Safety and immunogenicity of 2010-2011 H1N12009-containing trivalent inactivated influenza vaccine in children 12-59 months of age previously given AS03-adjuvanted H1N12009 pandemic vaccine: a PHAC/CIHR Influenza Research Network (PCIRN) study

Background

Concern arose in 2010 that reactogenicity, particularly febrile seizures, to influenza A/H1N1-containing 2010–2011 trivalent seasonal inactivated influenza vaccine (TIV) could occur in young children who had been previously immunized and/or infected with the pandemic strain. We conducted a pre-season study of 2010–2011 TIV safety and immunogenicity in children 12–59 months of age to inform public health decision making.

Methods

Children immunized with 1 or 2 doses of the pandemic vaccine, with or without the 2009–10 TIV, received 1 or 2 doses of 2010–11 TIV in an observational, multicentre Canadian study. Standard safety monitoring was enhanced by a telephone call at ∼24 h post-TIV when adverse events were expected to peak. Summary safety reports were rapidly reported to public health before the launch of public programs. TIV immunogenicity was assessed day 0, and 21 days after final vaccination. Clinical Trials Registration NCT01180621.

Results

Among 207 children, a general adverse event was reported by 60.9% of children post-dose one and by 58.3% post-dose two. Only severe fever (>38.5 °C) was more common in two-dose compared to one dose recipients (16.7%, n = 4 v. 1.0%, n = 2). At baseline 99.0% of participants had A/H1N1 hemagglutinin inhibition (HAI) titers ≥10, and 85.5% had a protective titer of ≥40 (95% CI 80.0, 90.0). Baseline geometric mean titers (GMT) were higher in recipients of a 2-dose schedule of pandemic vaccine compared to one-dose recipients: 153.1 (95% CI 126.2, 185.7) v. 78.8 ((58.1, 106.8, p < 0.001). At 21 days, all regulatory criteria for influenza vaccine immunogenicity were exceeded for A/H1N1 and H3N2, but responses to the B antigen were poor. No correlations between reactogenicity and either baseline high influenza titers or serologic response to revaccination were evident.

Conclusions

Infants and toddlers who received AS03-adjuvanted A/H1N1 2009 vaccine up to 11 months earlier retained high titers in the subsequent season but re-exposure to A/H1N1 2009 antigen in TIV resulted in no unusual adverse effects and 100% were sero-protected for A/H1N1 after receipt of the 2010–11 TIV.     

Safety and efficacy of a novel microneedle device for dose sparing intradermal influenza vaccination in healthy adults

Background

Intradermal vaccine delivery has been shown to induce good immune responses with low vaccine doses. Technologies for drug-delivery which specifically target the skin may render intradermal vaccination more accessible.

Methods

We conducted a prospective, randomized trial in 180 intended-to-treat healthy adults. Study objectives were to evaluate the safety and immunogenicity of low-dose intradermal (ID) influenza vaccines delivered using a novel microneedle device (MicronJet). This device replaces a conventional needle, and is designed specifically for intradermal delivery.Subjects were randomly assigned to receive either the full-dose standard flu shot (containing 15 μg hemagglutinin per strain) delivered intramuscularly using a conventional needle (IM group), a medium dose intradermal injection (6 μg hemagglutinin per strain) delivered with the MicronJet (ID2 group), or a low-dose intradermal injection (3 μg hemagglutinin per strain) delivered with the MicronJet (ID1 group). A marketed influenza vaccine for the 2006/2007 influenza season (α-RIX^® by GSK Biologicals) was used for all injections.Adverse events were recorded over a 42-day period. Immunogenicity was evaluated by changes in hemagglutination inhibition (HAI) antibody titer, and by comparing geometric mean titers (GMTs), seroconversion, and seroprotection rates between the study groups.

Results

Local reactions were significantly more frequent following intradermal vaccination, but were mild and transient in nature. At 21 days after injection, GMT fold increase was 22, 18 and 22 in the ID1, ID2 and IM groups respectively for the H1N1 strain; 9, 9 and 16 for the H3N2 strain and 9, 13 and 11 for strain B. The CPMP criteria for re-licensure of seasonal influenza vaccines were met in full for all study groups.

Conclusions

Low-dose influenza vaccines delivered intradermally using microneedles elicited immunogenic responses similar to those elicited by the full-dose intramuscular vaccination. The microneedle injection device used in this study was found to be effective, safe, and reliable.     

A randomised, single-blind, dose-range study to assess the immunogenicity and safety of a cell-culture-derived A/H1N1 influenza vaccine in adult and elderly populations

Background

Modern cell-culture production techniques and the use of adjuvants helps to ensure that the global demand for pandemic influenza vaccine can be met. This study aimed to assess the immunogenicty and safety profiles of various cell-culture-derived A/H1N1 pandemic vaccine formulations in healthy adult and elderly subjects.

Methods

Adult (18–60 years) subjects (n = 544) received vaccine either containing 3.75 μg of antigen with half the standard dose of MF59^® (Novartis Vaccines and Diagnostics) adjuvant, 7.5 μg antigen with a full dose of MF59, or a non-adjuvanted vaccine containing 15 μg of antigen. Elderly (≥61 years) subjects (n = 268) received either the 3.75 μg or 7.5 μg adjuvanted formulations. Two priming vaccine doses were administered 3 weeks apart, followed by a single booster dose of seasonal influenza vaccine 1 year later. Immunogenicity was assessed 3 weeks after each vaccination. The safety profile of each formulation was evaluated throughout the study.

Results

A single primary dose of each A/H1N1 vaccine formulation was sufficient to meet all three European (CHMP) licensure criteria for pandemic influenza vaccines in adult subjects. Two licensure criteria were met after one vaccine dose in elderly subjects; two primary doses were required to meet all three criteria in this age group. The highest antibody titres were observed in response to the 7.5 μg vaccine containing a full dose of MF59 adjuvant. All subjects rapidly generated seroprotective antibody titres in response to booster vaccination.

Conclusion

This study identified one 3.75 μg vaccine dose containing half the standard dose of MF59 adjuvant as optimal for adults, two doses were optimal for elderly subjects. The antigen-sparing properties of MF59, and rapid, modern, cell-culture production techniques represent significant steps towards meeting the global demand for influenza vaccine.     

Intradermal influenza vaccination in immunocompromized patients is immunogenic and feasible

Background

Many strategies, including intradermal vaccination, have been tested to augment antibody responses upon vaccination. This strategy has not been evaluated in different groups of immunocompromized patients. We conducted a prospective, randomized study to compare the humoral response upon standard intramuscular influenza vaccination with the response upon reduced-dose intradermal vaccination in patients treated with anti-tumor necrosis factor (TNF)-alpha, human immunodeficiency virus (HIV)-infected patients, hematologic stem cell transplantation (HSCT) patients, and healthy controls.

Methods

In total 156 immunocompromized patients and 41 healthy controls were randomized to receive either 0.5 mL of the 2005/2006 trivalent influenza vaccine intramuscular or 0.1 mL intradermal. Humoral responses, determined by hemagglutination inhibition assay, were measured before and 28 days postvaccination. Geometric mean titers (GMTs) and protection rates (PRs) are reported as primary outcomes, adverse events as a secondary outcome.

Results

Reduced-dose intradermal vaccination leads to similar GMTs and PRs, within all tested groups, compared to the standard intramuscular vaccination. Healthy controls yielded significantly better GMTs and PRs than immunocompromized patients. Local skin reactions after intradermal vaccination occurred less frequent and were milder in immunocompromized patients than in healthy subjects and were predictive for a positive vaccination outcome for individual subjects.

Conclusions

Intradermal influenza vaccination is a feasible alternative for standard intramuscular vaccination in several groups of immunocompromized patients, including those treated with anti-TNF, HIV-infected patients and HSCT patients. The occurrence of a local skin reaction after intradermal vaccination is predictive of a response to at least one of the vaccine antigens.     

Correlates of 2009 H1N1 influenza vaccination among day care-aged children, Miami-Dade County

Background

The aim of this study was to assess factors influencing 2009 H1N1 influenza vaccination among a demographically diverse group of day care-aged children. Day care children were chosen because they were an initial target group for vaccination and are at higher risk of influenza infection than children cared for at home.

Methods

A cross-sectional study was conducted from March to May 2010 among parents of day care aged children in 13 day care facilities in Miami-Dade County. Data was collected by an anonymous self-administered two-page 20 question survey which consisted of demographic variables and information regarding 2009 H1N1 influenza vaccine knowledge, attitude and acceptance. Data was analyzed using SAS to conduct both bivariate and multivariate analyses.

Results

There were 773 participants in the study. The response rate ranged from 42% to 72.2% among day care centers. A total of 172 parents (22.3%) and 225 (29.1%) children had received the 2009 H1N1 influenza vaccine. Non-Hispanic White and Black parents were more likely to vaccinate their children than Hispanic and Haitian parents. Primary reasons for non-vaccination included vaccine safety (36.7%) and side effects (27.1%). Among parents who spoke with a health care professional, 274 (61.4%) stated the health care professional recommended the vaccine.

Conclusion

Misperceptions about influenza vaccination among parents created a barrier to 2009 H1N1 influenza vaccination. Parents who got the vaccine, who believed the vaccine was safe and whose children had a chronic condition were more likely to immunize their children. Clear, reliable and consistent vaccine information to the public and health care providers and initiatives targeting minority groups may increase vaccination coverage among this population.     

Pre-vaccination immunity and immune responses to a cell culture-derived whole-virus H1N1 vaccine are similar to a seasonal influenza vaccine

Background

Immune responses to novel pandemic influenza vaccines may be influenced by previous exposure to antigenically similar seasonal strains.

Methods

An open-label, randomized, phase I/II study was conducted to assess the immunogenicity and safety of a non-adjuvanted, inactivated whole-virus H1N1 A/California/07/2009 vaccine. 408 subjects were stratified by age (18–59 and >60 years) and randomized 1:1 to receive two vaccinations with either 3.75 or 7.5 μg hemagglutinin antigen 21 days apart. Safety, immunogenicity and the influence of seasonal influenza vaccination and antibody cross-reactivity with a seasonal H1N1 strain was assessed.

Results

A single vaccination with either dose induced substantial increases in H1N1 A/California/07/2009 hemagglutination inhibition (HI) and neutralizing (MN) antibody titers in both adult and elderly subjects. A single 7.5 μg dose induced seroprotection rates of 86.9% in adults and 75.2% in elderly subjects. Two 7.5 μg vaccinations induced seroprotection rates in adult and elderly subjects of 90.9% and 89.1%, respectively. The robust immune response to vaccination was confirmed by analyses of neutralizing antibody titers. Both HI and MN antibodies persisted for ≥6 months post-vaccination. Between 34% and 49% of subjects had seroprotective levels of H1N1 A/California/07/2009 antibodies at baseline. Higher baseline HI titers were associated with receipt of the 2008–09 or 2009–10 seasonal influenza vaccine. High baseline A/California/07/2009 neutralizing antibody titers were also associated with high baseline titers against A/New Caledonia/20/99, a seasonal H1N1 strain which circulated and was included in the seasonal vaccine from 2000–01 to 2006–07. Pre-adsorption with A/H1N1/New Caledonia/20/99 antigen reduced A/H1N1/California/07/2009 baseline titers in 55% of tested sera. The vaccine was well tolerated with low rates of fever.

Conclusions

A whole-virus H1N1 A/California/07/2009 vaccine was safe and well tolerated and a single dose induced substantial immune responses similar to seasonal influenza vaccines, probably due to immunological priming by previous seasonal influenza vaccines or infections.     

Safety and immunogenicity of an MF59(®)-adjuvanted A/H5N1 pre-pandemic influenza vaccine in adults and the elderly

Background

The potential consequences of an avian influenza pandemic warrants the development of safe, highly immunogenic pre-pandemic A/H5N1 vaccines with cross-clade protection. In this randomized, controlled study we compared the immunogenicity and safety of an MF59^®-adjuvanted (Novartis Vaccines, Marburg, Germany) A/H5N1 pre-pandemic vaccine with that of a licensed, MF59-adjuvanted, seasonal influenza vaccine.

Methods

Healthy adult (18–60 years, n = 3372) and elderly (≥61 years, n = 275) volunteers received either an initial dose of a licensed, non-adjuvanted, trivalent, seasonal influenza vaccine (Agrippal^®) on Day 1, followed by one dose of MF59-H5N1 study vaccine on Day 22 and a second dose of MF59-H5N1 on Day 43, or alternatively, placebo on Day 1 followed by one dose of MF59-adjuvanted seasonal reference vaccine on Day 22 and a second dose of reference vaccine on Day 43. Homologous and cross-reactive A/H5N1 antibody responses were analysed by haemagglutination inhibition (HI), single radial haemolysis (SRH), and microneutralization (MN) assays three weeks after each vaccination. Vaccine safety was assessed throughout the study.

Results

Analysis by HI assay found that two doses of MF59-H5N1 resulted in a seroconversion rate of 56% and a geometric mean ratio (GMR) of 7.1 in adult subjects. Similar results were observed on analysis by SRH (GMR 4.03; seroconversion 78% and seroprotection 91%) and MN (seroconversion 67%) assays. These data met the European licensure criteria for influenza vaccines. No significant difference in immunogenicity was detected between the adult and elderly populations. Anti-A/H5N1 cross-clade antibodies were detected by SRH, 49% of adult and 32% of elderly subjects achieved seroconversion after the second vaccine dose. Overall, MF59-H5N1 containing 7.5 μg antigen was less reactogenic than the MF59-adjuvanted trivalent seasonal vaccine which contained 15 μg antigen for each component strain.

Conclusions

Two doses of MF59-H5N1 vaccine were well tolerated and induced adequate levels of seroprotection against homologous and cross-clade A/H5N1 virus. These data support the suitability of MF59-adjuvanted A/H5N1 vaccine for pre-pandemic use in adults and the elderly.     

Health care professionals’ awareness of,knowledge about and attitude to influenza vaccination

Objectives

Influenza vaccination is recommended to all health care professionals (HCPs). However, vaccination rate among HCPs is low and may be due to uncertainty about the effectiveness of the vaccine and fear of its adverse effects. Therefore, this study aimed to investigate the awareness, knowledge, and attitude of HCPs towards influenza vaccination and we ascertain reasons for not getting vaccinated.

Method

A cross-sectional conducted in 6 major hospitals in Saudi Arabia. 245 anonymous questionnaires were distributed to a convenient sample of staff during the 2012–2013 influenza season. The validated questionnaire consists of five sections that collect information about: demographics, attitude towards influenza vaccination, knowledge about influenza virus and vaccination, current practice and awareness of published guidelines.

Results

242 completed questionnaires were received, a response rate of 98%. 38% of HCPs reported getting vaccinated. The most common reasons given by HCPs for not getting vaccinated were: fear of contracting illness (16%), belief that they are not at risk from influenza because they are young and healthy (13%) and being unaware of vaccine availability (13%). Non-availability of vaccine (43%) was the highest barrier for not providing vaccine for patients and HCPs followed by safety concerns for the patients (35%) and the respondents (33%). Almost 75% of HCPs were not aware of the influenza immunization guidelines published by the Advisory Committee on Immunization Practices and Centre for Disease Control.

Conclusion

Despite the recommendations, only low percentage of HCPs in Saudi Arabian hospitals is vaccinated against influenza. The attention of health policy makers is needed to improve compliance of HCPs with guidelines on influenza vaccination.     

Clinical effectiveness of pneumococcal polysaccharide vaccine in men: California Men's Health Study

Objective

To examine the effectiveness of pneumococcal polysaccharide vaccine (PPV) among approximately 40,000 community-dwelling men aged 45 years and older in the California Men's Health Study (CMHS) cohort.

Methods

All participants completed an extensive questionnaire at baseline (2002–2003) and were followed for the occurrence of invasive pneumococcal disease (IPD) or all-cause pneumonia hospitalization through the end of 2009. Immunization status and incident IPD and pneumonia cases were ascertained through electronic medical records. The associations between vaccination and IPD or pneumonia hospitalization were assessed using time-dependent Cox proportional models to account for sociodemographics, time-updated vaccination status, and comorbidities.

Results

The median follow-up period of the 39,222 participants was 7.3 years. Among them, 11,902 (30.3%) had received at least one PPV vaccine at baseline and 7653 (19.5%) received their first PPV vaccine during the follow-up. There were 17 pneumococcal bacteremia cases, 647 hospitalized pneumonia cases, and no pneumococcal meningitis cases. The results suggested a reduced risk of pneumococcal bacteremia among men vaccinated at age ≥65 (adjusted hazard ratio [HR]: 0.35; 95% confidence interval [CI]: 0.06–1.91; p = 0.22). PPV vaccination did not show a protective effect against all-cause pneumonia hospitalization (adjusted HR: 1.18; 95% CI: 1.02–1.37, p = 0.03) among men vaccinated before 65 years old, but a moderate protective effect was suggested among men without chronic obstructive pulmonary diseases who were vaccinated after 65 years old (adjusted HR: 0.84; 95% CI: 0.67–1.06, p = 0.15).

Conclusions

The findings in this large cohort of men in Southern California suggested a benefit of PPV for protection against pneumococcal bacteremia among men vaccinated at age 65 years and older. PPV might not provide adequate protection against all-cause pneumonia hospitalization among men.     

Knowledge,attitudes and vaccination coverage of healthcare workers regarding occupational vaccinations

Objectives

Immunization of healthcare workers (HCWs) is a major issue for infection control in healthcare facilities. The aim of this study was to evaluate knowledge regarding occupational vaccinations, HBV, varicella and influenza vaccination rates and attitudes towards influenza vaccine among HCWs.

Design and setting

A cross-sectional survey was conducted in two wards (Medicine and Paediatrics) of a 1182-bed teaching hospital in Paris, France.

Methods

A standardized, anonymous, self-administered questionnaire was used.

Results

Of 580 HCWs, 395 (68%) completed the questionnaire. Knowledge about the occupational vaccinations of HCWs was low. HBV (69%), tuberculosis (54%) and influenza (52%) were the most cited vaccinations. Paediatric staff was more aware of influenza and pertussis immunizations (p < .05). HBV vaccination rate was 93%, among whom 65% were aware of their immune status. Influenza vaccination rate for 2006–2007 was 30% overall, ranging from 50% among physicians to 20% among paramedical staff (p < .05). Physicians based their refusal on doubts about vaccine efficacy, although paramedics feared side effects. Influenza vaccination was associated with knowledge of vaccine recommendations [OR = 1.75, 95% CI: 1.13–2.57] and contact with patients [OR = 3.05, 95% CI: 1.50–5.91].

Conclusions

Knowledge of recommended occupational vaccinations is insufficient in HCWs, except for HBV and influenza. Although the HBV vaccine coverage of HCWs is satisfactory, a large proportion of them is unaware of immune status. Influenza vaccine coverage remains low, especially among paramedical staff because of fear of side effects. As vaccine coverage is associated with knowledge, educational campaigns should be strengthened to increase the adhesion of HCWs to vaccinations.     

Health and economic impact of the seasonal influenza vaccination programme in England

Background

The seasonal influenza vaccination programme in England targets individuals over 65 years old and in clinical risk groups.

Methods

A model of influenza transmission and disease was fitted to weekly primary care consultations due to influenza in a typical pre-pandemic season (2006/2007). Different scenarios were constructed about influenza severity and how well vaccines match circulating strains to assess the impact and cost-effectiveness of the current vaccination programme.

Results

A well-matched vaccine may reduce the incidence of laboratory-confirmed influenza illness from 8.2% (95% range 4.3–13%) to 5.9% (95% range 2.9–9.7%), with 56–73% of this due to indirect protection. The programme is likely to be cost-effective unless both low severity and poor matching is assumed.

Conclusion

The current seasonal influenza vaccination programme appears to substantially reduce disease burden and provides good value for money.     

Factors mediating seasonal and influenza A (H1N1) vaccine acceptance among ethnically diverse populations in the urban south

Objective

We examined the acceptability of the influenza A (H1N1) and seasonal vaccinations immediately following government manufacture approval to gauge potential product uptake in minority communities. We studied correlates of vaccine acceptance including attitudes, beliefs, perceptions, and influenza immunization experiences, and sought to identify communication approaches to increase influenza vaccine coverage in community settings.

Methods

Adults ≥18 years participated in a cross-sectional survey from September through December 2009. Venue-based sampling was used to recruit participants of racial and ethnic minorities.

Results

The sample (N = 503) included mostly lower income (81.9%, n = 412) participants and African Americans (79.3%, n = 399). Respondents expressed greater acceptability of the H1N1 vaccination compared to seasonal flu immunization (t = 2.86, p = 0.005) although H1N1 vaccine acceptability was moderately low (38%, n = 191). Factors associated with acceptance of the H1N1 vaccine included positive attitudes about immunizations [OR = 0.23, CI (0.16, 0.33)], community perceptions of H1N1 [OR = 2.15, CI (1.57, 2.95)], and having had a flu shot in the past 5 years [OR = 2.50, CI (1.52, 4.10). The factors associated with acceptance of the seasonal flu vaccine included positive attitudes about immunization [OR = 0.43, CI (0.32, 0.59)], community perceptions of H1N1 [OR = 1.53, CI (1.16, 2.01)], and having had the flu shot in the past 5 years [OR = 3.53, CI (2.16, 5.78)]. Participants were most likely to be influenced to take a flu shot by physicians [OR = 1.94, CI (1.31, 2.86)]. Persons who obtained influenza vaccinations indicated that Facebook (χ² = 11.7, p = 0.02) and Twitter (χ² = 18.1, p = 0.001) could be useful vaccine communication channels and that churches (χ² = 21.5, p < 0.001) and grocery stores (χ² = 21.5, p < 0.001) would be effective “flu shot stops” in their communities.

Conclusions

In this population, positive vaccine attitudes and community perceptions, along with previous flu vaccination, were associated with H1N1 and seasonal influenza vaccine acceptance. Increased immunization coverage in this community may be achieved through physician communication to dispel vaccine conspiracy beliefs and discussion about vaccine protection via social media and in other community venues.     

Assessment of the immunogenicity and safety of varying doses of an MF59®-adjuvanted cell culture-derived A/H1N1 pandemic influenza vaccine in Japanese paediatric, adult and elderly subjects

Introduction

Effective vaccination strategies are required to combat future influenza pandemics. Here we report the results of three independent clinical trials performed in Japan to assess the immunogenicity, tolerability and safety of varying doses of a cell culture-derived MF59^®-adjuvanted A/H1N1 pandemic vaccine in healthy Japanese paediatric, adult and elderly subjects.

Methods

One hundred and twenty-three children (6 months–18 years), and 200 adults (19–60 years) were randomly assigned in a 1:1 ratio to receive two doses of vaccine containing either 7.5 μg antigen with a full (9.75 mg) adjuvant dose, or 3.75 μg antigen with a half (4.875 mg) adjuvant dose. One hundred elderly (≥61 years) subjects received only the low antigen/adjuvant vaccine formulation. Immunogenicity was assessed by haemagglutination inhibition assay at baseline and three weeks after the first and second vaccine doses on Days 22 and 43, respectively. Solicited and unsolicited adverse reactions were recorded for seven and 21 days post-immunization, respectively.

Results

In adult and elderly subjects, a single low antigen/adjuvant dose vaccination was sufficient to meet all of the three European licensure criteria established for influenza vaccines. One high, or two low antigen/adjuvant dose vaccinations were required to meet the licensure criteria in paediatric subjects. Both vaccine formulations were well tolerated, with the majority of adverse reactions mild to moderate in severity. None of the five serious adverse events reported throughout the three trials were considered to be vaccine-related by the investigators.

Conclusion

The use of MF59 adjuvant allows for much reduced vaccine antigen content, and a single dose administration schedule in adults and the elderly. The production of pandemic vaccine using modern cell culture techniques is highly advantageous in terms of the quantity, quality, and rapidity of antigen production; these benefits, in combination with the use of MF59, maximize manufacturing capacity and global vaccine supply. These data support the suitability of the investigational vaccine for use in the Japanese paediatric, adult, and elderly populations.     

A qualitative study of HPV vaccine acceptability among health workers, teachers, parents, female pupils, and religious leaders in northwest Tanzania

Background

As human papillomavirus (HPV) vaccines become available in developing countries, acceptability studies can help to better understand potential barriers and facilitators of HPV vaccination and guide immunisation programs.

Methods

Prior to a cluster-randomised phase IV trial of HPV vaccination delivery strategies in Mwanza Region, Tanzania, qualitative research was conducted to assess attitudes and knowledge about cervical cancer and HPV, and acceptability of and potential barriers to HPV vaccination of Tanzanian primary schoolgirls. Semi-structured interviews (n = 31) and group discussions (n = 12) were conducted with a total of 169 respondents (parents, female pupils, teachers, health workers and religious leaders).

Results

While participants had heard of cancer in general, most respondents had no knowledge of cervical cancer, HPV, or HPV vaccines. Only health workers had heard of cervical cancer but very few knew its cause or had any awareness about HPV vaccines. After participants were provided with information about cervical cancer and HPV vaccination, the majority stated that they would support HPV vaccination of their daughter to protect them against cervical cancer. Opt-out consent for vaccination was considered acceptable. Most preferred age-based vaccination, saying this would target more girls before sexual debut than class-based vaccination. Potential side effects and infertility concerns were raised by 5/14 of participating male teachers.

Discussion

Reported acceptability of HPV vaccination amongst parents, teachers and other community members was high in this population. Respondents stressed the need to provide adequate information about the vaccine to parents, that also addresses side effects and infertility concerns.     

Barriers to and facilitators of child influenza vaccine - perspectives from parents, teens, marketing and healthcare professionals

Background

The CDC recommends annual influenza vaccination for all children age 6 months and older, yet vaccination rates remain modest. Effective strategies to improve influenza vaccination for children are needed.

Methods

Eight focus groups with 91 parents, teens, pediatric healthcare staff and providers, and immunization and marketing experts were conducted, audiotaped, transcribed verbatim, and coded based on grounded theory.

Results

Three themes emerged: barriers, facilitators, and strategies. Barriers included fear, misinformation, and mistrust, with exacerbation of these barriers attributed to media messages. Many considered influenza vaccination unnecessary and inconvenient, but would accept vaccination if recipients or other family members were considered high risk, if recommended by their doctor or another trusted person, or if offered or mandated by the school. Access to better information regarding influenza disease burden and vaccine safety and efficacy were notable facilitators, as were prevention of the inconvenience of missing work or important events, and if the child requests to receive the vaccine. Marketing strategies included incentives, jingles, videos, wearable items, strategically-located information sheets or posters, and promotion by informed counselors. Practice-based strategies included staff buy-in, standing orders protocols, vaccination clinics, and educational videos. Teen-specific strategies included message delivery through schools, texting, internet, and social networking sites.

Conclusion

To improve influenza vaccination rates for children using practice-based interventions, participants suggested campaigns that provide better information regarding the vaccine, the disease and its implications, and convenient access to vaccination. Strategies targeting adolescents should use web-based social marketing technologies and campaigns based in schools.     

Influenza vaccination and risk of hospitalization among adults with laboratory confirmed influenza illness

Background

Influenza vaccine is moderately effective for preventing influenza illness. It is not known if vaccination reduces the risk of subsequent hospital admission among patients with vaccine failure and laboratory confirmed influenza illness.

Methods

Patients in a community cohort presenting with acute respiratory illness were prospectively enrolled and tested for influenza during 8 seasons to estimate seasonal vaccine effectiveness. Hospital admissions within 14 days after illness onset were identified for all participants aged ≥20 years with laboratory confirmed influenza. The association between vaccination and hospital admission was examined in a propensity score adjusted logistic regression model. The model was validated by examining the association between vaccination and hospital admission in participants without influenza.

Results

Influenza was identified in 1393 (28%) of 4996 participants. Sixty-two (6%) of 1020 with influenza A and 17 (5%) of 369 with influenza B were hospitalized. Vaccination was not associated with a reduced risk of hospital admission among all participants with influenza [adjusted odds ratio (aOR) = 1.08; 95% CI: 0.62, 1.88]; or among those with influenza A (aOR = 1.35; 95% CI: 0.71, 2.57) or influenza B (aOR = 0.67; 95% CI: 0.21, 2.15). Influenza vaccination was not associated with hospitalization after non-influenza respiratory illness (aOR = 1.14; 95% CI: 0.84, 1.54).

Conclusions

Influenza vaccination did not reduce the risk of subsequent hospital admission among patients with vaccine failure. These findings do not support the hypothesis that vaccination mitigates influenza illness severity.     

Influenza vaccination uptake amongst pregnant women and maternal care providers is suboptimal

Objective

To assess the uptake of influenza vaccination by pregnant women and maternity care providers and explore their attitudes towards influenza vaccination.

Design, setting and participants

Cross-sectional survey administered in a Victorian tertiary level public hospital to 337 pregnant women and 96 maternity care providers.

Results

31.3% of patients planned to or had received influenza vaccination this year, but only a quarter had received education about influenza. Women were more likely to receive influenza vaccination if they had been vaccinated in the last two years (RR 4.5, 95% CI: 3.1–6.4, p < 0.001), received education about influenza (RR 2.3, 95% CI: 1.6–3.2, p < 0.001) or believed that they were at high risk of influenza-related complications while pregnant (RR 2.0, 95% CI: 1.4–2.7, p < 0.001). While only 56.8% of maternity care providers believed pregnant women were at high risk of influenza-related complications, 72.9% would recommend influenza vaccination to all pregnant women. Of the maternity care providers studied, 69% planned to or had been vaccinated in 2011, with this group more likely to recommend vaccination to their patients (RR 2.0, 95% CI: 1.3–3.0, p < 0.001). Significantly more maternity care providers indicated that they would routinely recommend influenza vaccination than the proportion of patients who reported receiving education.

Conclusions

Influenza vaccination rates in pregnant women are low, reflecting inadequate patient education despite most maternity care providers indicating that they would routinely recommend influenza vaccination. Increasing influenza vaccination uptake by women in pregnancy will require better education of both women and maternity care providers.     

Association between obesity and vulnerability and serologic response to influenza vaccination in older adults

Background

Serologic response to influenza vaccination declines with age. Few other host factors are known to be associated with serologic response. Our objective was to determine whether obesity and vulnerability independently predicted serologic response to influenza vaccination.

Methods

Adults ≥50 years were recruited during the 2008–2009 influenza season. Subjects provided pre- and post-vaccination sera for measuring antibody titers to 2008–2009 vaccine components. Body mass index (BMI) was calculated as weight (kg)/height (m²). Data were collected on vulnerability using the vulnerable elders survey (VES13). Logistic regression evaluated the associations between obesity and vulnerability and the serologic response to vaccination (both seroprotection and seroconversion), adjusting for gender, age, comorbidities, pre-vaccination titer, and site.

Results

Mean (±standard deviation) age of 415 study subjects was 65 ± 10 years; 40% were obese. Mean BMI was 29 ± 5.6 kg/m²; mean VES13 was 1.6 ± 1.8. The proportions of subjects who seroconverted and had seroprotective titers were 40% and 49%, respectively, for A/Brisbane/59 (H1N1); 73% and 80% for A/Brisbane/10 (H3N2); and 34% and 94% for B/Florida. Modified VES-13 (score 0–10, with 10 being most vulnerable) was not associated with seroprotection against H1N1 or H3N2, and VES-13 was directly associated with seroconversion to H1N1 but not H3N2 or B. Obesity (BMI ≥ 30 kg/m² vs. BMI 18.5–30 kg/m²) was not associated with seroprotection for H1N1 or H3N2; obesity was directly associated with seroconversion to H3N2 but not H1N1 or B. Age was inversely associated with seroprotection and seroconversion against H1N1 and with seroconversion to influenza B.

Conclusion

Based on this sample of older healthy subjects, there were no consistent relationships between VES 13 or obesity and either seroprotection or seroconversion to three influenza vaccine antigens.