The safety of seasonal influenza vaccination among adults prescribed immune checkpoint inhibitors: A self-controlled case series study using administrative data.

BACKGROUND: Immune checkpoint inhibitor (ICI) therapy for patients undergoing cancer treatment carries a risk of severe immune-related adverse events (IRAEs). Questions remain about whether seasonal influenza vaccination might increase the risk of developing IRAEs among these patients given that vaccines are immunomodulatory. Previous vaccine safety studies on patients with cancer prescribed ICI therapy have demonstrated conflicting results. METHODS: Using health administrative data from Ontario, Canada among adults diagnosed with cancer who had been prescribed ICI therapy and who had received an influenza vaccine from 2012 to 2019, we conducted a self-controlled case series study. The pre-vaccination control period started 42-days post-ICI initiation until 14-days prior to vaccination, the risk period was 1-42 days post-vaccination, and the post-vaccination control period was after the risk period until ICI discontinuation or a maximum period of two years. Emergency department (ED) visit(s) and/or hospitalization for any cause after ICI initiation was used to identify severe IRAEs. We fitted a fixed-effects Poisson regression model accounting for seasonality and calendar time to estimate relative incidence of IRAEs between risk and control periods. RESULTS: We identified 1133 records of cancer patients who received influenza vaccination while prescribed ICI therapy. Most were aged ≥ 66 years (73 %), were male (63 %), had lung cancer (54 %), and had received ICI therapy with a programmed cell death protein 1(PD-1) inhibitor (91 %). A quarter (26 %) experienced an ED visit and/or hospitalization during the observation period. Rates of ED visits and/or hospitalizations in the risk vs. control periods were similar, with an incidence rate ratio of 1.04 (95 % CI: 0.75-1.45). Subgroup and sensitivity analyses yielded similar results. CONCLUSION: Seasonal influenza vaccination was not associated with an increased incidence of ED visit or hospitalization among adults with cancer treated with ICI therapy and our results support further evidence of vaccine safety.

Education increases COVID-19 vaccine uptake among people in Canadian federal prisons in a prospective randomized controlled trial: The EDUCATE study.

Education is key to behavioural adoption and acceptability of health interventions. We evaluated the impact of an educational intervention administered 1:1 to individuals incarcerated in four Canadian federal prisons on COVID-19 vaccine uptake. Eligible individuals (those who had refused all COVID-19 vaccines) were randomized 2:1 to receive the educational intervention or not (control group); those who received the intervention completed questionnaires assessing COVID-19 vaccine-related knowledge, attitudes, and beliefs pre- and post-educational intervention. The primary and secondary outcome measures were COVID-19 vaccine uptake and vaccine confidence, respectively. Between May 3 and September 9, 2022, 202 participants were randomized to receive the intervention, of whom 127 (63 %) agreed to participate. Participants who were randomized to the intervention had higher COVID-19 vaccine uptake vs. the control group (5 % vs 1 %, p = 0.046). COVID-19 vaccine-related knowledge, attitudes, and beliefs improved post-intervention. Education increases COVID-19 vaccine uptake and confidence among people in Canadian federal correctional facilities.

Can "Rover" help with mental health during the COVID-19 pandemic? Results from the Canadian Longitudinal Study on Aging (CLSA).

COVID-19 has negatively affected the mental health and well-being of adults, and thus it is important to examine potential factors which may influence mental health during the pandemic. We thus examined the association between pet ownership and depression/anxiety symptoms based on mental health disorder status during the COVID-19 pandemic. We included 12,068 cognitively healthy participants (45-86 years at study entry) from the Canadian Longitudinal Study on Aging (CLSA) comprehensive cohort who completed the first follow-up ([FU1]; 2015-2018), and COVID-19 Survey entry (April-May 2020) and exit (September-December 2020). Participants self-reported at FU1 if they owned a pet (yes/no). Participants were dichotomized as with or without a mental health disorder based on self-reported diagnosis of depression, anxiety, or mood disorders at baseline assessment (2011-2015) or FU1. Depressive symptoms were indexed using the 10-item Center for Epidemiological Studies Depression Scale (CESD-10) at FU1, and COVID-19 entry/exit surveys. Anxiety symptoms were assessed using the General Anxiety Disorder Questionnaire (GAD-7) at COVID-19 entry/exit surveys. Final models adjusted for age, sex, body mass index, income, education, living status, smoking status, relationship status, and alcohol intake. Forty-percent of participants owned a pet at FU1. Among those without a mental health disorder, there were no significant differences in CESD-10 between participants who owned pets compared with those without pets. For people with a mental health disorder, pet owners had higher CESD-10 (estimated mean difference range: 0.56-1.02 points; p < 0.05) and GAD-7 scores (estimated mean difference range: 0.28-0.57 points; p < 0.05) at both COVID-19 entry and exit surveys. Among people with mental health disorders, pet ownership was associated with poor mental health symptoms during April 2020 to December 2020 of the COVID-19 pandemic.

Influenza vaccine coverage and factors associated with non-vaccination among adults at high risk for severe outcomes: An analysis of the Canadian Longitudinal Study on Aging.

BACKGROUND: Influenza vaccination is recommended in Canada for older adults and those with underlying health conditions due to their increased risk of severe outcomes. Further research is needed to identify who within these groups is not receiving influenza vaccine to identify opportunities to increase coverage. OBJECTIVES: We aimed to 1) estimate influenza non-vaccination prevalence and 2) assess factors associated with non-vaccination among Canadian adults aged ≥65 and adults aged 46-64 with ≥1 chronic medical condition (CMC) due to their high risk of severe influenza outcomes. METHODS: We conducted a secondary analysis of cross-sectional data collected from 2015-2018 among participants of the Canadian Longitudinal Study on Aging. For both groups of interest, we estimated non-vaccination prevalence and used logistic regression models to identify factors associated with non-vaccination. We report adjusted odds ratios and 95% confidence intervals for the investigated variables. RESULTS: Overall, 29.5% (95% CI: 28.9%, 30.1%) of the 23,226 participants aged ≥65 years and 50.4% (95% CI: 49.4%, 51.3%) of the 11,250 participants aged 46-64 years with ≥1 CMC reported not receiving an influenza vaccination in the past 12 months. For both groups, lack of recent contact with a family doctor and current smoking were independently associated with non-vaccination. DISCUSSION: Influenza vaccination helps prevent severe influenza outcomes. Yet, half of adults aged 46-64 years with ≥1 CMC and more than one-quarter of all adults aged ≥65 years did not receive a recommended influenza vaccine in the year prior to the survey. Innovation in vaccination campaigns for routinely recommended vaccines, especially among those without annual family doctor visits, may improve coverage. CONCLUSION: Influenza vaccination coverage among Canadian adults aged 46-64 years with ≥1 CMC and adults aged ≥65 years remains suboptimal. Vaccination campaigns targeting those at high risk of severe outcomes without routine physician engagement should be evaluated to improve uptake.

Challenges related to human papillomavirus (HPV) vaccine uptake in Minnesota: clinician and stakeholder perspectives.

BACKGROUND: Human papillomavirus (HPV) vaccination rates among adolescents are increasing in Minnesota (MN) but remain below the Healthy People 2020 goal of 80% completion of the series. The goal of this study was to identify messaging and interventions impacting HPV vaccine uptake in MN through interviews with clinicians and key stakeholders. METHODS: We conducted semi-structured key participant interviews with providers and stakeholders involved in HPV vaccination efforts in MN between 2018 and 2019. Provider interview questions focused on messaging around the HPV vaccine and clinic-based strategies to impact HPV vaccine uptake. Stakeholder interview questions focused on barriers and facilitators at the organizational or state level, as well as initiatives and collaborations to increase HPV vaccination. Responses to interviews were recorded and transcribed. Thematic content analysis was used to identify themes from interviews. RESULTS: 14 clinicians and 13 stakeholders were interviewed. Identified themes were grouped into 2 major categories that dealt with messaging around the HPV vaccine, direct patient-clinician interactions and external messaging, and a third thematic category involving healthcare system-related factors and interventions. The messaging strategy identified as most useful was promoting the HPV vaccine for cancer prevention. The need for stakeholders to prioritize HPV vaccination uptake was identified as a key factor to increasing HPV vaccination rates. Multiple providers and stakeholders identified misinformation spread through social media as a barrier to HPV vaccine uptake. CONCLUSION: Emphasizing the HPV vaccine's cancer prevention benefits and prioritizing it among healthcare stakeholders were the most consistently cited strategies for promoting HPV vaccine uptake. Methods to combat the negative influence of misinformation about HPV vaccines in social media are an urgent priority.

Why don't adolescent girls in a rural Uganda district initiate or complete routine 2-dose HPV vaccine series: Perspectives of adolescent girls, their caregivers, healthcare workers, community health workers and teachers.

INTRODUCTION: Vaccination with the 2-dose HPV vaccine series among adolescent girls in Uganda remains low after almost 5 years since the vaccine was included into the routine national immunization program and barriers are not well understood. OBJECTIVE: We explored barriers that prevent eligible girls from initiating or completing the recommended 2-dose HPV vaccine series in Oyam District, Northern Uganda. METHODS: A qualitative study was conducted in Oyam District, Northern Uganda. Forty interviews were conducted with adolescent girls, their caregivers, Village Health Team Members, health workers and school administrators involved in HPV vaccination. All interviews were audio recorded and transcribed. NVivo version 11 was used for data management and content thematic approach for analysis guided by the Social Ecological Model. RESULTS: At individual level, low levels of knowledge about the vaccine, girls' frequent mobility between vaccine doses, school absenteeism and drop out, fear of injection pain and discouragement from caregivers or peers were key barriers. At the health facilities level, reported barriers included: few healthcare workers, inadequate knowledge about HPV vaccine, limited social mobilization and community engagement to promote the vaccine, limited availability of the HPV vaccine, unreliable transportation, lack of reminder strategies after the first dose of the vaccine, lack of vaccination strategy for out-of-school girls and un-friendly behaviour of some healthcare workers. Concerns about safety and efficacy of the vaccine, negative religious and cultural beliefs against vaccination, rumors and misconceptions about the vaccine, mistrust in government intentions to introduce the new vaccine targeting girls, busy schedules and the gendered nature of care work were key community level barriers. CONCLUSION: Our study revealed an interplay of barriers at individual, health facility and community levels, which prevent initiation and completion of HPV vaccination among adolescent girls. Strengthening HIV vaccination programs and ensuring high uptake requires providing appropriate information to the girls plus the community, school and health facility stakeholders; addressing cold chain challenges as well as adequate training of vaccinators to enable them respond to rumors about HPV vaccination.

Online media scans: Applying systematic review techniques to assess statewide human papillomavirus vaccination activities.

Background. Although the human papillomavirus (HPV) vaccine has been approved for use in adolescents in the US for over a decade, vaccination uptake remains low. Of concern, HPV vaccine coverage is below the national average in Minnesota, USA. To understand the reach of current HPV programming and research, we use an online media scan; this method may be applied to other jurisdictions to gain insight about various public health issues. Design and Methods. This online media scan describes the nature and scope of ongoing activities to increase HPV vaccination in Minnesota. The media scan included: a) structured internet searches of HPV vaccine health education/promotion activities ongoing in Minnesota since 2013, and b) searches in research databases of the published literature on HPV vaccination in Minnesota from 2013 to 2018. Results. Searches resulted in 880 online and 142 research article matches, with 40 and 36 meeting selection criteria. Results were categorized by activities focusing on race/ethnicity, sex, health providers, parents, lesbian, gay, bisexual, transgender and queer or questioning (LGBTQ) populations, geographic location, catchup vaccination, and insurance status. Most activities were statewide (52% health education/promotion and 35% research), followed by activities located in entirely urban areas (15% health education/promotion and 41% research) with only 6% of health education/promotion activities and 2% of research activities carried out in entirely rural areas. Conclusions. A range of local and statewide HPV vaccine health education/promotion and research activities were identified in Minnesota. Several efforts partnered with American Indian and Somali/Somali-American communities, but fewer activities focused on HPV vaccination among LGBTQ youth and HPV vaccination in rural areas.

National Trends in Parental Human Papillomavirus Vaccination Intentions and Reasons for Hesitancy, 2010-2015.

Background: Human papillomavirus (HPV) vaccination uptake remains lower than other recommended adolescent vaccines in the United States. Parental attitudes are important predictors of vaccine uptake, yet little is known about how they have changed over time. Methods: Participants included US residents aged 13-17 years with documented vaccination status who had received <3 doses of HPV vaccine whose parents responded to the National Immunization Survey-Teen, 2010-2015. Results: Of the 76971 participants, 63.0% were male, 58.8% were non-Hispanic white, and 14.4 years was the median age. The percentage of unvaccinated teens decreased from 2010 to 2015, yet, annually, parents of unvaccinated teens of both sexes most often reported that they were "not likely at all" to vaccinate their teen. The percentage decreased significantly from 41.5% to 31.2% (P < .001) for parents of unvaccinated females from 2010 to 2015 but did not change among parents of males from 2012 to 2015. Conversely, parents of undervaccinated teens of both sexes reported higher and increasing vaccination intent over time. In 2015, nearly one-third of parents of unvaccinated teens reported that the vaccine was "not needed/necessary." Concerns about vaccine safety and side effects declined among parents of unvaccinated females but increased among parents of males (7.3% to 14.8%; P < .001). Conclusions: Although parental vaccination intent and knowledge improved over time, intent remains low and many parents still have significant concerns about HPV vaccination, even after series initiation. Multiple strategies are needed to improve series initiation and completion in the United States.

Meningococcal carriage within households in the African meningitis belt: A longitudinal pilot study.

OBJECTIVES: Carriers of Neisseria meningitidis are a key source of transmission. In the African meningitis belt, where risk of meningococcal disease is highest, a greater understanding of meningococcal carriage dynamics is needed. METHODS: We randomly selected an age-stratified sample of 400 residents from 116 households in Bamako, Mali, and collected pharyngeal swabs in May 2010. A month later, we enrolled all 202 residents of 20 of these households (6 with known carriers) and collected swabs monthly for 6 months prior to MenAfriVac vaccine introduction and returned 10 months later to collect swabs monthly for 3 months. We used standard bacteriological methods to identify N. meningitidis carriers and fit hidden Markov models to assess acquisition and clearance overall and by sex and age. RESULTS: During the cross-sectional study 5.0% of individuals (20/400) were carriers. During the longitudinal study, 73 carriage events were identified from 1422 swabs analyzed, and 16.3% of individuals (33/202) were identified as carriers at least once. The majority of isolates were non-groupable; no serogroup A carriers were identified. CONCLUSIONS: Our results suggest that the duration of carriage with any N. meningitidis averages 2.9 months and that males and children acquire and lose carriage more frequently in an urban setting in Mali. Our study informed the design of a larger study implemented in seven countries of the African meningitis belt.

HPV vaccine uptake among overweight and obese US adolescents: An analysis of the National Health and Nutrition Examination Survey (NHANES) 2009-2014.

BACKGROUND: Human papillomavirus (HPV) vaccine uptake in the US is suboptimal; identifying risk factors associated with low vaccine uptake is critical to increase vaccination coverage. Some evidence suggests body mass index (BMI) is associated with low HPV vaccine uptake and increased risk of HPV infection in adults. BMI may therefore be an important factor in targeting HPV vaccine to US adolescents. METHODS: We investigated the relationship between BMI categories (underweight, normal weight, overweight and obese) and HPV vaccine uptake in 4109 adolescents (9-18 years old) using data from the 2009 to 2014 National Health and Nutrition Examination Survey (NHANES). We used modified Poisson regression to assess the relationship between BMI and receipt of at least one HPV vaccine, and BMI and completion of the vaccine three-dose series. We assessed the relationship between BMI and age at first HPV vaccination using linear regression. RESULTS: Receipt of at least one dose of HPV vaccine was low in both females (35%) and males (10%). High BMI was not associated with initiation of the HPV vaccine series, age at first HPV vaccination, or completion of the HPV vaccine three-dose course. CONCLUSIONS: We found no evidence that high BMI is associated with reduced initiation or completion of the HPV vaccination series, or age at initiation of the three-dose course among a general population sample of US adolescents. Our results suggest that efforts to increase HPV vaccine uptake need not consider targeting by weight status at this time.

Population-Level Persistence of Immunity 2 Years After the PsA-TT Mass-Vaccination Campaign in Mali.

BACKGROUND: In 2010, Africa's first preventive meningococcal mass vaccination campaign was launched using a newly developed Neisseria meningitidis group A (NmA) polysaccharide-tetanus toxoid conjugate vaccine, PsA-TT (MenAfriVac), designed specifically for the meningitis belt. Given PsA-TT's recent introduction, the duration of protection against meningococcal group A is unknown. METHODS: We conducted a household-based, age-stratified seroprevalence survey in Bamako, Mali, in 2012, 2 years after the vaccination campaign targeted all 1- to 29-year-olds. Randomly selected participants who had been eligible for PsA-TT provided a blood sample and responded to a questionnaire. Sera were analyzed to assess NmA-specific serum bactericidal antibody titers using rabbit complement (rSBA) and NmA-specific immunoglobulin G (IgG) by enzyme-linked immunosorbent assay. The proportion of participants putatively protected and the age group- and sex-specific rSBA geometric mean titers (GMTs) and IgG geometric mean concentrations (GMCs) were determined. RESULTS: Two years postvaccination, nearly all of the 800 participants (99.0%; 95% confidence interval [CI], 98.3%-99.7%) maintained NmA-specific rSBA titers ≥8, the accepted threshold for protection; 98.6% (95% CI, 97.8%-99.4%) had titers ≥128, and 89.5% (95% CI, 87.4%-91.6%) had titers ≥1024. The rSBA GMTs were significantly higher in females than in males aged <18 years at vaccination (P < .0001). NmA-specific IgG levels ≥2 µg/mL were found in 88.5% (95% CI, 86.3%-90.7%) of participants. CONCLUSIONS: Two years after PsA-TT introduction, a very high proportion of the population targeted for vaccination maintains high antibody titers against NmA. Assessing the duration of protection provided by PsA-TT is a priority for implementing evidence-based vaccination strategies. Representative, population-based seroprevalence studies complement clinical trials and provide this key evidence.

Higher Tetanus Toxoid Immunity 2 Years After PsA-TT Introduction in Mali.

BACKGROUND: In 2010, mass vaccination with a then-new meningococcal A polysaccharide-tetanus toxoid protein conjugate vaccine (PsA-TT, or MenAfriVac) was undertaken in 1- to 29-year-olds in Bamako, Mali. Whether vaccination with PsA-TT effectively boosts tetanus immunity in a population with heterogeneous baseline tetanus immunity is not known. We assessed the impact of PsA-TT on tetanus toxoid (TT) immunity by quantifying age- and sex-specific immunity prior to and 2 years after introduction. METHODS: Using a household-based, age-stratified design, we randomly selected participants for a prevaccination serological survey in 2010 and a postvaccination survey in 2012. TT immunoglobulin G (IgG) antibodies were quantified and geometric mean concentrations (GMCs) pre- and postvaccination among all age groups targeted for vaccination were compared. The probability of TT IgG levels ≥0.1 IU/mL (indicating short-term protection) and ≥1.0 IU/mL (indicating long-term protection) by age and sex was determined using logistic regression models. RESULTS: Analysis of 793 prevaccination and 800 postvaccination sera indicated that while GMCs were low pre-PsA-TT, significantly higher GMCs in all age-sex strata were observed 2 years after PsA-TT introduction. The percentage with short-term immunity increased from 57.1% to 88.4% (31.3-point increase; 95% confidence interval [CI], 26.6-36.0;, P < .0001) and with long-term immunity increased from 20.0% to 58.5% (38.5-point increase; 95% CI, 33.7-43.3; P < .0001) pre- and postvaccination. CONCLUSIONS: Significantly higher TT immunity was observed among vaccine-targeted age groups up to 2 years after Mali's PsA-TT mass vaccination campaign. Our results, combined with evidence from clinical trials, strongly suggest that conjugate vaccines containing TT such as PsA-TT should be considered bivalent vaccines because of their ability to boost tetanus immunity.