Influenza In Healthy Adults Research Articles

Seasonal flu, vaccinations and COVID-19

Seasonal flu, vaccinations and COVID-19

Vaccines for preventing influenza in healthy adults

Vaccines for preventing influenza in healthy adults

Vaccines for preventing influenza in healthy adults.

Vaccines for preventing influenza in healthy adults.

Lactococcus lactis JCM5805 activates anti-viral immunity and reduces symptoms of common cold and influenza in healthy adults in a randomized controlled trial

The effects of heat-killed Lactococcus lactis JCM5805 (JCM5805) on the pathogenesis of common cold and influenza were evaluated. A randomized, placebo-controlled, double-blinded study was conducted and 396 healthy subjects (placebo group n = 205, JCM5805 group n = 191) completed the intervention. Subjects consumed placebo capsules or JCM5805 capsules containing approximately 100 billion cells of heat-killed JCM5805 per day for 12 wk. Significantly fewer incident days were observed in the JCM5805 group than in the placebo group for the symptoms of sore throat (p < 0.05) and cough (p < 0.001). Cell surface expression of HLA-DR on plasmacytoid dendritic cells (pDC) and the expression of VIPERIN in peripheral blood mononuclear cells (PBMCs) were higher post-intervention compared to baseline in the JCM5805 group only (p < 0.05). The expression of IFNA in PBMCs was significantly higher in the JCM5805 group (p < 0.05). These data suggest that the intake of heat-killed JCM5805 stimulated pDC-related anti-viral immunity to mitigate the incidence of common cold and influenza symptoms.

Review: Neuraminidase inhibitors reduce symptomatic influenza; oseltamivir does not reduce hospitalizations.

Source Citation Jefferson T, Jones MA, Doshi P, et al. Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children. Cochrane Database Syst Rev. 2014;4:CD008965. 24...

Review: Influenza vaccine reduces influenza-like illness in healthy adults.

ACP Journal Club16 September 2014Review: Influenza vaccine reduces influenza-like illness in healthy adultsBruno Granwehr, MD, MS, FACPBruno Granwehr, MD, MS, FACPUniversity of Texas MD Anderson Cancer Center, Houston, Texas, USA (B.G.)Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-161-6-201409160-02006 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail Source CitationDemicheli V, Jefferson T, Al-Ansary LA, et al. Vaccines for preventing influenza in healthy adults. Cochrane Database Syst Rev. 2014;3:CD001269.Clinical Impact RatingsGIM/FP/GP: Allerg & Immunol: Infectious Disease: References1 Chu HY, Englund JA. Maternal immunization. Clin Infect Dis. 2014;59:560-8. [PMID: 24799324] Google Scholar2 Neuzil KM, Mellen BG, Wright PF, Mitchel EF Jr, Griffin MR. The effect of influenza on hospitalizations, outpatient visits, and courses of antibiotics in children. N Engl J Med. 2000;342:225-31. [PMID: 10648763] Google Scholar3 Pollyea DA, Brown JM, Horning SJ. Utility of influenza vaccination for oncology patients. J Clin Oncol. 2010;28:2481-90. [PMID: 20385981] Google Scholar4 Cooksley CD, Avritscher EB, Bekele BN, et al. Epidemiology and outcomes of serious influenza-related infections in the cancer population. Cancer. 2005;104:618-28. [PMID: 15973737] Google Scholar Author, Article, and Disclosure InformationAffiliations: University of Texas MD Anderson Cancer Center, Houston, Texas, USA (B.G.)This article was published at Annals.org on 2 September 2014. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited ByThe Effect of Detectable HIV Viral Load among HIV-Infected Children during Antiretroviral Treatment: A Cross-Sectional Study 16 September 2014Volume 161, Issue 6Page: JC6KeywordsCaregiversInfectious diseasesPregnancyResearch laboratoriesRisk managementSigns and symptomsVaccines ePublished: 16 September 2014 Issue Published: 16 September 2014 CopyrightCopyright © 2014 by American College of Physicians. All Rights Reserved.PDF DownloadLoading ...

Vaccines for preventing influenza in healthy adults

Different types of influenza vaccines are currently produced worldwide. Vaccination of pregnant women is recommended internationally, while healthy adults are targeted in North America. To identify, retrieve and assess all studies evaluating the effects (efficacy, effectiveness and harm) of vaccines against influenza in healthy adults, including pregnant women. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 2), MEDLINE (January 1966 to May 2013) and EMBASE (1990 to May 2013). Randomised controlled trials (RCTs) or quasi-RCTs comparing influenza vaccines with placebo or no intervention in naturally occurring influenza in healthy individuals aged 16 to 65 years. We also included comparative studies assessing serious and rare harms. Two review authors independently assessed trial quality and extracted data. We included 90 reports containing 116 data sets; among these 69 were clinical trials of over 70,000 people, 27 were comparative cohort studies (about eight million people) and 20 were case-control studies (nearly 25,000 people). We retrieved 23 reports of the effectiveness and safety of vaccine administration in pregnant women (about 1.6 million mother-child couples).The overall effectiveness of parenteral inactivated vaccine against influenza-like illness (ILI) is limited, corresponding to a number needed to vaccinate (NNV) of 40 (95% confidence interval (CI) 26 to 128). The overall efficacy of inactivated vaccines in preventing confirmed influenza has a NNV of 71 (95% CI 64 to 80). The difference between these two values depends on the different incidence of ILI and confirmed influenza among the study populations: 15.6% of unvaccinated participants versus 9.9% of vaccinated participants developed ILI symptoms, whilst only 2.4% and 1.1%, respectively, developed laboratory-confirmed influenza.No RCTs assessing vaccination in pregnant women were found. The only evidence available comes from observational studies with modest methodological quality. On this basis, vaccination shows very limited effects: NNV 92 (95% CI 63 to 201) against ILI in pregnant women and NNV 27 (95% CI 18 to 185) against laboratory-confirmed influenza in newborns from vaccinated women.Live aerosol vaccines have an overall effectiveness corresponding to a NNV 46 (95% CI 29 to 115).The performance of one-dose or two-dose whole virion pandemic vaccines was higher, showing a NNV of 16 (95% CI 14 to 20) against ILI and a NNV of 35 (95% CI 33 to 47) against influenza, while a limited impact on hospitalisation was found (NNV 94, 95% CI 70 to 1022).Vaccination had a modest effect on time off work and had no effect on hospital admissions or complication rates. Inactivated vaccines caused local harms. No evidence of association with serious adverse events was found, but the harms evidence base was limited.The overall risk of bias in the included trials is unclear because it was not possible to assess the real impact of bias. Influenza vaccines have a very modest effect in reducing influenza symptoms and working days lost in the general population, including pregnant women. No evidence of association between influenza vaccination and serious adverse events was found in the comparative studies considered in the review. This review includes 90 studies, 24 of which (26.7%) were funded totally or partially by industry. Out of the 48 RCTs, 17 were industry-funded (35.4%).

Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children.

BACKGROUND: Neuraminidase inhibitors (NIs) are stockpiled and recommended by public health agencies for treating and preventing seasonal and pandemic influenza. They are used clinically world wide. OBJECTIVE: To describe the potential benefits and harms of NIs for influenza in all age groups by reviewing all clinical study reports of published and unpublished randomised, placebo-controlled trials and regulatory comments. METHODS Search methods: We searched trial registries, electronic databases (to 22 July 2013) and regulatory archives, and corresponded with manufacturers to identify all trials. We also requested clinical study reports. We focused on the primary data sources of manufacturers but we checked that there were no published randomised controlled trials (RCTs) from non-manufacturer sources by running electronic searches in the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE (Ovid), EMBASE, Embase.com, PubMed (not MEDLINE), the Database of Reviews of Effects, the NHS Economic Evaluation Database and the Health Economic Evaluations Database. Selection criteria: Randomised, placebo-controlled trials on adults and children with confirmed or suspected exposure to naturally occurring influenza. Data collection and analysis: We extracted clinical study reports and assessed risk of bias using purpose-built instruments. We analysed the effects of zanamivir and oseltamivir on time to first alleviation of symptoms, influenza outcomes, complications, hospital stations and adverse events in the intention-to-treat (ITT) population. All trials were sponsored by the manufacturers. MAIN RESULTS: We obtained 107 clinical study reports from the European Medicines Agency (EMA), GlaxoSmithKline and Roche. We accessed comments by the US Food and Drug Administration (FDA), EMA and Japanese regulator. We included 53 trials in Stage 1 (a judgement of appropriate study design) and 46 in Stage 2 (formal analysis), including 20 oseltamivir (9623 participants) and 26 zanamivir trials (14,628 participants). Inadequate reporting put most of the zanamivir studies and half of the oseltamivir studies at a high risk of selection bias. There were inadequate measures in place to protect 11 studies of oseltamivir from performance bias due to non-identical presentation of placebo. Attrition bias was high across the oseltamivir studies and there was also evidence of selective reporting for both the zanamivir and oseltamivir studies. The placebo interventions in both sets of trials may have contained active substances. Time to first symptom alleviation. For the treatment of adults, oseltamivir reduced the time to first alleviation of symptoms by 16.8 hours (95% confidence interval (CI) 8.4 to 25.1 hours, P 1000) and nausea whilst on treatment (RD 4.15%, 95% CI 0.86 to 9.51); NNTH = 25 (95% CI 11 to 116).

Neuraminidase inhibitors for influenza: a review and public health perspective in the aftermath of the 2009 pandemic

The objectives of this study were to: (1) reflect on key stages in the discovery, development and pre-pandemic use of neuraminidase inhibitors (NAIs), (2) summarise the evidence of NAI effectiveness for treatment and prophylaxis of seasonal influenza prior to the 2009 pandemic, and (3) summarise the evidence base generated during the 2009 pandemic period. A rapid systematic review of evidence published to June 2010 was conducted where existing high-quality systematic reviews formed a baseline and were supplemented with data from other reviews, randomised controlled trials (RCTs) and observational studies. Severity and duration of symptoms; rates of severe illness, complications and death following treatment for influenza or influenza-like illness; rates of influenza and influenza-like illness following long-term prophylaxis or post-exposure prophylaxis of household contacts. Prior to the 2009 pandemic, evidence from RCTs conducted in seasonal influenza epidemics indicated that NAIs used to treat laboratory-confirmed influenza in healthy adults reduced the duration of illness by one day. NAIs provide high levels of protective efficacy in adults when given long-term or in household-based post-exposure prophylaxis for seasonal influenza. Several 2009 pandemic period observational studies suggest that early treatment may reduce rates of hospitalisation and in-hospital mortality, but data from that period do not substantially increase the evidence base on prophylaxis, although they confirm effectiveness. NAIs should be deployed during a future pandemic for either post-exposure prophylaxis or treatment depending on national policy considerations and logistics. The existing evidence base on effectiveness against severe outcomes requires supplementation.

Review: Oseltamivir relieves symptoms but does not reduce hospitalizations in influenza

Source Citation Jefferson T, Jones MA, Doshi P, et al. Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children. Cochrane Database Syst Rev. 2012;(1):CD008965. 22258996

Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children

Cochrane LibraryFree Access Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children First published: 06 March 2012 https://doi.org/10.1002/psb.878AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume23, Issue55 March 2012Pages 49-50 RelatedInformation

Influenza vaccination during pregnancy: a systematic review of effectiveness and adverse effects.

Review question/objective Objectives: 1. To synthesise the best available evidence on the effectiveness of influenza vaccination during pregnancy, for pregnant women, her foetus and the child up to six months of age. 2. To synthesise the best available evidence on the types and frequency of adverse events for pregnant women, her foetus and the child up to six months of age, associated with influenza vaccination during pregnancy. Review questions: 1. What are the beneficial effects of influenza vaccination during pregnancy for pregnant women, her foetus and child up to six months of age? 2. What are the adverse effects of influenza vaccination during pregnancy for pregnant women, her foetus and child up to six months of age? Inclusion criteria Types of participants This study will focus on pregnant women with or without risk factors for complications from influenza infection, their unborn child that is being carried at the time of the vaccination, and children up to the age of 6 months. Types of intervention(s) Inactivated influenza vaccination, irrespective of antigenic configuration or adjuvant, administered via any route, any dose, to pregnant women of any trimester. Studies investigating the monovalent H1N1 vaccine will be assessed separately, as well as in combination with the standard trivalent vaccine. Comparator: Pregnant women not vaccinated against influenza. Types of outcomes •Number and severity of influenza and influenza-like episodes and hospitalisation from influenza for pregnant women and their infant less than six months. •Adverse effects for pregnant women, including but not limited to local reaction, fever, anaphylaxis, Guillain Barre Syndrome and maternal death. •Effects on the foetus, including but not limited to spontaneous abortion, stillbirth, premature birth, birth weight, foetal growth and congenital malformation. •Adverse effects of maternal immunisation on the infant up to six months of age. The case definition of influenza will be accepted as a collection of respiratory and systemic symptoms as defined by the author, and/or laboratory confirmed influenza using viral isolation and/or serology. Severity for the mother and infants will be assessed by hospitalisation and/or death, and/or severe disease such as pneumonia.

Prior Infections With Seasonal Influenza A/H1N1 Virus Reduced the Illness Severity and Epidemic Intensity of Pandemic H1N1 Influenza in Healthy Adults

A new influenza A/H1N1 (pH1N1) virus emerged in April 2009, proceeded to spread worldwide, and was designated as an influenza pandemic. A/H1N1 viruses had circulated in 1918-1957 and 1977-2009 and were in the annual vaccine during 1977-2009. Serum antibody to the pH1N1 and seasonal A/H1N1 viruses was measured in 579 healthy adults at enrollment (fall 2009) and after surveillance for illness (spring 2010). Subjects reporting with moderate to severe acute respiratory illness had illness and virus quantitation for 1 week; evaluations for missed illnesses were conducted over holiday periods and at the spring 2010 visit. After excluding 66 subjects who received pH1N1 vaccine, 513 remained. Seventy-seven had reported with moderate to severe illnesses; 31 were infected with pH1N1 virus, and 30 with a rhinovirus. Determining etiology from clinical findings was not possible, but fever and prominent myalgias favored influenza and prominent rhinorrhea favored rhinovirus. Tests of fall and spring antibody indicated pH1N1 infection of 23% had occurred, with the rate decreasing with increasing anti-pH1N1 antibody; a similar pattern was seen for influenza-associated illness. A reducing frequency of pH1N1 infections was also seen with increasing antibody to the recent seasonal A/H1N1 virus (A/Brisbane/59/07). Preexisting antibody to pH1N1 virus, responses to a single vaccine dose, a low infection-to-illness ratio, and a short duration of illness and virus shedding among those with influenza indicated presence of considerable preexisting immunity to pH1N1 in the population. The 2009 A/H1N1 epidemic among healthy adults was relatively mild, most likely because of immunity from prior infections with A/H1N1 viruses.

Incidence of Influenza in Healthy Adults and Healthcare Workers: A Systematic Review and Meta-Analysis

BackgroundWorking in healthcare is often considered a risk factor for influenza; however, this risk has not been quantified. We aimed to systematically review evidence describing the annual incidence of influenza among healthy adults and healthcare workers (HCWs).Methods and FindingsWe searched OVID MEDLINE (1950 to 2010), EMBASE (1947 to 2010) and reference lists of identified articles. Observational studies or randomized trials reporting full season or annual influenza infection rates for healthy, working age adult subjects and HCWs were included. Influenza infection was defined as a four-fold rise in antibody titer, or positive viral culture or polymerase chain reaction.From 24,707 citations, 29 studies covering 97 influenza seasons with 58,245 study participants were included. Pooled influenza incidence rates (IR) (95% confidence intervals (CI)) per 100 HCWs per season and corresponding incidence rate ratios (IRR) (95% CI) as compared to healthy adults were as follows. All infections: IR 18.7 (95% CI, 15.8 to 22.1), IRR 3.4 (95% CI, 1.2 to 5.7) in unvaccinated HCWs; IR 6.5 (95% CI, 4.6 to 9.1), IRR 5.4 (95% CI, 2.8 to 8.0) in vaccinated HCWs. Symptomatic infections: IR 7.5 (95% CI, 4.9 to 11.7), IRR 1.5 (95% CI, 0.4 to 2.5) in unvaccinated HCWs, IR 4.8 (95% CI, 3.2 to 7.2), IRR 1.6 (95% CI, 0.5 to 2.7) in vaccinated HCWs.ConclusionsCompared to adults working in non-healthcare settings, HCWs are at significantly higher risk of influenza.

Protective efficacy of a trivalent recombinant hemagglutinin protein vaccine (FluBlok®) against influenza in healthy adults: A randomized, placebo-controlled trial

BackgroundDevelopment of influenza vaccines that do not use embryonated eggs as the substrate for vaccine production is a high priority. We conducted this study to determine the protective efficacy a recombinant, baculovirus-expressed seasonal trivalent influenza virus hemagglutinin (rHA0) vaccine (FluBlok®). MethodsHealthy adult subjects at 24 centers across the US were randomly assigned to receive a single injection of saline placebo (2304 subjects), or trivalent FluBlok containing 45 mcg of each rHA0 component (2344 subjects). Serum samples for assessment of immune responses by hemagglutination-inhibition (HAI) were taken from a subset of subjects before and 28 days after immunization. Subjects were followed during the 2007–2008 influenza season and combined nasal and throat swabs for virus isolation were obtained from subjects reporting influenza-like illness. ResultsRates of local and systemic side effects were low, and the rates of systemic side effects were similar in the vaccine and placebo groups. HAI antibody responses were seen in 78%, 81%, and 52% of FluBlok recipients to the H1, H3, and B components, respectively. FluBlok was 44.6% (95% CI, 18.8%, 62.6%) effective in preventing culture-confirmed influenza meeting the CDC influenza-like illness case definition despite significant antigenic mismatch between the vaccine antigens and circulating viruses. ConclusionsTrivalent rHA0 vaccine was safe, immunogenic and effective in the prevention of culture confirmed influenza illness, including protection against drift variants.

Neuraminidase inhibitors for preventing and treating influenza in healthy adults.

Neuraminidase inhibitors (NI) are recommended for use against influenza and its complications in inter-pandemic years and during pandemics. To assess the effects of NIs in preventing and treating influenza, its transmission, and its complications in otherwise healthy adults, and to estimate the frequency of adverse effects. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 3) which contains the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1950 to August 2009) and EMBASE (1980 to August 2009). Randomised controlled trials (RCTs) or quasi-randomised placebo-controlled trials of NIs in healthy adults exposed to naturally occurring influenza. Two review authors independently applied inclusion criteria, assessed trial quality, and extracted data. We structured the comparisons into prophylaxis, treatment, and adverse events, with further subdivision by outcome and dose. We identified four prophylaxis, 12 treatment and four post-exposure prophylaxis trials. In prophylaxis compared to placebo, NIs had no effect against influenza-like illnesses (ILI) (risk ratio (RR) ranging from 1.28 for oral oseltamivir 75 mg daily to 0.76 for inhaled zanamivir 10 mg daily). The efficacy of oral oseltamivir against symptomatic influenza was 76% (at 75 mg daily), and 73% (at 150 mg daily). Inhaled zanamivir 10 mg daily performed similarly. Neither NI had a significant effect on asymptomatic influenza. Oseltamivir induced nausea (odds ratio (OR) 1.79, 95% CI 1.10 to 2.93). Oseltamivir for post-exposure prophylaxis had an efficacy of 58% and 84% in two trials for households. Zanamivir performed similarly. The hazard ratios for time to alleviation of symptoms were in favour of the treated group 1.20 (1.06 to 1.35) for oseltamivir and 1.24 (1.13 to 1.36) for zanamivir. Because of the exclusion of a review of mainly unpublished trials of oseltamivir, insufficient evidence remained to reach a conclusion on the prevention of complications requiring antibiotics in influenza cases (RR 0.57, 95% CI 0.23 to 1.37). Analysis of the US FDA and Japan's PMDA regulators' pharmacovigilance dataset, revealed incomplete reporting and description of harms preventing us from reaching firm conclusions on the central nervous system toxicity of neuraminidase inhibitors. Numerous inconsistencies detected in the available evidence, followed by an inability to adequately access the data, has undermined confidence in our previous conclusions for oseltamivir. Independent RCTs to resolve these uncertainties are needed.

Neuraminidase inhibitors for preventing and treating influenza in healthy adults

This review was withdrawn from The Cochrane Library Issue 3, 2011 because the results are now out‐of‐date and we realise that the information therein (which has the potential for being used for policy decisions) could be used inappropriately. Please refer to the BMJ article www.bmj.com/content/342/bmj.c7258.full?sid=dc37372f‐dde0‐455c‐8725‐dd188f1fba4d for more information.

Review: Neuraminidase inhibitors relieve influenza symptoms and reduce laboratory-confirmed influenza in healthy adults

Source Citation Jefferson T, Jones M, Doshi P, Del Mar C. Neuraminidase inhibitors for preventing and treating influenza in healthy adults: systematic review and meta-analysis. BMJ. 2009;339:b5106....

Efficacy of Inactivated Split‐Virus Influenza Vaccine against Culture‐Confirmed Influenza in Healthy Adults: A Prospective, Randomized, Placebo‐Controlled Trial

A new trivalent inactivated split-virus influenza vaccine (TIV) was recently introduced in the United States. We assessed the efficacy of TIV against culture-confirmed influenza A and/or B. In this double-blind trial conducted from September 2006 to May 2007 in the Czech Republic and Finland, participants aged 18-64 years were randomized to receive 1 dose of TIV (n = 5103) or placebo (n = 2549). Influenza-like illnesses (ILI) (defined as at least 1 systemic symptom [fever {oral temperature, > or = 37.8 degrees C} and/or myalgia] and at least 1 respiratory symptom [cough and/or sore throat]) were identified by both active (biweekly phone contact) and passive surveillance. Nasal and throat swab specimens were collected for viral culture. The attack rate for culture-confirmed ILI was 3.2% in the placebo group, with most strains identified as influenza A (all except 1 were H3N2) matching the vaccine strain. There were 6 cases of influenza B, all of which were of a different lineage (Yamagata) than the vaccine strain. Vaccine efficacy against culture-confirmed influenza A and/or B due to strains antigenically matched to the vaccine was 66.9% (95% confidence interval [CI], 51.9%-77.4%; P < .001) and to any strain was 61.6% (95% CI, 46.0%-72.8%; P < .001). TIV is efficacious against culture-confirmed influenza in healthy adults. ClinicalTrials.gov identifier: NCT00363870.

Neuraminidase inhibitors for preventing and treating influenza in healthy adults: systematic review and meta-analysis

Objectives To update a 2005 Cochrane review that assessed the effects of neuraminidase inhibitors in preventing or ameliorating the symptoms of influenza, the transmission of influenza, and complications from influenza...