Vaccination Recommendations Research Articles

Analyzing the 7C psychological antecedents of vaccine acceptance throughout the COVID-19 pandemic among healthcare sector workers in France: A repeated cross-sectional study (CappVac-Cov)

BackgroundAcross various stages of the COVID-19 pandemic and related vaccine recommendations in France, we assessed the association of the 7C-psychological antecedents with vaccine uptake/intention for booster vaccination among healthcare-sector workers (HCSWs). We also assessed whether 7C-antecedent profiles changed over time. MethodologyThe Research Group for the Prevention of Occupational Infections in Healthcare Workers (GERES) conducted three repeated web-surveys which were disseminated by email chain-referral among HCSWs throughout France. The questionnaires waves took place: July-November 2021, February-March 2022 and January-March 2023 (P2, P3 and P4). We also reanalysed data from a prior similar study conducted late 2020-early 2021 (Moirangthem et al. (2022)) (P1). To evaluate the association of 7C-items with vaccine uptake-intention for future vaccination, we estimated adjusted prevalence ratios (aPR) using robust variance Poisson regression. We report the 7C-item population attributable loss in vaccine intention. ResultsThe four surveys (P1-P4) encompassed 5234, 339, 351 and 437 participants. At earlier stages of the vaccine campaign, the principal antecedents of vaccine intention were favorable perception of vaccination benefit-risk-balance (BRB) (vs. unfavorable, aPR: 2.32), reactance to employer encouragement for vaccination (motivates vs. dissuades-me, aPR:2.23), vaccine confidence (vs. not-being-confident, aPR: 1.71) and social conformism towards vaccination (favorable vs. skeptical opinion in private environment, aPR: 1.33). Under a vaccine mandate for HCSWs, only perceiving vaccination as a collective action was associated with current vaccine status (agree vs. disagree, aPR: 2.19). At later stages of the epidemic, hypothetical booster vaccine intentions were strongly associated with BRB perception (favorable vs. unfavorable, aPR: 2.07) and perceiving vaccination as a collective action (agree vs. disagree, aPR: 1.69). Fearing a severe side effect from vaccination decreased population vaccine intention by 26.2 %. ConclusionOur results suggest that both 7C-antecedents and their association with vaccine behaviour can change over time, and underscore the importance of assuring confidence in vaccine safety.

Socioeconomic determinants and reasons for non-acceptance to vaccination recommendations during the 3rd - 5th waves of the COVID-19 pandemic in Hungary

BackgroundIn Hungary, although six types of vaccines were widely available, the percentage of people receiving the primary series of COVID-19 vaccination remained below the EU average. This paper investigates the reasons for Hungary’s lower vaccination coverage by exploring changing attitudes towards vaccination, socio-demographic determinants, and individual reasons for non-acceptance during the 3rd - 5th pandemic waves of COVID-19.MethodsThe study’s empirical analysis is based on representative surveys conducted in Hungary between February 19, 2021, and June 30, 2022. The study used a total of 17 surveys, each with a sample size of at least 1000 respondents. Binomial logistic regression models were used to investigate which socio-demographic characteristics are most likely to influence vaccine hesitancy in Hungary. The study analysed 2506 open-ended responses to identify reasons for vaccine non-acceptance. The responses were categorised into four main categories and 13 sub-categories.ResultsBetween the third and fifth wave of the pandemic, attitudes towards COVID-19 vaccination have significantly changed. Although the proportion of vaccinated individuals has increased steadily, the percentage of individuals who reported not accepting the vaccine has remained almost unchanged. Socio-demographic characteristics were an important determinant of the observed vaccine hesitancy, although they remained relatively stable over time. Individuals in younger age groups and those with lower socioeconomic status were more likely to decline vaccination, while those living in the capital city were the least likely. A significant reason behind vaccine refusal can undoubtedly be identified as lack of trust (specifically distrust in science), facing an information barrier and the perception of low personal risk.ConclusionAlthough compulsory childhood vaccination coverage is particularly high in Hungary, voluntary adult vaccines, such as the influenza and COVID-19 vaccines, are less well accepted. Vaccine acceptance is heavily affected by the social-demographic characteristics of people. Mistrust and hesitancy about COVID-19 vaccines, if not well managed, can easily affect people’s opinion and acceptance of other vaccines as well. Identifying and understanding the complexity of how vaccine hesitancy evolved during the pandemic can help to understand and halt the decline in both COVID-19 and general vaccine confidence by developing targeted public health programs to address these issues.

Cost-effectiveness of recombinant influenza vaccine compared with standard dose influenza vaccine in adults 18–64 years of age

BackgroundThe Advisory Committee on Immunization Practices (ACIP) uses the Evidence to Recommendations Framework that includes cost-effectiveness analyses (CEA) for determining vaccine recommendations. ACIP’s preference for protecting adults ≥ 65 years is enhanced vaccines, including recombinant influenza vaccine (RIV4), adjuvanted or high dose influenza vaccine. Less is known about the CEA of enhanced vaccines for younger adults. MethodsWe used decision analysis modeling from a societal perspective to determine the cost-effectiveness, measured in quality adjusted life years (QALYs), of RIV4 compared with standard dose quadrivalent influenza vaccine (SD-IIV4) in adults 18–64 years old. Model inputs included 2018–2020 vaccine effectiveness (VE) estimates based on medical record data from a large local health system, 2019–2020 national vaccination and influenza epidemic parameters, with costs and population distributions fitted to the season. ResultsAmong adults ages 18–64 years, RIV4 cost $94,186/QALY gained, compared to SD-IIV4. Among those 50–64 years old, RIV4 was relatively more cost-effective ($61,329/QALY gained). Cost-effectiveness estimates for 18–64-year-olds were sensitive to the absolute difference in VE between SD-IIV4 and RIV4, among other parameters. Use of RIV4 in 18–64-year-olds would result in fewer cases (669,984), outpatient visits (261,293), hospitalizations (20,046) and deaths (1,018) annually. The majority (59 %; 597 of 1018) of the decreases in deaths occurred in the 50–64-year-olds. ConclusionsWhile RIV4 was effective and cost-effective relative to SD-IIV4 for both 50–64-year-old and 18–64-year-old adults, cost-effectiveness was sensitive to small changes in parameters among 18–64-year-olds. Because substantial public health benefits occur with enhanced vaccines, health systems and policy makers may opt for preferential product use in select age/risk groups (e.g., 50–64 year olds) to maximize their cost-benefit ratios.

A cost benefit analysis of varicella vaccination in South Korea

BackgroundThe introduction of varicella vaccination has significantly reduced the burden of chickenpox in many countries, but outbreaks still occur in populations with high vaccination coverage. To address this, some countries, including the United States, Germany, and Japan, have adopted a two-dose varicella vaccination recommendation. Economic evaluations are crucial for assessing vaccine recommendations; however, there are limited studies exist in Asian countries. Thus, our study aimed to evaluate the cost-benefit of one-dose and two-dose varicella vaccination programs compared to no vaccination in South Korea, incorporating updated data on disease burden and costs. MethodsWe utilized data from South Korea’s health databases to estimate varicella burden and vaccination records. Decision tree analysis was employed to compare costs and benefits of vaccination strategies over a ten-year period for the 2012 birth cohort. Sensitivity analyses were conducted to assess the impact of various variables. ResultsBoth one-dose and two-dose vaccination programs showed cost-benefit compared to no vaccination, with substantial societal cost savings. The one-dose program yielded a benefit-cost ratio (BCR) of1.43, while the two-dose program had a direct BCR of1.28. Sensitivity analyses confirmed the robustness of these findings. ConclusionOur study demonstrates the economic benefits of varicella vaccination in South Korea, aligning with findings from other countries. While the second dose did not show additional cost savings compared to the one-dose program, other factors like disease severity and transmission dynamics should be considered. Implementing either a one-dose or two-dose varicella vaccination regimen in South Korea could lead to cost reductions and improved cost-effectiveness compared to no vaccination, emphasizing the importance of vaccination programs in reducing disease burden and enhancing public health outcomes.

Durability of Humoral Responses after an Adapted SARS-CoV-2 mRNA Vaccine Dose in Hemodialysis Patients.

We recently showed that an adapted SARS-CoV-2 vaccine with wildtype and BA.4/BA.5 Omicron subtype epitopes induced a broad short-term immune response in hemodialysis patients. Antibodies with protective capacity were boosted significantly after a follow-up period of 3 weeks following a fifth vaccine dose. However, data on the longevity of the humoral response after bivalent vaccination are lacking but urgently needed to make recommendations for further booster vaccinations in this patient group. This study is an extension of our previously published data including 40 patients on hemodialysis with a follow-up period of 12 months after an adapted booster vaccine dose. We performed a detailed characterization of humoral immune responses and assessed breakthrough infections. In addition, the severity of breakthrough infections was assessed using an established grading system. Anti-S1 IgG and surrogate neutralizing antibodies significantly decreased during the period of 12 months (p < 0.01 and p < 0.001, respectively). Live-virus neutralizing antibodies against the wildtype and the BA.5 subtype also significantly decreased over time (p < 0.01 and p < 0.01, respectively). However, even 12 months after administration of the adapted vaccine dose, all 40/40 (100%) of hemodialysis patients showed detectable SARS-CoV-2 wildtype neutralization activity, with 35/40 (88%) also exhibiting detectable BA.5 subtype neutralization activity. During follow-up, 13/40 (33%) patients contracted a SARS-CoV-2 breakthrough infection, among which 12 cases were categorized as asymptomatic or mild, while only 1 case was classified as moderate disease activity. Thus, bivalent booster vaccination seems to induce a sustained immune response in hemodialysis patients over a period of 12 months with breakthrough infections occurring frequently but predominantly manifesting as asymptomatic or mild.

Prescribing hepatitis A vaccines in the UK

Hepatitis A is a liver infection caused by a virus that is spread by eating or drinking contaminated food and water or from direct contact (including some types of sexual contact) with an infected person. Hepatitis A virus infection causes liver inflammation that usually results in a mild illness. More rarely, severe symptoms with the potential to develop into liver failure can occur. UK health professionals involved in prescribing hepatitis A vaccines should make sure they are familiar with appropriate vaccine guidance and use current UK hepatitis A vaccine recommendations for international travel as part of their risk assessment. Although most people respond well to the hepatitis A vaccine, the importance of food and water hygiene should still be emphasised to all UK travellers visiting hepatitis A endemic areas.

Uptake and outcomes of VaxCheck, an adult life-course vaccination service: A study among community pharmacists

Vaccination rates among Canadian adults remain suboptimal. Community pharmacists have increasingly adopted an active role in vaccination and are trusted by the public to provide vaccination-related advice and care. The aim of this prospective descriptive study was to develop and test a novel clinical service, VaxCheck, to support proactive life-course vaccination assessments by community pharmacists. From October 2022-May 2023, 123 VaxCheck consultations were performed at 9 community pharmacies within the Wholehealth Pharmacy Partners banner in Ontario, Canada. Patient age averaged 60 years and 35.8 % had at least one chronic disease risk factor, 17.7 % had lifestyle-related risk factor(s), and 15.4 % were immunocompromised. 95.1 % of VaxCheck consultations resulted in at least one vaccine recommendation, averaging three vaccines per patient. Most frequently recommended vaccines were those against pneumococcal disease, tetanus/diphtheria, herpes zoster, COVID-19, and influenza, with acceptance rates highest for those available without a prescription and at no charge at the pharmacy. Patient feedback was positive with 85 % of respondents agreeing or strongly agreeing that they would recommend the service to others. Vaccine administration at the time of the consultation occurred with only 5.9 % of recommended vaccines, frequently impacted by limitations to scope of practice related to pharmacist ability to prescribe and/or administer the vaccine and lack of pharmacy access to publicly funded vaccine supply for those meeting eligibility criteria. Community pharmacists performing a VaxCheck consultation can proactively identify indicated vaccines for patients. Expansion in scope of practice and access to publicly funded vaccine is recommended to further support vaccine uptake.

Current recommendations for vaccines for patients planning pregnancy: a committee opinion.

Encounters for infertility care are opportunities to assess and update immunization status. Individuals of reproductive age are often unaware of their need for immunization, their immunization status, and the potentially severe consequences of preventable disease on pregnancy outcome. The purpose of this American Society for Reproductive Medicine (ASRM) Practice Committee document is to summarize current recommendations regarding vaccinations for individuals of reproductive age. This document replaces the ASRM Practice Committee document titled "Vaccination guidelines for female infertility patients," last published in 2018 (Fertil Steril 2018;110:838-41).

Effectiveness of Vaccination Against Tick-Borne Encephalitis in the Czech Republic, 2018-2022.

Background: Tick-borne encephalitis (TBE) is caused by the tick-borne encephalitis virus (TBEV). TBEV infection can cause symptoms of central nervous system (CNS) inflammation and result in severe consequences including death. TBE is an increasing health threat in the Czech Republic and elsewhere in Europe. In 2020, 23% of 3734 TBE cases reported to the European Centre for Disease Prevention and Control were from the Czech Republic. TBE vaccination is universally recommended in the Czech Republic, but a full analysis of TBE vaccine effectiveness (VE) in the Czech Republic has not been published. Methods: TBE is a notifiable disease in the Czech Republic with mandatory reporting of cases (i.e., laboratory-confirmed TBEV infected patient with symptoms of CNS inflammation) and vaccination history to public health authorities. TBE VE was estimated using the screening method utilizing public health surveillance data from 2018 to 2022 and online household surveys of the general population on TBE vaccine uptake conducted in 2019-2022. Results: In 2018-2022, 3648 TBE cases were reported in the Czech Republic; 98.1% (3105/3166) of TBE cases with known vaccination history were unvaccinated. Among 42,671 persons surveyed from the general population who had known TBE vaccination history, 66.5% were unvaccinated. VE against TBE was 97.6% (95% confidence interval 95.7-98.7). When stratified by age group, VE was 97.1% (88.4-99.3) in 1-15 years of age, 97.9% (95.3-99.0) in 16-59 years of age, and 96.9% (90.5-99.0) in ≥60 years of age. TBE vaccination averted an estimated 1020 TBE cases in the Czech Republic from 2018 to 2022. Conclusions: This first published study with a full analysis of TBE VE in the Czech Republic showed that vaccination was highly effective for the prevention of TBE including in children, an age group with increasing TBE disease burden. Vaccination averted hundreds of TBE cases and hospitalizations despite the relatively low compliance with TBE vaccine recommendations. To prevent additional TBE cases in the Czech Republic, enhanced efforts to increase TBE vaccine uptake are needed.

The Non-inferiority of Human Papillomavirus Vaccine Immunogenicity Among Women Over 26 Years: A Systematic Review.

Demonstrate the immunogenicity of the human papillomavirus (HPV) vaccine for the older age group (above 26 years) to prevent HPV infection with high-risk types and argue for extending vaccination recommendations for the older age group. Two authors searched PubMed, Embase, and the Cochrane Library from inception to December 2023 to collect information on clinical trials of HPV vaccine immunogenicity. The database search strategy used a combination of subject terms and free terms. Two authors first identified studies by reading the title, abstract, and full texts and, subsequently, based on the inclusion criteria. Studies eligible to be included are the clinical trials using one of the following types of HPV vaccines: 2vHPV, 4vHPV, and 9vHPV, and measuring the immunogenicity by the geometric mean concentration or titer (GMC/T) and seroconversion rate (SCR) among healthy women aged 9 to 55 years who had never received a prophylactic HPV vaccine, known serostatus for HPV, non-immunocompetence, or non-pregnant. This review included nine articles, seven RCTs, and two open-labeled studies. In summary, we have demonstrated that the immunogenicity of the HPV vaccines is non-inferior in the older age group. Even though the GMT declines with age, the SCR is similar in all age groups regardless of the serostatus. The immunogenicity of the bivalent vaccine is superior to that of the quadrivalent vaccine for the older age group. Additionally, the vaccine is more efficient in women under the age of 26, but older women will benefit from it.

Evaluation of the knowledge, attitudes and behavior of healthcare workers concerning influenza vaccination in a training and research hospital in Türkiye

Introduction and aim. Although increasing vaccination rates among healthcare workers (HCWs) is crucial for protecting their own health and preventing the spread of infections to patients, vaccination rates remain low. The purpose of this study is to evaluate the knowledge, attitudes, and behavior of healthcare workers concerning seasonal influenza vaccination in a training and research hospital in Türkiye. Material and methods. This cross-sectional descriptive study was conducted among 364 healthcare workers working in a training and research hospital in Ankara, Türkiye. A face-to-face questionnaire was completed by selected participants that included questions about their sociodemographic characteristics, receiving seasonal influenza vaccination, reasons for not receiving vaccination, attitudes and behavior towards seasonal influenza vaccination recommendations for their surroundings, knowledge of who should get the vaccine, and their immunization history. Results. Among the participants, 58.5% stated that they had never received an influenza vaccination, 35.7% mentioned not receiving the regular influenza vaccination, and only 5.8% reported receiving the influenza vaccination regularly every year. Reasons for not getting vaccinated included not trusting the influenza vaccine’s protection (60.1%), not believing they are in the risk group (38.9%), and not finding a suitable time to get vaccinated (36.1%). A total of 57.1% of the healthcare workers recommended the influenza vaccine for their surroundings. Conclusion. Influenza vaccination rates among healthcare workers are quite low. To maximize influenza vaccine uptake, awareness programs are needed to correct the misconceptions health care workers have about the vaccine, and diverse strategies should be implemented to encourage them to get vaccinated, thereby promoting influenza vaccination.

Updated vaccination and screening recommendations for hepatitis B: Implications for pharmacists

The number of new infections of hepatitis B is rising and a large number of cases are undiagnosed. These factors are contributing to hepatitis B-related liver complications, including liver cancer, and deaths that could be prevented. The Advisory Committee on Immunization Practices and the Centers for Disease Control and Prevention recently updated vaccination and screening/testing recommendations for hepatitis B. The updated recommendations remove the need for risk assessment before screening or vaccination. Pharmacists will play a key role in a concerted national effort to implement these updated recommendations. A multistakeholder advisory council convened by the Hepatitis B Foundation identified key barriers to screening and vaccination. The council also formulated strategies to optimize implementation of the updated recommendations. These strategies include educating pharmacists about the new recommendations and how they will help to reduce the burden of hepatitis B and liver cancer. Pharmacists could explore establishing pharmacy-provider collaborative practice agreements and potentially leverage capacity built with COVID-19 vaccine implementation. Hospital systems and other clinic settings could update their electronic health records to include prompts for hepatitis B vaccination and screening. Pharmacy systems can implement different reminder options to help patients complete the hepatitis B vaccine series. To address a lack of vaccine confidence, pharmacists can emphasize the cancer prevention benefit of hepatitis B screening and vaccination and engage with patients on an individual level to understand their concerns, assess vaccine status, and discuss vaccine recommendations. Effective implementation of the new recommendations will help achieve national and global goals of eliminating hepatitis B as a public health threat by 2030.

Expert panel opinion on adult pneumococcal vaccination in the post-COVID era (NAP- EXPO Recommendations-2024).

Pneumococcal diseases pose a significant public health concern in India, with substantial morbidity and mortality, with the elderly and those with coexisting medical conditions being most at risk. Pneumococcus was also seen to be one of the main reasons for co-infection, pneumonia and complications in COVID. Current guidelines recommend vaccination for specific adult populations, but there is a lack of uniformity and guidance on risk stratification, prioritisation and optimal timing. Nation Against Pneumococcal Infections - Expert Panel Opinion (NAP-EXPO) is a panel convened to review and update recommendations for adult pneumococcal vaccination in India. The panel of 23 experts from various medical specialties engaged in discussions and evidence-based reviews, discussed appropriate age for vaccination, risk stratification for COPD and asthma patients, vaccination strategies for post-COVID patients, smokers and diabetics, as well as methods to improve vaccine awareness and uptake. The NAP-EXPO recommends the following for adults: All healthy individuals 60 years of age and above should receive the pneumococcal vaccine; all COPD patients, regardless of severity, high-risk asthma patients, post-COVID cases with lung fibrosis or significant lung damage, should be vaccinated with the pneumococcal vaccine; all current smokers and passive smokers should be educated and offered the pneumococcal vaccine, regardless of their age or health condition; all diabetic individuals should receive the pneumococcal vaccine, irrespective of their diabetes control. Strategies to improve vaccine awareness and uptake should involve general practitioners (GPs), primary health physicians (PHPs) and physicians treating patients at high risk of pneumococcal disease. Advocacy campaigns should involve media, including social media platforms. These recommendations aim to enhance pneumococcal vaccination coverage among high-risk populations in India in order to ensure a reduction in the burden of pneumococcal diseases, in the post-COVID era. There is a need to create more evidence and data to support the recommendations that the vaccine will be useful to a wider range of populations, as suggested in our consensus.

Improving influenza vaccine uptake in clinical risk groups: patient, provider and commissioner perspectives on the acceptability and feasibility of expanding delivery pathways in England

BackgroundPeople under the age of 65 in clinical risk groups are at increased risk of severe complications and death from influenza. In England, influenza vaccine coverage rates in this cohort...

Influenza virus circulation and vaccine effectiveness during June 2021–May 2023 in Thailand

Thai Ministry of Public Health recommends influenza vaccination for certain risk groups. We evaluated 2023 Southern Hemisphere influenza vaccine effectiveness against medically attended influenza using surveillance data from nine Thai hospitals and a test-negative design. During June 2022–May 2023, influenza vaccine provided moderate protection against seeking care for influenza illness (adjusted vaccine effectiveness 51%; 95% confidence interval 28–67). Understanding vaccine effectiveness can help guide future antigen selection and support clinicians to make a strong influenza vaccine recommendation to patients.

Hospital Burden of All-Cause Pneumonia and Nonbacteremic Pneumococcal Pneumonia in Adults in France Between 2013 and 2019.

Community-acquired pneumonia (CAP) is associated with significant morbidity and mortality. The study objective was to describe the hospital burden of pneumonia in the adult population in France. This retrospective study was conducted from the National Health Insurance Database. All hospitalizations for pneumonia (all-cause) between 2013 and 2019 were included. Different risk categories for patients were established based on pneumococcal vaccine recommendations by French health authorities. A total of 2 199 240 episodes of CAP were registered over the study period (annual mean, 314 177 [standard deviation, 17 818.6]); 75% occurred in patients aged ≥65 years, among whom 47% were not classified in the moderate- or high-risk categories recommended for French pneumococcal vaccination. The incidence of CAP increased with age (117.9, 395.3, and 1916.7 per 100 000 for the age groups 18-49, 50-64, and ≥65 years, respectively, in 2019). Furthermore, being at risk of pneumococcal disease resulted in more severe outcomes, including longer episode duration (mean, 14 days in low-risk vs 17 days in high-risk patients) and higher risk of referral to critical care units (from 20% to 27%), of rehospitalization up to 180 days (from 39% to 67%), of in-hospital death (from 12% to 19%), and of 1-year mortality (from 26% to 49%). This study establishes the incidence of CAP in adults in France, describes the significant burden of disease, and highlights the need for better prevention policies.

Content validation of a Facebook HPV vaccination promotion intervention (#HPVvaxtalks) created for young Black adults (18-26 years old).

Despite the expansion in human papillomavirus (HPV) vaccination recommendations, vaccine uptake and completion remain low among Black individuals. An 8-week Facebook intervention (#HPVvaxtalks) was developed to increase knowledge and awareness of HPV risk factors, risk perceptions, and vaccination intention and uptake. This article details the formative phase of experts' feedback and participants' satisfaction on the components of the #HPVvaxtalks for content useability, acceptability, relevance, and visual appeal to inform further refinements. A convenience sample of 5 experts and 13 young Black adults were invited to provide feedback on #HPVvaxtalks intervention content. The experts reviewed and provided feedback via a survey and open-ended questions. After incorporating suggestions from experts' feedback, 13 participants viewed #HPVvaxtalks posts, took part in a virtual focus group, and completed a survey. Qualitative data were thematically analyzed and integrated with survey results. Experts and participants mean age were 41.9±2.3 and 21.2±1.9 years, respectively. Experts and participants reported positive ratings for intervention posts, including useability, acceptability, relevance, and visual appeal. Data provided areas for improvements of #HPVvaxtalks. CONCLUSION: Experts indicated strong content validity and participants showed satisfaction with #HPVvaxtalks content. Ensuring acceptability, relevance, and appeal of the intervention for the target population is an integral part of intervention development.

Surveillance of adverse events following immunisation in Australia, COVID-19 vaccines, 2021.

This report summarises Australia's spontaneous (passive) surveillance data for adverse events following immunisation (AEFI) for coronavirus disease 2019 (COVID-19) vaccines in 2021 reported to the Therapeutic Goods Administration (TGA). The TGA strongly promoted and facilitated adverse event reporting in preparation for, and during, the COVID-19 vaccine rollout as a core component of the most intensive vaccine safety monitoring ever conducted in Australia. There were 111,348 AEFI reports for COVID-19 vaccines administered in 2021, an annual AEFI reporting rate of 271.4 per 100,000 doses of COVID-19 vaccines administered to people aged ≥ 12 years. The annual AEFI reporting rate for non-COVID-19 vaccines in 2021 was 30.6 per 100,000 doses administered to people of all ages. Overall, the most frequently reported symptoms were headache, adverse events classified as 'gastrointestinal nonspecific symptoms and therapeutic procedures', myalgia, pyrexia and fatigue, which were consistent with common expected adverse events following COVID-19 vaccines used in Australia. The most commonly reported adverse events of special interest were myocarditis and/or pericarditis, followed by thrombosis and thromboembolism, and anaphylaxis. Of all COVID-19 vaccine AEFI reports, 762 (0.7%) included a fatal outcome, of which over 80% were in people aged ≥ 60 years. Thirteen deaths reported in 2021 were assessed as likely to be causally linked to vaccination. This report confirms the value of spontaneous post-marketing vaccine pharmacovigilance, especially in the context of new vaccines using novel vaccine technologies and near whole-of-population pandemic vaccination programs. The most frequently reported AEFI for COVID-19 vaccines were common, mild and temporary (lasting 1 or 2 days), and consistent with clinical trial and active surveillance data. Ongoing safety monitoring detected rare, unexpected conditions, such as myocarditis/pericarditis and thrombosis with thrombocytopenia syndrome (TTS), which were investigated and confirmed as safety signals, resulting in changes to vaccine recommendations and product information. The outcomes of TGA monitoring were published in weekly vaccine safety reports. Overall, COVID-19 vaccine safety monitoring provided critical information on the risks of vaccine related adverse events that enabled decisionmakers to undertake informed risk-benefit assessments.

Global antigenic landscape and vaccine recommendation strategy for low pathogenic avian influenza A (H9N2) viruses

The sustained circulation of H9N2 avian influenza viruses (AIVs) poses a significant threat for contributing to a new pandemic. Given the temporal and spatial uncertainty in theantigenicity of H9N2 AIVs, the immune protection efficiency of vaccines remains challenging. By developing an antigenicity prediction method for H9N2 AIVs, named PREDAC-H9, the global antigenic landscape of H9N2 AIVs was mapped. PREDAC-H9 utilizes the XGBoost model with 14 well-designed features. The XGBoost model was built and evaluated to predict the antigenic relationship between any two viruses with high values of 81.1%, 81.4%, 81.3%, 81.1%, and 89.4% in accuracy, precision, recall, F1 value, and area under curve (AUC), respectively. Then the antigenic correlation network (ACnet) was constructed based on the predicted antigenic relationship for H9N2 AIVs from 1966 to 2022, and ten major antigenic clusters were identified. Of these, four novel clusters were generated in China in the past decade, demonstrating the unique complex situation there. To help tackle this situation, we applied PREDAC-H9 to calculate the cluster-transition determining sites and screen out virus strains with thehigh cross-protective spectrum, thus providing aninsilico reference for vaccine recommendation. The proposed model will reduce the clinical monitoring workload and provide a useful tool for surveillance and control of H9N2 AIVs.

Exploring the utilization and perceptions of pre-travel health consultations in primary care settings in Saudi Arabia: a cross-sectional study

BackgroundInternational travel exposes individuals to diverse health risks, necessitating proactive pre-travel health preparations. Saudi Arabia has witnessed increased outbound travel. This study addresses a critical gap in knowledge by investigating the utilization and perceptions of pre-travel health consultations among adults in the Eastern Province of Saudi Arabia.MethodsThis cross-sectional study surveyed patients at the Family and Community Medicine Center of Imam Abdulrahman Bin Faisal University during January 2024 to explore perceptions of pre-travel health consultations among the Saudi Arabian population. Adults aged 18 years or older in the waiting area were invited to complete a self-administered questionnaire.ResultsOf the 772 participants, 624 (80.8%) engaged in international travel within the last year. However, 593 (76.8%) had never sought pre-travel health consultations. Age, gender, and education level significantly influenced the pursuit of pre-travel health advice, with older individuals, females, and those with higher educational attainment more likely to seek consultations. Participants perceived vaccination recommendations (597, 77.4%) and disease prevention information (678, 87.8%) as crucial parts of pre-travel health consultations. However, barriers to seeking advice included perceived low risk (445, 74.8%), lack of awareness (215, 36.3%), time constraints (128, 21.6%), and cost concerns (92, 15.5%).ConclusionThe low prevalence of pre-travel health consultations among travelers highlights the need for targeted educational campaigns and the integration of travel health services into primary healthcare. Addressing the identified barriers and leveraging preferred information sources are crucial steps towards enhancing the uptake of pre-travel health consultations, ultimately improving the health and safety of international travelers from the region.