Doses Of Influenza Vaccine Research Articles

Vaccine complacency and dose distribution inequities limit the benefits of seasonal influenza vaccination, despite a positive trend in use

Sustainable demand for seasonal influenza vaccines is a component of national security strategies for pandemic preparedness. However, the ongoing COVID-19 pandemic has revealed many weaknesses in the capacity of countries to design and execute sustainable vaccination programs. An influenza pandemic remains a global threat and yet there is no global monitoring system for assessing progress towards influenza vaccination coverage targets. The International Federation of Pharmaceutical Manufacturers and Associations’ (IFPMA) Influenza Vaccine Supply International Task Force (IVS) developed a survey method in 2008 to estimate seasonal influenza vaccination coverage rates, which in turn serves as a crude estimate of pandemic preparedness. It provides evidence to guide expanded efforts for pandemic preparedness, specifically for increasing COVID-19 vaccine immunization levels. Furthermore, the results presented herein serve as a proxy for assessing the state of pandemic preparedness at a global and regional level. This paper adds data from 2018 and 2019 to the previous analyses. The current data show an upward or stable global trend in seasonal influenza vaccine dose distributed per 1,000 population with a 7% increase between 2017 and 2018 and 6% increase between 2018 and 2019. However, considerable regional inequities in access to vaccine persist. Three regions, Africa, the Middle-east, and Southeast Asia together account for 50% of the global population but only 6% of distributed seasonal influenza vaccine doses. This is an important finding in the context of the ongoing COVID-19 pandemic, as distribution of influenza vaccine doses in many ways reflects access to COVID-19 vaccines. Moreover, improving seasonal vaccine uptake rates is critical for optimizing the annual benefits by reducing the huge annual influenza-associated societal burdens and by providing protection to vulnerable individuals against serious complications from seasonal influenza infections.

An evaluation of an influenza vaccination campaign targeting pregnant women in 27 clinics in two provinces of South Africa, 2015 \u2013 2018

IntroductionDespite prioritization, routine antenatal influenza vaccine coverage is < 16% in South Africa. We aimed to describe maternal influenza vaccine coverage in 27 antenatal clinics (ANCs) in Gauteng and Western Cape (WC) Provinces, where in collaboration with the Department of Health (DoH), we augmented the annual influenza vaccination programme among pregnant women.MethodsFrom 2015 through 2018, 40,230 additional doses of influenza vaccine were added to the available stock and administered as part of routine antenatal care. Educational talks were given daily and data were collected on women attending ANCs. We compared characteristics of vaccinated and unvaccinated women using multivariable logistic regression.ResultsWe screened 62,979 pregnant women during the period when Southern Hemisphere influenza vaccines were available (27,068 in Gauteng and 35,911 in WC). Vaccine coverage at the targeted clinics was 78.7% (49,355/62682), although pregnant women in WC were more likely to be vaccinated compared to those in the Gauteng (Odds ratio (OR) =3.7 p < 0.001). Women aged 25—29 and > 35 years were less likely to be vaccinated than women aged 18—24 years (OR = 0.9 p = 0.053; OR = 0.9 p < 0.001). HIV positive status was not associated with vaccination (OR = 1.0 p = 0.266). Reasons for not vaccinating included: vaccine stock-outs where ANCs depleted available stock of vaccines and/or were awaiting delivery of vaccines (54.6%, 6949/12723), refusal/indecision (25.8%, 3285), and current illness that contraindicated vaccination (19.6%, 2489).ConclusionAntenatal vaccination uptake was likely improved by the increased vaccine supply and vaccine education offered during our campaign.

Identification of sensitive indicators in immune response for leprosy affected patients: An observational clinical study of safety and immunogenicity of influenza vaccine.

Cured leprosy patients have special physical conditions, which could pose challenges for safety and immunogenicity after immunization. We performed an observational clinical study aimed to identify the safety and immunogenicity of influenza vaccine in cured leprosy patients. A total of 65 participants from a leprosarium were recruited into leprosy cured group or control group, and received a 0.5 ml dose of the inactivated split-virion trivalent influenza vaccine and a follow-up 28 days proactive observation of any adverse events. Hemagglutination and hemagglutination inhibition test was performed to evaluate serum antibody titer, flow cytometry was conducted to screen of cytokines level. The total rate of reactogenicity was 0.0% [0/41] in leprosy cured group and 37.5% [9/24] in control group. The seroconversion rate for H1N1 was difference between leprosy cured group and control group (41.83% vs 79.17%, P = .0082), but not for H3N2 (34.25% vs 50.00%, P = .4468). At day 0, leprosy cured group have relatively high concentration of interleukin-6, interleukin-10, tumor necrosis factor, interferon-γ, and interleukin-17 compared to control group. The interleukin-2 concentration increased 2 weeks after vaccination compared to pre-vaccination in leprosy cured group, but declined in control group (0.92 pg/ml vs −0.02 pg/ml, P = .0147). Leprosy cured group showed a more rapid down-regulation of interleukin-6 when influenza virus was challenged compared to control group (−144.38 pg/ml vs −11.52 pg/ml, P < .0001). Subgroup analysis revealed that the immunization administration declined interleukin-17 concentration in Tuberculoid type subgroup, but not in Lepromatous type subgroup or control group. Clinically cured leprosy patients are relatively safe for influenza vaccine. Leprosy cured patient have immune deficit in producing antibody. Interleukin-6 and interleukin-17 were 2 sensitive indicators in immune response for leprosy affected patients. The identification of indicators might be help management of leprosy and used as predictive markers in leprosy early symptom monitoring.

The Potential Role of Patient Portals to Improve Influenza Vaccination.

* Abbreviation: COVID-19 — : coronavirus disease 2019 Each year, before 2020, millions of children contracted influenza virus.1 From 2020 to 2021, protective measures to prevent the spread of coronavirus disease 2019 (COVID-19), such as mask wearing, social distancing, and frequent hand-washing, likely protected children from other infectiousdiseases, including seasonal influenza.2 However, as COVID-19 preventive measures begin to abate and children return to school and normal activities outside the home, the seasonal influenza will again be a threat to young children nationally. Children under 18 years of age are twice as likely to develop symptoms as adults over age 65 years, and those under 4 years of age are over 3 times as likely.1 Young children, especially those under 5 years old, are at the highest risk for severe illness and death from influenza.1,3 Children are also key drivers of transmission, on average spreading influenza to multiple age groups and for longer periods than adults.4 Influenza vaccination is still the best method of preventing influenza and its associated complications. Influenza vaccine should be given to children starting at age 6 months, and 2 doses of influenza vaccine, administered 28 days apart, should be given to a child under age 9 years if they have not previously received 2 doses during an influenza season. Previous studies have shown the importance of both doses, especially in vaccine-naive children. For example, in vaccine-naive children aged 2 years or younger, vaccine effectiveness is cut … Address correspondence to Melissa S. Stockwell, MD, MPH, Division of Child and Adolescent Health, Department of Pediatrics, Vagelos College of Physicians & Surgeons, Columbia University, 622 W 168th St, VC 417, New York, NY 10032. E-mail: mss2112{at}cumc.columbia.edu

Effect of processed aloe vera gel on immunogenicity in inactivated quadrivalent influenza vaccine and upper respiratory tract infection in healthy adults: A randomized double-blind placebo-controlled trial

BackgroundAloe vera is a functional food with various pharmacological functions, including an immune-modulating effect. Until now, A. vera has never been studied as an adjuvant in influenza vaccine, and its effects on upper respiratory tract infection (URI) are unknown. PurposeThe objective of our study was to investigate the effect of processed A. vera gel (PAG) on immunogenicity of quadrivalent inactivated influenza vaccine and URI in healthy adults. Study designA randomized, double-blind, placebo-controlled clinical trial was performed. MethodsThis study was conducted in 100 healthy adults at a single center from September 2017 to May 2018. Subjects were randomly divided into a PAG group (n = 50) and a placebo group (n = 50). The enrolled subjects were instructed to ingest the study drug for 8 weeks. The participants received a single dose of quadrivalent inactivated influenza vaccine after taking the study drug for the first 4 weeks of the study. The primary endpoint was seroprotection rate against at least one viral strain at 4 weeks post-vaccination. Other outcomes were seroprotection rate at 24 weeks post-vaccination, seroconversion rate, geometric mean fold increase (GMFI) at 4 and 24 weeks post-vaccination, seroprotection rate ratio and geometric mean titer ratio (GMTR) at 4 weeks post-vaccination between PAG and placebo groups, and incidence, severity, and duration of URI. ResultsThe European Committee for proprietary medicinal products (CPMP) evaluation criteria were met at least one in the PAG and placebo groups for all strains. However, there was no significant difference in the seroprotection rate at 4 weeks post-vaccination against all strains in both PAG and placebo groups. Among secondary endpoints, the GMFI at 4 weeks post-vaccination for the A/H3N2 was significantly higher in the PAG than in placebo group. The GMTR as adjuvant effect was 1.382 (95% CI, 1.014-1.1883). Kaplan–Meier curve analysis showed a reduction in incidence of URI (p = 0.035), and a generalized estimating equation model identified a decrease in repeated URI events (odds ratio 0.57; 95% CI, 0.39-0.83; p = 0.003) in the PAG group. ConclusionsOral intake of PAG did not show a significant increase in seroprotection rate from an immunogenicity perspective. However, it reduced the number of URI episodes. A well-designed further study is needed on the effect of PAG's antibody response against A/H3N2 in the future.

Sex differences in antibody responses to the 23-valent pneumococcal polysaccharide vaccination

There are profound sex-based differences in both humoral and cellular immune responses to vaccination.1 In general, women have higher antibody responses to bacterial and viral vaccines than men.2 For instance, women vaccinated with half the dose of the trivalent inactivated influenza vaccine produce similar humoral immune responses than men vaccinated with a full dose of the vaccine.3 Given that the 23-valent pneumococcal polysaccharide vaccine (PPSV23) is an important tool in our evaluation of the humoral immune response,4 we sought to reveal whether men and women have a different immunoglobulin G (IgG) antibody response to PPSV23.

The Case for Mandating COVID-19 Vaccines for Health Care Workers.

The Case for Mandating COVID-19 Vaccines for Health Care Workers.

WITHDRAWN: Author response to a Letter to the Editor on “Introductory paper: High dose influenza vaccine”

This article has been withdrawn at the request of the editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal .

Enrolling a rural community pharmacy as a Vaccines for Children provider to increase HPV vaccination: a feasibility study

BackgroundHuman papillomavirus (HPV) is the most common sexually transmitted infection in the U.S. with over 80 million infected individuals. High-risk strains are associated with 6 different cancers. Although infection is preventable, U.S. vaccination rates remain suboptimal and there are noted disparities between urban and rural communities due to economic barriers, lack of access, and low awareness and education.MethodsThe current pilot study sought to overcome these barriers through an interprofessional collaborative enrolling a community pharmacy in a rural, medically underserved Alabama county as a Vaccines for Children (VFC) provider to provide free vaccines to eligible adolescents. Program evaluation was conducted to determine the intervention’s feasibility. Potential efficacy was assessed by analyzing county-level HPV vaccination uptake and completion rates using state immunization registry data.ResultsOver the 8-month study, 166 total vaccines were administered to 89 adolescents ages 10–18, including 55 doses of HPV vaccine, 53 doses of Tdap vaccine, 45 doses of meningococcal vaccine, and 13 doses of influenza vaccine. Among these adolescents, mean age was 12.6 years old, and 64 (71.9%) were VFC patients. The pharmacy recorded an increase in total vaccine administration of 158.8%, an increase in prescription revenue of 34.8%, and an increase in total revenue by 24.4% during the course of the study, compared to the previous year.ConclusionsFindings from the current work demonstrate the potential of this strategy and can serve as a blueprint for statewide and national dissemination and implementation to ultimately increase access to vaccination services, increase vaccination rates, and reduce urban-rural vaccine disparities.

Two Dose Series of High-Dose Influenza Vaccine Is Associated with Longer Duration of Serologic Immunity in Patients with Plasma Cell Disorders

Background:Patients with plasma cell disorders (PCDs) are highly susceptible to infections, including influenza, which are a major source of morbidity. Seasonal influenza vaccination is routinely administered to patients with PCDs, yet influenza infections remain common. Combining the use of higher antigen dose and a booster strategy, we recently reported a randomized study of a two dose series of high-dose influenza vaccine, which was associated with fewer influenza infections than standard influenza vaccination in patients with PCDs (Branagan, et al, ASH 2016). However, the immunologic effects following this vaccination strategy remains unknown. Few studies have focused on serologic responses to influenza vaccination in PCD patients and there are none to the authors' knowledge which have measured longitudinal serologic responses over a single flu season.Methods:We conducted a double-blind, randomized clinical trial over the 2015-16 flu season, comparing two doses of Fluzone® High-Dose influenza vaccination (separated by 30 days) to standard of care influenza vaccination. Patients were allocated to the experimental arm in 2:1 ratio. Standard of care influenza vaccination was considered single age-based vaccination (standard dose <65 years and high-dose ≥ 65 years) and patients in this arm received a saline placebo injection at 30 days to assist in blinding. Eligibility criteria allowed any patient with a plasma cell disorder and no contraindication to trivalent inactivated influenza vaccine. HAI titers were analyzed by standardized procedure at four time points, baseline, 30 days following the initial vaccine, 30 days following the second vaccine, and at the end of the flu season (April 30).Results:122 total plasma cell disorder patients were enrolled (97 with disease requiring therapy and 25 with asymptomatic gammopathy). Forty-eight patients received a single standard of care influenza vaccination and 74 patients received two doses of Fluzone High-Dose vaccine. Median age was 67 years (range 42-90). Following the second vaccine / placebo, rates of total seroprotection (against all 3 influenza vaccine strains) were 86.3% for patients who received two high dose vaccines and 63.9% for standard vaccination patients. At the end of the flu season, rates of total seroprotection were 58.5% for patients who received two high dose vaccines and 33.3% for standard vaccination patients. Chi-square testing revealed that patients receiving the two dose vaccine strategy experienced significantly higher rates of total seroprotection following second vaccine (p<0.05). At the end of the flu season rates of seroprotection trended toward significance at the end of the flu season against all 3 vaccine strains (p=0.07), against the H3N2 strain (p=0.05) and were significantly higher against the H1N1 strain (p<0.05).Conclusions:We previously reported that a two dose strategy of Fluzone® High-Dose influenza vaccine is safely tolerated in patients with plasma cell disorders and associated with fewer laboratory-confirmed influenza infections. Unexpectedly, the current analysis revealed that protective HAI antibody titers rapidly fall in PCD patients. Typically, HAI titers slowly decrease following a peak protective response, but do not drop below protective levels until after 6 months. However, PCD patients in this study began to lose HAI seroprotection within 4 months and even as little as 30 days. Interestingly, patients who received the two dose series of high-dose influenza vaccine maintained higher rates of seroprotection at the end of the influenza season compared to those who received standard vaccination. The maintenance of seroprotection was greatest against the seasonal H1N1 strain (which was the predominate circulating strain during that particular 2015-2016 flu season). Importantly, these results suggest that a two dose series of high-dose vaccine provides may mitigate loss of vaccine-induced HAI titers and allow more durable serologic protection throughout the flu season. Studies are ongoing to further explore immune function following influenza vaccination, including cell-mediated responses. More studies are warranted to help determine the optimal dose and timing of influenza vaccination in PCD patients. Understanding the unique kinetics of serologic responses in PCD patients may have practice changing implications for other vaccines and therapies in this population. DisclosuresNo relevant conflicts of interest to declare.

Vaccine response following anti-CD20 therapy: a systematic review and meta-analysis of 905 patients

AbstractThe objective of this study was to perform a systematic review of the literature on vaccine responsiveness in patients who have received anti-CD20 therapy. PubMed and EMBASE were searched up to 4 January 2021 to identify studies of vaccine immunogenicity in patients treated with anti-CD20 therapy, including patients with hematologic malignancy or autoimmune disease. The primary outcomes were seroprotection (SP), seroconversion (SC), and/or seroresponse rates for each type of vaccine reported. As the pandemic influenza vaccine (2009 H1N1) has standardized definitions for SP and SC, and represented a novel primary antigen similar to the COVID-19 vaccine, meta-analysis was conducted for SC of studies of this vaccine. Pooled estimates, relative benefit ratios (RBs), and 95% confidence intervals (CIs) were calculated using a random-effects model. Thirty-eight studies (905 patients treated with anti-CD20 therapy) were included (19 studies of patients with hematologic malignancies). Patients on active (<3 months since last dose) anti-CD20 therapy had poor responses to all types of vaccines. The pooled estimate for SC after 1 pandemic influenza vaccine dose in these patients was 3% (95% CI, 0% to 9%), with an RB of 0.05 (95% CI, 0-0.73) compared with healthy controls and 0.22 (95% CI, 0.09-0.56) compared with disease controls. SC compared with controls seems abrogated for at least 6 months following treatment (3-6 months post anti-CD20 therapy with an RB of 0.50 [95% CI, 0.24-1.06] compared with healthy and of 0.44 [95% CI, 0.23-0.84] compared with disease controls). For all vaccine types, response to vaccination improves incrementally over time, but may not reach the level of healthy controls even 12 months after therapy.

Antibody Response and Protection After Receipt of Inactivated Influenza Vaccine: A Systematic Review.

Children are at increased risk of influenza-related complications. Public health agencies recommend 2 doses of influenza vaccine for children 6 months through 8 years of age receiving the vaccine for the first time. To systematically review studies comparing vaccine effectiveness (VE) and immunogenicity after 1 or 2 doses of inactivated influenza vaccine (IIV) in children. Data sources included Medline, Embase, and Cochrane Library databases. We included studies published in a peer reviewed journal up to April 2, 2019, with available abstracts, written in English, and with children aged 6 months through 8 years. VE among fully and partially vaccinated children was compared with that of unvaccinated children. We extracted geometric mean titers of serum hemagglutination inhibition (HAI) antibodies against influenza A(H1N1), A(H3N2), and B-lineage vaccine antigens after 1 and 2 IIV doses. Outcomes were evaluated by age, timing of doses, vaccine composition, and prevaccination titers. A total of 10 VE and 16 immunogenicity studies were included. VE was higher for fully vaccinated groups than partially vaccinated groups, especially for children aged 6-23 months. Our findings show increased HAI titers after 2 doses, compared with 1. Older children and groups with prevaccination antibodies have robust HAI titers after 1 dose. Similar vaccine strains across doses, not the timing of doses, positively affects immune response. Few studies focused on older children. Researchers typically administered one-half the standard dose of IIV. HAI antibodies are an imperfect correlate of protection. Findings support policies recommending 2 IIV doses in children to provide optimal protection against influenza.

Immunogenicity of trivalent seasonal influenza vaccine in patients with chronic obstructive pulmonary disease

ABSTRACT Objective: Current evidence on the immunogenicity of influenza vaccination in patients with chronic obstructive pulmonary disease (COPD) is limited. To address this need for additional knowledge, we conducted a study on the immunogenicity of trivalent seasonal influenza vaccine (TIV) in COPD patients. Methods: We recruited patients from respiratory outpatient clinics of three hospitals in Tangshan, Hebei province who had stable confirmed COPD, were less than 80 y old, and reported not having had influenza or receiving TIV during the study season prior to enrollment. Patients who had a history of allergy to any TIV component or were classified as having very severe COPD were excluded from the study. Eligible and consenting participants were given one dose of TIV after obtaining a baseline blood sample. A second blood sample was obtained 5 weeks later. We used hemagglutination inhibition (HI) assays to measure antibody responses. We considered seropositive to be an HI titer ≥1:10. We considered seroprotection to be an HI titer ≥1:40 and seroconversion to be either a change from seronegative to a post-vaccination titer of ≥1:40 or a fourfold rise in antibody titer among baseline seropositive subjects. Each subject was followed for 1 month to assess the frequency and type of adverse events. Results: Eighty-eight subjects completed our study; the median age was 64 y; most (62.5%) had moderately severe COPD; 48.9% of the subjects had comorbid conditions in addition to COPD. Post–vaccination seropositive rates for influenza H1N1, H3N2, and B were all 100%; corresponding seroprotection rates were 96.6%, 93.2%, and 98.9%; seroconversion rates were 81.8%, 87.5%, and 75.0%. There were no statistical differences in seroconversion (P = .10) and seroprotection (P = .30) among the three types of influenza virus. Geometric mean titers (1:) of HI antibodies to H1N1, H3N2, and B were 18.8 (95% CI: 14.0–25.1), 12.2 (95% CI: 9.6–15.4), and 31.8 (95% CI: 26.1–38.8) at baseline, and 267.0 (95% CI: 213.8–333.4), 190.3 (95% CI: 151.7–238.6), and 201.1 (95% CI: 166.5-242.8) after vaccination. Conclusion: The immunogenicity of one dose of influenza vaccine was excellent in COPD patients. Our study supports recommending influenza vaccination for COPD patients to provide protection from influenza and its complications.

Factors associated with influenza vaccination acceptance in Mexican healthcare workers: A multicenter cross-sectional study

Adherence of healthcare workers (HCWs) to influenza vaccination is far from optimal despite its being the most effective intervention for preventing influenza. In order to evaluate factors associated with influenza vaccination acceptance among Mexican HCWs during the 2017–2018 influenza season, a multicenter cross-sectional study spanning public and private hospitals was conducted. Participants were consecutively invited to answer a self-administered questionnaire. A total of 1513 out of 1553 questionnaires were evaluated. The median age of the participants was 32 (26–44) years and 65.8% were women. Nurses and physicians comprised 53.0% of the surveyed population. Total self-reported adherence to influenza vaccination among HCWs during the 2017–2018 season was 63.5% and varied across participating hospitals (P < 0.001). Factors positively associated with influenza vaccination were incremental doses of influenza vaccine received within the last 5 years (aOR = 1.94, 95% CI = 1.78–2.10), City 3 (aOR = 1.62, 95% CI = 1.19–2.20) and City 1 (aOR = 1.39, 95% CI = 1.02–1.91), whereas factors negatively associated were lack of a previous dose of influenza vaccine (aOR = 0.03, 95% CI = 0.01–0.08) and unawareness of the vaccination campaign (aOR = 0.57, 95% CI = 0.44–0.72). Lack of information and poor communication were barriers identified by both vaccinated and unvaccinated personnel. This study concluded that adherence to influenza vaccination in Mexican HCWs is suboptimal and that the factors associated with receipt of influenza vaccine are similar to those reported in other studies.

Seasonal influenza campaign 2020 in the context of SARS-CoV-2 pandemic: an unprecedented public health experience in Chile

In Chile, the Immunization Department of the Ministry of Health has carried out the seasonal influenza vaccination campaign annually since 1982 in collaboration with the national health services, regional health offices, and primary health care centres. With the aim of preventing deaths and serious morbidity in high-risk groups and preserving the integrity of health services, the seasonal influenza campaign had been the largest implemented in Chile until 2020, since in 2021 the vaccination campaign against SARS-CoV-2 is expected to become the largest ever implemented. In response to local demographic and epidemiological changes, and taking into account the new scientific evidence on the safety and immunogenicity of vaccines, the influenza vaccines available in Chile would increase annually as a result of campaign planning. In 2020, the influenza campaign had to be re-planned while in progress due to the addition of new high-risk groups to be vaccinated in accordance with the SARS-CoV-2 pandemic health alert modification of March 6th, 2020. Over the course of three weeks, the Immunization Department managed to increase the doses of available influenza vaccines from 6,799,800 previously agreed upon to 8,480,325 and thus serve high-risk groups, guaranteeing their access to state funded influenza vaccination.

Mapping the inequality of the global distribution of seasonal influenza vaccine

With an estimated annual worldwide death toll of between 290 000 and 650 000, seasonal influenza remains one of the deadliest respiratory diseases. Influenza vaccines provide moderate to high protection and have been on the World Health Organization’s Model List of Essential Medicines since 1979. Approximately 490 million doses of influenza vaccine are produced per year, but an investigation of geographic allocation reveals enormous disparities. Here, we present two maps that visualise the inequality of the distribution across 195 countries: a conventional choropleth map and a cartogram. In combination, these two maps highlight the widespread lack of coverage in Africa and many parts of Asia. As COVID-19 vaccines are now being distributed in developed countries, data for seasonal influenza vaccine distribution emphasises the need for policymakers to ensure equitable access to COVID-19 vaccines.

Safety and immunogenicity of high doses of quadrivalent influenza vaccine in children 6 months through

Quadrivalent high-dose inactivated influenza vaccine (Fluzone® High-Dose Quadrivalent, IIV4-HD) was licensed in the USA in 2019 for adults ≥ 65 years of age. This Phase II study examined safety and immunogenicity of 3 dose formulations of IIV4-HD in healthy children. In a randomized, modified double-blind, active-controlled trial in the USA and Canada, 661 children aged 6 months through < 18 years received 1 or 2 doses intramuscularly of standard-dose quadrivalent influenza vaccine (IIV4-SD; 15 µg HA/strain), IIV4-HD at 3 dose levels (30, 45, and 60 µg HA/strain), or adjuvanted trivalent influenza vaccine (aIIV3, 7.5 µg HA/strain). Rates of unsolicited AEs were similar irrespective of dose. No treatment-related serious adverse events or deaths were reported. Reactogenicity was slightly higher for IIV4-HD than IIV4-SD, although most solicited reactions were grade 1 or 2. Hemagglutination inhibition (HAI) and seroneutralization antibody titers were measured 28–35 days after each dose. Geometric mean HAI titers increased with increasing hemagglutinin dose, especially in children 6 months through < 3 years. For IIV4-HD 60 µg, in participants 6 months through < 18 years of age, the geometric mean titer ratio (95% confidence interval) versus IIV4-SD was 1.35 (0.94, 1.94) for A/H1N1, 2.51 (1.77, 3.55) for A/H3N2, 1.60 (1.17, 2.18) for B/Victoria, and 1.51 (1.13, 2.03) for B/Yamagata. The GMT ratio (95% confidence interval) for IIV4-HD 60 µg versus IIV4-SD was highest for participants 6 months through < 3 years of age: 4.24 (2.05, 8.76) for A/H1N1, 3.14 (1.53, 6.44) for A/H3N2, 2.04 (1.10, 3.77) for B/Victoria, and 1.92 (1.08, 3.41) for B/Yamagata; similarly, seroneutralization antibody GMT ratio was highest in these participants: 170 (84.6, 340) for A/H1N1, 7.13 (4.90, 10.4) for A/H3N2, 35.8 (22.1, 58.1) for B/Victoria, and 22.7 (14.7, 35.0) for B/Yamagata. This study showed that IIV4-HD (60 µg HA/strain) provides improved immunogenicity without affecting vaccine safety in children.

Racial disparities in influenza vaccination

Racial disparities in influenza vaccination

EASL position paper on the use of COVID-19 vaccines in patients with chronic liver diseases, hepatobiliary cancer and liver transplant recipients

According to a recent World Health Organization estimate, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, which originated in China in 2019, has spread globally, infecting nearly 100 million people worldwide by January 2021. Patients with chronic liver diseases (CLD), particularly cirrhosis, hepatobiliary malignancies, candidates for liver transplantation, and immunosuppressed individuals after liver transplantation appear to be at increased risk of infections in general, which in turn translates into increased mortality. This is also the case for SARS-CoV-2 infection, where patients with cirrhosis, in particular, are at high risk of a severe COVID-19 course. Therefore, vaccination against various pathogens including SARS-CoV-2, administered as early as possible in patients with CLD, is an important protective measure. However, due to impaired immune responses in these patients, the immediate and long-term protective response through immunisation may be incomplete. The current SARS-CoV-2 pandemic has led to the exceptionally fast development of several vaccine candidates. A small number of these SARS-CoV-2 vaccine candidates have already undergone phase III, placebo-controlled, clinical trials in healthy individuals with proof of short-term safety, immunogenicity and efficacy. However, although regulatory agencies in the US and Europe have already approved some of these vaccines for clinical use, information on immunogenicity, duration of protection and long-term safety in patients with CLD, cirrhosis, hepatobiliary cancer and liver transplant recipients has yet to be generated. This review summarises the data on vaccine safety, immunogenicity, and efficacy in this patient population in general and discusses the implications of this knowledge on the introduction of the new SARS-CoV-2 vaccines.

Influenza Vaccine Effectiveness in Mainland China: A Systematic Review and Meta-Analysis.

Influenza endangers human health but can be prevented in part by vaccination. Assessing influenza vaccine effectiveness (VE) provides scientific evidence for developing influenza vaccination policy. We conducted a systematic review and meta-analysis of studies that evaluated influenza VE in mainland China. We searched six relevant databases as of 30 August 2019 to identify studies and used Review Manager 5.3 software to analyze the included studies. The Newcastle–Ottawa scale was used to assess the risk of publication bias. We identified 1408 publications, and after removing duplicates and screening full texts, we included 21 studies in the analyses. Studies were conducted in Beijing, Guangzhou, Suzhou, and Zhejiang province from the 2010/11 influenza season through the 2017/18 influenza season. Overall influenza VE for laboratory confirmed influenza was 36% (95% CI: 25–46%). In the subgroup analysis, VE was 45% (95% CI: 18–64%) for children 6–35 months who received one dose of influenza vaccine, and 57% (95% CI: 50–64%) who received two doses. VE was 47% (95% CI: 39–54%) for children 6 months to 8 years, and 18% (95% CI: 0–33%) for adults ≥60 years. For inpatients, VE was 21% (95% CI: −11–44%). We conclude that influenza vaccines that were used in mainland China had a moderate effectiveness, with VE being higher among children than the elderly. Influenza VE should be continuously monitored in mainland China to provide evidence for policy making and improving uptake of the influenza vaccine.