Influenza and Influenza Vaccine: A Review

Neutralization potency of the 2023-24 seasonal influenza vaccine against circulating influenza H3N2 strains

Seasonal influenza is a severe disease that significantly impacts public health, causing millions of infections and hundreds of thousands of deaths each year. Seasonal influenza viruses, particularly the H3N2 subtype, exhibit high antigenic variability, often leading to mismatch between vaccine strains and circulating strains. Therefore, rapidly assessing the alignment between existing seasonal influenza vaccine and circulating strains is crucial for enhancing vaccine efficacy. This study, based on a pseudovirus platform, evaluated the match between current influenza H3N2 vaccine strains and circulating strains through cross-neutralization assays using clinical human immune sera against globally circulating influenza virus strains. The research results show that although mutations are present in the circulating strains, the current H3N2 vaccine strain still imparting effective protection, providing a scientific basis for encouraging influenza vaccination. This research methodology can be sustainably applied for the neutralization potency assessment of subsequent circulating strains, establishing a persistent methodological framework.

Enhanced Safety Surveillance of GSK's Inactivated Quadrivalent Seasonal Influenza Vaccine in Belgium, Germany, and Spain During the 2022/2023 Influenza Season

BACKGROUND

Seasonal influenza is prevented through annual vaccination, especially in children and older adults. These vaccines are annually updated based on World Health Organization recommendations and require continuous safety monitoring.

OBJECTIVE

We assessed the frequency and severity of adverse events within 7 days of administering GSK's inactivated quadrivalent seasonal influenza vaccine (IIV4) in Belgium, Germany, and Spain during the 2022/2023 influenza season.

METHODS

In this enhanced safety surveillance study, adults who received GSK's IIV4 and parents/guardians/legally acceptable representatives of vaccinated children (aged 6 months-17 years) were invited to complete adverse drug reaction cards reporting adverse events within 7 days post-vaccination.

RESULTS

In total, 1332 participants (53.6% female) received at least one dose of GSK's IIV4, including 43 children who received two doses. Overall, 97.8% of adverse drug reaction cards were completed and returned in the study. All participants in Belgium were adults, while 54.7% and 7.4% in Spain and Germany, respectively, were pediatric participants aged 6 months-17 years. After Dose 1, across all age groups, 49.8% of participants reported at least one adverse event. The most common adverse events (cumulative frequency >5%) following Dose 1 were injection-site pain (37.6%), fatigue (15.0%), headache (13.2%), injection-site swelling (9.3%), myalgia (7.6%), and injection-site erythema (7.4%). Across all countries, adverse events were most common in adults aged 18-65 years (59.7%), followed by those aged 3-17 years (47.0%), >65 years (35.7%), and 6-35 months (23.5%). After Dose 2, 18.6% of participants reported at least one adverse event, with general disorders and administration site conditions again being the most frequent.

CONCLUSIONS

Across all age and risk groups for serious disease, no serious adverse events related to GSK's IIV4 were reported within 7 days post-vaccination. This study supports and confirms the acceptable safety profile of GSK's IIV4 across all recommended age groups.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov number: not applicable.

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.

Vaccine effectiveness in patients admitted for influenza during the 2023-2024 season

BACKGROUND AND GOAL

Vaccination against influenza is widespread worldwide, reducing complications associated with infection. However, the impact of vaccination on mortality/ICU admission in hospitalized patients has been little studied.

MATERIAL AND METHODS

A retrospective observational study was conducted on 238 patients hospitalized for influenza from October 2023 to January 2024 to evaluate the vaccine's effectiveness in terms of the combined event of ICU admission/mortality during hospitalization. Additionally, the characteristics of vaccinated patients and the existence of bacterial superinfection were analyzed. Cox regression was performed using the SPSS program and the free «R» software.

RESULTS

A total of 238 patients were included. Those vaccinated were older (78.2±8.8 vs 69.97±16.6years; P<.001) and were more likely to have hypertension (82.2% vs 56.2%; P<.001), cardiovascular disease (36.6% vs 24.1%; P=.05), chronic bronchopathy (25.7% vs 8.8%; P=.001), or chronic kidney disease (22.8% vs 8.8%; P=0.005). They had lower levels of CRP (8.39±9.55 vs 11.03±10.75mg/dl; P=.05), procalcitonin (0.62±1.74 vs 1.67±4.57ng/dl; P=.05), and SOFA scores (1.13±0.9 vs 1.39±0.97; P=0.033). 11 patients were admitted to ICU (4.6%) and 11 died (4.6%). Influenza vaccination was associated as a protective factor against ICU admission/mortality in the Cox regression (HR=0.216; 95%CI: 0.062-0.759, P=.017). The presence of bacterial superinfection was similar between vaccinated and unvaccinated patients (63.4% vs 67.9%; P=.556).

CONCLUSIONS

Influenza vaccination may reduce the probability of ICU admission or death. This effect is likely due to better control of the immune response. We did not observe any relationship with the risk of presenting bacterial superinfection.

Head-to-head comparison of influenza vaccines in children: a systematic review and meta-analysis

Although vaccination is considered the most effective weapon against influenza, coverage rates, national vaccination policies, and funding vary largely around the globe. Despite their huge potential for achieving herd immunity, child-focused national vaccination strategies that favor pain-free nasal vaccines are uncommon. CENTRAL, Embase, and MEDLINE were last searched on November 13, 2023. Active-controlled randomized controlled trials comparing the live-attenuated intranasal vaccine with the inactivated intramuscular influenza vaccine in children were included. Event rates of laboratory-confirmed influenza virus infection, all-cause mortality, hospitalization, serious adverse events, adverse events, and financial outcomes were extracted based on the PRISMA 2020 Guideline. PROSPERO: CRD42021285412. Pooled odds ratios (ORs) with 95% confidence intervals (CI) were calculated using the random-effects model when at least three comparable outcomes were available. We found no significant difference between quadrivalent live-attenuated intranasal and trivalent inactivated intramuscular (OR = 1.48; 95% CI 0.49-4.45) or between trivalent live-attenuated intranasal and inactivated intramuscular vaccines (OR = 0.77, CI = 0.44-1.34) regarding their efficacy. However, the subgroup analysis of large, multi-center trials indicated that the trivalent live attenuated intranasal influenza vaccine was superior to the trivalent inactivated intramuscular influenza vaccine (12,154 people, OR = 0.50, CI = 0.28-0.88). Only 23 "vaccine-related serious adverse events" were recorded among 17 833 individuals, with no significant difference between methods. The widespread initiation of pediatric national flu vaccination programs prioritizing the live-attenuated intranasal influenza vaccine would be beneficial. Multi-continent, high-quality studies that include children younger than two years old and those living in subtropical and tropical regions are needed to further enhance our understanding.

Dual neutralization of influenza virus hemagglutinin and neuraminidase by a bispecific antibody leads to improved antiviral activity

Targeting multiple viral proteins is pivotal for sustained suppression of highly mutable viruses. In recent years, broadly neutralizing antibodies that target the influenza virus hemagglutinin and neuraminidase glycoproteins have been developed, and antibody monotherapy has been tested in preclinical and clinical studies to treat or prevent influenza virus infection. However, the impact of dual neutralization of the hemagglutinin and neuraminidase on the course of infection, as well as its therapeutic potential, has not been thoroughly tested. For this purpose, we generated a bispecific antibody that neutralizes both the hemagglutinin and the neuraminidase of influenza viruses. We demonstrated that this bispecific antibody has a dual-antiviral activity as it blocks infection and prevents the release of progeny viruses from the infected cells. We show that dual neutralization of the hemagglutinin and the neuraminidase by a bispecific antibody is advantageous over monoclonal antibody combination as it resulted an improved neutralization capacity and augmented the antibody effector functions. Notably, the bispecific antibody showed enhanced antiviral activity in influenza virus-infected mice, reduced mice mortality, and limited the virus mutation profile upon antibody administration. Thus, dual neutralization of the hemagglutinin and neuraminidase could be effective in controlling influenza virus infection.

Different effects of air pollutant concentrations on influenza A and B in Sichuan, China

BACKGROUND

The detrimental effects of air pollution on the respiratory system are well documented. Previous research has established a correlation between air pollutant concentration and the frequency of outpatient visits for influenza-like illness. However, studies investigating the variations in infection among different influenza subtypes remain sparse. We aimed to determine the correlation between air pollutant levels and different influenza subtypes in Sichuan Province, China.

METHODS

A generalized additive model and distributed lag nonlinear model were employed to assess the association between air pollutants and influenza subtypes, utilizing daily influenza data obtained from 30 hospitals across 21 cities in Sichuan Province. The analysis considered the temporal effects and meteorological factors. The study spanned from January 1, 2017, to December 31, 2019. To provide a more precise evaluation of the actual impact of air pollution on different subtypes of influenza, we also performed subgroup analyses based on factors such as gender, age, and geography within the population.

RESULTS

During the investigation, 17,462 specimens from Sichuan Province tested positive for influenza. Among these, 12,607 and 4855 were diagnosed with Flu A and B, respectively. The related risk of influenza A infection significantly increased following exposure to PM2.5 on Lag2 days (RR=1.008, 95 % confidence interval [CI]: 1.000-1.016), SO2 and CO on Lag1 days (RR=1.121, 95 % CI: 1.032-1.219; RR=1.151, 95 % CI: 1.030-1.289), and NO2 on Lag0 day (RR=1.089, 95 % CI: 1.035-1.145). PM10 and SO2 levels on Lag0 day, PM2.5 levels on Lag1 day, and CO levels on Lag6 day, with a reduced risk of influenza B (RR=0.987, 95 % CI: 0.976-0.997; RR=0.817, 95 % CI: 0.676-0.987; RR=0.979, 95 % CI: 0.970-0.989; RR=0.814, 95 % CI: 0.561-0.921).

CONCLUSION

The findings from the overall population and subgroup analyses indicated that the impact of air pollutant concentrations on influenza A and B is inconsistent, with influenza A demonstrating greater susceptibility to these pollutants. Minimizing the levels of SO2, CO, NO2, and PM2.5 can significantly decrease the likelihood of contracting influenza A. Analyzing the influence of environmental contaminants on different influenza subtypes can provide insights into seasonal influenza trends and guide the development of preventive and control strategies.

Influenza vaccination in older adults and patients with chronic disorders: A position paper from the Portuguese Society of Pulmonology, the Portuguese Society of Cardiology, the Portuguese Society of Diabetology, the Portuguese Society of Infectious Diseases and Clinical Microbiology, the Portuguese Society of Geriatrics and Gerontology, and the Study Group of Geriatrics of the Portuguese Society of Internal Medicine

Influenza affects millions of people worldwide each year and can lead to severe complications, hospitalizations, and even death, especially among vulnerable populations such as older adults and those with chronic medical conditions. Annual vaccination is considered the most effective measure for preventing influenza and its complications. Despite the widespread availability of influenza vaccines, however, vaccination coverage rates remain suboptimal in several countries. Based on the latest scientific evidence and expert opinions on influenza vaccination in older people and patients with chronic disease, the Portuguese Society of Pulmonology (SPP), the Portuguese Society of Diabetology (SPD), the Portuguese Society of Cardiology (SPC), the Portuguese Society of Geriatrics and Gerontology (SPGG), the Study Group of Geriatrics of the Portuguese Society of Internal Medicine (NEGERMI-SPMI), and the Portuguese Society of Infectious Diseases and Clinical Microbiology (SPDIMC) discussed best practices for promoting vaccination uptake and coverage and drew up several recommendations to mitigate the impact of influenza. These recommendations focus on the efficacy and safety of available vaccines; the impact of influenza vaccination on older adults; patients with chronic medical conditions, namely cardiac and respiratory conditions, diabetes, and immunosuppressive diseases; and health care professionals, optimal vaccination timing, and strategies to increase vaccination uptake and coverage. The resulting position paper highlights the critical role that vaccinations play in promoting public health, raising awareness, and encouraging more people to get vaccinated.

Influenza in Pregnancy: Maternal, Obstetric, and Fetal Implications, Diagnosis, and Management

Influenza(flu) in pregnancy is associated with higher rates of hospitalization, ICU admission, and death and with increased odds of congenital anomalies and stillbirth, but not preterm birth. Clinical manifestations of flu in pregnancy are the same as nonpregnant patients. Pregnant individuals with flu-like symptoms or flu exposure should be treated with antivirals. Diagnostic testing is not needed. Oseltamivir is the mainstay of treatment(and prophylaxis), and when given within 48 hours of symptom onset, it decreases morbidity and mortality. Influenza is associated with worse maternal, obstetric, and neonatal outcomes. These risks are mitigated by early oseltamivir treatment and maternal vaccination; hence the recommendation for universal vaccination in pregnancy.

Analysis of seasonal H3N2 influenza virus epidemic characteristics and whole genome features in Jining City from 2018 to 2023

Seasonal H3N2 influenza virus, known for its rapid evolution, poses a serious threat to human health. This study focuses on analyzing the influenza virus trends in Jining City (2018-2023) and understanding the evolving nature of H3N2 strains. Data on influenza-like cases were gathered from Jining City's sentinel hospitals: Jining First People's Hospital and Rencheng Maternal and Child Health Hospital, using the Chinese Influenza Surveillance Information System. Over the period from 2018 to 2023, 7844 throat swab specimens were assessed using real-time fluorescence quantitative PCR for influenza virus nucleic acid detection. For cases positive for seasonal H3N2 influenza virus, virus isolation was followed by whole genome sequencing. Evolutionary trees were built for the eight gene segments, and protein variation analysis was performed. From 2018 to 2023, influenza-like cases in Jining City represented 6.99% (237 299/3 397 247) of outpatient visits, peaking in December and January. Influenza virus was detected in 15.67% (1229/7844) of cases, primarily from December to February. Notably, no cases were found in the 2020-2021 season. Full genome sequencing was conducted on 70 seasonal H3N2 strains, revealing distinct evolutionary branches across seasons. Significant antigenic site variations in the HA protein were noted. No resistance mutations to inhibitors were found, but some strains exhibited mutations in PA, NS1, PA-X, and PB1-F2. Influenza trends in Jining City saw significant shifts in the 2020-2021 and 2022-2023 seasons. Seasonal H3N2 exhibited rapid evolution. Sustained vigilance is imperative for vaccine updates and antiviral selection.

A new antigen test device for rapid influenza A and B detection

Introduction

Tests for detection of influenza must demonstrate high sensitivity and specificity, affordability, and rapidness.

Methods

This study aimed to evaluate the performance of the LabOn-Time™ Influenza A + B Rapid test device (BMT Diagnostics, Ltd), as compared to Real-time polymerase chain reaction (RT-PCR), in identifying influenza A/B among 183 nasopharyngeal samples collected between February and April 2023 from patients with Influenza-like symptoms.

Results

Out of 70 participants with a positive RT-PCR result, 53 (75.7 %) had a positive LabOn-Time result. The LabOn-Time kit had a sensitivity of 75.7 % and specificity of 100 %. The odds ratio for showing a false negative LabOn-Time result for influenza B, compared to influenza A was 5.24 (95%CI: 1.35-20.31). All false negative LabOn-Time samples had a RT-PCT cycle threshold ≥20. Mean time from symptom onset was significantly lower in the false negative LabOn-Time cases compared to the positive cases (36 ± 15.3 vs. 42.6 ± 10.1, respectively). The mean number of symptoms reported per patient was significantly higher in positive compared to negative LabOn-Time cases (2.5 ± 0.5 vs. 1.9 ± 0.4, p < 0.001).

Conclusions

The LabOn-Time device, which is very simple and intuitive to operate, could significantly contribute to early detection of influenza A/B infection.

Epidemiologic and clinical updates on viral infections in Saudi Arabia

In the past two decades, the world has witnessed devastating pandemics affecting the global healthcare infrastructure and disrupting society and the economy worldwide. Among all pathogens, viruses play a critical role that is associated with outbreaks due to their wide range of species, involvement of animal hosts, easily transmitted to humans, and increased rates of infectivity. Viral disease outbreaks threaten public health globally due to the challenges associated with controlling and eradicating them. Implementing effective viral disease control programs starts with ongoing surveillance data collection and analyses to detect infectious disease trends and patterns, which is critical for maintaining public health. Viral disease control strategies include improved hygiene and sanitation facilities, eliminating arthropod vectors, vaccinations, and quarantine. The Saudi Ministry of Health (MOH) and the Public Health Authority (also known as Weqayah) in Saudi Arabia are responsible for public health surveillance to control and prevent infectious diseases. The notifiable viral diseases based on the Saudi MOH include hepatitis diseases, viral hemorrhagic fevers, respiratory viral diseases, exanthematous viral diseases, neurological viral diseases, and conjunctivitis. Monitoring trends and detecting changes in these viral diseases is essential to provide proper interventions, evaluate the established prevention programs, and develop better prevention strategies. Therefore, this review aims to highlight the epidemiological updates of the recently reported viral infections in Saudi Arabia and to provide insights into the recent clinical treatment and prevention strategies.

Pharmacovigilance in Vaccines: Importance, Main Aspects, Perspectives, and Challenges-A Narrative Review

Pharmacovigilance plays a central role in safeguarding public health by continuously monitoring the safety of vaccines, being critical in a climate of vaccine hesitancy, where public trust is paramount. Pharmacovigilance strategies employed to gather information on adverse events following immunization (AEFIs) include pre-registration data, media reports, clinical trials, and societal reporting. Early detection of AEFIs during clinical trials is crucial for thorough safety analysis and preventing serious reactions once vaccines are deployed. This review highlights the importance of societal reporting, encompassing contributions from community members, healthcare workers, and pharmaceutical companies. Technological advancements such as quick response (QR) codes can facilitate prompt AEFI reporting. While vaccines are demonstrably safe, the possibility of adverse events necessitates continuous post-marketing surveillance. However, underreporting remains a challenge, underscoring the critical role of public engagement in pharmacovigilance. This narrative review comprehensively examines and synthesizes key aspects of virus vaccine pharmacovigilance, with special considerations for specific population groups. We explore applicable legislation, the spectrum of AEFIs associated with major vaccines, and the unique challenges and perspectives surrounding pharmacovigilance in this domain.

Antenatal Care: A Comparative Review of Guidelines

Importance

Antenatal care plays a crucial role in safely monitoring and ensuring the well-being of both the mother and the fetus during pregnancy, ultimately leading to the best possible perinatal outcomes.

Objective

The aim of this study was to review and compare the most recently published guidelines on antenatal care.

Evidence Acquisition

A descriptive review of guidelines from the National Institute for Health and Care Excellence, the Public Health Agency of Canada, the World Health Organization, and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists regarding antenatal care was conducted.

Results

There is a consensus among the reviewed guidelines regarding the necessary appointments during the antenatal period, the proper timing for induction of labor, the number and frequency of laboratory examinations for the assessment of mother's well-being, and management strategies for common physiological problems during pregnancy, such as nausea and vomiting, heartburn, pelvic pain, leg cramps, and symptomatic vaginal discharge. In addition, special consideration should be given for mental health issues and timely referral to a specialist, reassurance of complete maternal vaccination, counseling for safe use of medical agents, and advice for cessation of substance, alcohol, and tobacco use during pregnancy. Controversy surrounds clinical evaluation during the antenatal period, particularly when it comes to the routine use of an oral glucose tolerance test and symphysis-fundal height measurement for assessing fetal growth, whereas routine cardiotocography and fetal movement counting are suggested practices only by Royal Australian and New Zealand College of Obstetricians and Gynaecologists. Of note, recommendations on nutritional interventions and supplementation are offered only by Public Health Agency of Canada and World Health Organization, with some minor discrepancies in the optimal dosage.

Conclusions

Antenatal care remains a critical factor in achieving positive outcomes, but there are variations depending on the socioeconomic status of each country. Therefore, the establishment of consistent international protocols for optimal antenatal care is of utmost importance. This can help provide safe guidance for healthcare providers and, consequently, improve both maternal and fetal outcomes.

Bacterial Vaccines for the Management of Recurrent Urinary Tract Infections: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Several bacterial immunisations have been developed to reduce the socioeconomic burden of urinary tract infections (UTIs) and the use of prophylactic antibiotics in the management of recurrent UTIs (rUTIs). This systematic review evaluates the effectiveness of vaccinations in preventing rUTIs.

METHODS

Medline, Embase, and Web of Science were searched from inception to December 2023. Data were collected from cohort studies with a comparator arm and randomised controlled trials (RCTs) investigating vaccination efficacy in adult rUTI patients according to predefined selection criteria (PROSPERO registration: CRD42022356662). A pooled analysis took place for RCTs, with a subgroup analysis for vaccine types and booster regimens. Other studies were synthesised narratively. The risk of bias was assessed using Cochrane Risk-of-Bias tools. The Grading of Recommendations, Assessment, Development, and Evaluations framework evaluated the quality of evidence.

KEY FINDINGS AND LIMITATIONS

Fourteen comparative studies were selected, including 2822 patients across five vaccination types. The pooled risk ratio of eight placebo-controlled studies of the percentage of patients UTI free in the short term (6-12 mo) was 1.52 (95% confidence interval [CI] 1.05-2.20) with a number needed to treat of 6.45 (95% CI 2.80-64.80). There is substantial heterogeneity and a slight risk of a publication bias.

CONCLUSIONS AND CLINICAL IMPLICATIONS

There is limited evidence to suggest that vaccinations are effective at reducing UTI recurrence in adult female patients in the short term. Owing to low quality of evidence, the literature requires further long-term RCTs with large sample sizes utilising standardised definitions for conclusive evidence of the long-term efficacy of vaccination in rUTI prevention.

PATIENT SUMMARY

We explored whether vaccines could help stop urinary tract infections (UTIs) from happening again. The latest information shows that these vaccines are safe and may help lower the chances of women getting UTIs again for about 6-12 mo.

Risk of stroke within 3, 7, 14, 21 and 30 days after influenza vaccination in Alberta, Canada: A population-based study

BACKGROUND AND PURPOSE

Influenza vaccination is associated with a longer-term protective effect against stroke; however, it has a short-term inflammatory response which may increase short-term risk of stroke. The aim was to investigate the association between influenza vaccination and short-term risk of stroke in adults.

METHODS

Administrative data were obtained from the Alberta Health Care Insurance Plan for all adults in Alberta, Canada, from September 2009 to December 2018. The hazard of any stroke (acute ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage and transient ischaemic attack) within 3, 7, 14, 21 and 30 days of influenza vaccination compared to unexposed time was analysed using Andersen-Gill Cox models, with adjustment for age, sex, anticoagulant use, atrial fibrillation, chronic obstructive pulmonary disease, diabetes, hypertension, income quintile, and rural or urban home location.

RESULTS

In the entire cohort consisting of 4,141,209 adults (29,687,899 person-years), 1,769,565 (42.7%) individuals received at least one vaccination. In total 38,126 stroke events were recorded with 1309 occurring within 30 days of a vaccination event. Influenza vaccination was associated with a significantly reduced hazard of stroke within 3 days (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.73-0.93), 7 days (HR 0.87, 95% CI 0.80-0.95), 14 days (HR 0.87, 95% CI 0.81-0.93), 21 days (HR 0.85, 95% CI 0.80-0.91) and 30 days (HR 0.66, 95% CI 0.65-0.68).

CONCLUSIONS

An increased early risk associated with vaccination was not observed. The risk of stroke was reduced at all time points within 30 days after influenza vaccination.

Insights from Avian Influenza: A Review of Its Multifaceted Nature and Future Pandemic Preparedness

Avian influenza viruses (AIVs) have posed a significant pandemic threat since their discovery. This review mainly focuses on the epidemiology, virology, pathogenesis, and treatments of avian influenza viruses. We delve into the global spread, past pandemics, clinical symptoms, severity, and immune response related to AIVs. The review also discusses various control measures, including antiviral drugs, vaccines, and potential future directions in influenza treatment and prevention. Lastly, by summarizing the insights from previous pandemic control, this review aims to direct effective strategies for managing future influenza pandemics.

A comprehensive review of oral microenvironment changes and orofacial adverse reactions after COVID-19 vaccination: The good, the bad, and the ugly

Background and Aims

Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have the potential to alter several biological systems concurrently with remolding the immune system, most of which are related to immunization, while some others are known as adverse effects. This review aims to explore the potential effects of vaccination on the oral microenvironment and classifies them as good, bad, or ugly, with a brief review of facial diseases following coronavirus disease 2019 (COVID-19) vaccination.

Methods

This study was a comprehensive review conducted through searching related articles in Medline, Scopus, and Google Scholar databases.

Results

On one side, the "Good" impacts of vaccination on the oro-nasal mucosa are explained as if the mucosal immune responses followed by SARS-CoV-2 vaccines are enough to provide immunity. On the other side, the possible "Bad" and "Ugly" effects of the vaccine, which manifest as orofacial adverse events and autoimmune reactivations, respectively, should be noted. Exacerbation of pre-existing autoimmune conditions such as lichen planus, pemphigus vulgaris, bullous pemphigoid, and Stevens-Johnson syndrome have been reported.

Conclusion

COVID-19 vaccines could affect different biological systems alongside stimulating the immune system, and some of these effects are referred to as adverse effects. Nonetheless, these adverse effects are treatable, and healthcare professionals should not prevent patients from taking the first available vaccination.

Influenza Vaccination in Children Younger than 5 Years in the Region of Murcia (Spain), a Comparative Analysis among Vaccinating and Non-Vaccinating Parents: Data from the FLUTETRA Study

The high burden of influenza in children has driven numerous countries towards universal vaccination of healthy children from 6 to 59 months of age. The Region of Murcia was one of the pioneer Spanish regions to conduct a universal vaccination campaign and to use live-attenuated intranasal vaccine (LAIV) if age appropriate. This study aims to evaluate the parents' likeliness to vaccinate their children and to compare the profile of vaccinating/non-vaccinating parents. This study was designed as a prospective, real-world, survey-based data collection in the 2022-2023 season campaign. This study's sample was selected from those children whose information was available in the local Public Health System databases PERSAN and VACUSAN. Children received LAIV or intramuscular vaccine (IIV) depending on their age as per standard practice. The parent self-vaccination/intention to vaccinate themselves in this campaign (OR = 4.75), the compliance with the official vaccination schedule (OR = 3.41), and the prescription of antibiotics more than twice in the previous year (OR = 2.24) were strongly associated with children's vaccination. Overall, vaccinating parents were very satisfied with the vaccine (IIV: 67.5% vs. LAIV: 68.8%, p = 0.320), and most parents would rather have their children vaccinated with LAIV for the next campaign (43.0%). The main reasons for vaccinating were to protect the child (LAIV: 85.9% vs. IIV: 89.4%), and the predominant reasons for not vaccinating were a lack of healthcare professional recommendation (30.9%), and lack of information about the vaccination campaign (21.5%) and the vaccine itself (21.0%). The clinical context of parents and children was determinant in decision making, which was also influenced by the presence or absence of recommendation by healthcare professionals. Parents were generally very satisfied with the vaccine and showed their preference towards LAIV for future campaigns.

Polyphenol rich sugarcane extract (PRSE) has potential antiviral activity against influenza A virus in vitro

Influenza A virus (IAV) is one of the major global public health concerns but the emerging resistance of IAV to currently available antivirals requires the need to identify potential alternatives. Polyphenol rich sugarcane extract (PRSE) is an extract prepared from the sugarcane plant Saccharum Officinarum. Herein we aimed to determine if PRSE had antiviral activity against IAV. We showed that treatment of IAV-infected cells with PRSE results in a dose-dependent inhibition of virus infection at concentrations that were non-cytotoxic. PRSE treatment limited the early stages of infection, reducing viral genome replication, mRNA transcription and viral protein expression. PRSE did not affect the ability of IAV to bind sialic acid or change the morphology of viral particles. Additionally, PRSE treatment attenuated the replication of multiple IAV strains of the H3N2 and H1N1 subtype. In conclusion, we show that PRSE displays antiviral activity against a broad range of IAV strains, in vitro.

Comparative analysis of symptom profile and risk of death associated with infection by SARS-CoV-2 and its variants in Hong Kong

The recurrent multiwave nature of coronavirus disease 2019 (COVID-19) necessitates updating its symptomatology. We characterize the effect of variants on symptom presentation, identify the symptoms predictive and protective of death, and quantify the effect of vaccination on symptom development. With the COVID-19 cases reported up to August 25, 2022 in Hong Kong, an iterative multitier text-matching algorithm was developed to identify symptoms from free text. Multivariate regression was used to measure associations between variants, symptom development, death, and vaccination status. A least absolute shrinkage and selection operator technique was used to identify a parsimonious set of symptoms jointly associated with death. Overall, 70.9% (54 450/76 762) of cases were symptomatic with 102 symptoms identified. Intrinsically, the wild-type and delta variant caused similar symptoms among unvaccinated symptomatic cases, whereas the wild-type and omicron BA.2 subvariant had heterogeneous patterns, with seven symptoms (fatigue, fever, chest pain, runny nose, sputum production, nausea/vomiting, and sore throat) more frequent in the BA.2 cohort. With ≥2 vaccine doses, BA.2 was more likely than delta to cause fever among symptomatic cases. Fever, blocked nose, pneumonia, and shortness of breath remained jointly predictive of death among unvaccinated symptomatic elderly in the wild-type-to-omicron transition. Number of vaccine doses required for reducing occurrence varied by symptoms. We substantiate that omicron has a different clinical presentation compared to previous variants. Syndromic surveillance can be bettered with reduced reliance on symptom-based case identification, increased weighing on symptoms predictive of death in outcome prediction, individual-based risk assessment in care homes, and incorporating free-text symptom reporting.

A novel film spray containing curcumin inhibits SARS-CoV-2 and influenza virus infection and enhances mucosal immunity

BACKGROUND

Infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and influenza virus is still a major worldwide health concern. Plants are a good source of bioactive compounds to be used as preventive measures for both inhibiting the virus binding and enhancing mucosal innate immunity. Curcumin has been shown to possess antiviral activity and modulate innate immunity. Therefore, the purpose of this study was to develop an oro-nasal film spray containing curcumin and determine its antiviral activity against SARS-CoV-2 and influenza virus infection, as well as its effects on mucosal innate immunity and inflammatory cytokines in vitro.

METHODS

The antiviral activity of the film spray against SARS-CoV-2, influenza A/H1N1, A/H3N2, and influenza B was assessed in vitro by plaque reduction assay. Cytotoxicity of the film spray to oral keratinocytes and nasal epithelial cells was assessed by MTT assay, and cytotoxicity to Vero and MDCK cells was assessed by an MTS-based cytotoxicity assay. Oral and nasal innate immune markers in response to the film spray were determined by ELISA and by a commercial Milliplex Map Kit, respectively.

RESULTS

Our data show that the film spray containing curcumin can inhibit both SARS-CoV-2 and influenza virus infections while maintaining cell viability. Results obtained among 4 viruses revealed that curcumin film spray demonstrated the highest inhibitory activity against SARS-CoV-2 with the lowest EC50 of 3.15 µg/ml and the highest SI value of 4.62, followed by influenza B (EC50 = 6.32 µg/ml, SI = 2.04), influenza A/H1N1 (EC50 = 7.24 µg/ml, SI = 1.78), and influenza A/H3N2 (EC50 > 12.5 µg/ml, SI < 1.03), respectively. Antimicrobial peptides LL-37 and HD-5, IL-6 and TNF-α produced by oral keratinocytes were significantly induced by the film spray, while hBD2 was significantly reduced.

CONCLUSION

Film spray containing curcumin possesses multiple actions against SARS-CoV-2 infection by inhibiting ACE-2 binding in target cells and enhancing mucosal innate immunity. The film spray can also inhibit influenza virus infection. Therefore, the curcumin film spray may be effective in preventing the viral infection of both SARS-CoV-2 and influenza.

Efficacy and safety of Lianhua Qingwen as an adjuvant treatment for influenza in Chinese patients: A meta-analysis

BACKGROUND

Lianhua Qingwen (LHQW) is a proprietary traditional Chinese medicine for the treatment of influenza (FLu). It is composed of 2 prescriptions, Maxing Shigan and Yinqiao, which has antiviral, antibacterial, and immunomodulatory effects. However its clinical suitability has not yet been investigated.

OBJECTIVE

This study aimed to evaluate the efficacy and safety of LHQW in the treatment of FLu.

METHODS

We searched several databases, including PubMed and China Biomedical Database for literature research, from inception to July 1, 2023. This meta-analysis included RCTs that compared the safety and efficacy of the combination of LHQW and conventional drugs (CD) with CD alone for IFU. The extracted data were analyzed using Revman5.4 software with risk ratio (RR), 95% confidence intervals (CI), and standardized mean difference.

RESULTS

Our meta-analysis included 32 articles with 3592 patients. The results showed that the effects of LHQW adjuvant therapy were superior to those of CD (clinical effective rate: RR = 1.22, 95% CI: 1.18-1.26, P < .00001; cure rate: RR = 1.54, 95% CI: 1.35-1.75, P < .00001), and adverse reactions after treatment were significantly lower than those before treatment (RR = 0.70, 95% CI: 0.50-0.98, P = .04).

CONCLUSION

This meta-analysis indicates that LHQW combined with CD may be more effective than CD alone for the treatment of FLu.

The role of meteorological factors on influenza incidence among children in Guangzhou China, 2019-2022

Objective

Analyzing the epidemiological characteristics of influenza cases among children aged 0-17 years in Guangzhou from 2019 to 2022. Assessing the relationships between multiple meteorological factors and influenza, improving the early warning systems for influenza, and providing a scientific basis for influenza prevention and control measures.

Methods

The influenza data were obtained from the Chinese Center for Disease Control and Prevention. Meteorological data were provided by Guangdong Meteorological Service. Spearman correlation analysis was conducted to examine the relevance between meteorological factors and the number of influenza cases. Distributed lag non-linear models (DLNM) were used to explore the effects of meteorological factors on influenza incidence.

Results

The relationship between mean temperature, rainfall, sunshine hours, and influenza cases presented a wavy pattern. The correlation between relative humidity and influenza cases was illustrated by a U-shaped curve. When the temperature dropped below 13°C, Relative risk (RR) increased sharply with decreasing temperature, peaking at 5.7°C with an RR of 83.78 (95% CI: 25.52, 275.09). The RR was increased when the relative humidity was below 66% or above 79%, and the highest RR was 7.50 (95% CI: 22.92, 19.25) at 99%. The RR was increased exponentially when the rainfall exceeded 1,625 mm, reaching a maximum value of 2566.29 (95% CI: 21.85, 3558574.07) at the highest rainfall levels. Both low and high sunshine hours were associated with reduced incidence of influenza, and the lowest RR was 0.20 (95% CI: 20.08, 0.49) at 9.4 h. No significant difference of the meteorological factors on influenza was observed between males and females. The impacts of cumulative extreme low temperature and low relative humidity on influenza among children aged 0-3 presented protective effects and the 0-3 years group had the lowest RRs of cumulative extreme high relative humidity and rainfall. The highest RRs of cumulative extreme effect of all meteorological factors (expect sunshine hours) were observed in the 7-12 years group.

Conclusion

Temperature, relative humidity, rainfall, and sunshine hours can be used as important predictors of influenza in children to improve the early warning system of influenza. Extreme weather reduces the risk of influenza in the age group of 0-3 years, but significantly increases the risk for those aged 7-12 years.

Natural History of Influenza B Virus-Current Knowledge on Treatment, Resistance and Therapeutic Options

Influenza B virus (IBV) significantly impacts the health and the economy of the global population. WHO global health estimates project 1 billion flu cases annually, with 3 to 5 million resulting in severe disease and 0.3 to 0.5 million influenza-related deaths worldwide. Influenza B virus epidemics result in significant economic losses due to healthcare expenses, reduced workforce productivity, and strain on healthcare systems. Influenza B virus epidemics, such as the 1987-1988 Yamagata lineage outbreak and the 2001-2002 Victoria lineage outbreak, had a significant global impact. IBV's fast mutation and replication rates facilitate rapid adaptation to the environment, enabling the evasion of existing immunity and the development of resistance to virus-targeting treatments. This leads to annual outbreaks and necessitates the development of new vaccination formulations. This review aims to elucidate IBV's evolutionary genomic organization and life cycle and provide an overview of anti-IBV drugs, resistance, treatment options, and prospects for IBV biology, emphasizing challenges in preventing and treating IBV infection.

Epidemiology and burden of Severe Acute Respiratory Infections (SARI) in the aftermath of COVID-19 pandemic: A prospective sentinel surveillance study in a Tunisian Medical ICU, 2022/2023

BACKGROUND

Severe Acute Respiratory Infections (SARI) caused by influenza and other respiratory viruses pose significant global health challenges, and the COVID-19 pandemic has further strained healthcare systems. As the focus shifts from the pandemic to other respiratory infections, assessing the epidemiology and burden of SARI is crucial for healthcare planning and resource allocation. Aim: to understand the impact of the post-pandemic period on the epidemiology of SARI cases, clinical outcomes, and healthcare resource utilization in Tunisia.

METHODS

This is a prospective study conducted in a Tunisian MICU part of a national sentinel surveillance system, focusing on enhanced SARI surveillance. SARI cases from week 39/2022, 26 September to week 19/2023, 13 May were included, according to a standardized case definition. Samples were collected for virological RT-PCR testing, and an electronic system ensured standardized and accurate data collection. Descriptive statistics were performed to assess epidemiology, trends, and outcomes of SARI cases, and univariate/multivariate analyses to assess factors associated with mortality.

RESULTS

Among 312 MICU patients, 164 SARI cases were identified during the study period. 64(39%) RT-PCR were returned positive for at least one pathogen, with influenza A and B strains accounting for 20.7% of cases at the early stages of the influenza season. The MICU experienced a significant peak in admissions during weeks 1-11/2023, leading to resource mobilization and the creation of a surge unit. SARI cases utilized 1664/3120 of the MICU-stay days and required 1157 mechanical ventilation days. The overall mortality rate among SARI cases was 22.6%. Age, non-COPD, and ARDS were identified as independent predictors of mortality.

CONCLUSIONS

The present study identified a relatively high rate of SARI cases, with 39% positivity for at least one respiratory virus, with influenza A and B strains occurring predominantly during the early stages of the influenza season. The findings shed light on the considerable resource utilization and mortality associated with these infections, underscoring the urgency for proactive management and efficient resource allocation strategies.

Exploring Cinnamoyl-Substituted Mannopyranosides: Synthesis, Evaluation of Antimicrobial Properties, and Molecular Docking Studies Targeting H5N1 Influenza A Virus

The pursuit of innovative combinations for the development of novel antimicrobial and antiviral medications has garnered worldwide interest among scientists in recent times. Monosaccharides and their glycosides, such as methyl α-d-mannopyranoside derivatives, play a significant role in the potential treatment of viral respiratory pathologies. This study was undertaken to investigate and assess the synthesis and spectral characterization of methyl α-d-mannopyranoside derivatives 2-6, incorporating various aliphatic and aromatic groups. The investigation encompassed comprehensive in vitro antimicrobial screening, examination of physicochemical properties, molecular docking analysis, molecular dynamics simulations, and pharmacokinetic predictions. A unimolar one-step cinnamoylation reaction was employed under controlled conditions to produce methyl 6-O-cinnamoyl-α-d-mannopyranoside 2, demonstrating selectivity at the C-6 position. This represented a pivotal step in the development of potential antimicrobial derivatives based on methyl α-d-mannopyranoside. Subsequently, four additional methyl 6-O-cinnamoyl-α-d-mannopyranoside derivatives were synthesized with reasonably high yields. The chemical structures of these novel analogs were confirmed through a thorough analysis of their physicochemical properties, elemental composition, and spectroscopic data. In vitro antimicrobial assays were conducted against six bacterial strains and two fungal strains, revealing promising antifungal properties of these methyl α-d-mannopyranoside derivatives in comparison to their antibacterial activity. Moreover, cytotoxicity testing revealed that the compounds are less toxic. Further supporting these findings, molecular docking studies were performed against the H5N1 influenza A virus, indicating significant binding affinities and nonbonding interactions with the target protein 6VMZ. Notably, compounds 4 (-7.2) and 6 (-7.0) exhibited the highest binding affinities. Additionally, a 100 ns molecular dynamics simulation was conducted to assess the stability of the complex formed between the receptor 6VMZ and methyl α-d-mannopyranoside derivatives under in silico physiological conditions. The results revealed a stable conformation and binding pattern within the stimulating environment. In silico pharmacokinetic and toxicity assessments of the synthesized molecules were performed using Osiris software (version 2.9.1). Compounds 4 and 6 demonstrated favorable computational and pharmacological activities, albeit with a low drug score, possibly attributed to their higher molecular weight and irritancy. In conclusion, this study showcases the synthesis and evaluation of methyl α-d-mannopyranoside derivatives as promising candidates for antimicrobial and antifungal agents. Molecular docking and dynamics simulations, along with pharmacological predictions, contribute to our understanding of their potential therapeutic utility, although further research may be warranted to address certain pharmacological aspects.

Deciphering the rule of antigen-antibody amino acid interaction

Purpose

Antigenic drift is the biggest challenge for mutagenic RNA virus vaccine development. The primary purpose is to determine the IEMM (immune escape mutation map) of 20 amino acids' replacement to reveal the rule of the viral immune escape.

Methods

To determine the relationship between epitope mutation and immune escape, we use universal protein tags as a linear epitope model. To describe and draw amino acid linkage diagrams, mutations of protein tags are classified into four categories: IEM (immune escape mutation), ADERM (antibody-dependent enhancement risk mutation), EQM (equivalent mutation), and IVM (invalid mutation). To overcome the data limitation, a general antigen-antibody (Ag-Ab) interaction map was constructed by analyzing the published three-dimensional (3D) Ag-Ab interaction patterns.

Results

(i) One residue interacts with multiple amino acids in antigen-antibody interaction. (ii) Most amino acid replacements are IVM and EQM. (iii) Once aromatic amino acids replace non-aromatic amino acids, the mutation is often IEM. (iv) Substituting residues with the same physical and chemical properties easily leads to IVM. Therefore, this study has important theoretical significance for future research on antigenic drift, antibody rescue, and vaccine renewal design.

Conclusion

The antigenic epitope mutations were typed into IEM, ADERM, EQM, and IVM types to describe and quantify the results of antigenic mutations. The antigen-antibody interaction rule was summarized as a one-to-many interaction rule. To sum up, the epitope mutation rules were defined as IVM and EQM predomination rules and the aryl mutation escape rule.

Neutrophil extracellular traps in influenza infection

Despite recent progress in developing novel therapeutic approaches and vaccines, influenza is still considered a global health threat, with about half a million mortality worldwide. This disease is caused by Influenza viruses, which are known for their rapid evolution due to different genetical mechanisms that help them develop new strains with the ability to evade therapies and immunization. Neutrophils are one of the first immune effectors that act against pathogens. They use multiple mechanisms, including phagocytosis, releasing the reactive oxygen species, degranulation, and the production of neutrophil extracellular traps. Neutrophil extracellular traps are used to ensnare pathogens; however, their dysregulation is attributed to inflammatory and infectious diseases. Here, we discuss the effects of these extracellular traps in the clinical course of influenza infection and their ability to be a potential target in treating influenza infection.

Evaluation of Hospitalized Patients with Community-Acquired Influenza-Like Illness During Two Influenza Seasons

Objective

Influenza is among the most important respiratory infections affecting all age groups and can lead to hospitalizations. We aimed to determine the frequency of influenza infections among acute admissions with influenza-like illness (ILI) and evaluate the demographic, clinical findings, and outcomes of patients with influenza.

Methods

This prospective, active surveillance study was conducted in a university hospital between 2015 and 2017. Patients hospitalized for at least 24 hours in the selected units with community-acquired ILI were screened according to certain influenza-predicting ICD-10 codes. Nasopharyngeal and pharyngeal swab samples were taken from patients who were eligible for the study. Patients tested for influenza with real-time polymerase chain reaction. Univariate and multivariate analyses were performed for data.

Results

Among 440 patients screened according to influenza-related ICD-10 codes, 112 were included. Influenza positivity was detected in 37 of the 112 patients. Clinical findings were similar between influenza positive and negative groups and also between influenza subtypes, excluding sore throat, which was more common in the H1N1 group. Alanine transaminase (ALT), aspartate transaminase (AST), and creatine kinase (CK) elevations were found to be significantly higher in the influenza-positive group. When influenza-positive patients with and without pneumonia were compared, the rate of vaccination in the same season was higher in patients without pneumonia than in patients with pneumonia (38.8% and 10.5%, respectively; p=0.04).

Conclusion

Integrating molecular tests detecting both influenza and other respiratory viruses into influenza surveillance programs can increase the efficacy and quality of these programs. The elevation of AST, ALT, and CK in influenza cases can be considered in distinguishing influenza from other ILI cases. Vaccination in the same season can reduce the risk of pneumonia in influenza-positive patients.

Development of a rapid, sensitive detection method for SARS-CoV-2 and influenza virus based on recombinase polymerase amplification combined with CRISPR-Cas12a assay

Respiratory tract infections are associated with the most common diseases transmitted among people and remain a huge threat to global public health. Rapid and sensitive diagnosis of causative agents is critical for timely treatment and disease control. Here, we developed a novel method based on recombinase polymerase amplification (RPA) combined with CRISPR-Cas12a to detect three viral pathogens, including SARS-CoV-2, influenza A, and influenza B, which cause similar symptom complexes of flu cold in the respiratory tract. The detection method can be completed within 1 h, which is faster than other standard detection methods, and the limit of detection is approximately 102 copies/μL. Additionally, this detection system is highly specific and there is no cross-reactivity with other common respiratory tract pathogens. Based on this assay, we further developed a more simplified RPA/CRISPR-Cas12a system combined with lateral flow assay on a manual microfluidic chip, which can simultaneously detect these three viruses. This low-cost detection system is rapid and sensitive, which could be applied in the field and resource-limited areas without bulky and expensive instruments, providing powerful tools for the point-of-care diagnostic.

Novel Influenza Vaccines: From Research and Development (R&D) Challenges to Regulatory Responses

Influenza vaccines faced significant challenges in achieving sufficient protective efficacy and production efficiency in the past. In recent decades, novel influenza vaccines, characterized by efficient and scalable production, advanced platforms, and new adjuvant technologies, have overcome some of these weaknesses and have been widely licensed. Furthermore, researchers are actively pursuing the development of next-generation and universal influenza vaccines to provide comprehensive protection against potential pandemic subtypes or strains. However, new challenges have emerged as these novel vaccines undergo evaluation and authorization. In this review, we primarily outline the critical challenges and advancements in research and development (R&D) and highlight the improvements in regulatory responses for influenza vaccines.

Influenza: seasonality and travel-related considerations

RATIONALE FOR REVIEW

This review aims to summarize the transmission patterns of influenza, its seasonality in different parts of the globe, air travel- and cruise ship-related influenza infections and interventions to reduce transmission.

KEY FINDINGS

The seasonality of influenza varies globally, with peak periods occurring mainly between October and April in the northern hemisphere (NH) and between April and October in the southern hemisphere (SH) in temperate climate zones. However, influenza seasonality is significantly more variable in the tropics. Influenza is one of the most common travel-related, vaccine-preventable diseases and can be contracted during travel, such as during a cruise or through air travel. Additionally, travellers can come into contact with people from regions with ongoing influenza transmission. Current influenza immunization schedules in the NH and SH leave individuals susceptible during their respective spring and summer months if they travel to the other hemisphere during that time.

CONCLUSIONS/RECOMMENDATIONS

The differences in influenza seasonality between hemispheres have substantial implications for the effectiveness of influenza vaccination of travellers. Health care providers should be aware of influenza activity when patients report travel plans, and they should provide alerts and advise on prevention, diagnostic and treatment options. To mitigate the risk of travel-related influenza, interventions include antivirals for self-treatment (in combination with the use of rapid self-tests), extending the shelf life of influenza vaccines to enable immunization during the summer months for international travellers and allowing access to the influenza vaccine used in the opposite hemisphere as a travel-related vaccine. With the currently available vaccines, the most important preventive measure involves optimizing the seasonal influenza vaccination. It is also imperative that influenza is recognized as a travel-related illness among both travellers and health care professionals.

A quick algorithmic review on management of viral infectious diseases in pediatric solid organ transplant recipients

Pediatric solid organ transplant is a life-saving procedure for children with end-stage organ failure. Viral infections are a common complication following pediatric solid organ transplantation (SOT), which can lead to increased morbidity and mortality. Pediatric solid organ transplant recipients are at an increased risk of viral infections due to their immunosuppressed state. The most commonly encountered viruses include cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), varicella-zoster virus (VZV), adenoviruses, and BK polyomavirus. Prevention strategies include vaccination prior to transplantation, post-transplant prophylaxis with antiviral agents, and preemptive therapy. Treatment options vary depending on the virus and may include antiviral therapy and sometimes immunosuppression modification. This review provides a Quick Algorithmic overview of prevention and treatment strategies for viral infectious diseases in pediatric solid organ transplant recipient.

Influenza Vaccination during Pregnancy: A Descriptive Study of the Knowledge, Beliefs, and Practices of Mexican Gynecologists and Family Physicians

BACKGROUND

Influenza in pregnancy is associated with elevated morbidity and mortality. Influenza vaccines are safe and effective in pregnancy. There are no Mexican surveys of physicians on knowledge, beliefs, and practices towards influenza and influenza immunization during pregnancy.

METHODS

A 32-question descriptive survey was conducted, addressing the general knowledge of influenza as well as beliefs and practices regarding influenza vaccination during pregnancy among Mexican physicians responsible for prenatal care, traditionally Obstetricians (OBGYNs) and Family Physicians (FPs).

RESULTS

A total of 206 surveys were available, 98 (47.6%) from OBGYNs and 108 (52.4%) from FPs, representing an estimated 2472 daily pregnancy consultations. In total, 54 of the 206 respondents (26.2%) were not aware that influenza is more severe during pregnancy, 106 of the 206 respondents (51.5%) ignored the potential side effects of influenza infection on the fetus, and 56.8% did not know when to vaccinate pregnant women. Pregnancy as a risk factor for developing influenza complications was only known by 99 of the 206 respondents (48.1%), and 6.1% believed that vaccination does not confer protection to the fetus.

CONCLUSIONS

The current beliefs of Mexican OBGYNs and FPs for both influenza morbidity and mortality, and the importance of influenza vaccination during pregnancy are suboptimal. The drivers of these beliefs should be assessed to improve influenza vaccination recommendations, as knowledge alone is not sufficient.

Air purifiers for reducing the incidence of acute respiratory infections in australian residential aged care facilities: A study protocol for a randomised control trial

INTRODUCTION

Adults living in Residential Aged Care Facilities (RACFs) are highly susceptible to seasonal respiratory infections. Evidence indicates that the aerosols contaminated with virus particles in closed indoor spaces may play a significant role in the transmission of respiratory infections. In this protocol paper, we outline details of a planned RCT which aims to evaluate the effectiveness of portable in room air purifiers in reducing the risk of ARIs among residents in Australian RACFs. This study uses a multi-centre double-blind randomised crossover design. Three RACFs in a regional area of New South Wales will be invited to participate in the study. Air purifiers with or without high-efficiency particulate absorbing (HEPA) filters will be placed in the rooms of residents who are enrolled in the trial. The primary outcome will be a reduction in the incidence of ARI and the secondary outcomes will be the time to first infection, number of emergency department admissions, hospital admissions, and medical consultations due to an ARI.

CONCLUSION

To our knowledge, this will be the first RCT using air purifiers in resident rooms to identify their effect in reducing ARIs in RACFs. If our findings indicate some potential benefit for in-room air purification, it will help provide support and justification for larger trials, which may include a facility wide approach to air purification.

Tumorigenesis mechanism and application strategy of the MDCK cell line: A systematic review

Influenza is an acute respiratory infectious disease caused by influenza virus that seriously endangers people's health. Influenza vaccination is the most effective means to prevent influenza virus infection and its serious complications. MDCK cells are considered to be superior to chicken embryos for the production of influenza vaccines, but the tumorigenicity of cells is a concern over the theoretical possibility of the risk of adverse events. The theoretical risks need to be adequately addressed if public confidence in programs of immunization are to be maintained. In this paper, studies of the tumorigenic potential of cell lines, with MDCK cells as an example, published since 2010 are reviewed. The mechanism of tumorigenicity of MDCK cells is discussed with reference to cell heterogeneity and epithelial to mesenchymal transition (EMT). Understanding the mechanism of the acquisition of a tumorigenic phenotype by MDCK cells might assist in estimating potential risks associated with using tumorigenic cell substrates for vaccine production.

Validation of Multi-epitope Peptides Encapsulated in PLGA Nanoparticles Against Influenza A Virus

BACKGROUND

Influenza is a highly contagious respiratory disease which poses a serious threat to public health globally, causing severe diseases in 3-5 million humans and resulting in 650,000 deaths annually. The current licensed seasonal influenza vaccines lacked cross-reactivity against novel emerging influenza strains as they conferred limited neutralising capabilities. To address the issue, we designed a multi-epitope peptide-based vaccine delivered by the self-adjuvanting PLGA nanoparticles against influenza infections.

METHODS

A total of six conserved peptides representing B- and T-cell epitopes of Influenza A were identified and they were formulated in either incomplete Freund's adjuvant containing CpG ODN 1826 or being encapsulated in PLGA nanoparticles for the evaluation of immunogenicity in BALB/c mice.

RESULTS

The self-adjuvanting PLGA nanoparticles encapsulating the six conserved peptides were capable of eliciting the highest levels of IgG and IFN- γ producing cells. In addition, the immunogenicity of the six peptides encapsulated in PLGA nanoparticles showed greater humoral and cellular mediated immune responses elicited by the mixture of six naked peptides formulated in incomplete Freund's adjuvant containing CpG ODN 1826 in the immunized mice. Peptide 3 from the mixture of six peptides was found to exert necrotic effect on CD3+ T-cells and this finding indicated that peptide 3 should be removed from the nanovaccine formulation.

CONCLUSION

The study demonstrated the self-adjuvanting properties of the PLGA nanoparticles as a delivery system without the need for incorporation of toxic and costly conventional adjuvants in multi-epitope peptide-based vaccines.

Formulation of Recombinant H1N1 Hemagglutinin in MF59 and Alum Adjuvants: A Comparison of the Vaccines Potency and Efficacy in BALB/C Mice

In this study, we reported the expression and potency of the recombinant H1N1 hemagglutinin (HA) vaccine as our in-house vaccine in a BALB/c mouse model. Recombinant H1N1 HA was produced in SF9 cell line, purified and formulated in MF59 adjuvant. Experimental mice were injected on days 0 and 14 with MF59-formulated vaccine, alum-based vaccine, and phosphate-buffered saline (PBS). Interleukin (IL)-2, IL-4, and interferon (IFN)-γ were assessed with commercial enzyme-linked immunosorbent assay (ELISA). Antibody responses and cytotoxic T lymphocyte (CTL) activity were assessed by hemagglutination inhibition and granzyme B ELISA, respectively. Moreover, the mice were challenged to show the vaccine efficacy. A considerable rise in IFN-γ and IL-4, as well as IFN-γ/IL-4 ratio, was observed in comparison with the alum-based vaccine and PBS group. Furthermore, our candidate vaccine showed superiority in humoral immune responses and CTL activity versus the alum-based vaccine and PBS group. The challenge showed that the survival rate in the vaccinated groups revealed a significant increase as compared with that in the PBS group. In conclusion, our candidate vaccine showed a robust Th1 response and CTL activity the alum-based vaccine. Moreover, a significant humoral immune response and a higher survival rate were detected in our vaccine as compared with the alum-based vaccine. It seems that the superiority of the MF59-based vaccine is due to the type of vaccine formulation in the candidate vaccine.

Common cold

The common cold is a unique human disease, as it is arguably the most common disease and because of the large number of respiratory viruses causing colds it is one of the most complex of human diseases. This review discusses the respiratory viruses and notes that all these viruses may cause the illness complex recognised as the common cold. The common cold is discussed as part of the "iceberg concept" of disease which ranges from asymptomatic infection to severe illness and death. The factors influencing the incidence of colds are discussed: crowding and sociability, stress, smoking and alcohol, immune status, sex, age, sleep, season, chilling, nutrition and exercise. The mechanism of symptoms related to the innate immune response is explained and symptomatic treatments are tabulated. Morbidity associated with common cold is discussed and possible vaccines.

Seasonal Influenza Vaccination Among Saudi Children: Parental Barriers and Willingness to Vaccinate Their Children in the Makkah Region

INTRODUCTION

The influenza virus produces everything from seasonal epidemics to unexpected pandemics, making its prevention and management a worldwide public health challenge. The main method to prevent and control seasonal influenza is vaccination. Children responded quite successfully to influenza vaccinations, particularly live vaccines. Despite the strong recommendations and effectiveness of seasonal influenza vaccinations in children, some parents still hesitate and refuse to give their children the shot.

OBJECTIVE

This study, given the importance of knowing the factors that contribute to parents' refusal of influenza vaccine, also aims to assess parental barriers and willingness to vaccinate their children in the Makkah region of Saudi Arabia.

METHODOLOGY

This is a descriptive cross-sectional study conducted among Saudi parents in the Makkah region. For data collection, an online survey was conducted between December 1, 2022, and February 11, 2023.

RESULTS

In total, 334 of the parents participated in our study. The result shows that there is a significant association between parents' gender and receiving the flu vaccine, with significantly more females (52.4%). Regarding the willingness to get the vaccine, the majority of the parents reported that they will get the vaccine and vaccinate their children, and the most common barrier that prevents parents from vaccinating their children is that they do not need it because they are healthy (21.48%). Furthermore, there is a strong relationship between educational level and knowledge about seasonal influenza vaccination; the majority of parents at each level of education have poor knowledge regarding influenza vaccines. In addition, nearly all of our participants (96.7%) believed the information provided by the Saudi Ministry of Health as well as the advice of their physicians.

CONCLUSION

This study highlights the need to increase awareness, educate the parents in the Makkah region about the importance of the influenza vaccine, and encourage them to vaccinate their children.

The epidemiological pattern of seasonal influenza in four sentinel sites in Iraq

Introduction

Influenza is an acute viral infection with significant morbidity and mortality. It occurs annually each winter, which is called seasonal influenza, and is preventable through safe vaccine.

Aim

The aim of this work is to know the epidemiological pattern of patients with seasonal influenza in Iraqi sentinel sites.

Methods

A cross-sectional study was carried out on records of patients who attended four sentinel sites and registered to have influenza-like illness (ILI) or severe acute respiratory infection (SARI), and laboratory investigated.

Results

The total number of cases was 1124; 36.2% of them aged 19-39 years; 53.9% were female; 74.9% lived in urban areas; 64.3% diagnosed as ILI; and 35.7% as SARI; 15.9% had diabetes, 12.7% had heart disease, 4.8% had asthma, 3% had a chronic lung disease, and 2% had hematological disease; 94.6% did not get influenza vaccine. About COVID-19 vaccine, 69.4% were not vaccinated, 3.5% got only one dose, and 27.1% completed two doses. Only the SARI cases needed admission; among them, 95.7% were cured. 6.5% were diagnosed with influenza-A virus, 26.1% had COVID-19, and 67.5% were negative. Among those with influenza, 97.3% had H3N2 subtype and 2.7% had H1N1 pdm09.

Conclusions

The percentage of influenza virus in Iraq is relatively small. The age, classification of case (ILI or SARI), having diabetes, heart disease, or immunological disease, and taking COVID-19 vaccine have a significant association with influenza.

Recommendations

It is needed for similar sentinel sites in other health directorates and for rising health education about seasonal influenza and its vaccine.

Surveillance of Influenza and Other Airborne Transmission Viruses during the 2021/2022 Season in Hospitalized Subjects in Tuscany, Italy

Winter in the northern hemisphere is characterized by the circulation of influenza viruses, which cause seasonal epidemics, generally from October to April. Each influenza season has its own pattern, which differs from one year to the next in terms of the first influenza case notification, the period of highest incidence, and the predominant influenza virus subtypes. After the total absence of influenza viruses in the 2020/2021 season, cases of influenza were again recorded in the 2021/2022 season, although they remained below the seasonal average. Moreover, the co-circulation of the influenza virus and the SARS-CoV-2 pandemic virus was also reported. In the context of the DRIVE study, oropharyngeal swabs were collected from 129 Tuscan adults hospitalized for severe acute respiratory infection (SARI) and analyzed by means of real-time polymerase chain reaction (RT-PCR) for SARS-CoV-2 and 21 different airborne pathogens, including influenza viruses. In total, 55 subjects tested positive for COVID-19, 9 tested positive for influenza, and 3 tested positive for both SARS-CoV-2 and the A/H3N2 influenza virus. The co-circulation of different viruses in the population requires strengthened surveillance that is no longer restricted to the winter months. Indeed, constant, year-long monitoring of the trends of these viruses is needed, especially in at-risk groups and elderly people.

Knockout of Noxa with CRISPR/Cas9 Increases Host Resistance to Influenza Virus Infection

The influenza virus induces cellular apoptosis during viral propagation, and controlling this virus-induced apoptosis process has been shown to have significant antiviral effects. The proapoptotic BH3-only protein Noxa is a strong inducer of apoptosis that can be activated by this virus, suggesting that Noxa has the potential as an anti-influenza target. To assess the value of Noxa as an antiviral target, we utilized CRISPR/Cas9 technology to produce a Noxa-knockout cell line. We found that the knockout of Noxa resulted in a dramatic reduction in the cytopathic effect induced by the influenza virus. Moreover, Noxa knockout decreased the expression of influenza viral proteins (NP, M2, HA, and NS2). In addition, Noxa deficiency triggered a complete autophagic flux to weaken influenza virus-induced autophagosome accumulation, indicating that Noxa may be a promising antiviral target for controlling influenza virus infections.

Rapid detection of influenza A viruses using a real-time reverse transcription recombinase-aided amplification assay

Introduction

Influenza A viruses (IAVs) are important pathogens of respiratory infections, causing not only seasonal influenza but also influenza pandemics and posing a global threat to public health. IAVs infection spreads rapidly, widely, and across species, causing huge losses, especially zoonotic IAVs infections that are more harmful. Fast and sensitive detection of IAVs is critical for controlling the spread of this disease.

Methods

Here, a real-time reverse transcription recombinase-aided amplification (real-time RT-RAA) assay targeting conserved positions in the matrix protein gene (M gene) of IAVs, is successfully established to detect IAVs. The assay can be completed within 20 min at 42°C.

Results

The sensitivity of the real-time RT-RAA assay was 142 copies per reaction at 95% probability, which was comparable to the sensitivity of the RT-qPCR assay. The specificity assay showed that the real-time RT-RAA assay was specific to IAVs, and there was no cross-reactivity with other important viruses. In addition, 100%concordance between the real-time RT-RAA and RT-qPCR assays was achieved after testing 120 clinical specimens.

Discussion

The results suggested that the real-time RT-RAA assay we developed was a specific, sensitive and reliable diagnostic tool for the rapid detection of IAVs.

NOX2 oxidase inhibitor GSK2795039 possess antiviral activity against H1N1 influenza A virus in vitro and vivo

The continuous zoonotic circulation and reassortment potential of influenza A viruses (IAV) in nature represents an enormous public health threat to humans. Beside vaccination antivirals are needed to efficiently control spreading of the disease. The previous research has shown that NOX2 involved in IAV replication, but the detailed mechanism has not been reported. In the present study we investigated the roles of NOX2 in host inflammatory response and IAV replication using a novel inhibitor GSK2795039. The drug significantly reduced H1N1 virus induced NOX2 activity and ROS release in human lung epithelial cells. The results of time course experiments suggested that GSK2795039 inhibited an early post-entry step of viral infection. Concomitantly, there was a decreased expression of pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interferon (IFN)-β and interleukin (IL)-6) in NOX2 suppressed cells. In vivo, compared with control groups, suppression of NOX2 improved the survival rate of mice infected with H1N1 virus (42.9% in GSK2795039 treated mice versus >0% of control mice) and viral burden also decreased in the GSK2795039 treated group. Thus, our data demonstrated a critical role for NOX2 in the establishment of H1N1 infection and subsequent inflammatory reactions, which suggest that GSK2795039 may be a potential therapeutic drug for IAV infection.

Exploration of influenza incidence prediction model based on meteorological factors in Lanzhou, China, 2014-2017

Humans are susceptible to influenza. The influenza virus spreads quickly and behave seasonally. The seasonality and spread of influenza are often associated with meteorological factors and have spatio-temporal differences. Based on the influenza cases and daily average meteorological factors in Lanzhou from 2014 to 2017, this study firstly aimed to analyze the characteristics of influenza incidence in Lanzhou and the impact of meteorological factors on influenza activities. Then, SARIMA(X) models for the prediction were established. The influenza cases in Lanzhou from 2014 to 2017 was more male than female, and the younger the age, the higher the susceptibility; the epidemic characteristics showed that there is a peak in winter, a secondary peak in spring, and a trough in summer and autumn. The influenza cases in Lanzhou increased with increasing daily pressure, decreasing precipitation, average relative humidity, hours of sunshine, average daily temperature and average daily wind speed. Low temperature was a significant driving factor for the increase of transmission intensity of seasonal influenza. The SARIMAX (1,0,0)(1,0,1)[12] multivariable model with average temperature has better prediction performance than the university model. This model is helpful to establish an early warning system, and provide important evidence for the development of influenza control policies and public health interventions.

Understanding the Role of HLA Class I Molecules in the Immune Response to Influenza Infection and Rational Design of a Peptide-Based Vaccine

Influenza A virus is a respiratory pathogen that is responsible for regular epidemics and occasional pandemics that result in substantial damage to life and the economy. The yearly reformulation of trivalent or quadrivalent flu vaccines encompassing surface glycoproteins derived from the current circulating strains of the virus does not provide sufficient cross-protection against mismatched strains. Unlike the current vaccines that elicit a predominant humoral response, vaccines that induce CD8+ T cells have demonstrated a capacity to provide cross-protection against different influenza strains, including novel influenza viruses. Immunopeptidomics, the mass spectrometric identification of human-leukocyte-antigen (HLA)-bound peptides isolated from infected cells, has recently provided key insights into viral peptides that can serve as potential T cell epitopes. The critical elements required for a strong and long-living CD8+ T cell response are related to both HLA restriction and the immunogenicity of the viral peptide. This review examines the importance of HLA and the viral immunopeptidome for the design of a universal influenza T-cell-based vaccine.

Therapeutic and palliative role of a Unani herbal decoction in COVID-19 and similar respiratory viral illnesses: Phytochemical & pharmacological perspective

ETHNOPHARMACOLOGICAL RELEVANCE

Outbreaks of respiratory viral infections like Severe Acute Respiratory Syndrome, Middle-East Respiratory Syndrome, and Coronavirus Disease-2019 have been a regular occurrence in the past 100 years. A significant proportion of the morbidity and mortality in influenza is attributed to the co-morbidities and complications induced by the disease, involving the vital organs and physiological functions. In this context, traditional medicines offer effective protective, palliative, and therapeutic benefits, as observed in several studies on various types of influenza, including COVID-19. The Unani herbal decoction comprising of 'Unnāb (Ziziphus jujuba Mill. fruit), Sapistān (Cordia dichotoma G. Forst. fruit), and Behīdāna (Cydonia oblonga Mill. seed) was originally prescribed by Hakim Ajmal Khan (1868-1927 AD) for various respiratory ailments as a bronchodilator, anti-inflammatory, and for clearing the respiratory tract. During COVID-19, the decoction was prescribed by the Ministry of Ayurveda, Yoga, Unani, Siddha, and Homeopathy (AYUSH), Government of India, for mild patients in home isolation, and also as a self-care drink for healthy people. Preliminary studies are of the view that the decoction could reduce COVID-19 incidence and prevent severe disease in the population where it was administered.

AIMS OF THE STUDY

We intend to review the pharmacological activity of the Unani decoction ingredients, i.e., Z. jujuba, C. dichotoma, and C. oblonga, in context with respiratory viral infections and their co-morbidities, to develop an understanding of its action mechanism.

METHODOLOGY

We reviewed Unani classical textbooks for information on the therapeutic activity of the decoction ingredients. Scientific studies published in English from the year 2000 onwards on leading scientific websites (PubMed, MEDLINE, Scopus, and Springer) were searched for information regarding the efficacy of the drugs in influenza and its common complications. Non-English language articles, or those published prior to 2000, and those which included plant parts other than those traditionally included in the decoction were excluded.

OBSERVATIONS

A wide range of therapeutic and palliative effects have been observed in the three herbs included in the Unani decoction, including anti-viral, anti-bacterial, immuno-modulatory, anti-inflammatory, hepato-, and nephroprotective, anti-atherosclerotic, anti-tussive, broncho-dilatory, and regulation of gut microbiota. Together, these effects can help to mitigate and prevent most of the complications caused as a result of respiratory viral infections.

CONCLUSION

The combined effects of ingredients in this Unani herbal decoction can potentially help to mitigate most of the pathological changes and complications caused by influenza viruses. With further clinical research, the decoction may be potentially utilized as a prophylactic and therapeutic against viral influenza.

Temporal proteomic analyses of human lung cells distinguish high pathogenicity influenza viruses and coronaviruses from low pathogenicity viruses

Newly re-emerging viruses are of significant global concern. In late 2019, a new coronavirus, SARS-CoV-2, emerged in China and soon spread worldwide, causing the COVID-19 pandemic, which to date has caused >6 M deaths. There has been a wealth of studies on this new virus since its emergence. The coronaviruses consist of many animal and human pathogens, with some of the human coronavirus, such as strain OC43, normally causing only mild cold-like symptoms. Viruses usurp host cellular processes to successfully replicate. We used tandem mass tag mass spectrometry-based proteomic analyses of human lung MRC-5 cells infected with OC43 for various periods of time to delineate virus-induced host cell alterations. Numerous proteins involved in lipid metabolism, molecular transport, small molecule biochemistry, cell death and survival, humoral immune response, and inflammatory response were dysregulated. Comparison of our findings to previous studies that examined a range of differentially pathogenic influenza A viruses (IAV), and to SARS-CoV-2 data, revealed that proteins involved in the cell cycle, cytokine signaling, DNA replication, and anti-inflammatory responses were generally similarly affected by virtually all tested IAV and CoV. However, proteins involved in necrosis, protein metabolism, ECM regulation, and signal transduction were generally different. In addition, the more pathogenic CoV and IAV activated Rb-dependent repression of E2F-mediated transcription, whereas less pathogenic influenza and coronaviruses either inhibited or had no effect on this pathway.