіз захворюваності на кір в Україні та стану популяційного імунітету

Since 2001, due to the effectiveness of vaccines, the Measles Elimination Initiative was introduced. However, there are periodic increases in its incidence. In terms of intensity, the measles epidemic process in Ukraine in 2017-2019 can be considered as an epidemic. In 2022, 205,153 cases of measles were reported worldwide (67% more than in 2021). In 2023, this indicator in the European Region of the World Health Organization increased 30 times compared to 2022. Thus, measles remains a pressing problem. Aim - to analyze the incidence of measles, particularly among vaccinated individuals, the state of specific population immunity, as well as to assess of the current epidemic situation. Materials and methods. An analysis was carried out: the incidence of measles in Ukraine (2017-11/30/2023), its level among vaccinated people (2017-2022), the rates of vaccination against measles, mumps and rubella (MMR) (2016-2023), the state of specific population immunity of the population (2019-2022). Descriptive-evaluative and analytical approaches of the epidemiological method, as well as methods of mathematical statistics were used. Results and conclusions. The previous rise in the incidence of measles in Ukraine (2017-2019) and the beginning of the current one (2023) occurred against the background of unsatisfactory coverage of the first and second doses of the MMR vaccinations (2016 - 45.5% and 30.2%; 2022 - 74.1% and 69.1%, respectively). The population of all age groups is involved in the intensification of the measles epidemic process (with the exception of patients who were ill in the pre-vaccination period). The high effectiveness of MMR-1 for children aged 1 to 4 years has been shown, with its decrease with increasing age and gaps in the coverage of MMR-2 for children aged 6 years. Unvaccinated adults remain at risk. In 2019-2021, the proportion of individuals with a protective level of specific antibodies was 89-91%, and by age groups - 83-91%. A significant decrease of this indicator was observed in 2022 compared to 2021 in all age groups, with the exception of children aged 1-4 years. Ensuring proper vaccine prevention in Ukraine is one of the primary tasks for reducing the cyclical outbreaks of measles and achieving its elimination. No conflict of interests was declared by the authors.