miRNome Profiling of Extracellular Vesicles in Patients With Severe COVID-19 and Identification of Predictors of Mortality.

BACKGROUND: Extracellular vesicles (EVs), containing microRNAs (miRNAs) and other molecules, play a central role in intercellular communication, especially in viral infections caused by SARS-CoV-2. This study explores the miRNA profiles in plasma-derived EVs from patients with severe COVID-19 vs controls, identifying potential mortality predictors. METHODS: This prospective study included 36 patients with severe COVID-19 and 33 controls without COVID-19. EV-derived miRNAs were sequenced, and bioinformatics and differential expression analysis between groups were performed. The plasma miRNA profile of an additional cohort of patients with severe COVID-19 (n = 32) and controls (n = 12) was used to compare with our data. Survival analysis identified potential mortality predictors among the significantly differentially expressed (SDE) miRNAs in EVs. RESULTS: Patients with severe COVID-19 showed 50 SDE miRNAs in plasma-derived EVs. These miRNAs were associated with pathways related to inflammation and cell adhesion. Fifteen of these plasma-derived EV miRNAs were SDE in the plasma of severe cases vs controls. Two miRNAs, hsa-miR-1469 and hsa-miR-6124, were identified as strong mortality predictors with an area under the receiver operating characteristic curve of 0.938. CONCLUSIONS: This research provides insights into the role of miRNAs within EVs in severe COVID-19 and their potential as clinical biomarkers for mortality.

Safety and Immunogenicity of Respiratory Syncytial Virus Prefusion F Protein Vaccine when Co-administered with Adjuvanted Seasonal Quadrivalent Influenza Vaccine in Older Adults: A Phase 3 Randomized Trial.

BACKGROUND: We evaluated co-administration of adjuvanted seasonal quadrivalent influenza vaccine (FLU-aQIV) and respiratory syncytial virus (RSV) prefusion F protein-based vaccine (RSVPreF3 OA) in ≥65-year-olds. METHODS: This phase 3, open-label trial randomized ≥65-year-olds to receive FLU-aQIV and RSVPreF3 OA concomitantly (Co-Ad) or sequentially, 1 month apart (Control). Primary objectives were to demonstrate the non-inferiority of FLU-aQIV and RSVPreF3 OA co-administration versus sequential administration in terms of hemagglutination inhibition (HI) titers for each FLU-aQIV strain and RSV-A and RSV-B neutralization titers, 1 month post-vaccination. Reactogenicity and safety were also assessed. RESULTS: Overall, 1045 participants were vaccinated (Co-Ad: 523; Control: 522). Non-inferiority of FLU-aQIV and RSVPreF3 OA co-administration versus sequential administration was demonstrated in terms of HI titers for the A/Victoria(H1N1), B/Victoria, and B/Yamagata influenza strains and RSV-A neutralization titers (upper limits [ULs] of 95% confidence intervals [CIs] for adjusted geometric mean titer [GMT] ratios [Control/Co-Ad] ≤1.50) but not for A/Darwin(H3N2) HI titers (95% CI UL = 1.53). The immune response to A/Darwin(H3N2) was further assessed post-hoc using a microneutralization assay; the post-vaccination adjusted GMT ratio (Control/Co-Ad) was 1.23 (95% CI: 1.06-1.42, ie, UL ≤1.50), suggesting an adequate immune response to A/Darwin(H3N2) following co-administration. RSV-B neutralization titers were comparable between groups (95% CI UL for adjusted GMT ratio ≤1.50). Solicited adverse events were mostly mild or moderate and transient; unsolicited and serious adverse event rates were balanced between groups. CONCLUSIONS: Adjuvanted FLU-aQIV and RSVPreF3 OA had acceptable reactogenicity/safety profiles when co-administered in ≥65-year-olds, without clinically relevant interference with the immune responses to either vaccine. CLINICAL TRIALS REGISTRATION: NCT05568797.

Incidence and prevalence of headache in influenza: A 2010-2021 surveillance-based study.

BACKGROUND AND PURPOSE: Influenza is a common cause of acute respiratory infection, with headache being one of the symptoms included in the European Commission case definition. The prevalence of headache as a symptom of influenza remains unknown. We aimed to describe the incidence and prevalence of headache in patients with influenza. METHODS: All consecutive patients who met the definition criteria of influenza-like illness during the influenza seasons 2010-2011 through 2021-2022 were included. The seasonal cumulative incidence of influenza per 1000 patients at risk and the prevalence of headache as an influenza symptom were calculated, including the 95% confidence intervals (CIs). Subgroup analyses were done based on patients' sex, age group, microbiological confirmation, vaccination status, and influenza type/subtype/lineage. RESULTS: During the study period, 8171 patients were eligible. The incidence of headache in the context of influenza varied between 0.24 cases per 1000 patients (season 2020-2021) and 21.69 cases per 1000 patients (season 2017-2018). The prevalence of headache was 66.1% (95% CI = 65.1%-67.1%), varying between 49.6% (season 2021-2022) and 80.1% (season 2010-2011). The prevalence of headache was higher in women (67.9% vs. 65.7%, p = 0.03) and higher in patients between 15 and 65 years old. Headache was more prevalent in patients infected with B subtypes than A subtypes (68.7% vs. 56.9%, p < 0.001). There were no notable differences regarding vaccination status or microbiological confirmation of the infection. CONCLUSIONS: Headache is a common symptom in patients with influenza, with a prevalence higher than that observed in other viral infections.

Early estimates of nirsevimab immunoprophylaxis effectiveness against hospital admission for respiratory syncytial virus lower respiratory tract infections in infants, Spain, October 2023 to January 2024.

The monoclonal antibody nirsevimab was at least 70% effective in preventing hospitalisations in infants with lower respiratory tract infections (LRTI) positive for respiratory syncytial virus (RSV) in Spain (Oct 2023-Jan 2024), where a universal immunisation programme began late September (coverage range: 79-99%). High protection was confirmed by two methodological designs (screening and test-negative) in a multicentre active surveillance in nine hospitals in three regions. No protection against RSV-negative LRTI-hospitalisations was shown. These interim results could guide public-health decision-making.

Factors associated to the presence of headache in patients with influenza infection and its consequences: a 2010-2020 surveillance-based study.

Headache is a common symptom of influenza infection; however, its causes and consequences remain uncertain. In this manuscript, we analyzed which demographic and clinical factors were associated with the presence of headache during the course of influenza infection and whether patients with headache had a different prognosis, evaluated by need of hospitalization, sick leave or school absenteeism. The influence study (NCT05704335) was an observational study that analyzed data routinely collected from the Health Sentinel Network between 2010 and 2020. During the study period, 7832 cases were considered, among which, 5275 (67.4%) reported headache. The presence of headache was independently associated with myalgia (2.753; 95%CI: 2.456-3.087, P < 0.001), asthenia (OR: 1.958; 95%CI: 1.732-2.214, P < 0.001), shivering (OR: 1.925; 95%CI: 1.718-2.156, P < 0.001), nasopharyngeal erythema (OR: 1.505; 95%CI: 1.293-1.753, P < 0.001), fever (OR: 1.469; 95%CI: 1.159-1.861; P = 0.001), sudden onset of symptoms (OR: 1.380; 95%CI: 1.120-1.702, p = 0.004), female sex (OR: 1.134; 95%CI: 1.023-1.257, P = 0.018), and gastrointestinal symptoms (OR: 1.169; 95%CI: 1.039-1.315; P = 0.01). Patients with headache had a sex and age adjusted lower odds of being referred to the hospital (OR: 0.463; 95%CI: 0.264-0.812, P = 0.007) and a higher odd of having a sick leave and/or school absenteeism (absenteeism (OR: 1.342; 95%CI: 1.190-1.514, P < 0.001). In conclusion, the presence of headache seems associated with symptoms caused by the innate immune response. These findings support a headache pathophysiology linked with the innate immune response. Due to the potential negative consequences and its treatable nature, clinicians should systematically evaluate it and, whenever necessary, treat it too.

Possible Mpox Protection from Smallpox Vaccine-Generated Antibodies among Older Adults.

Smallpox vaccination may confer cross-protection to mpox. We evaluated vaccinia virus antibodies in 162 persons ≥50 years of age in Spain; 68.5% had detectable antibodies. Highest coverage (78%) was among persons 71-80 years of age. Low antibody levels in 31.5% of this population indicates that addressing their vaccination should be a priority.

InfluenCEF study: Clinical phenotype and duration of headache attributed to influenza infection.

INTRODUCTION: Headache is a frequent symptom of infections. We aimed to characterize the clinical phenotype and duration of headache attributed to influenza infection. METHODS: Prospective cohort study done in 53 primary care centers between January and April 2023. Patients were included if they had a confirmed influenza diagnosis, were older than 15 years and had a new-onset headache. Patients' demographics, prior medical history, headache phenotype and duration, associated symptoms and patients' outcomes were assessed. The International Classification of Headache Disorders criteria for headache attributed to a systemic viral infection, migraine and tension-type headache were assessed. RESULTS: Of the 478 patients 75 fulfilled eligibility criteria. The mean age was 43, 56% were men, and 27% had a prior headache history. The headache phenotype was a bilateral headache (52%), with frontal topography (48%), pressing quality (61%), moderate intensity, rhinorrhea (79%), nasal congestion (76%), and photophobia (59%). All patients fulfilled headache attributed to acute systemic viral infection criteria, 43% fulfilled migraine criteria and 31% tension-type headache criteria. The median duration of the headache was four (Inter-quartile range: two-six) days. CONCLUSION: The clinical phenotype of headache attributed to influenza infection was similar to other infections, with more pronounced cranial autonomic symptoms. The headache was an early symptom and was self-limited within a few days.Trial Registration: The study protocol is registered in ClinicalTrial.gov (NCT05704335).

Potential Effects on Elderly People From Nirsevimab Use in Infants.

Nirsevimab therapy has the potential to revolutionize infant respiratory syncytial virus (RSV) prophylaxis. But other populations suffering RSV, such the elderly or those over 60, may also be protected by using this novel antibody in the infant group. It is true that some studies link the use of nirsevimab to a reduction in the virus's ability to spread by lowering the viral load in infants as a result of the drug's long half-life. However, this protective effect may not be very significant because RSV transmission in the elderly typically comes from other elderly people or from school-aged children. Furthermore, RSV may be transmitted at any time of the year and not just during the period of nirsevimab protection due to its existence in human reservoirs. The reasons made here show that, even though nirsevimab treatment in infants may protect the elderly, this benefit would be limited and testimonial. Therefore, immunizing the elderly with currently licensed and developing vaccines should be a priority.

El uso de nirsevimab puede suponer una revolución en la prevención del virus respiratorio sincitial (VRS) en lactantes. Sin embargo, el uso de este nuevo anticuerpo en dicho grupo de edad podría proteger también a otros grupos que conviven con ellos, como por ejemplo las personas de edad avanzada o grupo de personas mayores de 60 años. Si bien es cierto que algunos estudios sugieren una disminución en la propagación del virus con el uso de nirsevimab, al reducir la carga viral en lactantes como consecuencia de la prolongada vida media del fármaco, este efecto protector podría ser de escasa relevancia, ya que la transmisión del VRS en personas de edad avanzada sucede en la mayor parte de los casos desde personas de la misma edad o desde niños en edad escolar. Adicionalmente, la presencia de VRS en reservorios humanos puede permitir que el VRS se transmita en cualquier época del año, no limitándose únicamente al periodo de protección de nirsevimab. Los argumentos aquí expuestos demuestran que, si bien el uso de nirsevimab en lactantes podría tener un efecto protector en las personas de edad avanzada, este solo sería testimonial y limitado. En consecuencia, debe priorizarse la inmunización de los pacientes de edad avanzada con las vacunas actualmente autorizadas y en desarrollo.

Analyzing Changes in Attitudes and Behaviors towards Seasonal Influenza Vaccination in Spain's Adult Population over Three Seasons.

Background/Objectives: The experience of the COVID-19 pandemic has turned the spotlight on the importance of public health measures and disease prevention. Despite this, the acceptance of influenza vaccination has remained low in most countries (and far from the 75% target set by the World Health Organization). The objective of this study has been to investigate how attitudes and behaviors regarding influenza vaccination in the Spanish adult population have changed over the last three years (from 2021 to 2024) in order to analyze trends in influenza vaccination. Methods: To this end, a cross-sectional study was conducted through 2206 telephone interviews, and the results were compared with those obtained in previous campaigns. Results: The findings indicate a significant decline in overall vaccination intent. Healthcare professionals remain the most influential factor in encouraging vaccination, yet there is a notable increase in the lack of vaccine recommendations, contributing to the decision not to vaccinate. This study also reveals low awareness of the influenza vaccine campaign, emphasizing the need for improved public health communication. Conclusions: To counteract these trends, this study recommends intensifying awareness campaigns, strengthening the role of healthcare providers in vaccine advocacy, and tailoring communication strategies. These efforts are crucial to enhancing vaccination coverage and protecting vulnerable populations against influenza.

Association of viral loads of influenza A (H3N2) with age and care setting on presentation-a prospective study during the 2022-2023 influenza season in Spain.

OBJECTIVES: The aim of this study was to analyze the viral load (VL) using cycle threshold (Ct) in patients infected with influenza A (H3N2). METHODS: This prospective study was conducted during the 2022-2023 influenza season in sentinel, non-sentinel, and hospitalized patients of Castilla y León (Spain). Respiratory samples were obtained from nasopharyngeal swabs and analyzed by quantitative reverse transcription-polymerase chain reaction specific for influenza A (H3N2) to obtain the Ct value. RESULTS: A total of 1047 individuals were enrolled (174 [16.6%] sentinel, 200 [19.1%] non-sentinel, 673 [64.3%] hospitalized). The mean Ct value was lower in infants, young children, and in the elderly, with a sharp increase in the last from 65 years until 90 years. In addition, the lower Ct values were observed in non-sentinel patients and then in hospitalized patients, probably because non-sentinel are outpatients in the acute phase of the influenza infection. CONCLUSIONS: A higher VL (lower Ct value) is related to the extreme ages of life: children and the elderly. Furthermore, a higher VL is related with the care setting, being probably higher in outpatients because they are in the acute phase of the disease and slightly lower in hospitalized patients because they are attended during the post-acute phase.

Corrigendum: Impaired antigen-specific B-cell responses after Influenza vaccination in kidney transplant recipients receiving co-stimulation blockade with Belatacept.

[This corrects the article DOI: 10.3389/fimmu.2022.918887.].

Impact on the time elapsed since SARS-CoV-2 infection, vaccination history, and number of doses, on protection against reinfection.

SARS-CoV-2 reinfections have been frequent, even among those vaccinated. The aim of this study is to know if hybrid immunity (infection + vaccination) is affected by the moment of vaccination and number of doses received. We conducted a retrospective study in 746 patients with a history of COVID-19 reinfection and recovered the dates of infection and reinfection and vaccination status (date and number of doses). To assess differences in the time to reinfection(tRI) between unvaccinated, vaccinated before 6 months, and later; and comparing one, two or three doses (incomplete, complete and booster regime) we performed the log-rank test of the cumulative incidence calculated as 1 minus the Kaplan-Meier estimator. Also, an adjusted Cox-regression was performed to evaluate the risk of reinfection in all groups. The tRI was significantly higher in those vaccinated vs. non-vaccinated (p < 0.001). However, an early incomplete regime protects similar time than not receiving a vaccine. Vaccination before 6 months after infection showed a lower tRI compared to those vaccinated later with the same regime (adj-p < 0.001). Actually, early vaccination with complete and booster regimes provided lower length of protection compared to vaccinating later with incomplete and complete regime, respectively. Vaccination with complete and booster regimes significantly increases the tRI (adj-p < 0.001). Vaccination increases the time it takes for a person to become reinfected with SARS-CoV-2. Increasing the time from infection to vaccination increases the time in which a person could be reinfected and reduces the risk of reinfection, especially in complete and booster regimes. Those results emphasize the role of vaccines and boosters during the pandemic and can guide strategies on future vaccination policy.

RSV Risk Profile in Hospitalized Adults and Comparison with Influenza and COVID-19 Controls in Valladolid, Spain, 2010-2022.

INTRODUCTION: We aimed to describe the risk profile of respiratory syncytial virus (RSV) infections among adults ≥ 60 years in Valladolid from January 2010 to August 2022, and to compare them with influenza and COVID-19 controls. METHODS: This was a retrospective cohort study of all laboratory-confirmed RSV infections identified in centralized microbiology database during a 12-year period. We analyzed risk factors for RSV hospitalization and severity (length of stay, intensive care unit admission, in-hospital death or readmission < 30 days) and compared severity between RSV patients vs. influenza and COVID-19 controls using multivariable logistic regression models. RESULTS: We included 706 RSV patients (635 inpatients and 71 outpatients), and 598 influenza and 60 COVID-19 hospitalized controls with comparable sociodemographic profile. Among RSV patients, 96 (15%) had a subtype identified: 56% A, 42% B, and 2% A + B. Eighty-one percent of RSV patients had cardiovascular conditions, 65% endocrine/metabolic, 46% chronic lung, and 43% immunocompromising conditions. Thirty-six percent were coinfected (vs. 21% influenza and 20% COVID-19; p = < .0001 and 0.01). Ninety-two percent had signs of lower respiratory infection (vs. 85% influenza and 72% COVID-19, p = < .0001) and 27% cardiovascular signs (vs. 20% influenza and 8% COVID-19, p = 0.0031 and 0.0009). Laboratory parameters of anemia, inflammation, and hypoxemia were highest in RSV. Among RSV, being a previous smoker (adjusted OR 2.81 [95% CI 1.01, 7.82]), coinfection (4.34 [2.02, 9.34]), and having cardiovascular (3.79 [2.17, 6.62]), neurologic (2.20 [1.09, 4.46]), or chronic lung (1.93 [1.11, 3.38]) diseases were risks for hospitalization. Being resident in care institutions (1.68 [1.09, 2.61]) or having a coinfection (1.91[1.36, 2.69]) were risks for higher severity, while RSV subtype was not associated with severity. Whereas RSV and influenza patients did not show differences in severity, RSV patients had 68% (38-84%) lower odds of experiencing any severe outcome compared to COVID-19. CONCLUSIONS: RSV especially affects those with comorbidities, coinfections, and living in care institutions. RSV vaccination could have an important public health impact in this population.

Respiratory Syncytial Virus Risk Profile in Hospitalized Infants and Comparison with Influenza and COVID-19 Controls in Valladolid, Spain, 2010-2022.

INTRODUCTION: We aimed to describe the risk profile of RSV infections among children aged ≤ 24 months in Valladolid from January 2010 to August 2022 and to compare them with influenza and COVID-19 controls. METHODS: We conducted a retrospective cohort study of all laboratory-confirmed RSV, influenza, and COVID-19 infections. We analyzed risk factors for RSV hospitalization and severity (length-of-stay ≥ 8 days, intensive-care-unit admission, in-hospital death or readmission < 30 days) and compared severity between hospitalized RSV patients vs. influenza and COVID-19 controls using multivariable logistic regression models. RESULTS: We included 1507 patients with RSV (1274 inpatient), 32 with influenza, and 52 COVID-19 controls. Hospitalized RSV (mean age 5.3 months) and COVID-19 (4 months) were younger than influenza (9.1 months) patients. Sixteen percent of patients had RSV within the first month of life. Most infants did not have comorbidities (74% RSV, 56% influenza, and 69% COVID-19). Forty-one percent of patients with RSV and influenza were coinfected vs. 27% COVID-19 (p = 0.04). Among RSV, hospitalization risk factors were prematurity (adjusted OR 3.11 [95% CI 1.66, 4.44]) and coinfection (2.03 [1.45, 2.85]). Risks for higher severity were maternal smoking (1.89 [1.07, 3.33]), prematurity (2.31 [1.59, 3.34]), chronic lung disease (2.20 [1.06, 4.58]), neurodevelopmental condition (4.28 [2.10, 8.73]), and coinfection (2.67 [2.09, 3.40]). Breastfeeding was protective against hospitalization (0.87 [0.80, 0.95]) and severity (0.81 [0.74, 0.88]), while complete vaccination schedule was protective against severity (0.51 [0.27, 0.97]). RSV had 2.47 (1.03, 5.96) higher risk of experiencing any severe outcome compared to influenza and did not show significant differences vs. COVID-19. CONCLUSIONS: RSV hospitalizations were more frequent and severe than influenza, while severity was comparable to the early pandemic COVID-19. Currently, both influenza and COVID-19 vaccines are included in the maternal and childhood Spanish immunization schedule between the ages of 6 and 59 months. RSV monoclonal antibody is recommended for ≤ 6 months but a third of patients were aged 6-24 months. Maternal RSV vaccination can protect their children directly from birth and indirectly through breastfeeding.

Old and new aspects of influenza. / Nuevos y viejos aspectos de la gripe.

Influenza is a classic infectious disease that, through the continuous variation of the viruses that produce it, imposes new challenges that we must solve as quickly as possible. The COVID-19 pandemic has substantially modified the behavior of influenza and other respiratory viruses, and in the coming years we will have to coexist with a new pathogen that will probably interact with existing pathogens in a way that we cannot yet glimpse. However, knowledge prior to the pandemic allows us to focus on the aspects that must be modified to make influenza an acceptable challenge for the future. In this review, emphasis is placed on the most relevant aspects of epidemiology, disease burden, diagnosis, and vaccine prevention, and how scientific and clinical trends in these aspects flow from the previously known to future challenges.

Adjuvants for COVID-19 Vaccines.

In recent decades, the improvement of traditional vaccines has meant that we have moved from inactivated whole virus vaccines, which provoke a moderate immune response but notable adverse effects, to much more processed vaccines such as protein subunit vaccines, which despite being less immunogenic have better tolerability profiles. This reduction in immunogenicity is detrimental to the prevention of people at risk. For this reason, adjuvants are a good solution to improve the immunogenicity of this type of vaccine, with much better tolerability profiles and a low prevalence of side effects. During the COVID-19 pandemic, vaccination focused on mRNA-type and viral vector vaccines. However, during the years 2022 and 2023, the first protein-based vaccines began to be approved. Adjuvanted vaccines are capable of inducing potent responses, not only humoral but also cellular, in populations whose immune systems are weak or do not respond properly, such as the elderly. Therefore, this type of vaccine should complete the portfolio of existing vaccines, and could help to complete vaccination against COVID-19 worldwide now and over the coming years. In this review we analyze the advantages and disadvantages of adjuvants, as well as their use in current and future vaccines against COVID-19.

Group 1 and group 2 hemagglutinin stalk antibody response according to age.

Objective: Antibodies elicited by seasonal influenza vaccines mainly target the head of hemagglutinin (HA). However, antibodies against the stalk domain are cross-reactive and have been proven to play a role in reducing influenza disease severity. We investigated the induction of HA stalk-specific antibodies after seasonal influenza vaccination, considering the age of the cohorts. Methods: A total of 166 individuals were recruited during the 2018 influenza vaccine campaign (IVC) and divided into groups: <50 (n = 14), 50-64 (n = 34), 65-79 (n = 61), and ≥80 (n = 57) years old. Stalk-specific antibodies were quantified by ELISA at day 0 and day 28 using recombinant viruses (cH6/1 and cH14/3) containing an HA head domain (H6 or H14) from wild bird origin with a stalk domain from human H1 or H3, respectively. The geometric mean titer (GMT) and the fold rise (GMFR) were calculated, and differences were assessed using ANOVA adjusted by the false discovery rate (FDR) and the Wilcoxon tests (p <0.05). Results: All age groups elicited some level of increase in anti-stalk antibodies after receiving the influenza vaccine, except for the ≥80-year-old cohort. Additionally, <65-year-old vaccinees had higher group 1 antibody titers versus group 2 before and after vaccination. Similarly, vaccinees within the <50-year-old group showed a higher increase in anti-stalk antibody titers when compared to older individuals (≥80 years old), especially for group 1 anti-stalk antibodies. Conclusion: Seasonal influenza vaccines can the induction of cross-reactive anti-stalk antibodies against group 1 and group 2 HAs. However, low responses were observed in older groups, highlighting the impact of immunosenescence in adequate humoral immune responses.

Impact of COVID-19 on Adherence to Treatment in Patients with HIV.

In patients with human immunodeficiency virus (HIV), adherence to treatment is affected by the adverse effects of treatment, the presence of additional comorbidities, the complexity of dosage, and family and community support. However, one recent circumstance that was likely to have influenced therapeutic adherence was the COVID-19 pandemic and the applied containment measures. An observational retrospective study of a sample of patients with HIV was conducted to establish the relationship between sociodemographic, clinical, and pharmacological variables and therapeutic adherence before and after the pandemic. Adherence was measured using the validated simplified medication adherence questionnaire (SMAQ) and medication possession rate. A statistical analysis was performed to determine the mean, standard deviation, and median of the quantitative variables and the frequencies of the qualitative variables, and the relationship between the dependent and independent variables was analysed using the chi-squared test and Student's t-test. No statistically significant differences were found between treatment adherence measured before and 22 months after the start of the pandemic. Sex, occupation, treatment regimen, viral load levels, and COVID-19 disease status did not influence adherence during either period. However, the age of patients with HIV had an impact on adherence during both periods (p = 0.008 and p = 0.002, respectively), with the age group under 45 years being less adherent. In addition, experiencing adverse drug reactions (ADRs) was shown to have an impact on adherence before the pandemic (p = 0.006) but not afterwards. The COVID-19 pandemic was not shown to have an impact on the degree of adherence to antiretroviral treatment in patients with HIV. Instead, adherence was influenced by patient age and ADR occurrence; therefore, measures must be taken in this regard. The SMAQ demonstrated sensitivity in assessing adherence.

The Impact of the COVID-19 Pandemic on Influenza Vaccination Attitudes and Actions in Spain's Adult Population.

Seasonal influenza is an acute respiratory infection caused by the influenza virus which constitutes a significant public health issue associated with high morbidity and mortality. The aim of this study was to investigate changes in attitudes, perceptions, and practices regarding influenza vaccination in the Spanish adult population during the COVID-19 pandemic, as well as their vaccination intentions, with special attention paid to those over 65 years old and in high-risk groups. To this end, a cross-sectional study was conducted through 2219 telephone interviews, and the results were compared with results obtained a year earlier. Regarding the reasons for deciding to get vaccinated in the 2022/23 season, a significant increase was observed in vaccine confidence (36.7% vs. 42.8%), social responsibility (32.5% vs. 43.8%), and in awareness of the importance of vaccination due to COVID-19 (21.7% vs. 25.4%). Advanced age (OR 2.8, 95% CI 2.0-3.9), belonging to high-risk groups (OR 2.7, 95% CI 2.0-3.7), and prior vaccination (OR 25.3, 95% CI 19.5-32.7) emerged as significant predictors for the intent to receive the influenza vaccine in the 2022/23 season. Continuously observing shifts in perceptions and behaviors related to influenza immunization is crucial to pinpoint factors that may influence the willingness to receive the vaccine and, in this way, design public health strategies that achieve a greater acceptance of it.