Annual Vaccination Research Articles

Estimating Influenza Illnesses Averted by Year-Round and Seasonal Campaign Vaccination for Young Children, Kenya.

In Kenya, influenza virus circulates year-round, raising questions about optimum strategies for vaccination. Given national interest in introducing influenza vaccination for young children 6-23 months of age, we modeled total influenza-associated illnesses (inclusive of hospitalizations, outpatient illnesses, and non‒medically attended illnesses) averted by multiple potential vaccination strategies: year-round versus seasonal-campaign vaccination, and vaccination starting in April (Southern Hemisphere influenza vaccine availability) versus October (Northern Hemisphere availability). We modeled average vaccine effectiveness of 50% and annual vaccination coverage of 60%. In the introduction year, year-round vaccination averted 6,410 total illnesses when introduced in October and 7,202 illnesses when introduced in April, whereas seasonal-campaign vaccination averted 10,236 (October) to 11,612 (April) illnesses. In the year after introduction, both strategies averted comparable numbers of illnesses (10,831-10,868 for year-round, 10,175-11,282 for campaign). Campaign-style vaccination would likely have a greater effect during initial pediatric influenza vaccine introduction in Kenya; however, either strategy could achieve similar longer-term effects.

Health disparities among in multicultural and non-multicultural families in South Korea

Abstract South Korea has experienced significant immigrant growth, with international marriages playing a key role in this demographic change. In 2019, international marriages accounted for 10.3% of all marriages, increasing the number of multicultural households. Multicultural families in Korea faced controversies over accepting new members in a society traditionally considered racially and ethnically homogenous. In rural areas, where patriarchal and conservative values prevail, there is greater discrimination and negative perception towards foreigners compared to urban areas, impacting access to healthcare. This potentially adversely affects the health of married immigrants. However, research on this issue is limited. This study aims to examine the differences in health behaviors, access to care, and health status between multicultural and non-multicultural families in rural and urban areas. Using a cross-sectional study design based on the 2023 Community Health Survey, the sample included 228,216 adults from non-multicultural families and 3,373 adults from multicultural families. Adjusted differences in outcome were estimated using regression models, including linear probability and logistic models. Overall, there were minimal or no differences in health behaviors and health status between adults from multicultural and non-multicultural families. However, significant differences were observed in access to care, such as annual health check-ups (0.72 [0.64, 0.81]) and vaccinations (0.84 [0.76, 0.94]). Non-multicultural families showed regional differences in all outcomes, whereas multicultural families exhibited minimal or no regional differences. These findings suggest that multicultural families may face barriers beyond regional environments, limiting their access to care and potentially leading to long-term negative health outcomes. Targeted policy development for multicultural families in Korea is necessary to address this issue. Key messages • Access to health care may vary for individual and local factors, especially for people with different ethnicities or cultures. • Multicultural families may encounter greater barriers than individual and regional characteristics, requiring the development of tailored policies for immigrants and multicultural families.

Co-administration of COVID-19 and flu vaccines in healthcare workers: results from three campaigns

Abstract The COVID-19 pandemic, along with seasonal influenza, highlights the need for innovative public health strategies. Co-administering COVID-19 and influenza vaccines offers advantages for healthcare workers (HCWs), streamlining vaccination efforts and enhancing public health resilience. Recent evidence supports the safety and efficacy of this approach, endorsed by health authorities worldwide. However, its acceptance remains a concern. This study explores HCWs’ acceptance of vaccine co-administration in three campaigns post the introduction of the anti-SARS-CoV-2 vaccine. During three consecutive flu seasons from October 2021 to January 2024, a cross-sectional study was conducted in a large Italian teaching hospital. Data for 2021/2022, 2022/2023 and 2023/2024 were compared, focusing on healthcare workers present in all datasets. McNemar’s test examined changes in acceptance of co-administration. In addition, a conditional logistic regression model was designed to assess the determinants of co-administration through the vaccination campaigns in the three years. During these vaccination campaigns 7457 HCWs were observed (62.78% women, median age 43). Co-administration surged, particularly in 2022/2023, showing a 280.71% increase, consistent across all professional categories (p < 0.001). Controlling for gender and professional category, acceptance of coadministration showed a significant association respectively with “open days” twice a month (OR 2.9 CI [2.7; 3.6]) and a hospital vaccination clinic two days a week on weekdays (OR 4.5 CI [4.1; 5.4]) compared to conducting vaccinations at a clinic open everyday during the campaign period; no association was highlighted with age. This study investigates a facet of an increasingly significant topic, demonstrating that co-administering vaccines for SARS-CoV-2 and influenza is emerging as an effective strategy in annual vaccination campaigns, thanks to its safety and the streamlining of logistical and organizational processes. Key messages • The co-administration of vaccines offers a promising strategy to enhance vaccination rates among healthcare workers. • By identifying factors influencing acceptance, it aims to inform targeted interventions for maximizing vaccine uptake and public health resilience.

Immunogenicity and Antibody Persistence of the Inactivated Quadrivalent Influenza Vaccine in Pediatric Patients Post-Chemotherapy or Allogeneic Hematopoietic Stem Cell Transplantation Versus Healthy Controls

Pediatric patients who have undergone hematopoietic stem cell transplantation (HSCT) or chemotherapy are at increased risk for severe influenza complications, necessitating annual vaccination. This study evaluated the immunogenicity and antibody persistence of the 2021–2022 seasonal quadrivalent influenza vaccine in pediatric patients post-HSCT or chemotherapy, compared to healthy controls. A prospective cohort study included 80 pediatric participants divided into three groups: chemotherapy (n = 33), HSCT (n = 27), and healthy controls (n = 20). All participants were vaccinated with the 2021–2022 GC FLU Quadrivalent vaccine. Hemagglutination inhibition (HI) assays measured seroprotection rates (SPR), geometric mean titers (GMT), and seroconversion rates (SCR) for the four vaccine antigens (A/H1N1, A/H3N2, B/Victoria, B/Yamagata) at one, three, and six months post-vaccination. At one month post-vaccination, all groups met the 70% SPR threshold for A/H1N1 and A/H3N2, but not for B/Victoria. For B/Yamagata, the SPR was low in the chemotherapy and HSCT groups (18.18% and 33.33%, respectively), compared to 80.00% in controls (p < 0.0001 and p = 0.0015). While A/H1N1 and A/H3N2 GMTs were protective in all groups, only controls achieved protective levels for B/Yamagata. Over time, the control group maintained >70% SPR for A/H1N1 up to six months, but the chemotherapy and HSCT groups declined by three and six months, respectively. For A/H3N2, the SPR in controls dropped below 70% at three months, while it remained above 70% in the chemotherapy and HSCT groups until three months. None of the groups achieved protective GMTs for B strains at three or six months. Pediatric patients post-HSCT or chemotherapy demonstrated a comparable immune response to healthy controls for A/H1N1 and A/H3N2, but the rapid decline in A/H1N1 antibody levels suggests the need for ongoing monitoring and adjusted vaccination schedules. The poor response to B antigens, particularly B/Yamagata, underscores the need for improved vaccination strategies in these vulnerable populations.

Interferon as an immunoadjuvant to enhance antibodies following influenza B infection and vaccination in ferrets

Despite annual vaccination, influenza B viruses (IBV) continue to cause significant morbidity and mortality in humans. We have found that IBV infection resulted in a weaker innate and adaptive immune response than influenza A viruses (IAV) in ferrets. To understand and overcome the weak immune responses to IBV in ferrets, we administered type-I or type-III interferon (IFN) to ferrets following infection or vaccination and evaluated their effects on the immune response. IFN signaling following viral infection plays an important role in the initial innate immune response and affects subsequent adaptive immune responses. In the respiratory tract, IFN lambda (IFNL) has regulatory effects on adaptive immunity indirectly through thymic stromal lymphopoietin (TSLP), which then acts on immune cells to stimulate the adaptive response. Following IBV infection or vaccination, IFN treatment (IFN-Tx) upregulated gene expression of early inflammatory responses in the upper respiratory tract and robust IFN, TSLP, and inflammatory responses in peripheral blood cells. These responses were sustained following challenge or vaccination in IFN-Tx animals. Serum IFNL and TSLP levels were enhanced in IFN-Tx animals following challenge/rechallenge over mock-Tx; however, this difference was not observed following vaccination. Antibody responses in serum of IFN-Tx animals following IBV infection or vaccination increased more quickly and to higher titers and were sustained longer than mock-Tx animals over 3 months. Following rechallenge of infected animals 3 months post treatment, antibody levels remained higher than mock-Tx. However, IFN-Tx did not have an effect on antibody responses following challenge of vaccinated animals. A strong direct correlation was found between TSLP levels and antibody responses following challenge-rechallenge and vaccination-challenge indicating it as a useful tool for predicting adaptive immune responses following IBV infection or vaccination. The effects of IFN on strengthening both innate and adaptive responses to IBV may aid in development of more effective treatments following infection and improved influenza vaccines.

Multiplexed Antibody Sequencing and Profiling of the Human Hemagglutinin-specific Memory B Cell Response following Influenza Vaccination.

Influenza virus is a highly contagious respiratory pathogen causing between 9.4 and 41 million infections per year in the United States in the last decade. Annual vaccination is recommended by the World Health Organization, with the goal to reduce influenza severity and transmission. Ag-specific single B cell sequencing methodologies have opened up new avenues into the dissection of the Ab response to influenza virus. The improvement of these methodologies is pivotal to reduce the associated costs and optimize the operational workflow and throughput, especially in the context of multiple samples. In this study, PBMCs and serum samples were collected longitudinally from eight influenza vaccinees either vaccinated yearly for four consecutive influenza seasons or once for one season. Following the serological and B cell profiling of their polyclonal Ab response to a panel of historical, recent, and next-generation influenza vaccine hemagglutinin (HA) and virus strains, a single multiplexed Ag-specific single B cell sequencing run allowed to capture HA-specific memory B cells that were analyzed for preferential Ig H chain/L chain pairing, isotype/subclass usage, and the presence of public BCR clonotypes across participants. Binding and functional profiles of representative private and public clonotypes confirmed their HA specificity, and their overall binding and functional activity were consistent with those observed at the polyclonal level. Collectively, this high-resolution and multiplexed Ab repertoire analysis demonstrated the validity of this optimized methodology in capturing Ag-specific BCR clonotypes, even in the context of a rare B cell population, such as in the case of the peripheral Ag-specific memory B cells.

28 Vaccination experiences for children with special needs - An examination of the impact of behaviours on vaccine uptake

Abstract Background While vaccines have been one of the most effective medical interventions to reduce the morbidity and mortality of many communicable illnesses, many factors have led to suboptimal immunization rates amongst paediatric patients. One of which that has not been explored widely in research literature is the impact of maladaptive behaviours on annual immunization rates. Behaviours such as aggression, agitation and flight are common amongst children with a neurodevelopmental diagnosis such as autism spectrum disorder, global developmental delay, and intellectual delay. When children are young, physical restraints by parents are often the method used to aid in the administration of the vaccine. However, as they age physical restraints is often regarded as inappropriate. Objectives The purpose of this study is to determine the extent in which disruptive behaviours (aggression, agitation and flight) affect annual vaccination rates for children with a neurodevelopmental diagnosis above the age of 6 years where physical restraining for vaccinations is no longer deemed appropriate or safe. Design/Methods Families with children diagnosed with Autism Spectrum Disorder (ASD), Intellectual Disorder (ID), and/or Global Developmental Delay (GDD) aged 6-17 years, seen through outpatient clinics at the Ron Joyce Children’s Health Centre of McMaster Children’s hospital in Hamilton between November 2022 – April 2023 were invited to participate in this cross sectional survey. The study aimed to capture both quantitative data on vaccine uptake and qualitative data on how vaccination experiences could be improved for children with neurodiversity. Results A total of 109 participants completed the survey. Among them, forty-three (39%) participants had a diagnosis of ASD and sixty-six (51.2%) had a diagnosis of global developmental delay or intellectual disability. Forty-six (45.6%) and 82 (76%) did not receive the Covid-19 and the influenza vaccination respectively. Of the children that did not receive the CoVid-19 vaccine, fourteen (30%) of the families had brought their child to be vaccinated, but the health care team could not administer the vaccine due to their child’s behaviours and twenty-one (37%) of the families anticipated that the vaccination would be a difficult experience because of their child’s behaviours and did not bring their child to get vaccinated. Of the children that did not receive the influenza vaccine, fifteen (18%) families had brought their child to be vaccinated, but the health care team could not administer the vaccine due to the child’s behaviours and 42 (50%) families anticipated that the vaccination would be a difficult experience because of their child’s behaviours and did not bring their child to get vaccinated. The main themes that emerged from the studies on ways to improve the vaccination experience for families include administering the vaccine in a low sensory environment, decreasing wait time, and ensuring clinic staff have experience in caring for children with special needs. Conclusion Children with special needs are a vulnerable population warranting concerted effort to ensure equitable access to immunizations. Interventions such as clinics specifically designed for children with neurodiversity should be implemented with the hope to further improve immunization rates within this population.

Contribution of immunoglobulin products in influencing seasonal influenza infection and severity in antibody immune deficiency patients receiving immunoglobulin replacement therapy

Seasonal and pandemic influenza infection present a potential threat to patients with antibody deficiency. The acceptance and effect of the current recommendation for annual vaccination against influenza for patients with antibody deficiency is not well investigated and due to antigenic drift or shift the protective capacity of regular IgG replacement therapy (IgRT) is considered low. This narrative review considers the effect of influenza vaccination in immunodeficient patients and discusses available information on the effect of immunoglobulin products on seasonal influenza infectivity and severity in antibody deficiency patients receiving IgRT. The humoral immune response to seasonal influenza vaccination is reduced in patients with antibody immune deficiency. However, there is no evidence that the proportion of patients with primary antibody deficiency who develop influenza illness, and the severity of such illness, is increased when compared with the general population. The IgRT that patients receive has been shown to contain neutralizing antibodies as a consequence of past flu infections against both the hemagglutinin and neuraminidase surface proteins and other viral internal proteins of different influenza A virus strains. Studies have demonstrated not only significant levels of specific but also cross-reactive antibodies against seasonal influenza virus strains. Thus, despite the yearly changes in influenza viral antigenicity that occur, IgRT could potentially contribute to the protection of patients against seasonal influenza. Currently, only limited clinical data are available confirming a preventative effect of IgRT with respect to seasonal influenza infection. In conclusion, there is some evidence that IgRT could contribute to protection against seasonal influenza in patients with antibody-related immunodeficiency. However, additional clinical data are needed to confirm the extent and relevance of this protection and identify the main responsible virus targets of that protection.

Psychological distress among healthcare providers during the COVID-19 pandemic: patterns over time

BackgroundCOVID-19 added to healthcare provider (HCP) distress, but patterns of change remain unclear. This study sought to determine if and how emotional distress varied among HCP between March 28, 2021 and December 1, 2023.MethodsThis longitudinal study was embedded within the 42-month prospective COVID-19 Cohort Study that recruited HCP from four Canadian provinces. Information was collected at enrollment, from annual exposure surveys, and vaccination and illness surveys. The 10-item Kessler Psychological Distress Scale (K10) was completed approximately every six months after March 28, 2021. Linear mixed effects models, specifically random intercept models, were generated to determine the impact of time on emotional distress while accounting for demographic and work-related factors.ResultsBetween 2021 and 2023, the mean K10 score fell by 3.1 points, indicating decreased distress, but scores increased during periods of high levels of mitigation strategies against transmission of SARS-CoV-2, during winter months, and if taking antidepression, anti-anxiety or anti-insomnia medications. K10 scores were significantly lower for HCP who were male, older, had more children in their household, experienced prior COVID-19 illness(es), and for non-physician but regulated HCP versus nurses. A sensitivity analysis that included only those who had submitted at least five K10 surveys consisted of the factors in the full model excluding previous COVID-19 illness, occupation, and season, after adjustment. Models were also created for K10 anxiety and depression subscales.ConclusionsK10 scores decreased as the COVID-19 pandemic continued but increased during periods of high mitigation and the winter months. Personal and work-place factors also impacted HCP distress scores. Further research into best practices in distress identification and remediation is warranted to ensure future public health disasters are met with healthcare systems that are able to buffer HCP against short- and long-term mental health issues.

Influenza vaccine allocation in tropical settings under constrained resources.

Influenza virus seasonality, synchronicity, and vaccine supply differ substantially between temperate and tropical settings, and optimal vaccination strategy may differ on this basis. Many national vaccine recommendations focus on high-risk groups, elderly populations, and healthcare workers despite previous analyses demonstrating broad benefits to vaccinating younger high-contact age groups. In this study, we parameterized an age-structured nonseasonal asynchronous epidemiological model of influenza virus transmission for a tropical low-income setting. We evaluated timing and age allocation of vaccines across vaccine supplies ranging from 10 to 90% using decade-based age groups. Year-round vaccination was beneficial when compared with more concentrated annual vaccine distribution. When targeting a single age group for vaccine prioritization, maximum vaccine allocation to the 10-19 high-contact age group minimized annual influenza mortality for all but one vaccine supply. When evaluating across all possible age allocations, optimal strategies always allocated a plurality of vaccines to school-age children (10-19). The converse, however, was not true as not all strategies allocating a plurality to children aged 10-19 minimized mortality. Allocating a high proportion of vaccine supply to the 10-19 age group is necessary but not sufficient to minimize annual mortality as distribution of remaining vaccine doses to other age groups also needs to be optimized. Strategies focusing on indirect benefits (vaccinating children) showed higher variance in mortality outcomes than strategies focusing on direct benefits (vaccinating the elderly). However, the indirect benefit approaches showed a lower mean mortality and a lower minimum mortality than vaccination focused on the elderly.

Cost-Effectiveness of Influenza Vaccination in Healthy Children: A 10-Year Population-Based Study

Background/Objectives: Seasonal influenza annually puts a significant burden on the pediatric population, especially the youngest, causing severe illness and death. Additionally, associated healthcare costs cause a significant financial strain on healthcare systems. While vaccination is the most effective prevention method, its cost-effectiveness for healthy children remains unassessed. Methods: Using the Pedianet database spanning from 2009 to 2019, we analyzed influenza cases among 6-month-olds to 14-year-olds in Italy. Data included influenza-related medical visits, prescriptions, exams, emergency visits, hospitalizations, and costs. Adverse events and quality-adjusted life years (QALYs) were considered from the existing literature. A static decision-tree model compared annual vaccination strategies, assessing probabilities for influenza or influenza-like illnesses by vaccination status. Incremental cost-effectiveness ratios (ICERs) were calculated, along with sensitivity analyses and cost-effectiveness acceptability curve generation. Results: Mean total influenza costs for vaccinated children averaged EUR 18.6 (range 0–3175.9, including EUR 15.79 for the influenza vaccination), whereas costs for unvaccinated children were consistently lower at around EUR 4.6 (range 0–3250.1). The average ICER for years where vaccine and virus strains are matched was EUR 29,831 per QALY, which is below the EUR 40,000 threshold set by the Italian National Health Services. The ICER values range from EUR 13,736 (2017/2018) to EUR 72,153 (2013/2014). Averted influenza costs averaged EUR 23 per case, with fluctuations over the years. In most observed years, influenza vaccination was cost-effective from the healthcare providers’ standpoint. The exception was 2009–2010, due to a mismatch between vaccine and virus strains. Conclusions: This study highlights the economic viability of influenza vaccination, especially when virus and vaccine strains align. It demonstrates the potential of vaccination programs in preserving children’s health and well-being while managing healthcare costs.

Has Ghana's Rotavirus Vaccine Switch Met Programmatic Expectations? An Analysis of National Surveillance Data; 2018-2022.

Ghana introduced a 2-dose schedule rotavirus vaccine, Rotarix, into childhood immunization in 2012 but switched to a 3-dose schedule vaccine, Rotavac, in 2020 on account of programmatic advantages offered by the latter, including lower cost per fully immunized child and lower cold chain volume requirement. The objective of the study was to assess the effect of the vaccine switch on the trends of rotavirus vaccine uptake and health facility outpatient department (OPD) attendance due to diarrhea among children aged 1-11 months. A retrospective analysis was conducted on childhood immunization and diarrhea surveillance data for 2018-2022. The uptake of the different rotavirus vaccine products and the proportion of health facility OPD attendance attributed to diarrhea, respectively, were compared between the pre- and postswitch study periods. The uptake of rotavirus vaccine was sustained following the switch. There were no significant differences in vaccination coverages (rota1, Rotarix coverage [94.3%], vs rota1, Rotavac coverage [95.3%]; P = .757; rota2, Rotarix coverage [91.3%], vs rota2, Rotavac coverage [92.7%]; P = .789). The proportions of health facility OPD attendance due to diarrhea were comparable (preswitch [12.4%] vs postswitch [12.1%]; P = .838). Ghana's rotavirus vaccine switch yielded expected programmatic benefits without any untoward effects. The trends of vaccine uptake and reduction in diarrhea morbidity were sustained. These experiences and lessons from the rotavirus vaccine switch are vital for potential switches for other vaccines in the current immunization schedule to mitigate the annual vaccine expenditure.

Severe Bacterial Superinfection of Influenza Pneumonia in Immunocompetent Young Patients: Case Reports

Influenza can lead to or coexist with severe bacterial pneumonia, with the potential to permanently damage lung tissue, refractory to conservative treatment in the post-COVID-19 period. It can lead to serious complications; therefore, annual vaccinations are recommended. This case series with a literature review pertains to two young female patients with an insignificant past medical history, who required emergency lobectomy due to bacterial complications after influenza infection. Urgent lobectomy proves to be a feasible therapeutic option for selected patients with pleural complications.

Cost effectiveness analysis comparing varying booster intervals of vaccination policies to address COVID-19 situation in Thailand, 2023.

The COVID-19 booster immunization policy is cost-effective, but evidence on additional booster doses and appropriate strategies is scarce. This research compared the cost-effectiveness of annual, twice-a-year, and biennial booster dose policies. We performed stochastic modeling using compartmental susceptible-exposed-infectious-recovered models and a system dynamic model. We evaluated four policy scenarios: (1) hypothetical no-booster immunization policy; (2) twice-a-year vaccination policy; (3) annual vaccination policy; and (4) biennial vaccination policy. In addition, we conducted a one-way sensitivity analysis by adjusting R0 from 1.8 to 3.0 in all scenarios (epidemic stage) and by decreasing the vaccination cost by 50% at the end of the first year to reflect the current policy direction to enhance domestic vaccine production. Compared to non-booster policies, all three booster strategies reduced the number of cases, hospital admissions, and severe infections remarkably. Without a booster, total cases would reach 16,220,615 (95% confidence interval [CI] 6,726,550-29,661,112) by day 1,460, whereas, with a twice-a-year booster, the total cases would reach 597,901 (95% CI 526,230-694,458) in the same period. Even though the no booster scenario exhibited the lowest cost by approximately the first 500 days, by day 1,460 the biennial booster scenario demonstrated the lowest cost at 72.0 billion baht (95% CI 68.6-79.4 billion). The most cost-saving policy was the biennial booster scenario. The annual booster scenario also stood as a cost-effective option for most outcomes. In the epidemic stage and in an assumption where the vaccination costs dropped, all booster policies became more cost-effective or cost-saving compared with the main assumption. This study underscores the significance of the COVID-19 vaccine booster policy. Implementing policies should take into consideration cost-effectiveness, feasibility, and public communication.

Influenza vaccine for 2024-2025.

Annual vaccination in the US against influenza A and B viruses is recommended for everyone ≥6 months old without a contraindication.1,2 Influenza vaccines available in the US for the 2024-2025 season are listed in Table 2.

Outcomes of a Short-Duration, Large-Scale Canine Rabies Vaccination Campaign in Central Cambodia.

WHO and WOAH advocate for annual high-coverage canine rabies vaccination campaigns as the most sustainable approach to eliminate the risk of dog rabies transmission to humans. It is estimated that Cambodia has one of the highest human rabies deaths per capita of any country (5.8 human deaths per 100,000 people), highlighting the urgent need to implement an effective canine rabies vaccination program. To this end, a coalition of government and non-government organizations conducted a pioneering short-duration dog rabies vaccination campaign over 10 days across Phnom Penh and Kandal Provinces in May 2023. Over 10 working days, 120 vaccination teams, each consisting of two vaccinators and one tuk-tuk driver, traveled door-to-door to deliver parenteral rabies vaccines to all dogs that could be held by the teams or members of the community. Spatial team management and data collection were conducted through the WVS Data Collection Application. A total of 74,983 dogs were vaccinated, giving a mean vaccination rate of 62.5 dogs per team per day. An additional 2145 cats were vaccinated. Of all dogs encountered by the teams, 84.0% could be vaccinated, with 99.1% of those being identified as owned. Post-vaccination surveys of 4356 households estimated a mean vaccination coverage of 70.7% in owned dogs across the districts of Phnom Penh Province. Short-duration, large-scale canine rabies vaccination campaigns can achieve high vaccination coverage using a door-to-door approach in urban centers of Cambodia. Data gathered through the campaign yielded insights to support the refinement and planning of a wider rabies control strategy and is anticipated to drive further support for subsequent campaigns in Cambodia.

Estimating the time required to reach HPV vaccination targets across Europe

ABSTRACT Background Cervical cancer (CC) is one of the most common causes of cancer-related deaths in women. The World Health Organization (WHO) has called for the CC elimination as a public health priority and has urged countries to achieve a 90% vaccine coverage rate of human papilloma virus (HPV) vaccination among 15-year-old girls by 2030. Research design and methods Regression models were fitted to the WHO HPV vaccine coverage rate data to estimate when the 90% vaccine coverage rate target would be achieved in 22 European countries. Results The mean vaccine coverage rate of included countries was 62.2% (SD: 18.3). Nine countries (Iceland, Norway, Portugal, Ireland, Hungary, Spain, Sweden, Denmark, and Switzerland) are expected to achieve a 90% vaccine coverage rate by 2030. Six countries (Estonia, Cyprus, Netherlands, France, Germany, and Italy) are expected to reach a 90% vaccine coverage rate between 2030 and 2040 whereas seven countries (Belgium, Bulgaria, Finland, Latvia, Luxembourg, Malta, and Slovenia) are not expected to achieve the 90% vaccine coverage rate target by 2040. Conclusion The majority of European countries are not on track to achieve 90% vaccine coverage rate by 2030. To achieve this, a significant increase in the annual vaccine coverage rate growth rate is required.

Course and complications of influenza A in seniors over 65 years of age.

Influenza A and B viruses cause epidemics every year, with approximately 3-5 million serious cases and about 290,000 to 650,000 deaths worldwide. Most patients die from bacterial complications of influenza. The aim of our study was to describe the clinical pictures of influenza and the development of the complications in seniors over 65 years of age, who were treated in University Hospital Pilsen. The course of the disease and changes in laboratory parameters were evaluated with regard to the method of treatment performed. A descriptive retrospective study was performed. Clinical and laboratory data of seniors with the diagnosis of influenza were extracted from electronic medical records and later analysed. The data were processed with Excel 2016 and Statistica. A collection of 261 seniors, of whom 218 were hospitalized and 43 treated in an outpatient setting, has been studied. Patients who later developed complications had elevated values of CRP, procalcitonin, urea, and creatinine. The antiviral drug oseltamivir was administered to 226 of 261 seniors. Forty-seven seniors (18.0%) died from influenza and its complications (severe pneumonia with acute respiratory insufficiency or heart failure). The course of influenza in seniors was usually more severe and required hospitalization along with antiviral treatment. The mortality rate in the monitored group exceeded 18%. Annual timely vaccination, but also other preventive measures, and maybe considering other risk groups are methods to prevent severe or even fatal cases of influenza.

Evidence base for yearly respiratory virus vaccines: Current status and proposed improved strategies.

Annual vaccination is widely recommended for influenza and SARS-CoV-2. In this essay, we analyse and question the prevailing policymaking approach to these respiratory virus vaccines, especially in the United States. Every year, licensed influenza vaccines are reformulated to include specific strains expected to dominate in the season ahead. Updated vaccines are rapidly manufactured and approved without further regulatory requirement of clinical data. Novel vaccines (i.e. new products) typically undergo clinical trials, though generally powered for clinically unimportant outcomes (e.g. lab-confirmed infections, regardless of symptomatology or antibody levels). Eventually, the current and future efficacy of influenza and COVID-19 vaccines against hospitalization or death carries considerable uncertainty. The emergence of highly transmissible SARS-CoV-2 variants and waning vaccine-induced immunity led to plummeting vaccine effectiveness, at least against symptomatic infection, and booster doses have since been widely recommended. No further randomized trials were performed for clinically important outcomes for licensed updated boosters. In both cases, annual vaccine effectiveness estimates are generated by observational research, but observational studies are particularly susceptible to confounding and bias. Well-conducted experimental studies, particularly randomized trials, are necessary to address persistent uncertainties about influenza and COVID-19 vaccines. We propose a new research framework which would render results relevant to the current or future respiratory viral seasons. We demonstrate that experimental studies are feasible by adopting a more pragmatic approach and provide strategies on how to do so. When it comes to implementing policies that seriously impact people's lives, require substantial public resources and/or rely on widespread public acceptance, high evidence standards are desirable.

Preliminary Findings From the Dynamics of the Immune Responses to Repeat Influenza Vaccination Exposures (DRIVE I) Study: A Randomized Controlled Trial.

Studies have reported that repeated annual vaccination may influence influenza vaccination effectiveness in the current season. We established a 5-year randomized placebo-controlled trial of repeated influenza vaccination (Flublok; Sanofi Pasteur) in adults 18-45 years of age. In the first 2 years, participants were randomized to receive vaccine or saline placebo as follows: placebo-placebo (P-P), placebo-vaccine (P-V), or vaccine-vaccine (V-V). Serum samples were collected each year just before vaccination and after 30 and 182 days. A subset of serum samples collected at 5 time points from 95 participants were tested for antibodies against vaccine strains. From 23 October 2020 through 11 March 2021 we enrolled and randomized 447 adults. Among vaccinated individuals, antibody titers increased between days 0 and 30 against each of the vaccine strains, with smaller increases for repeat vaccinees who on average had higher prevaccination titers in year 2. There were statistically significant differences in the proportions of participants achieving ≥4-fold rises in antibody titer for the repeat vaccinees for influenza A(H1N1), B/Victoria, and B/Yamagata, but not for A(H3N2). Among participants who received vaccination in year 2, there were no significant differences between the P-V and V-V groups in geometric mean titers at day 30 or the proportions of participants with antibody titers ≥40 at day 30 for any of the vaccine strains. In the first 2 years, during which influenza did not circulate, repeat and first-time vaccinees had similar postvaccination geometric mean titers to all 4 vaccine strains, indicative of similar levels of clinical protection. Clinical Trials Registration. NCT04576377.