https://globalinfectiousdisease.com/research/ Published infectious-disease literature filtered to Influenza. en Wed, 09 Sep 2026 07:02:01 GMT https://globalinfectiousdisease.com/research/articles/10-1002-14651858-cd016384-84f72db7/ https://globalinfectiousdisease.com/research/articles/10-1002-14651858-cd016384-84f72db7/ Tue, 01 Sep 2026 00:00:00 GMT The review offers implications for practice, including communication strategies, training, and supply provision, intended to support policymakers and decision-makers managing IPC during ongoing and future pandemic responses. COVID-19 SARS Influenza Health policy Transmission dynamics Treatment Systematic review https://globalinfectiousdisease.com/research/articles/10-1016-j-ijregi-2026-100921-cadd83ba/ https://globalinfectiousdisease.com/research/articles/10-1016-j-ijregi-2026-100921-cadd83ba/ Tue, 01 Sep 2026 00:00:00 GMT The article addresses respiratory illness in young children in a high-burden Bangladeshi setting and reports seasonal influenza findings that may be relevant to planning vaccination or other interventions. The abstract also notes that broader testing would be needed because most cases were negative for the pathogens included. Influenza Journal article https://globalinfectiousdisease.com/research/articles/10-1016-j-vaccine-2026-129009-9ffc71a1/ https://globalinfectiousdisease.com/research/articles/10-1016-j-vaccine-2026-129009-9ffc71a1/ Tue, 01 Sep 2026 00:00:00 GMT Findings support continued COVID-19 vaccine recommendations, demonstrating protection across the 2024-2025 season for adults including those with underlying medical conditions. COVID-19 Influenza Vaccination Vaccine effectiveness Cohort study https://globalinfectiousdisease.com/research/articles/10-1111-imr-70167-2d927d23/ https://globalinfectiousdisease.com/research/articles/10-1111-imr-70167-2d927d23/ Tue, 01 Sep 2026 00:00:00 GMT The article supports continued consideration of vaccine designs that target conserved influenza regions because the abstract describes limited protection from existing vaccines against some seasonal and pandemic viruses. It does not provide evidence of clinical effectiveness for a particular vaccine design. Influenza Vaccination Journal article https://globalinfectiousdisease.com/research/articles/10-1111-irv-70311-546e8afd/ https://globalinfectiousdisease.com/research/articles/10-1111-irv-70311-546e8afd/ Tue, 01 Sep 2026 00:00:00 GMT The findings are positioned as relevant to surveillance for cross-species transmission and potential spillover risk, given the documented mammalian-adaptation mutation and expanding host range of clade 2.3.4.4b. H5N1 Influenza One Health Surveillance Outbreak investigation Transmission dynamics Journal article https://globalinfectiousdisease.com/research/articles/10-1371-journal-pone-0355415-e4d17955/ https://globalinfectiousdisease.com/research/articles/10-1371-journal-pone-0355415-e4d17955/ Tue, 01 Sep 2026 00:00:00 GMT The findings describe a possible way to prioritize biosecurity or surveillance resources around poultry facilities using observed wintering-waterfowl presence. This is an evidence-context signal from the supplied article and does not establish that the ranking method is validated for current surveillance or outbreak prediction. Influenza H5N1 Surveillance Outbreak investigation Treatment Journal article https://globalinfectiousdisease.com/research/articles/10-1007-s12311-026-02074-3-199c1b40/ https://globalinfectiousdisease.com/research/articles/10-1007-s12311-026-02074-3-199c1b40/ Thu, 27 Aug 2026 00:00:00 GMT The review maps the clinical spectrum of an immune-mediated post-infectious neurological syndrome across age groups and common viral triggers, which may inform recognition of ataxia syndromes following infection. COVID-19 SARS Varicella Influenza Zoster Treatment Vaccination Systematic review https://globalinfectiousdisease.com/research/articles/10-1093-ofid-ofag522-4f2a4986/ https://globalinfectiousdisease.com/research/articles/10-1093-ofid-ofag522-4f2a4986/ Thu, 27 Aug 2026 00:00:00 GMT The results suggest that deploying this specific immunization strategy may help curb institutional transmission episodes during years with active seasonal pathogen circulation, thereby potentially reducing operational disruptions within elderly care infrastructure. Influenza COVID-19 Vaccination Treatment Outbreak investigation Transmission dynamics Journal article https://globalinfectiousdisease.com/research/articles/10-1002-evj-70314-8c1f8d64/ https://globalinfectiousdisease.com/research/articles/10-1002-evj-70314-8c1f8d64/ Wed, 26 Aug 2026 00:00:00 GMT The genetic proximity to foreign viral strains highlights cross-border animal trade as a potential introduction pathway, emphasizing the need for continuous genomic monitoring to track strain evolution and guide control measures. Influenza Genomic epidemiology Surveillance Outbreak investigation Transmission dynamics Genomic study https://globalinfectiousdisease.com/research/articles/10-1007-s10198-026-01985-6-b3161585/ https://globalinfectiousdisease.com/research/articles/10-1007-s10198-026-01985-6-b3161585/ Wed, 26 Aug 2026 00:00:00 GMT The findings suggest that public acceptance of preparedness policies may depend on perceived moral legitimacy as well as expected effectiveness and financial cost. The abstract reports that incorporating these preference differences into economic evaluation could inform consideration of societal acceptability. Influenza Outbreak investigation Health policy Journal article https://globalinfectiousdisease.com/research/articles/10-1128-jvi-01099-26-63a5e8f1/ https://globalinfectiousdisease.com/research/articles/10-1128-jvi-01099-26-63a5e8f1/ Wed, 26 Aug 2026 00:00:00 GMT Standardized laboratory screening techniques detailed in the review may accelerate the preliminary evaluation of candidate treatments targeting influenza infections. Influenza Treatment Journal article https://globalinfectiousdisease.com/research/articles/10-3389-fcimb-2026-1927565-f4aec762/ https://globalinfectiousdisease.com/research/articles/10-3389-fcimb-2026-1927565-f4aec762/ Wed, 26 Aug 2026 00:00:00 GMT The paper presents integrated surveillance as relevant to preparedness and to earlier detection and response for human or animal health threats in West Africa. This relevance is framed as an operational and preparedness priority in the abstract. Influenza One Health Surveillance Climate and environment Journal article https://globalinfectiousdisease.com/research/articles/10-3389-fvets-2026-1911871-a563845d/ https://globalinfectiousdisease.com/research/articles/10-3389-fvets-2026-1911871-a563845d/ Wed, 26 Aug 2026 00:00:00 GMT Identifying the virus in a new territory emphasizes the necessity for sustained genomic monitoring to evaluate ecological spread, animal health implications, and potential cross-species dynamics. Influenza Surveillance Transmission dynamics Genomic epidemiology One Health Genomic study https://globalinfectiousdisease.com/research/articles/10-1007-s15010-026-02917-5-60e9f363/ https://globalinfectiousdisease.com/research/articles/10-1007-s15010-026-02917-5-60e9f363/ Tue, 25 Aug 2026 00:00:00 GMT The authors propose that community-based screening can help identify asymptomatic viral reservoirs and underreported viral circulation, such as adenovirus, linking viral detection to clinical and economic impact. SARS COVID-19 Influenza Surveillance Vaccination Journal article https://globalinfectiousdisease.com/research/articles/10-1128-spectrum-02680-25-e0a60f04/ https://globalinfectiousdisease.com/research/articles/10-1128-spectrum-02680-25-e0a60f04/ Tue, 25 Aug 2026 00:00:00 GMT The authors frame the work as relevant to mitigating inflammation and lung damage associated with influenza virus infection, positioning Sotetsuflavone as a candidate HIF-1α-targeted therapeutic against influenza-associated immunopathology. Influenza Treatment Journal article https://globalinfectiousdisease.com/research/articles/10-1177-2752535x261481203-1656f630/ https://globalinfectiousdisease.com/research/articles/10-1177-2752535x261481203-1656f630/ Tue, 25 Aug 2026 00:00:00 GMT Identifying these community-specific viewpoints can help shape targeted educational initiatives that address information gaps and strengthen local engagement strategies. COVID-19 Influenza Vaccination Commentary https://globalinfectiousdisease.com/research/articles/10-33321-cdi-2026-50-020-ab952e89/ https://globalinfectiousdisease.com/research/articles/10-33321-cdi-2026-50-020-ab952e89/ Tue, 25 Aug 2026 00:00:00 GMT The report highlights a high hospital burden from confirmed influenza admissions, alongside moderate severity as indicated by intensive care unit admission proportions, and very low influenza-attributed mortality. Influenza Surveillance Journal article https://globalinfectiousdisease.com/research/articles/10-33321-cdi-2026-50-021-5d1ab8a5/ https://globalinfectiousdisease.com/research/articles/10-33321-cdi-2026-50-021-5d1ab8a5/ Tue, 25 Aug 2026 00:00:00 GMT The report documents an unprecedented two-year suppression of influenza activity in Australia concurrent with COVID-19 PHSMs, providing a descriptive baseline relevant to understanding how non-pharmaceutical measures and pandemic-era conditions can shape seasonal influenza epidemiology. Influenza COVID-19 Surveillance Journal article https://globalinfectiousdisease.com/research/articles/10-1080-22221751-2026-2716499-8ada39ff/ https://globalinfectiousdisease.com/research/articles/10-1080-22221751-2026-2716499-8ada39ff/ Mon, 24 Aug 2026 00:00:00 GMT The paper is relevant to outbreak preparedness because it describes a rapid antigen test intended for Nipah virus detection in settings where nucleic-acid testing may be difficult to use. The abstract frames the assay as potentially useful for point-of-care diagnosis in resource-limited contexts. MERS SARS COVID-19 Measles Influenza Diagnostics Outbreak investigation One Health Journal article https://globalinfectiousdisease.com/research/articles/10-1128-mbio-01819-26-a523b688/ https://globalinfectiousdisease.com/research/articles/10-1128-mbio-01819-26-a523b688/ Mon, 24 Aug 2026 00:00:00 GMT The authors frame the work as a candidate broad-spectrum, host-directed gene therapy and rapid-response countermeasure for HMGB1-driven inflammatory diseases and emerging respiratory pathogens, although only preclinical evidence is presented. Influenza Treatment Journal article https://globalinfectiousdisease.com/research/articles/10-3390-vetsci13090858-b0dde081/ https://globalinfectiousdisease.com/research/articles/10-3390-vetsci13090858-b0dde081/ Mon, 24 Aug 2026 00:00:00 GMT The authors proposed using influential network nodes to target veterinary surveillance and control resources toward municipalities considered more likely to be involved in disease introduction or persistence, with relevance to poultry industry and public health protection. Influenza Surveillance Transmission dynamics Cross-sectional study https://globalinfectiousdisease.com/research/articles/10-1007-s40471-026-00405-w-511150c9/ https://globalinfectiousdisease.com/research/articles/10-1007-s40471-026-00405-w-511150c9/ Fri, 21 Aug 2026 00:00:00 GMT Clarifying the scope and availability of these monitoring frameworks may streamline epidemiological investigations and support more effective emergency management strategies. SARS COVID-19 Influenza Surveillance Outbreak investigation Health policy Journal article https://globalinfectiousdisease.com/research/articles/10-1038-s41467-026-76300-1-faba830b/ https://globalinfectiousdisease.com/research/articles/10-1038-s41467-026-76300-1-faba830b/ Fri, 21 Aug 2026 00:00:00 GMT The findings support preventing unpasteurized milk from H5N1-positive herds or suspect cows from being fed to calves and identify routes of transmission as a research priority for interventions and vaccination strategies. H5N1 Influenza Transmission dynamics Vaccination Journal article https://globalinfectiousdisease.com/research/articles/10-1088-2976-601x-ae8dd4-7e93f829/ https://globalinfectiousdisease.com/research/articles/10-1088-2976-601x-ae8dd4-7e93f829/ Fri, 21 Aug 2026 00:00:00 GMT The research highlights critical gaps in agricultural risk management that could facilitate pathogen persistence and impact broader food security frameworks. Influenza H5N1 One Health Outbreak investigation Climate and environment Health policy Journal article https://globalinfectiousdisease.com/research/articles/10-3389-fimmu-2026-1876199-5452e66f/ https://globalinfectiousdisease.com/research/articles/10-3389-fimmu-2026-1876199-5452e66f/ Fri, 21 Aug 2026 00:00:00 GMT The findings provide preclinical evidence that a mucosally delivered vaccine strategy targeting multiple influenza antigens may be relevant to research on protection against antigenically drifted seasonal influenza strains. The evidence is limited to mouse immunogenicity and challenge outcomes and does not establish effectiveness in humans. Influenza Vaccination Journal article https://globalinfectiousdisease.com/research/articles/10-18203-issn-2454-2156-intjscirep20262820-f57292ba/ https://globalinfectiousdisease.com/research/articles/10-18203-issn-2454-2156-intjscirep20262820-f57292ba/ Thu, 20 Aug 2026 00:00:00 GMT The case draws attention to influenza infection as a reported complication in a patient receiving rituximab who had declined vaccination. Its relevance is limited to illustrating an individual clinical event and does not establish population-level risk or vaccine effectiveness. Influenza Vaccination Treatment Journal article https://globalinfectiousdisease.com/research/articles/10-1080-22221751-2026-2713325-ffe02d63/ https://globalinfectiousdisease.com/research/articles/10-1080-22221751-2026-2713325-ffe02d63/ Wed, 19 Aug 2026 00:00:00 GMT The work addresses agricultural and zoonotic risk management by testing a sequence-driven vaccine strategy intended to sustain efficacy despite continuous viral mutation. Influenza H5N1 Vaccination One Health Journal article https://globalinfectiousdisease.com/research/articles/10-1128-aem-00757-26-05c365cd/ https://globalinfectiousdisease.com/research/articles/10-1128-aem-00757-26-05c365cd/ Wed, 19 Aug 2026 00:00:00 GMT Implementing affordable environmental monitoring could strengthen early warning capabilities within congregate living arrangements. Establishing standardized operational procedures alongside environmental tracking may improve institutional readiness during infectious disease events. SARS COVID-19 Influenza Surveillance Outbreak investigation Journal article https://globalinfectiousdisease.com/research/articles/10-1128-spectrum-02656-25-9893e5e9/ https://globalinfectiousdisease.com/research/articles/10-1128-spectrum-02656-25-9893e5e9/ Wed, 19 Aug 2026 00:00:00 GMT The authors frame the work as identifying potential therapeutic targets to improve outcomes of influenza B infection in elderly populations, highlighting age-dependent innate immune dysregulation as a relevant concern. Influenza Treatment Journal article https://globalinfectiousdisease.com/research/articles/10-3389-fpubh-2026-1846269-4100e280/ https://globalinfectiousdisease.com/research/articles/10-3389-fpubh-2026-1846269-4100e280/ Wed, 19 Aug 2026 00:00:00 GMT Findings support self-collected nasal swabs as a feasible surveillance option that may enable earlier sampling and higher pathogen detection, particularly when collected within 7 days of symptom onset. Influenza Surveillance Vaccination Vaccine effectiveness Treatment Journal article https://globalinfectiousdisease.com/research/articles/10-1128-jvi-00259-26-0f37d0e2/ https://globalinfectiousdisease.com/research/articles/10-1128-jvi-00259-26-0f37d0e2/ Tue, 18 Aug 2026 00:00:00 GMT The identification of ckATP1A1-AS1 as an antiviral factor contributes to understanding host defenses against influenza A viruses, which pose an ongoing zoonotic threat to humans and other species. The dual-mechanism antiviral activity—coordinating innate immunity and directly targeting viral replication steps—may inform future therapeutic or breeding strategies. Influenza One Health Journal article https://globalinfectiousdisease.com/research/articles/10-1128-jvi-00615-26-76b3d29b/ https://globalinfectiousdisease.com/research/articles/10-1128-jvi-00615-26-76b3d29b/ Tue, 18 Aug 2026 00:00:00 GMT Identifying alternative replication niches in livestock anatomy aids in evaluating cross-species transmission risks and monitoring viral adaptation pathways in agricultural environments. Influenza H5N1 One Health Journal article https://globalinfectiousdisease.com/research/articles/10-1128-jvi-02225-25-426e78ad/ https://globalinfectiousdisease.com/research/articles/10-1128-jvi-02225-25-426e78ad/ Tue, 18 Aug 2026 00:00:00 GMT The findings identify RELMα as a host factor associated with influenza A virus growth in epithelial cells and suggest that epithelial-cell pathways could be investigated as potential therapeutic targets. The supplied evidence is preclinical and does not establish effectiveness, safety, or relevance in humans. Influenza AIDS Treatment Journal article https://globalinfectiousdisease.com/research/articles/10-3389-fcimb-2026-1891757-80f41449/ https://globalinfectiousdisease.com/research/articles/10-3389-fcimb-2026-1891757-80f41449/ Tue, 18 Aug 2026 00:00:00 GMT The experimental outcomes highlight a candidate mechanism for host-directed antiviral interventions, though translational applicability to human respiratory disease management remains unestablished. Influenza Treatment Journal article https://globalinfectiousdisease.com/research/articles/10-3390-vaccines14080709-dbfd1331/ https://globalinfectiousdisease.com/research/articles/10-3390-vaccines14080709-dbfd1331/ Tue, 18 Aug 2026 00:00:00 GMT The discussion addresses persistent worldwide influenza burdens and outlines practical barriers to broad deployment, including production volume, financial constraints, temperature-controlled storage demands, and equitable international distribution. Influenza SARS COVID-19 Vaccination Surveillance Commentary https://globalinfectiousdisease.com/research/articles/10-3390-vaccines14080711-df070019/ https://globalinfectiousdisease.com/research/articles/10-3390-vaccines14080711-df070019/ Tue, 18 Aug 2026 00:00:00 GMT Seasonal influenza vaccination provided substantial protection against severe respiratory outcomes in a high-risk population with COPD, supporting vaccination as a public health intervention in this group. Influenza Vaccination Vaccine effectiveness Surveillance Journal article https://globalinfectiousdisease.com/research/articles/10-1021-acsanm-6c02570-1f62847d/ https://globalinfectiousdisease.com/research/articles/10-1021-acsanm-6c02570-1f62847d/ Mon, 17 Aug 2026 00:00:00 GMT Avian influenza is described as a threat to the poultry industry and public health, motivating alternative vaccine platforms beyond conventional egg-based inactivated vaccines; an effective mRNA-based avian vaccine could support both animal and potentially zoonotic disease control. Influenza COVID-19 Vaccination Journal article https://globalinfectiousdisease.com/research/articles/10-1099-jgv-0-002305-f9f44a4e/ https://globalinfectiousdisease.com/research/articles/10-1099-jgv-0-002305-f9f44a4e/ Mon, 17 Aug 2026 00:00:00 GMT The findings indicate that Arctic breeding grounds may act as sites for viral amplification, reassortment, and dissemination along migratory flyways, with potential for transcontinental spread of HPAIVs. Influenza H5N1 Transmission dynamics Journal article https://globalinfectiousdisease.com/research/articles/10-15359-rcv-44-2-2-6b79e381/ https://globalinfectiousdisease.com/research/articles/10-15359-rcv-44-2-2-6b79e381/ Mon, 17 Aug 2026 00:00:00 GMT Detection of H5N2 antibodies in an unvaccinated domestic duck indicates potential viral circulation in the region, highlighting the need to strengthen surveillance and control strategies for avian influenza in Guatemala. Influenza Surveillance Journal article https://globalinfectiousdisease.com/research/articles/10-3389-fpubh-2026-1926271-c2905cb7/ https://globalinfectiousdisease.com/research/articles/10-3389-fpubh-2026-1926271-c2905cb7/ Mon, 17 Aug 2026 00:00:00 GMT The findings identify a reported intention-to-action gap in influenza vaccination among the surveyed healthcare professionals. The authors indicate that targeted education and more accessible vaccination services may be relevant areas for addressing this gap, but the abstract does not establish that these measures would be effective. Influenza Vaccination Cross-sectional study https://globalinfectiousdisease.com/research/articles/10-3390-vaccines14080706-9ff137c3/ https://globalinfectiousdisease.com/research/articles/10-3390-vaccines14080706-9ff137c3/ Mon, 17 Aug 2026 00:00:00 GMT The synthesis addresses ongoing clinical uncertainty regarding potential autoimmune complications following widespread mRNA immunization campaigns. Identifying the gap in extended monitoring frameworks underscores the necessity for sustained epidemiological tracking beyond immediate post-vaccination periods. COVID-19 Influenza Vaccination Systematic review https://globalinfectiousdisease.com/research/articles/10-3390-vaccines14080705-edd7b616/ https://globalinfectiousdisease.com/research/articles/10-3390-vaccines14080705-edd7b616/ Sat, 15 Aug 2026 00:00:00 GMT The synthesized data offers practical guidance for structuring future immunization initiatives and allocating resources to improve coverage in older adult populations. Influenza SARS COVID-19 Vaccination Vaccine safety Systematic review https://globalinfectiousdisease.com/research/articles/10-1093-cid-ciag489-7c47875c/ https://globalinfectiousdisease.com/research/articles/10-1093-cid-ciag489-7c47875c/ Thu, 13 Aug 2026 00:00:00 GMT The findings provide evidence that genomic sequencing can be used to refine classification of suspected household influenza transmission events. Within the supplied article, the results are relevant to evaluating household transmission and treatment effects, but they do not establish a broader population-level surveillance signal. Influenza Transmission dynamics Genomic epidemiology Treatment Genomic study https://globalinfectiousdisease.com/research/articles/10-1111-irv-70303-d7a345bf/ https://globalinfectiousdisease.com/research/articles/10-1111-irv-70303-d7a345bf/ Thu, 06 Aug 2026 00:00:00 GMT The findings indicate that seasonal influenza vaccination provided meaningful protection against hospitalisation in 2024/25, with the largest benefit observed in children, supporting continued vaccination efforts in Northern Ireland. Influenza Vaccination Surveillance Vaccine effectiveness Journal article https://globalinfectiousdisease.com/research/articles/10-1016-j-ijid-2026-109089-f7d2319d/ https://globalinfectiousdisease.com/research/articles/10-1016-j-ijid-2026-109089-f7d2319d/ Sat, 01 Aug 2026 00:00:00 GMT The authors highlight a high prevalence and rapid onset of influenza-associated pulmonary aspergillosis in critically ill patients and call for protocolized screening and timely diagnostics. COVID-19 Influenza Diagnostics Treatment Cohort study https://globalinfectiousdisease.com/research/articles/10-1016-j-jinf-2026-106784-7587e5cb/ https://globalinfectiousdisease.com/research/articles/10-1016-j-jinf-2026-106784-7587e5cb/ Sat, 01 Aug 2026 00:00:00 GMT The documented compatibility indicates potential administrative advantages for coordinating seasonal and shingles immunisations within standard adult care pathways. COVID-19 Influenza Zoster SARS Vaccination Treatment Randomised controlled trial https://globalinfectiousdisease.com/research/articles/10-1016-j-lanmic-2026-101422-edc10908/ https://globalinfectiousdisease.com/research/articles/10-1016-j-lanmic-2026-101422-edc10908/ Sat, 01 Aug 2026 00:00:00 GMT The findings suggest LAIV-induced increases in pneumococcal density in vaccinated toddlers may transiently raise pneumococcal acquisition risk among household members, which has implications for transmission modelling at individual and population scales. Influenza Vaccination Transmission dynamics Randomised controlled trial https://globalinfectiousdisease.com/research/articles/10-1016-j-lanmic-2026-101490-acbdd747/ https://globalinfectiousdisease.com/research/articles/10-1016-j-lanmic-2026-101490-acbdd747/ Sat, 01 Aug 2026 00:00:00 GMT The authors identify maternal vaccination and timely childhood immunisation as potentially relevant to reducing the early-life period of limited influenza B antibody protection. This is an interpretation reported by the study and does not establish intervention effectiveness. Influenza Vaccination Cohort study https://globalinfectiousdisease.com/research/articles/10-1016-j-vaccine-2026-128782-31151627/ https://globalinfectiousdisease.com/research/articles/10-1016-j-vaccine-2026-128782-31151627/ Sat, 01 Aug 2026 00:00:00 GMT The modeled results indicate that a fully funded influenza vaccination policy for older adults could reduce modeled influenza-related health outcomes while lowering societal costs in the evaluated setting. The abstract specifically highlights implementation for older adults, including the oldest age groups. Influenza Vaccination Health policy Commentary https://globalinfectiousdisease.com/research/articles/10-1016-j-vaccine-2026-128821-769efdf1/ https://globalinfectiousdisease.com/research/articles/10-1016-j-vaccine-2026-128821-769efdf1/ Sat, 01 Aug 2026 00:00:00 GMT Contemporaneous incidence estimates for 30 safety outcomes across five organ systems can inform benefit-risk framing for new and existing respiratory vaccines during the COVID-19 endemic era and highlight the need to account for age and sex when interpreting expected rates. COVID-19 Influenza SARS Vaccination Surveillance Vaccine safety Cohort study