Previous Seasonal Influenza Research Articles

P-1316. Influenza Antiviral Prescribing Practices for Outpatients with an Acute Respiratory Illness and at Increased Risk for Influenza-Associated Complications pre- and post-COVID-19 pandemic — United States, 2016–2022

Abstract Background Early antiviral treatment (< 2 days after illness onset) can reduce the risk of influenza-associated complications and is recommended for outpatients at increased risk. However, in previous influenza seasons, antivirals have been underprescribed. We describe influenza antiviral prescribing practices for outpatients from 2016-2022. Methods We analyzed influenza antiviral prescription data from 5 US Influenza Vaccine Effectiveness Network sites pre-pandemic, 2016-2017 through 2019-2020, and post-pandemic, 2021–2022 (2020-2021 season not included due to low influenza circulation). Patients enrolled were aged ≥6 months presenting with an acute respiratory illness with a new or worsening cough ≤7 days duration. All had respiratory specimens collected for influenza RT-PCR testing. Patients at increased risk for severe outcome included those aged < 2 years, ≥ 65 years, and those with at least one underlying medical condition. Electronic medical records were examined to determine whether antivirals were prescribed within 7 days after enrollment. Results Among 21,483 patients at increased risk enrolled in the US Flu VE Network between 2016-2017 and 2021-2022, 8% (1,852) were prescribed antivirals within 7 days. In pre-pandemic seasons, the average proportion of those prescribed antivirals was 9.5% overall and lowest during the 2019-2020 season (6%); post-pandemic, this proportion decreased to 1%. Among confirmed influenza cases, 40% (874/2210) of those at increased risk who presented for care < 2 days after illness onset were prescribed antivirals across all 5 seasons. Similarly, during the pre-pandemic seasons the average proportion of patients prescribed antivirals was 40% with the lowest percentage observed during the 2019-2020 season (26%). This proportion continued to trend downward post-pandemic (21%). Conclusion Over the last several seasons, influenza antiviral medications have been infrequently prescribed, including among those at increased risk for severe illness who present early in their illness. Efforts to increase appropriate antiviral prescribing may reduce influenza-associated complications among outpatients presenting early for care. Disclosures All Authors: No reported disclosures

Increasing uptake of Live Attenuated Influenza Vaccination (LAIV) in two-year-olds through appointment times and dates: A pilot intervention in Cwm Taf Morgannwg University Health Board

BackgroundThe Live Attenuated Influenza Vaccine (LAIV) protects two-year-old children against influenza and serious illness, however uptake across Wales is sub-optimal and below Welsh Government targets. Awareness of the vaccine and its effectiveness, convenience of appointments/clinics and lack of central appointment provision may influence uptake. We piloted provision of set appointment dates and times to investigate impact on uptake of LAIV amongst two-year-olds and identify potential operational issues in a pragmatic selection of general practices. MethodsParents/guardians of two-year-olds in pilot practices (n=9) were sent a personalised letter using the UK Government Notify System, a scheduled vaccination appointment and an evidence-based Frequently Asked Questions sheet. Children in non-pilot practices (n=37) received a general letter and FAQ sheet, without a scheduled appointment. Intervention practices were selected based on low LAIV uptake amongst two-year-olds in the two previous influenza seasons. A mixed-methods, uncontrolled, evaluation of the pilot included analysis of vaccination practice-level uptake data and qualitative data from baseline and follow-up stakeholder surveys. Further patient-level analysis of the intervention to determine individual effects and impact on deprivation-based health inequalities is planned. FindingsCompared to the previous year, pilot practices saw a median increase in LAIV uptake amongst two-year-olds of 30·4% (IQR 11·7% to 33·6%), whilst non-pilot practices saw a median decrease of 4·7% (IQR 16·0% to 2·2%). Uptake increased for 100% (9/9) of the pilot practices, but for only 35% (13/37) of non-pilot practices, compared to the previous year. Qualitative feedback noted advantages including saved administration time and improved planning, but also disadvantages including wasted clinical time from non-attenders. InterpretationThe findings indicate that issuing appointment dates and times should be considered as part of a range of measures to improve LAIV uptake in two-year-olds amongst low performing practices. However, the pragmatic, unblinded nature of the study design and the within practice annual comparisons are limitations, and mean results should be interpreted with caution. Further controlled evaluation, including assessment of lost time due to DNAs and feasibility of scaling, is needed. FundingThere was no additional funding provided to undertake this study. Staff time was contributed by Cwm Taf Morgannwg University Health Board and Public Health Wales.

Factors Associated with Influenza-like Illness among Inmates in an All-male Prison, Songkhla Province, Thailand, 2023

On 9 Feb 2023, the Office of Disease Prevention and Control Region 12Songkhlawas informed of an influenza-like illness (ILI) cluster in an all-male prison in Songkhla Province. We investigated to identify the causative agent, possible sources and risk factors, and provide control measures. We conducted an active case finding by interviewing inmates and officers. Prison facilities and hygiene behaviors of inmates and officers were inspected. A retrospective cohort study was performed. Basic and effective reproductive numbers were estimated. The overall attack rate was 12.6% (474/3,648). Most cases were inmates from Wing C (80.4%). There were no severe cases or deaths. Of ten specimens tested, all were positive for influenza B/Victoria lineage, V1a.3a.2. Fifty-four percent of inmates had received influenza vaccine within the last 12 months. A mismatch between the viral strain in the vaccine and the one causing this outbreak likely contributed to the outbreak as the vaccine provided to the inmates was manufactured during the previous year's influenza season. Vaccine effectiveness was 36.2% against ILI. Having high-risk conditions (adjusted odds ratios (AOR) 2.83, 95% confidence interval (CI) 1.27–6.32) and sharing drinking glasses (AOR 2.02, 95% CI 1.21–3.36) were significant risk factors. The basic reproductive number for ILI in this outbreak was 1.36. The effective reproductive number ranged from 0.18–3.69. For effective management of ILI outbreaks in prisons, a continuous program of influenza vaccination following updated World Health Organization recommendations and a comprehensive surveillance system with rigorous respiratory illness management practices are suggested.

Establishment of Reference Reagents for Single-Radial-Immunodiffusion Assay on the 2022/23 Seasonal Influenza Vaccine in Japan and Their Quality Validation

Potency tests for influenza vaccines are currently performed using a single-radial immunodiffusion (SRID) assay, which requires a reference antigen and anti-hemagglutinin (HA) serum as reference reagents. Reagents must be newly prepared each time a strain used for vaccine production is modified. Therefore, establishing reference reagents of consistent quality is crucial for conducting vaccine potency tests accurately and precisely. Here, we established reference reagents for the SRID assay to conduct lot release tests of quadrivalent influenza vaccines in Japan during the 2022/23 influenza season. The potency of reference antigens during storage was confirmed. Furthermore, we evaluated the cross-reactivity of each antiserum raised against the HA protein of the 2 lineages of influenza B virus toward different lineages of influenza B virus antigens to select a suitable procedure for the SRID assay for accurate measurement. Finally, the intralaboratory reproducibility of the SRID assay using the established reference reagents was validated, and the SRID reagents had sufficient consistent quality, comparable to that of the reagents used for testing vaccines during previous influenza seasons. Our study contributes to the quality control of influenza vaccines.

Interim Influenza Vaccine Effectiveness Against Laboratory-Confirmed Influenza - California, October 2023-January 2024.

Surveillance data can provide rapid, within-season influenza vaccine effectiveness (VE) estimates to guide public health recommendations. Mandatory reporting of influenza vaccine administration to California's immunization information registry began January 1, 2023, and mandatory reporting of all influenza laboratory test results, including negative results, was instituted in California on June 15, 2023. These data, collected by the California Department of Public Health during October 1, 2023-January 31, 2024, were used to calculate interim influenza VE against laboratory-confirmed influenza by comparing the odds of vaccination among case-patients (persons who received a positive influenza laboratory test result) and control patients (those who received a negative influenza laboratory test result). VE was calculated as 1 - adjusted odds ratio using mixed-effects logistic regression, with age, race, and ethnicity as fixed effects and specimen collection week and county as random effects. Overall, during October 1, 2023-January 31, 2024, estimated VE was 45% among persons aged ≥6 months, 56% among children and adolescents aged 6 months-17 years, 48% among adults aged 18-49 years, 36% among those aged 50-64 years, and 30% among those aged ≥65 years. Consistent with some previous influenza seasons, influenza vaccination provided moderate protection against laboratory-confirmed influenza among infants, children, adolescents, and adults. All persons aged ≥6 months without a contraindication to vaccination should receive annual influenza vaccination to reduce influenza illness, severe influenza, and strain on health care resources. Influenza vaccination remains the best way to prevent influenza.

Development of Real-Time Surveillance for Serious Adverse Events in a Pragmatic Clinical Trial Using National Registers in Finland.

We developed a hybrid safety surveillance approach for a large, pragmatic clinical trial of a high-dose quadrivalent influenza vaccine (QIV-HD), using both active and passive data collection methods. Here, we present the methods and results for the passive register-based surveillance of serious adverse events (SAEs), which replaced conventional SAE reporting during the trial. The trial recruited over 33,000 older adults of whom 50% received the QIV-HD while the rest received a standard-dose vaccine (QIV-SD) as a control vaccine. We collected diagnoses related to all acute hospitalizations during the six months following vaccination from national registers. During the blinded phase of the trial, we utilized a cohort study design and compared the incidences of 1811 ICD10 diagnosis groups (SAE categories) between the trial population and older adults vaccinated with the QIV-SD outside the trial, either during the study or the previous influenza season. Based on a real-time probabilistic comparison, we flagged SAE categories with higher incidence in the trial population and then evaluated possible causal associations between each flagged category and the trial intervention. Our novel approach to safety surveillance provided information, which we could evaluate in real-time during the trial. The trial participants experienced 1217hospitalizations related to any SAE categories, contributed by 941 patients. We flagged 10 SAE categories for further analysis during the study but based on further data review, none presented strong evidence of causality with vaccination. Safety signals can be detected and evaluated in real-time during a pragmatic vaccine trial with register-based follow-up, utilizing passive data collection and population level comparison. Compared to conventional methods of safety follow-up, this method is likely to be more comprehensive, objective and resource effective.

Impact of Actively Offering Influenza Vaccination to Frail People during Hospitalisation: A Pilot Study in Italy.

Despite the worldwide recommendations for influenza immunisation, vaccination coverage for patients exposed to the highest risk of severe complications is still far from the optimal target. The need to take advantage of alternative methods to provide vaccination is essential. This study presents a hospital-based strategy which offers influenza vaccination to inpatients at discharge. This study was conducted during the 2022-2023 influenza season at the University Hospital of Palermo. A questionnaire was administered to identify the determinants for the acceptance of influenza vaccination in the frail population. Overall, 248 hospitalised patients were enrolled, of which 56.1% were female and 52.0% were over 65 years of age. The proportion of patients vaccinated against influenza during hospitalisation was 62.5%, an increase of 16% in influenza vaccination uptake among frail people in comparison with the previous influenza season (46.8% vaccinated during the 2021-22 influenza season). Factors significantly associated with vaccination acceptance were the following: to have received influenza vaccine advice from hospital healthcare workers (OR = 3.57, p = 0.001), to have been previously vaccinated for influenza (OR = 3.16 p = 0.005), and to have had a low level of education (OR = 3.56, p = 0.014). This study showed that offering influenza vaccination to hospitalised patients could be an effective strategy to increase vaccination coverage in the most vulnerable population, and these findings could be useful for planning and improving future influenza vaccination campaigns.

Evolution of Influenza A(H3N2) Viruses in 2 Consecutive Seasons of Genomic Surveillance, 2021-2023.

The circulation and the genomic evolution of influenza A(H3N2) viruses during the 2021/2022 and 2022/2023 seasons were studied and associated with infection outcomes. Remnant influenza A-positive samples following standard-of-care testing from patients across the Johns Hopkins Health System (JHHS) were used for the study. Samples were randomly selected for whole viral genome sequencing. The sequence-based pEpitope model was used to estimate the predicted vaccine efficacy (pVE) for circulating H3N2 viruses. Clinical data were collected and associated with viral genomic data. A total of 121 683 respiratory specimens were tested for influenza at JHHS between 1 September 2021 and 31 December 2022. Among them, 6071 (4.99%) tested positive for influenza A. Of these, 805 samples were randomly selected for sequencing, with hemagglutinin (HA) segments characterized for 610 samples. Among the characterized samples, 581 were H3N2 (95.2%). Phylogenetic analysis of HA segments revealed the exclusive circulation of H3N2 viruses with HA segments of the 3C.2a1b.2a.2 clade. Analysis of a total of 445 complete H3N2 genomes revealed reassortments; 200 of 227 of the 2022/2023 season genomes (88.1%) were found to have reassorted with clade 3C.2a1b.1a. The pVE was estimated to be -42.53% for the 2021/2022 season and 30.27% for the 2022/2023 season. No differences in clinical presentations or admissions were observed between the 2 seasons. The increased numbers of cases and genomic diversity of influenza A(H3N2) during the 2022/2023 season were not associated with a change in disease severity compared to the previous influenza season.

How to increase COVID-19 vaccine uptake among children? determinants associated with vaccine compliance.

Three aims: to elucidate determinants associated with COVID-19 vaccine uptake in children and the association with parental vaccination; to compare rates of PCR-positive SARS-CoV-2 results between vaccinated and unvaccinated children; to estimate the rate of parental COVID-19 vaccination and its association with the vaccination rate of their children. We performed a retrospective chart review of all children aged 5-11 years registered at a central district in Israel from November 21st, 2021 to April 30th, 2022, and characterized COVID-19 vaccinated vs. unvaccinated individuals. Data retrieved from the electronic medical files included: demographics [age, gender, sector, socioeconomic status (SES)]; COVID-19 vaccination (first and second doses) and influenza vaccination status; co-morbidities; and parental vaccinations for COVID-19. We divided the population into three distinct demographic groups: non-ultra-orthodox Jews (43,889 children), ultra-orthodox Jews (13,858 children), and Arabs (4,029 children). Of the 61,776 children included in the study, 20,355 (32.9%) received at least one dose of the COVID-19 vaccine. Vaccination rates were similar amongst males and females and were higher in children aged 9-11 years compared to children aged 5-6 years. Multivariate analysis identified five independent determinants that were significantly (p < 0.001) associated with low vaccination rates: Arab and ultra-orthodox sectors (odds ratios: 0.235 and 0.617, respectively); children aged 5-8 years; children of low SES; and children who had not received previous seasonal influenza vaccination. Relatively high vaccination rates were noted amongst children with the following medical co-morbidities: treatment with biological agents (42.9%); solid tumor transplantation (42.9%); type 1 diabetes mellitus (38.5%), asthma (38.2%), and attention deficit and hyperactivity disorder (ADHD) (37.6%). Regarding the uptake of two vaccine doses among children with co-morbidities, it was highest in those with type 1 diabetes mellitus, heart failure, treatment with biological agents, asthma and obesity. This study highlights several pediatric sub-populations with low and high vaccine uptake. It is essential to focus on determinants associated with low vaccination rates.

The impact of repeated vaccination on relative influenza vaccine effectiveness among vaccinated adults in the United Kingdom.

Annual seasonal influenza vaccination is recommended for individuals at high risk of developing post-infection complications in many locations. However, reduced vaccine immunogenicity and effectiveness have been observed among repeat vaccinees in some influenza seasons. We investigated the impact of repeated influenza vaccination on relative vaccine effectiveness (VE) among individuals who were recommended for influenza vaccination in the United Kingdom with a retrospective cohort study using primary healthcare data from the Clinical Practice Research Datalink, a primary care database in the United Kingdom. Relative VE was estimated against general practitioner-diagnosed influenza-like illnesses (GP-ILI) and medically attended acute respiratory illnesses (MAARI) among participants who have been repeatedly vaccinated compared with first-time vaccinees using proportional hazards models. Relative VE against MAARI may be reduced for individuals above 65 years old who were vaccinated in the current and previous influenza seasons for some influenza seasons. However, these findings were not conclusive as we could not exclude the possibility of residual confounding in our dataset. The use of routinely collected data from electronic health records to examine the effects of repeated vaccination needs to be complemented with sufficient efforts to include negative control outcomes to rule out residual confounding.

Cross-sectional assessment of predictors for COVID-19 vaccine uptake: an online survey in Greece

ObjectiveTo estimate the percentage of the general population vaccinated against the COVID-19 and to investigate the factors associated with COVID-19 vaccine uptake. Material and methodsWe conducted an online cross-sectional study in Greece during August 2021. We included individuals over 18 years of age. Independent variables included socio-demographic data of the participants and attitudes towards COVID-19 vaccination and pandemic. Our outcome variable was COVID-19 vaccination status, measured through “yes/no” answers. ResultsMost participants had been vaccinated against the COVID-19 (87.8%). Multivariate analysis identified that increased age and a higher level of education were associated with an increased likelihood of COVID-19 vaccination. Also, participants working in health services, participants without a previous COVID-19 diagnóstico, and those with previous seasonal influenza vaccination history had a greater probability to take a COVID-19 vaccine. Additionally, increased self-perceived severity of COVID-19, knowledge regarding COVID-19, and trust in COVID-19 vaccines and scientists were associated with COVID-19 vaccine uptake. On the other hand, the likelihood of vaccination was lower for participants who were more concerned about the side effects of COVID-19 vaccination. ConclusionsUnderstanding the factors affecting individuals' decision to take a COVID-19 vaccine is essential to improve the COVID-19 vaccination coverage rate. Policymakers and scientists should scale up their efforts to increase the COVID-19 vaccination rate among specific population groups such as young people, people with a low level of education, etc.

Effectiveness of influenza vaccination in preventing influenza in primary care, Navarre, Spain, 2021/22.

Compared with individuals unvaccinated in the current and three previous influenza seasons, in 2021/22, influenza vaccine effectiveness at primary care level was 37% (95% CI: 16 to 52) for current season vaccination, regardless of previous doses, and 35% (95% CI: −3 to 45) for only previous seasons vaccination. Against influenza A(H3N2), estimates were 39% (95% CI: 16 to 55) and 24% (95% CI: −8 to 47) suggesting moderate effectiveness of current season vaccination and possible remaining effect of prior vaccinations.

Cross-sectional assessment of predictors for COVID-19 vaccine uptake: an online survey in Greece

ObjectiveTo estimate the percentage of the general population vaccinated against the COVID-19 and to investigate the factors associated with COVID-19 vaccine uptake. Material and methodsWe conducted an online cross-sectional study in Greece during August 2021. We included individuals over 18 years of age. Independent variables included socio-demographic data of the participants and attitudes towards COVID-19 vaccination and pandemic. Our outcome variable was COVID-19 vaccination status, measured through “yes/no” answers. ResultsMost participants had been vaccinated against the COVID-19 (87.8%). Multivariate analysis identified that increased age and a higher level of education were associated with an increased likelihood of COVID-19 vaccination. Also, participants working in health services, participants without a previous COVID-19 diagnóstico, and those with previous seasonal influenza vaccination history had a greater probability to take a COVID-19 vaccine. Additionally, increased self-perceived severity of COVID-19, knowledge regarding COVID-19, and trust in COVID-19 vaccines and scientists were associated with COVID-19 vaccine uptake. On the other hand, the likelihood of vaccination was lower for participants who were more concerned about the side effects of COVID-19 vaccination. ConclusionsUnderstanding the factors affecting individuals' decision to take a COVID-19 vaccine is essential to improve the COVID-19 vaccination coverage rate. Policymakers and scientists should scale up their efforts to increase the COVID-19 vaccination rate among specific population groups such as young people, people with a low level of education, etc.

Effects of Ownership Text Message Wording and Reminders on Receipt of an Influenza Vaccination

Despite the availability of safe and effective vaccines, many people fail to get vaccinated. Messages using behavioral science principles may increase vaccination rates. To determine the effect on influenza vaccination rates of a text message telling patients that an influenza vaccine had been reserved for them. As part of a larger influenza vaccine messaging megastudy, in this randomized clinical trial, 11 188 patients in 2 large health systems were assigned to receive a text message that stated "a flu shot has been reserved for you," a text message that stated "flu shots will be available," or no text message. Both messages included the option to reply yes (Y) or no (N) to indicate that the patient wanted to get vaccinated. Patients 18 years or older were included if they had new or routine (nonsick) primary care appointments scheduled from September 20, 2020, through March 31, 2021. The evening before the scheduled appointment, patients in the 2 message conditions were sent 3 back-to-back SMS messages containing the study wording. Patients in the usual care control group did not receive any study messages. Receipt of an influenza vaccine on the date of the patient's scheduled appointment. A total of 11 188 patients were randomized to the reserved or the available message conditions or to usual care. The 10 158 patients analyzed in the study had a mean (SD) age of 50.61 (16.28) years; 5631 (55.43%) were women; and 7025 (69.16%) were White. According to health records, 4113 (40.49%) had been vaccinated in the previous influenza season, and 5420 (53.36%) were patients at Penn Medicine. In an intent-to-treat analysis, changes in vaccination rates in response to the reserved message did not reach statistical significance (increase of 1.4 percentage points, or 4% [P = .31]) compared with the message conveying that influenza vaccines were available. Relative to the usual care control, the reserved message increased vaccination rates by 3.3 percentage points, or 11% (P = .004). Patients in the reserved message condition were more likely to text back Y (1063 of 3375 [31.50%]) compared with those in the available message condition (887 of 3351 [26.47%]; χ2 = 20.64; P < .001), and those who replied Y were more likely to get vaccinated (1532 of 1950 [78.56%]) compared with those who did not (749 of 4776 [15.68%]; χ2 = 2400; P < .001). This study found that patients who received text messages regarding flu vaccination had greater vaccine uptake than those who received no message. Messages that increase the likelihood that patients will indicate their intention to be vaccinated may also increase vaccination behavior. ClincalTrials.gov Identifier: NCT04565353.

All-cause mortality during the influenza season 2019-2020: comparison with previous influenza seasons in the territory of the local health authority "Central Tuscany", Italy.

Because of the 24 months latency in the release of official data on causes of death, and in consideration of the limited testing capacity during the first pandemic wave, to estimate the COVID-19-related mortality in 2020, the evaluation of all-cause mortality excess is often used instead. Our study aimed at assessing whether in Central Tuscany, Italy, an excess all-cause mortality occurred in the 2019-2020 influenza season, which partly overlapped with the months of the first pandemic wave in which the impact of COVID-19 was the highest. Age- and sex-adjusted mortality rates for 2019-2020 influenza season were compared with those of influenza seasons 2009-2010 to 2016-2017. No all-cause mortality excess was observed in the 2019-2020 influenza season, which, on the contrary, was characterized by the lowest all-cause mortality rate. Our finding can be explained by the imposition, in early March 2020, of a national lockdown, which came into effect in an early epidemic phase in Tuscany, and thus limited the transmission of SARS-CoV-2 infection, as well as influenza, in the territory. In March and April, by causing the death of vulnerable elderly patients who had been spared by the mild seasonal flu in the prior months, COVID-19 acted with a harvesting effect.

Operationalizing influenza vaccination in an urban safety-net emergency department.

Influenza vaccination is a recommended tool in preventing influenza-related illnesses, medical visits, and hospitalizations. With many patients remaining unvaccinated each year, the Emergency Department (ED) represents a unique opportunity to provide vaccinations to patient not yet vaccinated. However, busy urban safety-net EDs maybe challenged to safely execute such a vaccination program. The aim of this quality improvement project was to assess influenza vaccination feasibility in the ED and improve influenza vaccination rates in our community. The quality improvement work-group, comprised of ED physicians, nurses, and pharmacists, designed and implemented an influenza vaccination protocol that aligned with the ED workflow. The outcome measure was the total number of patients vaccinated per month and per influenza season. Process measures included the type of influenza vaccine administered and type of care area within ED. Balancing measures were also included. Following the initiative, a total of 337 patients received influenza vaccinations in the ED between September 1, 2018 and December 31, 2020 compared to none during the previous influenza season. With each influenza season, the number of vaccinated patients increased from 61 to 134 and 142, respectively. The average age of the patients was 48.23±15.29, 52.89±15.91, and 44.92±18.97years old. Most patients received the vaccination while roomed in the high acuity section of the adult ED. No adverse effects or automated dispensing cabinet stockouts were observed. Our structured program indicates that influenza vaccine administration to eligible patients is feasible in a busy urban safety-net ED. Piloting new and further developing existing ED-based influenza vaccination programs have the potential to significantly benefit public health.

A Knowledge, Attitude, and Perception Study on Flu and COVID-19 Vaccination during the COVID-19 Pandemic: Multicentric Italian Survey Insights.

In January 2020, Chinese health authorities identified a novel coronavirus strain never before isolated in humans. It quickly spread across the world, and was eventually declared a pandemic, leading to about 310 million confirmed cases and to 5,497,113 deaths (data as of 11 January 2022). Influenza viruses affect millions of people during cold seasons, with high impacts, in terms of mortality and morbidity. Patients with comorbidities are at a higher risk of acquiring severe problems due to COVID-19 and the flu—infections that could impact their underlying clinical conditions. In the present study, knowledge, attitudes, and opinions of the general population regarding COVID-19 and influenza immunization were evaluated. A multicenter, web-based, cross-sectional study was conducted between 10 February and 12 July 2020, during the first wave of SARS-CoV-2 infections among the general population in Italy. A sample of 4116 questionnaires was collected at the end of the study period. Overall, 17.5% of respondents stated that it was unlikely that they would accept a future COVID-19 vaccine (n = 720). Reasons behind vaccine refusal/indecision were mainly a lack of trust in the vaccine (41.1%), the fear of side effects (23.4%), or a lack of perception of susceptibility to the disease (17.1%). More than 50% (53.8%; n = 2214) of the sample participants were willing to receive flu vaccinations in the forthcoming vaccination campaign, but only 28.2% of cases had received it at least once in the previous five seasons. A higher knowledge score about SARS-CoV-2/COVID-19 and at least one flu vaccination during previous influenza seasons were significantly associated with the intention to be vaccinated against COVID-19 and influenza. The continuous study of factors, determining vaccination acceptance and hesitancy, is fundamental in the current context, in regard to improve vaccination confidence and adherence rates against vaccine preventable diseases.

Influenza and Influenza-Like Respiratory Virus Infections in Children During the 2019/20 Influenza Seazon and the COVID-19 Pandemic in Poland: Data from the Department of Influenza Research, the National Influenza Center at the National Institute of Public Health, National Institute of Hygiene-National Research Institute and 16 Voivodeship Sanitary and Epidemiological Stations

BackgroundThis population study aimed to investigate influenza and influenza-like respiratory virus infections in children during the 2019/20 influenza season and the coronavirus disease 2019 (COVID-19) pandemic in Poland.Material/MethodsThis study analyzed data from the National Influenza Centre, the Department of Influenza Research at the National Institute of Public Health, and 16 Voivodeship Sanitary and Epidemiological Stations in Poland. Nose and throat swabs were obtained from children during the 2019/20 influenza season and the COVID-19 pandemic. Viral RNA detection was performed using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) to diagnose influenza virus infection and viral subtypes.ResultsIn the analyzed group, both cases of influenza A and B and infections with influenza-like viruses were confirmed. Among all cases caused by influenza viruses, influenza A was more frequent than B, with predominance of the A/H1N1/pdm09 subtype. The flu-like virus which infected most children was the human respiratory syncytial virus (RSV). The greatest number of cases with RSV was registered in the group of the youngest children (0–4 years).ConclusionsThis population study from Poland showed that during the COVID-19 pandemic, and during the winter influenza season of 2019/20, influenza and influenza-like viral infections in children showed some differences from previous influenza seasons. The findings highlight the importance of viral infection surveillance and influenza vaccination in the pediatric population.

Parents' Willingness to Vaccinate Their Children Against Seasonal Influenza After the COVID-19 Pandemic in Saudi Arabia: A Retrospective Cross-Sectional Survey.

PurposeTo explore the impact of the novel coronavirus (COVID-19) pandemic on caregivers’ willingness to vaccinate their children against influenza in 2021 in Saudi Arabia and the factors influencing this decision.Patients and MethodsAn online survey of 2501 caregivers in Saudi Arabia with children aged 6 months–18 years was conducted between July 15, 2021, and August 2, 2021. A convenience sample of participants that met the inclusion criteria was used as the study sample. Social Science Package Statistical (SPSS) was used for the statistical analysis. Categorical variables were reported as frequencies and percentages. The Chi-square test was used for categorical variables to assess the difference between the variables and the parents’ willingness to vaccinate their children against seasonal influenza after the COVID-19 pandemic.ResultsOf the 2501 respondents to the survey, 1185 (47.3%) parents plan to give their children the influenza vaccine next year, which is an increase from 745 (29.8%) in the previous year. The following were the main reasons for not giving children the vaccine: children were less likely to get seasonal flu (617, 24.7%), fear of side effects (491, 19.6%), and fear of needles and syringes (484, 19.4%). Among the parents, 1222 (48.9%) were more likely to receive the seasonal flu vaccine themselves the following year, and 1361 (54.4%), which is more than half, were concerned about their children contracting seasonal influenza.ConclusionParents’ decision-making to vaccinate their children against seasonal influenza has been influenced by the COVID-19 pandemic. Numerous factors including a caregiver who had received the seasonal influenza vaccine themselves, who had vaccinated or planned to vaccinate their children during the previous or current seasonal influenza season, and/or who had a higher education level were associated with increased willingness to receive the flu vaccine.

A Note on Excess Mortality Attributable to COVID-19 in the United States.

Annual influenza outbreaks constitute a major public health concern in the United States. But this health burden appears dwarfed by the impact of COVID-19. Our aim is to quantify the excess mortality attributable to COVID-19, compared to previous influenza seasons. We retrospectively compare weekly mortality figures attributable to influenza and pneumonia in the United States from 2013 to 2019 with corresponding figures attributable to influenza, pneumonia, and COVID-19 from 2019 to 2021. We utilize a difference in differences regression methodology to estimate excess mortality observed in 2019-21 compared to 2013-2019. Mortality patterns attributable to influenza, pneumonia, and COVID-19 differ significantly from the 2013-19 experience. Notably, distinct, aperiodic mortality waves occur in the 2019-2021 window, and mortality is well in excess of what is observed in typical influenza seasons. The COVID-19 pandemic has led to considerable excess mortality in the United States, and has strained public health resources. One might expect that the mortality waves observed during the pandemic will be damped by increasing levels of vaccination, and prior infections.