Multimorbidity is associated with uptake of influenza vaccination

ObjectivePatients with chronic conditions have higher rates of severe influenza-related illness and mortality. However, influenza vaccination coverage in high-risk populations continues to be suboptimal. We describe the association between cumulative disease morbidity, measured by a previously validated multimorbidity index, and influenza vaccination among community-dwelling adults.MethodsWe obtained interview and medical record data for participants ≥18 years who sought outpatient care for influenza-like illness between 2011 and 2016 as part of an outpatient-based study of influenza vaccine effectiveness. We defined cumulative disease morbidity by using medical diagnosis codes to calculate a multimorbidity-weighted index (MWI) for each participant. MWI and influenza vaccination status was evaluated by logistic regression. Akaike information criterion was calculated for all models.ResultsOverall, 1458 (48%) of participants out of a total of 3033 received influenza vaccination. The median MWI was 0.9 (IQR 0.00–3.5) and was higher among vaccinated participants (median 1.6 versus 0.0; p < 0.001). We found a positive linear association between MWI and vaccination, and vaccination percentages were compared between categories of MWI. Compared to patients with no multimorbidity (MWI = 0), odds of vaccination were 17% higher in the second category (MWI 0.01–1.50; [OR: 1.17, 95% CI: 0.92–1.50]), 58% higher in the third category (MWI 1.51–3.00; [OR: 1.58, 95% CI: 1.26–1.99]), 130% higher in the fourth category (MWI 3.01–6.00; [OR: 2.30, 95% CI: 1.78–2.98]) and 214% higher in the fifth category (MWI 6.01–45.00;[OR: 3.14, 95% CI: 2.41–4.10]). Participants defined as high-risk had 86% greater odds of being vaccinated than non-high-risk individuals (OR: 1.86, 95% CI: 1.56–2.21). The AIC was lowest for MWI compared with high-risk conditions.ConclusionsOur results suggest a dose response relationship between level of multimorbidity and likelihood of influenza vaccination. Compared with high-risk condition designations, MWI provided improved precision and a better model fit for the measurement of chronic disease and influenza vaccination.     

2014-2015年中国40岁及以上慢性阻塞性肺疾病患者肺炎疫苗接种状况

目的 了解我国≥40岁慢性阻塞性肺疾病（慢阻肺）患者的肺炎疫苗接种状况,为慢阻肺的防控提供科学依据。方法 将2014-2015年中国居民慢性阻塞性肺疾病监测中支气管舒张试验后测试FEV₁/FVC<70%的调查对象作为慢阻肺患者,其中9 067名通过询问调查明确肺炎疫苗接种情况的患者被纳入本研究分析。应用复杂抽样调整方法,估计慢阻肺患者中的肺炎疫苗接种率及其95% CI,并对其影响因素进行分析。结果 我国≥40岁慢阻肺患者的5年内肺炎疫苗接种率是0.8%（95% CI：0.3%～1.4%）。40～岁组患者的肺炎疫苗接种率是0.3%（95% CI：0.2%～0.5%）,≥60岁组患者的接种率为1.2%（95% CI：0.3%～2.1%）（P<0.05）;城镇患者的接种率（1.5%）高于乡村患者（0.4%）（P<0.05）;慢阻肺患者的气流受限程度越严重,其肺炎疫苗接种率越高（P<0.05）;合并其他慢性肺部疾病或糖尿病的患者接种率为1.7%、2.1%,高于未合并的患者（P<0.05）;曾经吸烟的慢阻肺患者肺炎疫苗接种率为1.4%,现在吸烟的患者接种率为0.6%。慢阻肺患者的肺炎疫苗接种与年龄、文化程度、职业、气流受限严重程度分级、流感疫苗接种史有关。结论 我国≥40岁慢阻肺患者的肺炎疫苗接种率非常低,需要采取多种措施加强对慢阻肺患者的健康教育与肺炎疫苗接种推荐。     

Effectiveness of quadrivalent influenza vaccination in the first year of a funded childhood program in Queensland,Australia, 2018

BackgroundFollowing high influenza activity in 2017, the state of Queensland, Australia, funded a quadrivalent inactivated influenza vaccination program for children aged 6 months to <5 years in 2018. We calculated influenza vaccine effectiveness (VE) among children eligible for this program.MethodsA matched case-control study was conducted. Cases were identified using Queensland 2018 influenza notification data among children age-eligible for funded vaccination. Controls were drawn from Australian Immunisation Register records of Queensland resident children age-eligible for funded influenza vaccine. Up to 10 controls per case were matched for location and birthdate. First dose vaccination was valid if received ≥14 days prior to specimen collection; a second dose was valid if received ≥28 days after first dose receipt. VE was calculated for vaccine doses and adherence to national recommendations for two doses in the first season (schedule completeness) and adjusted (VE_adj) for sex and First Nations status.ResultsThere were 1,125 cases and 10,645 matched controls analysed. Overall VE_adj against laboratory-confirmed influenza was 51% (95% confidence interval (CI) 41–60). VE_adj was 60% (95% CI 46–70) for children who received two doses in 2018, and 60% (95% CI 48–69) for children vaccinated appropriately according to schedule completeness. VE increased with age.ConclusionsModerate vaccine effectiveness was observed for children eligible for the funded program in Queensland in 2018, adding to the sparse evidence for influenza vaccine use in Australian children. Adhering to the national first season two dose schedule for influenza vaccine receipt in children ensures maximum protection.     

Factors associated with repeated influenza vaccine uptake among aged care staff in an Australian sample from 2017 to 2019

Background/AimInfluenza vaccination is strongly recommended every year for aged care staff to protect themselves and minimise risk of transmission to residents. This study aimed to determine the factors associated with repeated annual influenza vaccine uptake among Australian aged care staff from 2017 to 2019.MethodsDemographic, medical and vaccination data collected from the staff, who participated in an observational study from nine aged care facilities under a single provider in Sydney Australia, were analysed retrospectively. Based on the pattern of repeated influenza vaccination from 2017 to 2019, three groups were identified: (1) unvaccinated all three years; (2) vaccinated occasionally(once or twice) over three years; and (3)vaccinated all three years. Multinomial logistic regression analysis was performed to better understand the factors associated with the pattern of repeated influenza vaccination.ResultsFrom a total of 138 staff, between 2017 and 2019, 28.9 % (n = 40) never had a vaccination, while 44.2 % (n = 61) had vaccination occasionally and 26.8 % (n = 37) had vaccination all three years. In the multinomial logistic regression model, those who were<40 years old (OR = 0.57, 95 % CI: 0.19–0.90, p < 0.05) and those who were current smokers (OR = 0.20; 95 % CI: 0.03–0.76, p < 0.05) were less likely to have repeated vaccination for all three years compared to the unvaccinated group. Those who were<40 years old (OR = 0.61; 95 % CI: 0.22–0.68, p < 0.05) and those who were born overseas (OR = 0.50; 95 % CI:0.27–0.69, p < 0.05) were more likely to be vaccinated occasionally compared to the unvaccinated group.ConclusionThe significant predictors of repeated vaccine uptake across the three-year study period among aged care staff were age, smoking status and country of birth (Other vs Australia). Targeted interventions towards the younger age group (<40 years old), smokers and those who were born overseas could improve repeated influenza vaccination uptake in the aged care workforce.     

Comparative safety of high-dose versus standard-dose influenza vaccination in patients with end-stage renal disease

BackgroundHigh-dose influenza vaccine (HDV) is an alternative vaccination strategy in patients with end-stage renal disease (ESRD), though the safety of HDV has not been evaluated in this population. The objective of this study was to estimate the relative occurrence of adverse vaccine reactions in patients with ESRD following vaccination with HDV compared with standard-dose influenza vaccine (SDV).MethodsUsing data from the United States Renal Data System, we identified patients with ESRD aged ≥ 65 years at influenza vaccination during yearly influenza seasons from 2010 through 2016. Patients were followed after vaccination to observe serious (anaphylaxis, angioedema, seizure, encephalopathy, Guillain-Barré syndrome [GBS], and short-term, all-cause mortality) and milder (urticaria/hives, rash, pain in limb, cellulitis, myalgia/myositis, fever, nausea and vomiting, diarrhea, and syncope) adverse events. Propensity score-weighted hazard ratios (HRs) and 95% confidence intervals (CIs) for HDV versus SDV were estimated with Cox proportional hazards models.ResultsOf 520,876 vaccinations observed (mean age = 74.7 years at vaccination; 63% white race), 7.4% were HDV. For serious events, the weighted HRs were null for seizure, encephalopathy, and mortality and inestimable due to too few cases for anaphylaxis, angioedema, and GBS. For milder vaccine reactions, the weighted HRs demonstrated generally increased risks in the HDV group, including rash (HR = 1.86; 95% CI, 1.34–2.57), diarrhea (HR = 1.26; 95% CI, 1.07–1.50), pain in limb (HR = 1.23; 95% CI, 1.12–1.34), and myalgia/myositis (HR = 1.16; 95% CI, 1.04–1.30).ConclusionsThe risks of serious adverse events were low and similar between treatment groups; however, HDV recipients had increased risks of several milder adverse events compared with SDV recipients, consistent with clinical trial findings in the general population of older adults. These results add important information to inform the risk-benefit tradeoff of the use of HDV versus SDV in patients with ESRD.     

Burden of medically attended influenza infection and cases averted by vaccination – United States, 2016/17 through 2018/19 influenza seasons

BackgroundEpidemics of seasonal influenza vary in intensity annually, and influenza vaccine effectiveness (VE) fluctuates based in part on antigenic match to circulating viruses. We estimated the incidence of influenza and influenza cases averted by vaccination in four ambulatory care sites in the United States, during seasons when overall influenza VE ranged from 29% to 40%.MethodsWe conducted active surveillance for influenza at ambulatory care settings at four sites within the United States Influenza Vaccine Effectiveness Network. We extrapolated the total number of influenza cases in the source populations served by these organizations based on incidence of medically attended acute respiratory illness in the source population and influenza test results in those actively tested for influenza. We estimated the number of medically attended influenza cases averted based on incidence, vaccine coverage, and VE.ResultsFrom 2016/17 through 2018/19, incidence of ambulatory visits for laboratory-confirmed influenza ranged from 31 to 51 per 1,000 population. Incidence was highest in children aged 9–17 years (range, 56 to 81 per 1,000) and lowest in adults aged 18–49 years (range, 23–32 per 1,000). Medically attended cases averted by vaccination ranged from a high of 46.6 (95 % CI, 12.1– 91.9) per 1,000 vaccinees in children aged 6 months to 8 years, to a low of 6.9 (95 % CI, ?5.1– 27.3) per 1,000 vaccinees in adults aged ≥ 65 years.DiscussionEven in seasons with low vaccine effectiveness for a particular virus subtype, influenza vaccines can still lead to clinically meaningful reductions in ambulatory care visits for influenza.     

Effectiveness of recombinant zoster vaccine (RZV) in patients with inflammatory bowel disease

Background and AimsPatients with Inflammatory bowel disease (IBD) are at an increased risk of developing herpes zoster (HZ). The effectiveness of the recombinant zoster vaccine (RZV) in patients with IBD is unknown.MethodsIn this retrospective cohort study using Explorys (October 2017–April 2020; IBM Corporation, Somers, NY, USA), the effectiveness of RZV for the prevention of HZ in patients with IBD ≥ 50 years was compared to general population aged ≥ 50 years. Rates of de-novo HZ were compared between patients with IBD and the general population and stratified by number of RZV doses received. Results are presented as odds ratios (OR) with 95% confidence intervals (CI).ResultsThe overall proportion of IBD patients ≥ 50 years who received HZ vaccination with the live zoster vaccine (ZVL) or RZV was low (n = 11320, out of 112,200 IBD patients in the cohort). A total of 1670 patients received RZV. Receipt of the RZV resulted in a significantly lower rate of HZ in IBD patients (OR 0.36, 95% CI 0.23–0.56) compared to the general population (OR 0.74, 95% CI 0.59–0.92). However, despite vaccination, patients with IBD who received the RZV were still 3-times more likely to develop HZ during the study follow up period compared to the general population receiving the RZV (OR 3.06, 95% CI 1.87–5.02) and unvaccinated IBD patients were 6-times more likely to develop HZ compared to general population (OR 6.21, 95% CI 6.02–6.41).ConclusionThe recombinant zoster vaccine is effective in reducing the risk of HZ in patients with IBD compared to the general population. During our follow up period, patients with IBD, however, still remain at an increased risk for HZ despite vaccination.     

Predictors of pneumococcal vaccination among Australian adults at high risk of pneumococcal disease

BackgroundAlthough nearly all Australian children are vaccinated against pneumococcal disease, pneumococcal vaccine uptake is low among high-risk adults. This study aimed to identify perceived barriers to pneumococcal vaccination among high-risk adults.MethodsThis paper reports combined data on pneumococcal vaccination collected from three different online, cross-sectional surveys that were administered in Australia between August 2019 and September 2020. Using Poisson regression, we identified characteristics and beliefs associated with self-reported pneumococcal vaccination among adults aged 65 and over or with chronic health conditions.ResultsThe weighted estimate for pneumococcal vaccine coverage was 24% for high-risk adults under 65 and 53% for adults aged 65 and over. Nearly half of those under 65 reported they had never heard of the pneumococcal vaccine, while 26% of those aged 65 and over had never heard of the vaccine. Among those under 65, pneumococcal vaccination was associated with high perceived disease susceptibility (PR = 1.97, 95% CI: 1.23, 3.18), not having heard of the pneumococcal vaccine (PR = 0.44, 95% CI: 0.28–0.69), awareness that their chronic health condition puts them at increased risk of pneumonia (PR = 2.44, 95% CI: 1.51–3.98), and having a doctor recommend the vaccine (PR = 3.02, 95% CI: 2.05–4.44). Among adults aged 65 and over, self-reported pneumococcal vaccination was associated with influenza vaccination in the previous 12 months (PR = 4.28, 95% CI: 2.85–6.44) and awareness that they are eligible for free pneumococcal vaccination (PR = 5.02, 95% CI: 2.34–10.77).ConclusionAwareness of pneumococcal vaccines was low among adults at high risk of pneumococcal disease, which appears to be contributing to low vaccine uptake. A doctor’s recommendation was associated with increased uptake of pneumococcal vaccine, so interventions should be developed to promote pneumococcal vaccine uptake in GP practices.     

Social and demographic patterns of influenza vaccination coverage in Norway,influenza seasons 2014/15 to 2020/21

AimsTo examine influenza vaccination coverage among risk groups (RG) and health care workers (HCW), and study social and demographic patterns of vaccination coverage over time.MethodsVaccination coverage was estimated by self-report in a nationally representative telephone survey among 14 919 individuals aged 18–79 years over seven influenza seasons from 2014/15 to 2020/21. We explored whether belonging to an influenza RG (being >=65 years of age and/or having >=1 medical risk factor), being a HCW or educational attainment was associated with vaccination status using logistic regression.ResultsVaccination coverage increased from 27 % to 66 % among individuals 65–79 years, from 13 % to 33 % among individuals 18–64 years with >=1 risk factor, and from 9 % to 51 % among HCWs during the study period. Being older, having a risk factor or being a HCW were significantly associated with higher coverage in all multivariable logistic regression analyses. Higher education was also consistently associated with higher coverage, but the difference did not reach significance in all influenza seasons. Educational attainment was not significantly associated with coverage while coverage was at its lowest (2014/15–2017/18), but as coverage increased, so did the differences. Individuals with intermediate or lower education were less likely to report vaccination than those with higher education in season 2018/19, OR = 0.61 (95 % CI 0.46–0.80) and OR = 0.58 (95 % CI 0.41–0.83), respectively, and in season 2019/20, OR = 0.69 (95 % CI 0.55–0.88) and OR = 0.71 (95 % CI 0.53–0.95), respectively. When the vaccine was funded in the COVID-19 pandemic winter of 2020/21, educational differences diminished again and were no longer significant.ConclusionsWe observed widening educational differences in influenza vaccination coverage as coverage increased from 2014/15 to 2019/20. When influenza vaccination was funded in 2020/21, differences in coverage by educational attainment diminished. These findings indicate that economic barriers influence influenza vaccination decisions among risk groups in Norway.     

Variability in influenza vaccination opportunities and coverage among privately insured children

BackgroundUniversal influenza vaccination has been recommended since 2010, yet influenza vaccination rates among children aged 6 months to 17 years remain low compared with other routinely recommended childhood vaccines.ObjectiveAssess in-plan vaccination coverage, opportunities, and missed opportunities during the 2016–2017 influenza season.Study Design:Retrospective analyses using 2016–2017 MarketScan® data for 2,768,799 privately insured children aged 1–17 years by the end of 2016 who were continuously enrolled in the same insurance plan during the 2016–2017 influenza season (defined as August 1, 2016 through May 31, 2017). We assessed in-plan vaccination coverage (percentage receiving ≥ 1 dose of influenza vaccine from August 2016-May 2017) and vaccination opportunities (percentage with ≥ 1 provider visit between September 2016 – May 2017). Among children who remained unvaccinated at the end of the season, those with ≥ 1 influenza vaccination opportunity between September 2016-May 2017 were determined to have a missed opportunity.ResultsIn-plan vaccination coverage during the 2016–17 season was 67.7% in infants (born 2015), 49.5% in toddlers (born 2012–2014), 35.0% in school-aged children (born 2004–2011), and 22.3% in teenagers (born 1999–2003). Like vaccination coverage, vaccination opportunities decreased with age (infants: 97.7%, toddlers: 91.9%, school-aged children: 82.6%, teenagers: 79.3%). Among unvaccinated children, 93.1%, 84.1%, 73.6% and 73.6% of each age group had a missed opportunity for influenza vaccination.ConclusionOpportunities for and coverage with influenza vaccination vary even among privately insured children. Along with continued efforts to reduce missed opportunities, effective strategies to bring children to their doctor for annual influenza vaccination are needed, particularly for older children.     

Duration of influenza vaccine effectiveness in the elderly in Japan: A retrospective cohort study using large-scale population-based registry data

BackgroundThe immune response to influenza vaccination in the elderly is likely to be lower than that in young adults. Clinical protection may not persist year-round in the elderly. However, the effectiveness of influenza vaccine in the elderly has not been adequately studied, especially in terms of the duration of effectiveness.MethodsWe used a linked database of healthcare administrative claims data and vaccination records maintained by the municipality of a city in Kanto region of Japan. We studied individuals who were aged 65 years or older at baseline and were followed up between April 1, 2014 to March 31, 2020. The duration of influenza vaccine effectiveness by age category was analyzed using a time-dependent piecewise Cox proportional hazard model with time-dependent vaccine status, prior season vaccination and covariates confirmed in the baseline period (age, sex, cancer, diabetes, chronic obstructive pulmonary diseases, asthma, chronic kidney diseases, and cardiovascular diseases).ResultsWe identified an analysis population of 83,146 individuals, of which 7,401 (8.9%) had experienced influenza and 270 (0.32%) underwent influenza-related hospitalization. Individuals who were vaccinated during the first season (n = 47,338) were older than non-vaccinated individuals (n = 35,808) (average age, 75.8 vs. 74.1 years, respectively). The multivariable analysis showed a lower incidence of influenza in vaccinated individuals (hazard ratio [HR], 0.47; 95% confidence interval [CI], 0.43–0.51; P < 0.001), while the incidence of hospitalization for influenza did not differ significantly by vaccination status (HR, 0.79; 95% CI, 0.53–1.18; P = 0.249). Protective effectiveness against incidence was maintained for 4 or 5 months after vaccination in those aged 65–69 and 80-years, 5 months in 70–79 years.ConclusionsOur study identified moderate vaccine effectiveness in preventing the incidence of influenza in the Japanese elderly. Vaccine effectiveness showed a trend of gradual attenuation. Clinicians should suspect influenza infection even in those vaccinated, especially in elderly individuals who had received vaccination more than 4 or 5 months previously.     

Human papillomavirus (HPV) vaccine uptake among a community-recruited sample of gay,bisexual, and other men who have sex with men in the three largest cities in Canada from 2017 to 2019

IntroductionIn 2015/2016, Canada’s largest provinces implemented publicly-funded human papillomavirus (HPV) vaccination programs for gay, bisexual, and other men who have sex with men (GBM) ≤ 26 years old. We sought to describe HPV vaccine uptake among GBM and determine barriers and facilitators to vaccine initiation with a focus on healthcare access and utilization.MethodsEngage is a cohort study among GBM aged 16 + years in three Canadian cities recruited from 2017 to 2019 via respondent driven sampling (RDS). Men completed a comprehensive questionnaire at baseline. By publicly-funded vaccine eligibility (≤26 years old = eligible for vaccination, ≥27 years old = ineligible), we described HPV vaccine uptake (initiation = 1 + dose, completion = 3 doses) and explored factors associated with vaccine initiation using Poisson regression. All analyses were weighted with the RDS-II Volz-Heckathorn estimator.ResultsAcross the three cities, 26–35% and 14–21% of men ≤ 26 years and 7–26% and 2–9% of men ≥ 27 years initiated and completed HPV vaccination, respectively. Vaccine initiation was significantly associated with STI/HIV testing or visiting a HIV care specialist in the past six months (≤26: prevalence ratio[PR] = 2.15, 95% confidence interval[CI] 1.06–4.36; ≥27: PR = 2.73, 95%CI 1.14–6.51) and past hepatitis A or B vaccination (≤26: PR = 2.88, 95%CI 1.64–5.05; ≥27: PR = 2.03, 95%CI 1.07–3.86). Among men ≥ 27 years old, vaccine initiation was also positively associated with accessing PrEP, living in Vancouver or Toronto, but negatively associated with identifying as Latin American and increasing age. Vaccine initiation was twice as likely among men ≥ 27 years with private insurance versus no insurance.ConclusionsSixty-five to 74% of men eligible for publicly-funded vaccine across the three cities remained unvaccinated against HPV by 2019. High vaccine cost may partly explain even lower uptake among men ≥ 27 years old. Men seeking sexual health care were more likely to initiate vaccination; bundling vaccination with these services may help improve HPV vaccine uptake.     

Association between health insurance coverage and uptake of seasonal influenza vaccine in Brazos County,Texas

BackgroundLack of health insurance may limit access to influenza vaccination, resulting in higher risk of infection.MethodsThe Brazos County Health Department obtained medical records summarizing vaccination and health insurance status of all influenza cases occurring in December 2017 (n = 417). The odds of influenza vaccination were estimated for those with public or private health insurance as compared to uninsured individuals using multivariate logistic regression analysis adjusted for age and race.ResultsHealth insurance coverage among Brazos County residents with influenza was 62.4%. Public and private health insurance was associated with higher odds of influenza vaccination compared to no insurance (aOR: 2.05; 95% CI: 1.00–4.21 and aOR: 1.77; 95% CI: 1.07–2.92, respectively), particularly among adults 18–64 years of age.ConclusionsInfluenza vaccination is strongly associated with health insurance. Expansion of programs that facilitate access to health services or provide free influenza vaccines may improve influenza prevention among the uninsured.     

吸烟对不同收入人群慢性病患病的影响

目的探讨吸烟对不同经济状况人群的健康影响。方法采用多阶段分层整群随机抽样的方法，在全国共抽取95个县、950个村(居委会)，每个样本村(居委会)随机抽取60户家庭，全国共抽取55200户家庭中15～65岁男性5．93万人。结果研究发现在控制年龄、经济状况、文化程度、就业状况、工作岗位的情况下，不论农村、城镇，与从不吸烟的人相比，有吸烟史的人群慢性病患病率均高(农村OR=1．185，95％CI：1．121～1．253；城镇OR=1．083，95％CI：1．010～1．161)；吸烟对农村男性患慢性病的影响(戒烟OR=2．764，95％CI：2．471～3．092)要大于城镇的相应人群(戒烟OR=2．112，95％CI：1．844～2．419)；另外发现吸烟对低收入人口患慢性病的影响(城镇OR=2．076，95％CI：1．551～2．780；农村OR=2．903，95％CI：2．248～3．749)大于对高收入人口的影响(城镇OR=1．785，95％CI：1．285～2．479；农村OR=2．466，95％CI：1．941～3．134)。结论吸烟对收入低下的人群健康损害更大，应该引起重视。     

Association of spontaneous abortion with receipt of inactivated influenza vaccine containing H1N1pdm09 in 2010–11 and 2011–12

IntroductionInactivated influenza vaccine is recommended in any stage of pregnancy, but evidence of safety in early pregnancy is limited, including for vaccines containing A/H1N1pdm2009 (pH1N1) antigen. We sought to determine if receipt of vaccine containing pH1N1 was associated with spontaneous abortion (SAB).MethodsWe conducted a case-control study over two influenza seasons (2010–11, 2011–12) in the Vaccine Safety Datalink. Cases had SAB and controls had live births or stillbirths and were matched on site, date of last menstrual period, and age. Of 919 potential cases identified using diagnosis codes, 485 were eligible and confirmed by medical record review. Exposure was defined as vaccination with inactivated influenza vaccine before the SAB date; the primary exposure window was the 1–28 days before the SAB.ResultsThe overall adjusted odds ratio (aOR) was 2.0 (95% CI, 1.1–3.6) for vaccine receipt in the 28-day exposure window; there was no association in other exposure windows. In season-specific analyses, the aOR in the 1–28 days was 3.7 (95% CI 1.4–9.4) in 2010–11 and 1.4 (95% CI 0.6–3.3) in 2011–12. The association was modified by influenza vaccination in the prior season (post hoc analysis). Among women who received pH1N1-containing vaccine in the previous influenza season, the aOR in the 1–28 days was 7.7 (95% CI 2.2–27.3); the aOR was 1.3 (95% CI 0.7–2.7) among women not vaccinated in the previous season. This effect modification was observed in each season.ConclusionSAB was associated with influenza vaccination in the preceding 28 days. The association was significant only among women vaccinated in the previous influenza season with pH1N1-containing vaccine. This study does not and cannot establish a causal relationship between repeated influenza vaccination and SAB, but further research is warranted.     

Anal human papillomavirus among men who have sex with men in three metropolitan cities in southern China: implications for HPV vaccination

IntroductionMen who have sex with men (MSM), especially those infected with human immunodeficiency virus (HIV), are at disproportionate risk for human papillomavirus (HPV) infection. Data about anal HPV prevalence among MSM in southern China are limited.MethodsMSM were recruited between January 1 and August 31, 2017 in three metropolitan cities: Guangzhou, Shenzhen and Wuxi. A self-completed tablet-based questionnaire was used to collect information about socio-demographic/sexual behavioral characteristics, history of sexually transmitted infections (STIs) and recreational drug use. An anal brush was used to collect exfoliated cells for HPV DNA testing and genotyping, and a blood sample was taken for HIV testing. Penile/anal warts were checked by a clinician.ResultsA total of 536 MSM were enrolled, including 39 HIV-positive and 497 HIV-negative individuals. Compared with HIV-negative MSM, prevalence of any HPV genotype (79.5% vs 46.7%), any high-risk genotype (64.1% vs 36.6%) and any nonavalent vaccine-preventable genotype (53.9% vs 31.6%) was significantly higher in HIV-positive MSM, with all P < 0.01. HIV infection (adjusted odds ratio [AOR], 4.28; 95% confidence interval [CI], 1.87–9.80), using recreational drugs (AOR, 1.87; 95% CI, 1.22–2.87), having ≥ 3 years of sexual experience (AOR, 1.52; 95% CI, 1.01–2.28), having ≥ 6 lifetime male partners (AOR, 1.92; 95% CI, 1.29–2.86), and engaging receptive anal intercourse (AOR, 2.30; 95% CI, 1.48–3.57) were associated with higher anal HPV prevalence. Any HPV prevalence increased with age, from 24.5% at < 20 years to 55.8% at ≥ 40 years.ConclusionsAnal HPV prevalence was high among MSM in southern China, significantly associated with HIV status and sexual experience. HPV prevalence increased with age among MSM. A targeted HPV vaccination program for teenage MSM might be necessary. Our findings will inform targeted HPV modelling among MSM in China.     

Parental perceptions of childhood seasonal influenza vaccination in Singapore: A cross-sectional survey

PurposeSeasonal influenza vaccination is recommended in children aged 6–59 months, but little is known about child vaccination coverage and determinants in Asian settings. We report the results of a survey of knowledge, attitudes, practices, and determinants of child influenza vaccination in Singapore.MethodsIn December 2015-March 2016, we conducted a survey of 332 parents of children aged 6 months to 5 years attending pre-schools. We assessed child influenza vaccine coverage and parental knowledge, attitudes, and practices of child influenza vaccination. We used multivariable regression and structural equation models to identify factors associated with child influenza vaccination.ResultsKnowledge about influenza, perceived benefit of vaccination, and willingness to vaccinate were high. However, only 32% of children had ever received influenza vaccine, and only 15% in the past year. Factors independently associated with child influenza vaccination included: being recommended influenza vaccine by a child’s doctor (prevalence ratio (PR) = 2.47, 95% CI: 1.75–3.48); receiving influenza vaccine information from a private general practitioner (PR = 1.47, 95% CI: 1.05–2.04); regularly receiving pre-travel influenza vaccine (PR = 1.64, 95% CI: 1.19–2.25); higher willingness to vaccinate (PR = 1.58, 95% CI:1.24–2.04 per unit increase in willingness score); and feeling well-informed about influenza vaccine (PR = 1.44, 95% CI: 1.04–1.99). Parents who obtained influenza vaccine information from television were less likely to have vaccinated their child (PR = 0.44, 95% CI: 0.23–0.85). Path analysis indicated that being recommended vaccination by a child's doctor increased willingness to vaccinate and self-efficacy (feeling well-informed about influenza vaccine). Median willingness-to-pay for a dose of influenza vaccine was SGD30 (interquartile range: SGD20-SGD50), and was higher in parents of vaccinated compared with unvaccinated children (SGD45 vs SGD30, p = 0.0012).ConclusionKnowledge and willingness to vaccinate was high in this parent population, but influenza vaccine uptake in children was low. Encouraging medical professionals to recommend vaccination of eligible children is key to improving uptake.