Improved immunogenicity of high-dose influenza vaccine compared to standard-dose influenza vaccine in adult oncology patients younger than 65 years receiving chemotherapy: A pilot randomized clinical trial

Vaccination of Adults With Cancer: ASCO Guideline

PURPOSE

To guide the vaccination of adults with solid tumors or hematologic malignancies.

METHODS

A systematic literature review identified systematic reviews, randomized controlled trials (RCTs), and nonrandomized studies on the efficacy and safety of vaccines used by adults with cancer or their household contacts. This review builds on a 2013 guideline by the Infectious Disease Society of America. PubMed and the Cochrane Library were searched from January 1, 2013, to February 16, 2023. ASCO convened an Expert Panel to review the evidence and formulate recommendations.

RESULTS

A total of 102 publications were included in the systematic review: 24 systematic reviews, 14 RCTs, and 64 nonrandomized studies. The largest body of evidence addressed COVID-19 vaccines.

RECOMMENDATIONS

The goal of vaccination is to limit the severity of infection and prevent infection where feasible. Optimizing vaccination status should be considered a key element in the care of patients with cancer. This approach includes the documentation of vaccination status at the time of the first patient visit; timely provision of recommended vaccines; and appropriate revaccination after hematopoietic stem-cell transplantation, chimeric antigen receptor T-cell therapy, or B-cell-depleting therapy. Active interaction and coordination among healthcare providers, including primary care practitioners, pharmacists, and nursing team members, are needed. Vaccination of household contacts will enhance protection for patients with cancer. Some vaccination and revaccination plans for patients with cancer may be affected by the underlying immune status and the anticancer therapy received. As a result, vaccine strategies may differ from the vaccine recommendations for the general healthy adult population vaccine.Additional information is available at www.asco.org/supportive-care-guidelines.

Systematic review of the efficacy, effectiveness and safety of high-dose seasonal influenza vaccines for the prevention of laboratory-confirmed influenza in individuals ≥18 years of age

This review sought to assess the efficacy, effectiveness and safety of high-dose inactivated influenza vaccines (HD-IIV) for the prevention of laboratory-confirmed influenza in individuals aged 18 years or older. A systematic literature search was conducted in electronic databases and grey literature sources up to 7 February 2020. Randomised controlled trials (RCTs) and non-randomised studies of interventions (NRSIs) were included. The search returned 28,846 records, of which 36 studies were included. HD-IIV was shown to have higher relative vaccine efficacy in preventing influenza compared with standard-dose influenza vaccines (SD-IIV3) in older adults (Vaccine effectiveness (VE) = 24%, 95% CI 10-37, one RCT). One NRSI demonstrated significant effect for HD-IIV3 against influenza B (VE = 89%, 95% CI 47-100), but not for influenza A(H3N2) (VE = 22%, 95% CI -82 to 66) when compared with no vaccination in older adults. HD-IIV3 showed significant relative effect compared with SD-IIV3 for influenza-related hospitalisation (VE = 11.8%, 95% CI 6.4-17.0, two NRSIs), influenza- or pneumonia-related hospitalisation (VE = 13.7%, 95% CI 9.5-17.7, three NRSIs), influenza-related hospital encounters (VE = 13.1%, 95% CI 8.4-17.7, five NRSIs), and influenza-related office visits (VE = 3.5%, 95% CI 1.5-5.5, two NRSIs). For safety, HD-IIV were associated with significantly higher rates of local and systemic adverse events compared with SD-IIV (combined local reactions, pain at injection site, swelling, induration, headache, chills and malaise). From limited data, compared with SD-IIV, HD-IIV were found to be more effective in the prevention of laboratory-confirmed influenza, for a range of proxy outcome measures, and associated with more adverse events.

An Open-label Randomized Controlled Parallel-group Pilot Study Comparing the Immunogenicity of a Standard-, Double-, and Booster-dose Regimens of the 2014 Seasonal Trivalent Inactivated Influenza Vaccine in Kidney Transplant Recipients

BACKGROUND

Immunogenicity of influenza vaccine in transplant recipients is suboptimal and alternative vaccination regimens are necessary.

METHODS

We compared the immunogenicity of a standard-dose trivalent inactivated influenza vaccination (SDTIIV), double-dose trivalent inactivated influenza vaccination (DDTIIV), and booster-dose trivalent inactivated influenza vaccination (BDTIIV) of the 2014 seasonal trivalent inactivated influenza vaccine in kidney transplant recipients. We randomized 176 participants to SDTIIV (59), DDTIIV (59), and BDTIIV regimens (58). Antibody titers were determined by hemagglutination inhibition at enrollment and 21 d postvaccination. Seroprotection rates (SPRs), seroconversion rates (SCRs), and geometric mean ratios (GMRs) were analyzed separately for participants with low (<1:40) and high (≥1:40) prevaccination antibody titers.

RESULTS

Vaccination was confirmed for 172 participants. Immunogenicity analysis was done for 149 participants who provided postvaccination blood samples. In the subgroup with high prevaccination antibody titers, all vaccination regimens induced SPR > 70% to all antigens, but SCR and GMR were below the recommendations. In the subgroup with low prevaccination antibody titers, DDTIIV and BDTIIV regimens induced adequate SCR > 40% and GMR > 2.5 for all antigens, whereas SDTIIV achieved the same outcomes only for influenza B. SPRs were >70% only after DDTIIV (A/H1N1-77.8%) and BDTIIV (A/H3N2-77.8%). BDTIIV regimen independently increased seroprotection to A/H1N1 (PR = 2.58; P = 0.021) and A/H3N2 (PR = 2.21; P = 0.004), whereas DDTIIV independently increased seroprotection to A/H1N1 (PR = 2.59; P = 0.021).

CONCLUSIONS

Our results suggest that DDTIIV and BDTIIV regimens are more immunogenic than SDTIIV, indicating the need for head-to-head multicenter clinical trials to further evaluate their efficacy.

Infection risk and prophylaxis in patients with lymphoid cancer

Infections are a common cause of morbidity and mortality in patients with lymphoid cancer. With evolving cancer therapeutics, including new targeted and immunotherapies, clinicians need to be aware of additional risk factors and infections that may arise in patients treated with these agents. This "How I Treat" article will highlight fundamental issues including risk factors for infection, infectious diseases screenings and antimicrobial prophylaxis recommendations in patients with lymphoid cancers. We present 4 scenarios of patients with lymphoid cancers with varied infections and describe a treatment approach based on a combination of evidence-based data and experience, as there are limitations in objective infection data especially with newer agents. The goal of this discussion is to provide a framework for institutions and health care providers to develop their own approach in preventing and treating infections in patients with lymphoid cancer.

Clinical efficacy and safety of high dose trivalent influenza vaccine in adults and immunosuppressed populations - A systematic review and meta-analysis

OBJECTIVES

Influenza is associated with significant morbidity and mortality, especially in older and immunocompromised patients. Few data are available on the clinical benefit of high dose trivalent influenza vaccine (TIV). We aimed to assess the clinical efficacy and safety of high dose TIV.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs), evaluating high dose versus standard dose TIV for prevention of seasonal influenza in adult population. Primary outcome was laboratory-confirmed influenza. Subgroups analyses included older adults and immunocompromised patients.

RESULTS

We included 16 trials, 47,857 patients; 10 included older adults and three immunocompromised patients. Laboratory confirmed influenza was significantly reduced with high dose TIV (relative risk 0.76, 95% confidence interval 0.64 to 0.9). This outcome stemmed mainly from one trial in older adults. Specifically, A(H3N2) laboratory confirmed influenza, but not A(H1N1) or B lineages, was reduced. No difference in mortality or hospitalizations was demonstrated. Immunological response was significantly higher with high dose vaccine. Serious adverse events were significantly less common in the high dose group.

CONCLUSIONS

High dose TIV lowers the rates of laboratory confirmed influenza, mainly A (H3N2), in older adults vs. standard dose. Further studies should address immunocompromised patients and report clinical outcomes.

Use of High-Dose Influenza and Live Attenuated Influenza Vaccines by US Primary Care Physicians

BACKGROUND

Several different types of influenza vaccine are licensed for use in adults in the USA including high-dose inactivated influenza vaccine (HD-IIV) and live attenuated influenza vaccine (LAIV). HD-IIV is licensed for use in adults ≥ 65 years, and recommendations for use of LAIV have changed several times in recent years.

OBJECTIVE

We sought to examine family physicians' (FPs) and general internal medicine physicians' (GIMs) perceptions, knowledge, and practices for use of HD-IIV and LAIV during the 2016-2017 and 2018-2019 influenza seasons.

DESIGN

E-mail and mail surveys conducted February-March 2017, January-February 2019.

PARTICIPANTS

Nationally representative samples of FPs and GIMs.

MAIN MEASURES

Surveys assessed HD-IIV practices (2017), knowledge and perceptions (2019), and LAIV knowledge and practices (2017, 2019).

KEY RESULTS

Response rates were 67% (620/930) in 2017 and 69% (642/926) in 2019. Many physicians believed HD-IIV is more effective than standard dose IIV in patients ≥ 65 years (76%) and reported their patients ≥ 65 years believe they need HD-IIV (67%). Most respondents incorrectly thought ACIP preferentially recommends HD-IIV for adults ≥ 65 years (88%); 65% "almost always/always" recommended HD-IIV for adults ≥ 65 years. Some physicians incorrectly thought ACIP preferentially recommends HD-IIV for adults < 65 years with cardiopulmonary disease (38%) or immunosuppression (48%); some respondents recommended HD-IIV for these groups (25% and 28% respectively). In 2017, 88% of respondents knew that ACIP recommended against using LAIV during the 2016-2017 influenza season, and 4% recommended LAIV to patients. In 2019, 63% knew that ACIP recommended that LAIV could be used during the 2018-2019 influenza season, and 8% recommended LAIV.

CONCLUSIONS

Many physicians incorrectly thought ACIP had preferential recommendations for HD-IIV. Physicians should be encouraged to use any available age-appropriate influenza vaccine to optimize influenza vaccination particularly among older adults and patients with chronic conditions who are more vulnerable to severe influenza disease.

Analysis of MarketScan Data for Immunosuppressive Conditions and Hospitalizations for Acute Respiratory Illness, United States

Increasing use of immunosuppressive biologic therapies poses a challenge for infectious diseases. Immunosuppressed patients have a high risk for influenza complications and an impaired immune response to vaccines. The total burden of immunosuppressive conditions in the United States, including those receiving emerging biologic therapies, remains unknown. We used the national claims database MarketScan to estimate the prevalence of immunosuppressive conditions and risk for acute respiratory illnesses (ARIs). We studied 47.2 million unique enrollees, representing 115 million person-years of observation during 2012–2017, and identified immunosuppressive conditions in 6.2% adults 18–64 years of age and 2.6% of children <18 years of age. Among 542,105 ARI hospitalizations, 32% of patients had immunosuppressive conditions. The risk for ARI hospitalizations was higher among enrollees with immunosuppression than among nonimmunosuppressed enrollees. Future efforts should focus on developing improved strategies, including vaccines, for preventing influenza in immunosuppressed patients, who are an increasing population in the United States.

Immunogenicity and safety of high-dose versus standard-dose inactivated influenza vaccine in rheumatoid arthritis patients: a randomised, double-blind, active-comparator trial

BACKGROUND

Patients with rheumatoid arthritis have increased risk of seasonal influenza and influenza-related complications but have reduced vaccine immunogenicity. It is unknown whether patients with rheumatoid arthritis would benefit from more immunogenic vaccine formulations. This study investigated the immunogenicity and safety of a high-dose trivalent inactivated influenza vaccine (HD-TIV) in patients with rheumatoid arthritis compared to a standard-dose quadrivalent influenza vaccine (SD-QIV).

METHODS

This study was a treatment-stratified, randomised, double-blind trial to compare the immunogenicity and safety of SD-QIV (15 μg of haemagglutinin [HA] per strain) versus HD-TIV (60 μg of HA per strain) in adults with rheumatoid arthritis who are positive for rheumatoid factor or anti-cyclic citrullinated peptide, or both, recruited during the 2016-17 and 2017-18 influenza seasons at three hospitals affiliated with McGill University (Montreal, QC, Canada). Participants had received treatment for rheumatoid arthritis with conventional or targeted synthetic disease-modifying antirheumatic drugs (DMARDs) or biological DMARDs, or combinations of them, were still on treatment at the time of enrolment, and their treatment had not been modified during the 3 months before enrolment. They were stratified into one of three groups according to treatment. Patients who, at enrolment, were taking conventional or targeted synthetic DMARDs (methotrexate, hydroxychloroquine, and sulfasalazine) as monotherapy or in combination were stratified to group 1; those who were taking a biological DMARD (anti-tumour necrosis factor or anti-interleukin 6), with or without methotrexate, hydroxychloroquine, or sulfasalazine (or a combination thereof) were stratified to group 2; and those who were taking abatacept, tofacitinib, or rituximab, with or without methotrexate, hydroxychloroquine, or sulfasalazine (or a combination thereof) were stratified to group 3. Participants were randomly allocated (1:1) to receive the SD-QIV or HD-TIV vaccine. Randomisation was based on a computer-generated allocation sequence, and participants, investigators, and research nurses responsible for safety assessments were masked to vaccine assignment. The primary outcome was the seroconversion rate (as measured by haemagglutination-inhibition assay) per strain at day 28. Analysis was done in the modified intention-to-treat population, which included all randomly assigned participants for whom seroconversion status was available. Safety was assessed throughout the surveillance period (day 0-186). This trial is registered at ClinicalTrials.gov, number NCT02936180.

FINDINGS

Between Oct 24, 2016, and Dec 6, 2017, 696 patients with rheumatoid arthritis were invited to participate in the study and 279 were randomly assigned and vaccinated (140 [50%] received SD-QIV and 139 [50%] HD-TIV). 136 patients who received SD-QIV and 138 who received HD-TIV were included in the modified intention-to-treat anaysis. Patients who received HD-TIV were more likely to seroconvert than those who received SD-QIV: the odds ratio was 2·99 (95% CI 1·46-6·11) for seroconversion to strain A/H3N2, 1·95 (1·19-3·22) for seroconversion to strain B/Bris, 3·21 (1·57-6·56) for seroconversion to strain A/H1N1 (in 2016-2017), and 2·44 (1·18-5·06) for seroconversion to strain A/H1N1 (in 2017-2018). Similar results were observed in patients from groups 1 and 2; the number of individuals in group 3 was insufficient to draw conclusions. Local and systemic adverse events were similar in both vaccine groups, no serious adverse events were reported between days 0 and 28 in any group, and neither vaccine increased rheumatoid arthritis disease activity.

INTERPRETATION

Our data suggest that in patients with seropositive rheumatoid arthritis, HD-TIV is safe and more immunogenic than SD-QIV. These results are the first evidence to support the use of the HD-TIV in these patients.

FUNDING

The Arthritis Society-Canada.

Influenza vaccine strategies for solid organ transplant recipients

PURPOSE OF REVIEW

The aim of this study was to highlight recent evidence on important aspects of influenza vaccination in solid organ transplant recipients.

RECENT FINDINGS

Influenza vaccine is the most evaluated vaccine in transplant recipients. The immunogenicity of the vaccine is suboptimal after transplantation. Newer formulations such as inactivated unadjuvanted high-dose influenza vaccine and the administration of a booster dose within the same season have shown to increase response rates. Intradermal vaccination and adjuvanted vaccines did not show clear benefit over standard influenza vaccines. Recent studies in transplant recipients do not suggest a higher risk for allograft rejection, neither after vaccination with a standard influenza vaccine nor after the administration of nonstandard formulation (high-dose, adjuvanted vaccines), routes (intradermally) or a booster dose. Nevertheless, influenza vaccine coverage in transplant recipients is still unsatisfactory low, potentially due to misinterpretation of risks and benefits.

SUMMARY

Annual influenza vaccination is well tolerated and is an important part of long-term care of solid organ transplant recipients.

Alternative-Dose versus Standard-Dose Trivalent Influenza Vaccines for Immunocompromised Patients: A Meta-Analysis of Randomised Control Trials

The study compared immunogenicity and safety between alternative higher-dose and standard-dose trivalent vaccines in immunocompromised individuals. A literature search was performed using the PubMed, Embase, and Cochrane databases from inception until March 2019 to identify studies comparing the immunogenicity of alternative higher-dose (including high-dose, double-dose, and booster-dose vaccines) and standard-dose trivalent influenza vaccines in patients who underwent transplantation or chemotherapy. Effect estimates from the individual studies were derived and calculated using the DerSimonian and Laird random-effect model. The protocol for this systematic review is registered with PROSPERO (number CRD42019129220). Eight relevant studies involving 1020 patients were included in the systematic review and meta-analysis. The meta-analysis demonstrated that the higher-dose strategy provided had significantly superior seroconversion and seroprotection for A/H1N1 strains than the standard dose. Regarding H3N2 and B strains, no differences in immunogenicity responses were noted. No differences in safety were observed between the vaccination strategies. Alternative higher-dose vaccination strategies appear to associate with superior immunogenicity responses for A/H1N1 strains, and the strategies were generally well tolerated in immunocompromised populations. Future studies should clarify the optimal timing, frequency and dose of vaccination and assess whether these strategies improve vaccine immunogenicity and clinical outcomes.

Immunogenicity of high-dose trivalent inactivated influenza vaccine: a systematic review and meta-analysis

INTRODUCTION

High-dose trivalent, inactivated, split-virus influenza vaccine (IIV3-HD) has been available in the US since 2009 for adults aged ≥ 65 years. To better understand how IIV3-HD provides improved protection against influenza, we systematically reviewed clinical studies comparing immune responses to IIV3-HD and standard-dose trivalent vaccine (IIV3-SD).

AREAS COVERED

The primary objective was to determine the relative hemagglutination inhibition (HAI) antibody response of IIV3-HD vs. IIV3-SD in adults aged ≥ 65 years. Based on seven randomized studies including more than 18,500 adults aged ≥ 65 years, combined HAI geometric mean titer (GMT) ratios (95% confidence interval) approximately 1 month post-vaccination were 1.74 (1.65-1.83) for influenza A/H1N1, 1.84 (1.73-1.95) for influenza A/H3N2, and 1.47 (1.36-1.58) for influenza B. HAI GMT ratios in these studies were similar irrespective of sex, older age (≥ 75 years), frailty, and underlying conditions. Trends were similar for A/H3N2 neutralization and anti-neuraminidase antibody titers. In immunocompromised individuals, HAI GMT ratios were mostly > 1.

EXPERT OPINION

In agreement with its improved efficacy and effectiveness, IIV3-HD is consistently more immunogenic than IIV3-SD in adults aged ≥ 65 years. IIV3-HD also appears more immunogenic in immunocompromised individuals.

Influenza vaccination of cancer patients during PD-1 blockade induces serological protection but may raise the risk for immune-related adverse events

Background

Immune checkpoint inhibiting antibodies were introduced into routine clinical practice for cancer patients. Checkpoint blockade has led to durable remissions in some patients, but may also induce immune-related adverse events (irAEs). Lung cancer patients show an increased risk for complications, when infected with influenza viruses. Therefore, vaccination is recommended. However, the efficacy and safety of influenza vaccination during checkpoint blockade and its influence on irAEs is unclear. Similarly, the influence of vaccinations on T cell-mediated immune reactions in patients during PD-1 blockade remains poorly defined.

Methods

We vaccinated 23 lung cancer patients and 11 age-matched healthy controls using a trivalent inactivated influenza vaccine to investigate vaccine-induced immunity and safety during checkpoint blockade.

Results

We did not observe significant differences between patients and healthy controls in vaccine-induced antibody titers against all three viral antigens. Influenza vaccination resulted in protective titers in more than 60% of patients/participants. In cancer patients, the post-vaccine frequency of irAEs was 52.2% with a median time to occurrence of 3.2 months after vaccination. Six of 23 patients (26.1%) showed severe grade 3/4 irAEs. This frequency of irAEs might be higher than the rate previously published in the literature and the rate observed in a non-study population at our institution (all grades 25.5%, grade 3/4 9.8%).

Conclusions

Although this is a non-randomized trial with a limited number of patients, the increased rate of immunological toxicity is concerning. This finding should be studied in a larger patient population.

Immunogenicity and reactogenicity of high- vs. standard-dose trivalent inactivated influenza vaccine in healthcare workers: a pilot randomized controlled trial

OBJECTIVES

To compare immunogenicity, reactogenicity and acceptability of high- and standard-dose trivalent inactivated influenza vaccine (HDTIV, SDTIV) in 18- to 64-year-olds.

METHODS

We randomized 18- to 64-year-olds to HDTIV or SDTIV in two consecutive years. We collected serum on days 0 and 21, measured haemagglutination inhibition geometric mean titres (GMT) and compared seroconversion, day 21 titres, seroprotection, reactogenicity and acceptability.

RESULTS

Immunogenicity was evaluable in 42 of 47 2014 participants, all 33 both-year participants and 87 of 90 2015-only participants. First-dose HDTIV recipients experienced seroconversion more frequently than SDTIV recipients to A(H3N2) in 2014 (13/21, 62% vs. 4/21, 19%, p 0.01) and to all vaccine strains in 2015: (A(H1N1): 24/42, 57% vs. 15/59, 25%; A(H3N2): 42/42, 100% vs. 47/59, 80%; B: 25/42, 60% vs. 13/59, 22%; all p <0.01). Day 21 haemagglutination inhibition GMT were higher in first and two sequential-year HDTIV vs. SDTIV recipients: A(H1N1): GMT 749 and 768 vs. 384 (p <0.0001, p 0.002); A(H3N2): 1238 and 956 vs. 633 (p 0.0003, p 0.1); and B: 1113 and 1086 vs. 556 (p 0.0005, p 0.02). HDTIV was more reactogenic (local pain score 3 vs. 1 of 10 on day 0/1, p 0.0003), but recipients were equally willing to be revaccinated (HDTIV: 76/83 (92%); SDTIV: 76/80 (95%), p 0.54). The ratios of day 21 GMT in SDTIV recipients vaccinated in 0 to 4 prior years to those in SDTIV and HDTIV recipients vaccinated in 15 or more prior years were A(H1N1): 3.73 and 1.38; A(H3N2) 3.07 and 1.16; and B: 2.01 and 1.21.

CONCLUSIONS

HDTIV is more immunogenic and reactogenic and as acceptable as SDTIV in 18- to 64-year-olds.

Efficacy and effectiveness of high-dose versus standard-dose influenza vaccination for older adults: a systematic review and meta-analysis

BACKGROUND

Influenza is responsible for a significant disease burden annually, especially in older adults. This study reviews the relative vaccine efficacy or effectiveness (rVE) of high-dose inactivated trivalent influenza vaccine (HD-IIV3) compared to standard-dose influenza vaccines (SD-IIV3) in adults ≥65 against influenza-associated outcomes to inform evidence-based decision-making to shift clinical practice and standard of care in this population.

METHODS

A systematic review was conducted for studies assessing the rVE of HD-IIV3 against probable/laboratory-confirmed influenza-like illness (ILI), hospital admissions, and death in adults ≥65. Results from individual seasons were meta-analyzed and a random-effects model was used to estimate pooled rVEs.

RESULTS

After screening 992 studies, seven studies were meta-analyzed. HD-IIV3 demonstrated better protection against ILI compared to SD-IIV3 (rVE = 19.5%; 95% CI: 8.6-29.0%). HD-IIV3 was also more effective at preventing hospital admissions from all-causes (rVE = 9.1%; 95% CI: 2.4-15.3%), as well as from influenza (rVE = 17.8%; 95% CI: 8.1-26.5%), pneumonia (rVE = 24.3%, 95% CI: 13.9-33.4%), and cardiorespiratory events (rVE = 18.2%; 95% CI: 6.8-28.1%). rVE against post-influenza mortality was 22.2% (95% CI: -18.2-48.8%) and 2.5% (95% CI: -5.2-9.5%) against all-cause mortality.

CONCLUSIONS

Available evidence suggests HD-IIV3 is more effective than SD-IIV3 at reducing the clinical outcomes associated with influenza infection in older adults and should be considered for routine use in the 65+ population.

Seasonal influenza vaccine in immunocompromised persons

Immunocompromised persons are at high risk of complications from influenza infection. This population includes those with solid organ transplants, hematopoietic stem cell transplants, solid cancers and hematologic malignancy as well as those with autoimmune conditions receiving biologic therapies. In this review, we discuss the impact of influenza infection and evidence for vaccine effectiveness and immunogenicity. Overall, lower respiratory disease from influenza is common; however, vaccine immunogenicity is low. Despite this, in some populations, influenza vaccine has demonstrated effectiveness in reducing severe disease. Various strategies to improve influenza vaccine immunogenicity have been attempted including two vaccine doses in the same influenza season, intradermal, adjuvanted, and high-dose vaccines. The timing of influenza vaccine is also important to achieve optimal immunogenicity. Given the suboptimal immunogenicity, family members and healthcare professionals involved in the care of these populations should be vaccinated. Health care professional recommendation for vaccination is an important factor in vaccine coverage.

Influenza vaccines in immunosuppressed adults with cancer

BACKGROUND

This is an update of the Cochrane review published in 2013, Issue 10.Immunosuppressed cancer patients are at increased risk of serious influenza-related complications. Guidelines, therefore, recommend influenza vaccination for these patients. However, data on vaccine effectiveness in this population are lacking, and the value of vaccination in this population remains unclear.

OBJECTIVES

To assess the effectiveness of influenza vaccine in immunosuppressed adults with malignancies. The primary review outcome is all-cause mortality, preferably at the end of the influenza season. Influenza-like illness (ILI, a clinical definition), confirmed influenza, pneumonia, any hospitalisations, influenza-related mortality and immunogenicity were defined as secondary outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and LILACS databases up to May 2017. We searched the following conference proceedings: ICAAC, ECCMID, IDSA (infectious disease conferences), ASH, ASBMT, EBMT (haematological), and ASCO (oncological) between the years 2006 to 2017. In addition, we scanned the references of all identified studies and pertinent reviews. We searched the websites of the manufacturers of influenza vaccine. Finally, we searched for ongoing or unpublished trials in clinical trial registry databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs), prospective and retrospective cohort studies and case-control studies were considered, comparing inactivated influenza vaccines versus placebo, no vaccination or a different vaccine, in adults (16 years and over) with cancer. We considered solid malignancies treated with chemotherapy, haematological cancer patients treated or not treated with chemotherapy, cancer patients post-autologous (up to six months after transplantation) or allogeneic (at any time) haematopoietic stem cell transplantation (HSCT).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risk of bias and extracted data from included studies adhering to Cochrane methodology. Meta-analysis could not be performed because of different outcome and denominator definitions in the included studies.

MAIN RESULTS

We identified six studies with a total of 2275 participants: five studies comparing vaccination with no vaccination, and one comparing adjuvanted vaccine with non-adjuvanted vaccine. Three studies were RCTs, one was a prospective observational cohort study and two were retrospective cohort studies.For the comparison of vaccination with no vaccination we included two RCTs and three observational studies, including 2202 participants. One study reported results in person-years while the others reported results per person. The five studies were performed between 1993 and 2015 and included adults with haematological diseases (three studies), patients following bone marrow transplantation (BMT) (two studies) and solid malignancies (three studies).One RCT and two observational studies reported all-cause mortality; the RCT showed similar mortality rates in both arms (odds ratio (OR) 1.25 (95% CI 0.43 to 3.62; 1 study, 78 participants, low-certainty evidence)); and the observational studies demonstrated a significant association between vaccine receipt and lower risk of death, adjusted hazard ratio 0.88 (95% CI 0.78 to 1; 1 study, 1577 participants, very low-certainty evidence) in one study and OR 0.42 (95% CI 0.24 to 0.75; 1 study, 806 participants, very low-certainty evidence) in the other. One RCT reported a reduction in ILI with vaccination, while no difference was observed in one observational study. Confirmed influenza rates were lower with vaccination in one RCT and the three observational studies, the difference reaching statistical significance in one. Pneumonia was observed significantly less frequently with vaccination in one observational study, but no difference was detected in another or in the RCT. One RCT showed a reduction in hospitalisations following vaccination, while an observational study found no difference. No life-threatening or persistent adverse effects from vaccination were reported. The strength of evidence was limited by the low number of included studies and by their low methodological quality and the certainty of the evidence for the mortality outcome according to GRADE was low to very low.For the comparison of adjuvanted vaccine with non-adjuvanted vaccine, we identified one RCT, including 73 patients. No differences were found for the primary and all secondary outcomes assessed. Mortality risk ratio was 0.54 (95% CI 0.05 to 5.73; low-certainty evidence) in the adjuvanted vaccine group. The quality of evidence was low due to the small sample size and the large confidence intervals for all outcomes.

AUTHORS' CONCLUSIONS

Observational data suggest lower mortality and infection-related outcomes with influenza vaccination. The strength of evidence is limited by the small number of studies and low grade of evidence. It seems that the evidence, although weak, shows that the benefits overweigh the potential risks when vaccinating adults with cancer against influenza. However, additional placebo or no-treatment controlled RCTs of influenza vaccination among adults with cancer is ethically questionable.There is no conclusive evidence regarding the use of adjuvanted versus non-adjuvanted influenza vaccine in this population.

Microarray profile of the humoral immune response to influenza vaccination in breast cancer patients treated with chemotherapy

BACKGROUND

Patients treated with chemotherapy have an impaired response to influenza virus vaccination compared to healthy controls. Little is known about the broadness of the antibody response in these patients.

METHODS

Breast cancer patients on FEC (5-fluorouracil, epirubicin and cyclophosphamide) chemotherapy regimens were vaccinated with influenza virus vaccine. Sera were obtained before and three weeks after vaccination. In addition to the determination of virus-specific antibody titres by hemagglutination inhibition assay, the broadness of the response was assessed by the use of a protein microarray and baseline titres were compared with an age-matched reference group.

RESULTS

We included 38 breast cancer patients and found a wide variety in serum antibody response after vaccination. Patients with a history of influenza vaccination had higher pre-vaccination titres, which were comparable to the reference group. Increasing number of cycles of chemotherapy did not have a negative effect on influenza array antibody levels, nor on the HI antibody response.

CONCLUSIONS

Overall there was a broad serum antibody response to the influenza virus vaccine in patients treated with chemotherapy for breast cancer.

Fluzone® High-Dose Influenza Vaccine

INTRODUCTION

Fluzone® High-Dose (IIV3-HD) is a trivalent, inactivated, split-virus influenza vaccine indicated for use in older adults (≥65 years of age). It contains 60 µg hemagglutinin of each influenza strain, which is four times the hemagglutinin content of standard-dose influenza vaccines, including Fluzone (IIV3-SD). IIV3-HD has been licensed for use in older adults in the US since December 2009 and in Canada since February 2016. Areas covered: In this review, we summarize postlicensure studies on the immunogenicity, safety, and effectiveness of IIV3-HD and estimates of its cost-effectiveness in older adults. We also discuss the potential application of IIV3-HD in adults 50-64 years of age and in individuals who may respond poorly to standard-dose influenza vaccines. Expert commentary: Multiple studies conducted since 2004 have consistently shown that, in older adults, IIV3-HD induces substantially greater antibody responses and better protection against influenza and influenza-associated hospitalization than IIV3-SD. Health economic analyses suggest that IIV3-HD can be a cost-effective alternative to standard-dose trivalent or quadrivalent inactivated influenza vaccines and can even be cost-saving compared to IIV3-SD in older adults. Further investigation of IIV3-HD vaccination as a way to improve immune responses and protection against influenza in immunocompromised individuals is warranted.