Pandemic influenza is a strong motivator for participation in vaccine clinical trials among HIV-positive Canadian adults

Factors that impact on recruitment to vaccine trials in the context of a pandemic or epidemic: a qualitative evidence synthesis

BACKGROUND

The World Health Organization declared the COVID-19 pandemic on 11 March 2020. Vaccine development and deployment were swiftly prioritised as a method to manage and control disease spread. The development of an effective vaccine relies on people's participation in randomised trials. Recruitment to vaccine trials is particularly challenging as it involves healthy volunteers who may have concerns around the potential risks and benefits associated with rapidly developed vaccines.

OBJECTIVES

To explore the factors that influence a person's decision to participate in a vaccine trial in the context of a pandemic or epidemic.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was June 2021.

SELECTION CRITERIA

We included qualitative studies and mixed-methods studies with an identifiable qualitative component. We included studies that explored the perspectives of adults aged 18 years or older who were invited to take part in vaccine trials in the context of a pandemic or epidemic.

DATA COLLECTION AND ANALYSIS

We assessed the title, abstracts and full texts identified by the search. We used a sampling frame to identify data-rich studies that represented a range of diseases and geographical spread. We used QSR NVivo to manage extracted data. We assessed methodological limitations using an adapted version of the Critical Skills Appraisal Programme (CASP) tool for qualitative studies. We used the 'best-fit framework approach' to analyse and synthesise the evidence from our included studies. We then used the Confidence in the Evidence from Reviews of Qualitative research (GRADE-CERQual) assessment to assess our confidence in each finding and develop implications for practice.

MAIN RESULTS

We included 34 studies in our review. Most studies related to HIV vaccine trials. The other studies related to Ebola virus, tuberculosis, Zika virus and COVID-19. We developed 20 key findings, under three broad themes (with seven subthemes), that described the factors that people consider when deciding whether to take part in a vaccine trial for a pandemic or epidemic disease. Our GRADE-CERQual confidence was high in nine of the key findings, moderate in 10 key findings and low in one key finding. The main reason for downgrading review findings were concerns regarding the relevance and adequacy of the underlying data. As a result of the over-representation of HIV studies, our GRADE-CERQual assessment of some findings was downgraded in terms of relevance because the views described may not reflect those of people regarding vaccine trials for other pandemic or epidemic diseases. Adequacy relates to the degree of richness and quantity of data supporting a review finding. Moderate concerns about adequacy resulted in a downgrading of some review findings. Some factors were considered to be under the control of the trial team. These included how trial information was communicated and the inclusion of people in the community to help with trial information dissemination. Aspects of trial design were also considered under control of the trial team and included convenience of participation, provision of financial incentives and access to additional support services for those taking part in the trial. Other factors influencing people's decision to take part could be personal, from family, friends or wider society. From a personal perceptive, people had concerns about vaccine side effects, vaccine efficacy and possible impact on their daily lives (carer responsibilities, work, etc.). People were also influenced by their families, and the impact participation may have on relationships. The fear of stigma from society influenced the decision to take part. Also, from a societal perspective, the level of trust in governments' involvement in research and trial may influence a person's decision. Finally, the perceived rewards, both personal and societal, were influencing factors on the decision to participate. Personal rewards included access to a vaccine, improved health and improved disease knowledge, and a return to normality in the context of a pandemic or epidemic. Potential societal rewards included helping the community and contributing to science, often motivated by the memories of family and friends who had died from the disease.

AUTHORS' CONCLUSIONS

This review identifies many of the factors that influence a person's decision to take part in a vaccine trial, and these reflect findings from reviews that examine trials more broadly. However, we also recognise some factors that become more important in connection with a vaccine trial in the context of a pandemic or epidemic. These factors include the potential stigma of taking part, the possible adverse effects of a vaccine, the added motivation for helping society, the role of community leaders in trial dissemination, and the level of trust placed in governments and companies developing vaccines. These specific influences need to be considered by trial teams when designing, and communicating about, vaccine trials in the context of a pandemic or epidemic.

Predictors of Seasonal Influenza Vaccination Willingness among High-Risk Populations Three Years after the Onset of the COVID-19 Pandemic

High-risk populations are at increased risk of severe influenza-related illness, hospitalization, and death due to influenza. The aim of our study was to assess the willingness of high-risk populations to take the influenza vaccine for the 2022-2023 season, and to investigate the factors associated with such willingness. We conducted a cross-sectional study in Greece in September 2022 using a convenience sample. We considered demographic characteristics, COVID-19-related variables, resilience, social support, anxiety, depression, and COVID-19-related burnout as potential predictors. Among participants, 39.4% were willing to accept the seasonal influenza vaccine, 33.9% were unwilling, and 26.8% were hesitant. Multivariable analysis identified that increased age and increased family support were associated with increased influenza vaccination willingness. Moreover, participants that have received COVID-19 booster doses were more willing to accept the influenza vaccine. In contrast, adverse effects because of COVID-19 vaccination and exhaustion due to measures against COVID-19 reduced influenza vaccination willingness. We found that the intention of high-risk populations to receive the influenza vaccine was low. Our study contributes to an increased understanding of the factors that affect vaccination willingness. Public health authorities could use this information to update vaccination programs against influenza. Emphasis should be given on safety and effectiveness issues.

Why not? Motivations for entering a volunteer register for clinical trials during the COVID-19 pandemic

Backgrounds

Healthy volunteers play a key role in clinical trials and it is crucial to develop recruitment strategies that capitalise on their motivations and maximise their participation. The COVID-19 pandemic has shown the importance of finding motivated healthy volunteers for the development of new vaccines. Public registers represent a promising way to promote the participation of healthy volunteers in the research field, but their adoption is still limited. The current study aimed to explore the motivations of healthy volunteers to enrol in an Italian public register for clinical trials during the COVID-19 pandemic and their attitude toward participating in a phase 1 COVID-19 vaccine clinical trial. The impacts of different enrolling interview modalities (in person, by phone, by mail) on motivation, understanding of information and trust in researchers were also investigated.

Methods

An online survey investigating experience with COVID-19, motivations to enrol, trust in researchers, political and healthcare authorities and pharmacological companies was presented to people applying as healthy volunteers in the public register for clinical trials at Phase 1 Unit Research Centre of ASST Monza, Italy, and considering to participate in a COVID-19 vaccine clinical trial. Data were collected in June 2021.

Results

Altruistic motivations were the main driver for enrolling in the public register, while self-interested motivations were secondary. No gender differences were found. As for enrolling modalities, no differences emerged between in-person and interviews for motivation to enrol, understanding of information and trust in researchers. Email modality led to significantly lower volunteers’ satisfaction and understanding of information but similar trust in research.

Conclusions

This study supports the validity of different interview modalities (in person and by phone) for the enrolment of healthy volunteers for clinical trials and highlights the positive role of public registers for the recruitment procedures.

Barriers to adult vaccination in Canada: A qualitative systematic review

Background:

In recent years, Canadian health care professionals have observed an increase in vaccine refusal. The objective of this study is to review published literature and identify the main themes related to vaccine hesitancy and barriers to vaccination in Canadian adults and recent immigrants.

Methods:

A qualitative systematic review was performed. A comprehensive search of MEDLINE (1946 to January 2021) and EMBASE (1974 to January 2021) was conducted to identify existing literature that addressed the primary research question. Studies were eligible for inclusion if the study population involved 1) the general population, 2) Indigenous populations, 3) recent immigrants to Canada or 4) Canadian health care professionals.

Results:

Thirty-four studies were included with a focus on the general population (n = 22), health care professionals (n = 10) and recent immigrant populations (n = 2). The most frequently reported barriers were lack of vaccine information (41%), lack of access to vaccination (38%), fear of adverse reactions (38%), financial reasons (29%), lack of awareness of vaccine existence (29%), antivaccine sentiments (24%), notion that older adults do not need vaccination (18%), misconceptions on vaccine effectiveness (12%), potential sexual health promotion stigma (6%) and fear of needles (3%).

Interpretation:

Barriers to vaccination among Canadians and recent immigrants continue to be a challenge in the health care system.

Conclusions:

The greatest yield in improving vaccination rates is likely to come from supporting vaccine-hesitant individuals in shifting their thinking to greater vaccine acceptance. Pharmacists are well positioned to address vaccine hesitancy and involvement through education, facilitation and administration of vaccines. Can Pharm J (Ott) 2022;155:xx-xx.

Barriers and motivations to volunteers' participation in preventive vaccine trials: a systematic review

INTRODUCTION

The recruitment of volunteers in preventive vaccine trials (PVT) is a challenge, since vaccine hesitancy and debates on vaccines are combined to usual difficulties of enrollment in clinical trials. Areas covered: Current knowledge of the reasons leading to the volunteers' participation or non-participation in PVT mainly focuses on data from preventive HIV vaccine trials. A systematic PubMed search was conducted using PRISMA guidelines to identify articles or reviews that reported barriers and motivations to participation in PVT regardless of the targeted disease or population. Expert commentary: In view of the barriers and motivations reviewed here, improvements in recruitment could be made through a better explanation of the prevented disease, of the expected individual and collective benefit and of all ethical protective principles associated to the trials. Use of decision aids as well as patient and public involvement may improve given information and may enhance comprehension of participants and their participation in PVT. Further prospective and interventional studies are needed to analyze if these leads may improve acceptation level in PVT.

Barriers of Influenza Vaccination Intention and Behavior - A Systematic Review of Influenza Vaccine Hesitancy, 2005 - 2016

BACKGROUND

Influenza vaccine hesitancy is a significant threat to global efforts to reduce the burden of seasonal and pandemic influenza. Potential barriers of influenza vaccination need to be identified to inform interventions to raise awareness, influenza vaccine acceptance and uptake.

OBJECTIVE

This review aims to (1) identify relevant studies and extract individual barriers of seasonal and pandemic influenza vaccination for risk groups and the general public; and (2) map knowledge gaps in understanding influenza vaccine hesitancy to derive directions for further research and inform interventions in this area.

METHODS

Thirteen databases covering the areas of Medicine, Bioscience, Psychology, Sociology and Public Health were searched for peer-reviewed articles published between the years 2005 and 2016. Following the PRISMA approach, 470 articles were selected and analyzed for significant barriers to influenza vaccine uptake or intention. The barriers for different risk groups and flu types were clustered according to a conceptual framework based on the Theory of Planned Behavior and discussed using the 4C model of reasons for non-vaccination.

RESULTS

Most studies were conducted in the American and European region. Health care personnel (HCP) and the general public were the most studied populations, while parental decisions for children at high risk were under-represented. This study also identifies understudied concepts. A lack of confidence, inconvenience, calculation and complacency were identified to different extents as barriers to influenza vaccine uptake in risk groups.

CONCLUSION

Many different psychological, contextual, sociodemographic and physical barriers that are specific to certain risk groups were identified. While most sociodemographic and physical variables may be significantly related to influenza vaccine hesitancy, they cannot be used to explain its emergence or intensity. Psychological determinants were meaningfully related to uptake and should therefore be measured in a valid and comparable way. A compendium of measurements for future use is suggested as supporting information.

Pandemic H1N12009 influenza and HIV: a review of natural history, management and vaccine immunogenicity

PURPOSE OF REVIEW

The 2009 pandemic HIN1 influenza strain (H1N12009) produced more severe disease and increased risk for mortality. As an at-risk population for more severe influenza illness, particular concern regarding HIV patients triggered a focused effort to evaluate disease burden and vaccine efficacy in these populations.

RECENT FINDINGS

As with other immune-compromised individuals, most HIV-infected individuals recovered without major consequence. Although HIV infection was assumed to be a risk factor for more severe disease and death, the published literature does not indicate this to be so. Neuraminadase inhibitors were well tolerated by this population and there was no evidence of clinically significant pharmacokinetic interactions with antiretroviral therapy. Immunogenicity was increased with H1N12009 vaccine compared to the historical results of nonpandemic vaccines and optimized by the use of adjuvants. Booster dosing was also of benefit. H1N12009 vaccine was generally well tolerated without evidence of detrimental effect on HIV status.

SUMMARY

The worse case scenario was not realized for H1N12009 in the general population or in those with HIV. Immunization with adjuvant represents a key measure to protect this population from H1N12009 and other future novel influenza strains.