Field evaluation of typhoid conjugate vaccine in a catch-up campaign among children aged 9 months to 15 years in Sindh,Pakistan

BackgroundTyphoid conjugate vaccine (TCV) has recently been introduced in the expanded program for immunization (EPI) in Pakistan. Before its introduction in routine immunization, a onetime catchup campaign among children 9 months to 15 years old was conducted in November 2019. We performed field evaluation of TCV against culture confirmed Salmonella Typhi (S. Typhi) among 9 months to 15 years old children during the catch up campaign in Karachi and Hyderabad.MethodsA rapid assessment of blood culture confirmed S. Typhi was performed. Age eligible cases of culture confirmed S. Typhi were identified from the laboratory networks of Aga Khan University Hospital Karachi and Hyderabad, Kharadar General Hospital Karachi, and Liaqat University of Medical & Health Sciences (LUMHS) Hyderabad. Information on sociodemographic, typhoid vaccination history and antimicrobial resistance was collected using a structured questionnaire.Patient medical records and lab reports were also reviewed to collect information on diagnosis and antimicrobial susceptibility information. Information about the population vaccination coverage during catch-up campaign was obtained from the provincial EPI office. Field performance of TCV in catchup campaign was measured by calculating the effectiveness using rapid screening method which is less resource-intensive technique of calculating vaccine effectiveness (VE).ResultsOverall, 968 culture confirmed typhoid cases were enrolled. Among them, 82% (793/968) were from Karachi and 18% (175/968) from Hyderabad. The average age of the participants was 5.68 years, and 54% (523/968) were male. 6% (62/968) of the culture confirmed S. Typhi cases were multidrug resistant (MDR), and 61% (586/968) were extensively drug resistant (XDR). The VE using the TCV coverage data provided by EPI was 98%.ConclusionTCV is effective against culture confirmed S. Typhi among children aged 9 months to 15 years in the catch-up campaign setting. While typhoid vaccination can significantly decrease the burden of typhoid disease, improvements in sanitation and hygiene are necessary for the prevention of spread of enteric fever. Longer term follow up will be needed to assess the duration of protection and requirement for booster doses of TCV.     

Effectiveness of typhoid conjugate vaccine against culture-confirmed typhoid in a peri-urban setting in Karachi: A case-control study

BackgroundEnteric fever, caused by Salmonella Typhi and S. Paratyphi, is a cause of high morbidity and mortality among children in South Asia. Rising antimicrobial resistance presents an additional challenge. Typhoid Conjugate Vaccines (TCV) are recommended by the World Health Organization for use among people 6 months to 45 years old living in endemic settings. This study aimed to assess the effectiveness of TCV against culture-confirmed S. Typhi in Lyari Town, Karachi, Pakistan. This peri-urban town was one of the worst affected by the outbreak of extensively drug resistant (XDR) typhoid that started in November 2016.MethodsA matched case-control study was conducted following a mass immunization campaign with TCV at three key hospitals in Lyari Town Karachi, Pakistan. Children aged 6 months to 15 years presenting with culture-confirmed S. Typhi were enrolled as cases. For each case, at least 1 age-matched hospital control and two age-matched community controls were enrolled. Adjusted odds ratios with 95% confidence intervals (CIs) were calculated using conditional logistic regression.ResultsOf 82 typhoid fever patients enrolled from August 2019 through December 2019, 8 (9·8%) had received vaccine for typhoid. Of the 164 community controls and 82 hospital controls enrolled, 38 (23·2%) community controls and 27 (32·9%) hospital controls were vaccinated for typhoid. The age and sex-adjusted vaccine effectiveness was found to be 72% (95% CI: 34% − 88%). The consumption of meals prepared outside home more than once per month (adjusted odds ratio: 3·72, 95% CI: 1·55- 8·94; p-value: 0·003) was associated with the development of culture-confirmed typhoid.ConclusionA single dose of TCV is effective against culture confirmed typhoid among children aged 6 months to 15 years old in an XDR typhoid outbreak setting of a peri-urban community in Karachi, Pakistan.     

Knowledge,attitudes, and practices regarding seasonal influenza vaccination during pregnancy in Costa Rica: A mixed-methods study

BackgroundInfluenza increases stillbirth risk, morbidity and mortality in pregnant women. Vaccination protects pregnant women against severe disease and indirectly protects their infants, but coverage among pregnant women remains low worldwide. We aimed to describe knowledge, attitudes, and practices (KAP) regarding seasonal influenza vaccination among postpartum women and prenatal care physicians in Costa Rica.MethodsWe conducted cross-sectional KAP surveys to women one to three days after childbirth at Costa Rican Social Security Fund maternity hospitals, and obstetricians and general practitioners who provided prenatal care in 2017. Principal components analysis, multiple imputation, and logistic regression were used to examine associations between influenza vaccination and demographics, prenatal care, and sources of information—separately for postpartum women and physicians. We also held two focus groups of six healthcare workers each to further describe vaccination KAP.ResultsWe surveyed 642 postpartum women and 146 physicians in maternity hospitals in five Costa Rican provinces of whom 85.5 % (95 % CI: 82.6 %-88.0 %) and 57.9 % (95 % CI: 49.6 %-65.7 %) were vaccinated for influenza, respectively. Factors associated with influenza vaccination for postpartum women included tetanus vaccination (aOR: 3.62, 95 % CI: 1.89–6.92); received vaccination recommendations from clinicians during prenatal check-ups (aOR: 3.39, 95 % CI: 2.06–5.59); had other children in household vaccinated for influenza (aOR: 2.25, 95 % CI: 1.08–4.68); and secondary/university education (aOR: 0.15–0.31) with no formal education as reference. For postpartum women, reasons for vaccination were perceived benefits for mother and infant, whereas not being offered vaccines was most cited for non-vaccination. Most prenatal care physicians recommended influenza vaccines during prenatal check-ups but believed vaccination causes flu-like symptoms.ConclusionVaccination campaigns and provisions of free vaccines effectively increased knowledge and coverage among women in Costa Rica. To improve access, women should be offered vaccines during prenatal care appointments. Educating healthcare workers about vaccine benefits for themselves and patients is needed to mitigate safety concerns.     

Physician clinical decision support system prompts and administration of subsequent doses of HPV vaccine: A randomized clinical trial

BackgroundHPV vaccine is effective in preventing several cancers and anogenital warts, yet rates of HPV vaccination series completion in the United States are low. A primary reason identified by parents for vaccinating children against HPV is a health care provider’s recommendation. Although most clinicians embrace vaccine recommendations, they are not always carried out evenly and subsequent HPV vaccines are missed.MethodsUsing an electronic health records-based decision support system (CHICA) clinicians were randomized to either usual practice or to receive an automated reminder to recommend the 2nd or 3rd dose of HPV vaccine. The reminder was delivered to clinicians of all intervention group eligible adolescents who had already initiated the vaccine series. Logistic regression models with generalized estimating equations were used for data analysis.ResultsA total of 1285 clinical encounters were observed across 29 randomized pediatric providers over a 13-month time frame (50.7% control group, 49.3% intervention group). Overall, patients were 44.9% female, 59.4% Black, 22.1% Hispanic, and 48.8% were ages 11–12 yrs. Within the control group, 421 (64.7%) received a subsequent HPV vaccine, compared to 481 (75.9%) (OR: 1.72, (95% CI 1.35–2.19)). Adjusted analysis showed no difference between the groups (aOR 1.52 (95% CI 0.88–2.62)) or when examined by age (11-12yrs aOR 1.66, (95% CI 0.79–3.48)) and 13-17yrs (aOR 1.19, (95% CI 0.76–1.85)) or gender female (aOR 1.39 (95% CI 0.71–2.72)) and males (aOR 1.67 (95% CI 0.95–2.92)). When results were stratified by both age and gender, there was similarly no statistically significant effect between the two groups.ConclusionsAutomated physician reminders for subsequent 2nd and 3rd doses of HPV vaccination were used. Despite increased rates of vaccination in the intervention group, the differences did not reach the level of statistical significance. Future studies with multifaceted approaches may be needed to examine the efficacy of computer-based reminders.Clinical Trial Registration: NCT02558803, “HPV Vaccination: Evaluation of Reminder Prompts for Doses 2 & 3”.     

Parental and provider vaccine hesitancy and non-timely childhood vaccination in Switzerland

ObjectiveAlthough medical providers are a trusted vaccination information source for parents, they do not universally support vaccination. Complementary medicine (CM) providers are particularly likely to hold vaccine hesitant (VH) views, and VH parents often consult with them. Little research compares VH of parents and providers, and if and how each is associated with uptake of recommended childhood vaccines.MethodsWe defined non-timely receipt as recommended vaccines given > 1 month later than officially recommended, based on vaccination records. We administered versions of the Parent Attitudes about Childhood Vaccines (PACV) 5-item survey instrument to 1256 parents and their children’s pediatricians (N = 112, 40 CM-oriented, 72 biomedical [not CM-oriented]) to identify moderately (PACV-score 5–6) and highly (PACV-score 7+) hesitant providers/parents. We obtained multivariable adjusted odds ratios to test relationships between parental VH and provider type/VH, and between non-timely receipt of selected childhood vaccines and parental VH and provider type/VH.ResultsNo biomedical providers were VH, 9 CM providers were moderately VH, and 17 were highly VH. Parents seeing moderately and highly hesitant providers had adjusted odds ratio (AOR) for being VH = 6.6 (95% confidence interval (CI), 3.1–14.0) and AOR = 31.3 (95% CI 16.8–58.3), respectively. Across all vaccine uptake endpoints, children of moderately and highly hesitant parents had 1.9–3.8 and 7.1–12.3 higher odds of non-timely vaccination, and children seeing highly hesitant CM providers had 4.9–9.4 higher odds. Children seeing moderately hesitant CM providers had 3.3 higher odds of non-timely vaccination for the 1st dose of measles and 3.5 higher odds for 1st dose of polio/pertussis/tetanus.ConclusionVH by both parents and providers each is associated with non-timely childhood vaccination. As VH parents are more likely to consult with VH providers, interventions aimed at increasing timely vaccination need to primarily target VH providers and their clients.     

Vaccination coverage and factors associated with routine childhood vaccination uptake in rural Vellore,southern India, 2017

BackgroundVellore district in southern India was selected for intensified immunization efforts through India’s Mission Indradhanush campaign based on 74% coverage in the National Family Health Survey in 2015. As rural households rely almost entirely on the Universal Immunization Program (UIP), we assessed routine immunization coverage and factors associated with vaccination status of children in rural Vellore.MethodsWe conducted a cross-sectional household survey among parents or primary caretakers of children aged 12–23 months during August–September 2017 using two-stage, EPI cluster sampling. We verified vaccination histories from vaccination cards and collected data on sociodemographic and non-socio-demographic characteristics by using mobile data capture. Associations with vaccination status were examined with univariate and multivariate logistic regression models.ResultsA total of 643 children were included. Coverage of BCG, third dose pentavalent/DPT, measles/MR vaccines and full vaccination (BCG, three doses of polio and pentavalent/DPT and measles/MR vaccines) among children with vaccination cards (n = 606) was 94%, 96%, 93% and 84%, respectively. Of children with vaccination cards, 70.8% had received all recommended doses according to the UIP schedule. No socio-demographic differences were identified, but parents’ familiarity with the schedule (Adjusted Prevalence Odds Ratio (aPOR): 2.06, 95%CI = 1.26–3.38) and receiving information on recommended vaccinations during antenatal visits (aPOR: 2.16, 95% CI = 1.13–4.12) were significantly associated with full vaccination status of the children.ConclusionsWe found higher UIP antigen coverage and proportion of fully vaccinated children than previously reported from rural Vellore. However, adherence to the recommended schedule was still not optimal. Our study highlights the potential of improving parental awareness of vaccination schedule and targeting health education interventions at pregnant women during antenatal visits to sustain and improve routine immunization coverage.     

Factors associated with the willingness of primary caregivers to avail of a dengue vaccine for their 9 to 14-year-olds in an urban community in the Philippines

To help address the need for preventive measures against dengue fever, a leading cause of child mortality in the Philippines, vaccine trials are ongoing and a tetravalent vaccine (Dengvaxia™, Sanofi Pasteur) has been developed. It is hypothesized that while acceptability would be high among primary caregivers (i.e., parents/guardians), the willingness to have one's child immunized against dengue would be associated with socio-demographic variables, attitudes and knowledge regarding dengue and vaccination, and past experience with dengue. This study aimed to assess the aforementioned factors’ association with primary caregivers’ willingness to avail of a dengue vaccine for their 9 to 14-year-old children in an urban community in the Philippines.A cross-sectional study utilizing interviews was conducted to determine which factors were associated with willingness-to-avail assuming a free vaccine, and a case study utilizing a focus group discussion was employed to capture some underlying reasons for their willingness. Data were analyzed using multiple logistic regression and thematic analysis.Among the 202 study participants, 193 (95.54%) were willing to avail of the vaccine. There was a high probability of vaccine acceptance by primary caregivers (95.54%), with good attitude towards vaccination (≥12/15 points) [aOR 10.62, 90% CI (1.73–26.28)] and large household size (>5) [aOR 9.63, 90% CI (2.04–45.58)] being positively associated with willingness-to-avail, and good knowledge regarding dengue fever [aOR 0.10, 90% CI (0.03–0.74)] and older age (>44 years) [aOR 0.14, 90% CI (0.03–0.61)] being negatively associated.Crude analysis showed that household size, knowledge regarding dengue, and attitude towards vaccination were significantly associated with willingness. Multivariate analysis revealed that these factors and the primary caregiver’s age were associated with willingness. Thematic analysis showed various perceptions regarding dengue and vaccination. Knowing these factors are associated with willingness-to-avail of the vaccine may help in understanding the audience of health promotion projects aimed at increasing immunization coverage.     

Vaccine confidence among parents: Large scale study in eighteen European countries

BackgroundDespite the fact that vaccines save 2–3 million lives worldwide every year, a percentage of children are not getting appropriately vaccinated, thus leading to disease outbreaks. One of the major reasons of low vaccine uptake in Europe is vaccine hesitancy, contributing to the recent measles outbreaks. Monitoring of vaccine hesitancy is valuable in early identification of vaccine concerns.MethodsWe performed an eighteen country European survey on parents’ attitudes and behaviors regarding their children’s immunization. Parents having at least one child 1–4 years old were mostly recruited by primary care paediatricians to reply to a web-based questionnaire.The questionnaire was developed by the European Academy of Paediatrics Research in Ambulatory Setting Network steering committee, based on similar surveys. An individual level hesitancy score was constructed using the answers to 21 questions, and correlations of the score with socio-demographic characteristics and types of providers were explored. To assess inter country differences, a country level self -reported confidence was defined.ResultsFifty six percent and 24% of 5736 respondents defined themselves as “not at all hesitant”, and “somewhat hesitant”, respectively. Parents who consulted general practitioners were more hesitant than parents who consulted pediatricians (p < 0.05). Consultation with homeopathists was associated with the highest reported hesitancy (p < 0.05). Vaccine confidence was highest in Portugal and Cyprus, and lowest in Bulgaria and Poland.ConclusionThe majority of parents in Europe believe in the importance of childhood vaccination. However, significant lack of confidence was found in certain European countries, highlighting the need for continuous monitoring, awareness and response plans. The possible influence of different types of healthcare providers on parental decisions demonstrated for the first time in our survey, calls for further research. Monitoring and continuous medical education efforts aimed mostly at those professionals who might not be likely to recommend vaccination are suggested.     

Seroprevalence of chronic hepatitis B virus infection and immunity to measles,rubella, tetanus and diphtheria among schoolchildren aged 6–7 years old in the Solomon Islands, 2016

The Western Pacific Region (WPR) established a goal to decrease chronic hepatitis B virus (HBV) infection among children to <1% and to achieve ≥95% hepatitis B vaccine birth dose (HepB-BD) and ≥95% three-dose (HepB3) coverage by 2017. In 2016, we conducted a national serosurvey in the Solomon Islands among 6–7-year-old school children to assess progress towards the control goal and immunity to measles, rubella, tetanus and diphtheria. Eighty schools were selected systematically proportional to their 6–7-year-old population; all 6–7-year-olds were enrolled. We collected basic demographic information and vaccination history. Children were tested for HBV surface antigen (HBsAg) using a rapid test, and for immunity to measles, rubella, tetanus, and diphtheria using a multiplex bead assay. In total, 1,249 out of 1,492 children (84%) were enrolled, among whom 1,169 (94%) underwent HBsAg testing and 1,156 (93%) provided dried blood spots. Almost 80% (n = 982) of enrolled children had vaccination cards, among whom 59% (n = 584) received a timely HepB-BD (within 24 hours of birth), 95% (n = 932) received HepB3, and >90% received vaccines for diphtheria, tetanus, and measles (rubella vaccine was not available at the time). HBsAg prevalence was 3.1% (95% confidence interval (CI): 2.0%–4.9%), with 55% of identified cases from one province. Among 982 children with vaccination cards, HBsAg prevalence was higher among children who had not received a timely HepB-BD and at least two HepB doses compared to those who had (4% vs. 2%). Of 1,156 tested children, immunoprotection estimates were 99% (95% CI: 98%–99%) for measles, 99% (95% CI: 97%–100%) for rubella, 85% (95% CI: 83%–87%) for tetanus, and 51% (95% CI: 47%–55%) for diphtheria. Improving timely HepB-BD coverage and maintaining high HepB3 coverage could help Solomon Islands reach the regional HBV control goal. Low immunity to tetanus and diphtheria suggests the need to introduce booster doses to ensure long-term protection.     

Influenza vaccination uptake among Canadian adults before and during the COVID-19 pandemic: An analysis of the Canadian Longitudinal study on Aging (CLSA)

IntroductionUnderstanding how influenza vaccine uptake changed during the 2020/2021 influenza season compared to previous pre-pandemic seasons is a key priority, as is identifying the relationship between prior influenza vaccination and COVID-19 vaccine willingness.MethodsWe analyzed data from a large, nationally representative cohort of Canadian residents aged 50 and older to assess influenza vaccination status three times between 2015 and 2020. We investigated: 1) changes in self-reported influenza vaccine uptake, 2) predictors of influenza vaccine uptake in 2020/2021, and 3) the association between influenza vaccination history and self-reported COVID-19 vaccine willingness using logistic regression models.ResultsAmong 23,385 participants analyzed for aims 1–2, influenza vaccination increased over time: 14,114 (60.4%) in 2015–2018, 15,692 (67.1%) in 2019/2020, and 19,186 (82.0%; combining those already vaccinated and those planning to get a vaccine) in 2020/2021. After controlling for socio-demographics, history of influenza vaccination was most strongly associated with influenza vaccination in 2020/2021 (adjusted odds ratio [aOR] 147.9 [95% CI: 120.9–180.9]); this association remained after accounting for multiple health and pandemic-related factors (aOR 140.3 [95% CI: 114.5–171.8]). To a lesser degree, those more concerned about COVID-19 were also more likely to report influenza vaccination in fall 2020, whereas those reporting a very negative impact of the pandemic were less likely to get vaccinated. Among 23,819 participants with information on COVID-19 vaccine willingness during the last quarter of 2020 (aim 3), prior influenza vaccination was most strongly associated with willingness to get a COVID-19 vaccine (aOR 15.1 [95% CI: 13.5–16.8] for those who had received influenza vaccine at all previous timepoints versus none).ConclusionsOur analysis highlights the importance of previous vaccination in driving vaccination uptake and willingness. Efforts to increase vaccination coverage for influenza and COVID-19 should target individuals who do not routinely engage with immunization services regardless of demographic factors.     

Using classification and regression tree analysis to explore parental influenza vaccine decisions

Background and objectivesInfluenza poses a public health threat for children and adults. The CDC recommends annual influenza vaccination for children <18 years, yet vaccine uptake remains low for children (57.9%) and adults (37.1%). Given that parental decision-making is key in childhood vaccine uptake, there is a critical need to understand vaccine hesitancy among parents who decide not to vaccinate their children. This study aims to explore predictors of children’s influenza vaccine status given parental vaccination status and examine the factors that contribute to concordance or discordance between parental and children’s vaccine uptake.MethodsClassification and regression tree (CART) analyses were used to identify drivers of parental decisions to vaccinate their children against influenza. Hierarchy and interactions of these variables in predicting children’s vaccination status were explored.ResultsFrom a nationally representative sample of non-Hispanic Black and White parents who completed an online survey (n = 328), the main factors influencing parents’ decisions to vaccinate their children were vaccine behavior following physician recommendation, knowledge of influenza recommendations for children, influenza vaccine confidence and disease risk. Among unvaccinated parents, the greatest concordance was observed among parents who usually do not get vaccinated following physician recommendation and had lower knowledge of recommendations for influenza vaccination for children. The greatest discordance was observed among unvaccinated parents who had lower hesitancy about recommended vaccines.ConclusionsUnderstanding drivers of parental decisions to vaccinate themselves and their children can provide insights on health communication and provider approaches to increase influenza vaccine coverage and prevent influenza related mortality.     

The effects of parent’s health literacy and health beliefs on vaccine hesitancy

Parental vaccine hesitancy is a key factor influencing children’s vaccination against infectious diseases such as the COVID-19. The current study aims to investigate how parent’s health literacy and health belief affect parental hesitancy toward the COVID-19 vaccination, and navigate effective measures to help parents make vaccination decision for children. A mixed-mode web survey was conducted among parents of children aged 3–11 years. Parental vaccine hesitancy, health literacy, and health beliefs were assessed. Parallel mediation model examined whether the association between parent's health literacy and vaccine hesitancy was mediated by health beliefs. In total, 11.3% of the 346 participants reported vaccine hesitancy. Hesitant parents were more likely to be he mother (Father: 4.5%; Mother: 12.9%) and with children having allergic issues (Allergic: 18.3%; Non-allergic: 9.8%). Meanwhile, parents with lower health literacy were more likely to show hesitancy towards vaccinating their children (β = −6.87, 95% CI = [−10.50, −3.11]). This relationship was partially mediated by more perceived barriers in vaccination (β = −2.53, 95%CI = [−4.09, −1.02]), but not other health beliefs. In other words, parents with better health literacy may perceive fewer barriers in making vaccination decision for their children, thus being less hesitant. Accordingly, healthcare professionals and policy makers could design education service to promote parents’ health literacy, and remove the perceived barriers as well as increase their confidence in following the COVID-19 vaccine guidance for children.     

Validation of parental reports of rotavirus vaccination of their children compared to the national immunization registry

BackgroundThe introduction of rotavirus vaccines into national immunization programs necessitates vaccine effectiveness evaluations. Parental report of vaccination status is a simple and accessible source of information; however, its validity is unclear.AimsTo validate parental reports of rotavirus immunization compared to documentation of vaccination in national immunization registry, and to assess vaccine effectiveness by each method.MethodsParents of 1272 children aged 2–59 months from northern Israel hospitalized for gastroenteritis in 2011–2015 were interviewed on the sociodemographics and rotavirus vaccination status of their child. Rotavirus immunization status based on parental report was compared to that documented in the national immunization registry, which was considered the gold standard. Stool samples collected from patients were tested for rotavirus antigen by immunochromotgraphy. In a rotavirus test-negative case-control study, vaccination history was compared between children found positive for rotavirus and those who tested negative. Vaccine effectiveness for ≥ 1 dose vs. zero doses was calculated as: (1-adjusted odds ratio) * 100.ResultsThe sensitivity and specificity of parental report of their child's immunization with a rotavirus vaccine were 97% (95% CI 96–98), and 75% (95% CI 65–82), respectively. Kappa coefficient was 0.69 (p < 0.001) for the agreement between the two methods. Rotavirus vaccine effectiveness was 72% (95% CI 54–84) when using parental report of rotavirus immunization and 79% (95% CI 62–88) when using the registry.ConclusionParental report of their child's immunization with a rotavirus vaccine demonstrated high sensitivity, although the specificity was relatively low. Vaccine effectiveness was similar regardless of method used to determine rotavirus immunization status. Parental report of vaccination status can be useful in vaccine effectiveness assessment.     

COVID-19 vaccine hesitancy among people living with HIV in a low-resource setting: A multi-center study of prevalence,correlates and reasons

BackgroundHesitancy to COVID-19 vaccine may worsen the burden of COVID-19 among people living with HIV (PLHIV), who are at a higher risk of COVID-19-related hospitalization and death, compared to HIV non-infected individuals. Therefore, we evaluate the predictors and reasons for COVID-19 vaccine hesitancy among unvaccinated PLHIV in six antiretroviral therapy (ART) clinics across northern Nigeria.MethodologyIn this cross-sectional study, conducted between October 2021 and February 2022 in six hospitals across two geopolitical regions of Nigeria, we utilized interviewer-administered questionnaires to assess COVID-19 vaccine hesitancy among a convenience sample of 790 eligible adult PLHIV. Hesitancy was defined as answering ‘no' or ‘maybe’ to a question asking participants their willingness to accept the COVID-19 vaccine. A multivariate logistic regression model was used to estimate the adjusted odds ratio (aOR) and 95% confidence interval (CI) of the factors associated with COVID-19 vaccine hesitancy among PLHIV.ResultsOf the total 660 unvaccinated participants included in the analysis (61.82% female, mean age [SD] of 39.76 [10.75]), 381 (57.72%) were hesitant to COVID-19 vaccine. Being 50 years and older (aOR: 0.43; 95% CI: 0.21–0.89), being unemployed (aOR: 0.57; 95% CI: 0.34–0.95), experiencing the adverse effects of ART (aOR: 0.36; 95% CI: 0.15–0.86), and perception of being at high risk of contracting COVID-19 (aOR: 0.22; 95% CI: 0.13–0.37) were associated with significantly lower odds of hesitancy. Conversely, being female (aOR: 1.64; 95% CI: 1.02–2.61) and attending ART clinics at state administrative capital cities (IIDH Kano [aOR: 2.40; 95% CI: 1.10–5.25], MMSH Kano [aOR: 5.59; 95% CI: 1.97–10.66], YSSH Damaturu [aOR: 9.88; 95% CI: 4.02–24.29] vs. GH Gashua) were associated with significantly higher odds of hesitancy. The most common reasons for hesitancy include fear of potential adverse effects, skepticism about vaccine efficacy, the rapid development of the COVID-19 vaccine, and the perceived lack of effort to develop a cure or vaccine for HIV/AIDS.ConclusionInterventions aimed at combating misperceptions and misinformation regarding the COVID-19 vaccination program may reduce the prevalence of COVID-19 vaccine hesitancy among unvaccinated PLHIV.     

Vaccine timeliness and prevalence of undervaccination patterns in children ages 0–19 months,U.S., National Immunization Survey-Child 2017

ObjectivesTypically, early childhood vaccination coverage in the U.S. is measured as the proportion of children by age 24 months who completed recommended vaccine series. However, these measures do not reflect whether vaccine doses were received at the ages recommended by the U.S. Advisory Committee on Immunization Practices, or whether children received vaccines concomitantly, per the ACIP recommended schedule. This study’s objective was to quantify vaccine timeliness and prevalence of specific patterns of undervaccination in U.S. children ages 0–19 months.MethodsUsing 2017 National Immunization Survey-Child data, we calculated days undervaccinated for the combined 7-vaccine series and distinguished undervaccination patterns indicative of parental vaccine hesitancy, such as spreading out vaccines across visits (“shot-limiting”) or starting some but not all recommended vaccine series (“selective vaccination”), from other non-hesitancy patterns, such as missing final vaccine doses or receiving all doses, with some or all late. We measured associations between demographic, socioeconomic and other characteristics with undervaccination patterns using multivariable log-linked binomial regression. Analyses accounted for the complex survey design.ResultsAmong n = 15,333 U.S. children, only 41.2% received all recommended vaccine doses on-time by age 19 months. Approximately 20.9% of children had an undervaccination pattern suggestive of parental vaccine hesitancy, and 36.2% had other undervaccination non-hesitancy patterns. Uninsured children and those with lower levels of maternal education were more likely to exhibit undervaccination patterns suggestive of parental hesitancy. Lower levels of maternal education were also associated with other non-hesitancy undervaccination patterns.ConclusionsMore than half of children in the U.S. are undervaccinated at some point by 19 months of age. Ongoing assessment of vaccine timeliness and immunization schedule adherence could facilitate timely and targeted public health interventions in populations with high levels of undervaccination.     

Long-term effectiveness of pentavalent and monovalent rotavirus vaccines against hospitalization in Taiwan children

BackgroundTwo rotavirus vaccines (RV1 and RV5) are available on the private market in Taiwan, not included in national immunization program. Scanty reports evaluated the rotavirus vaccine effectiveness (VE) in Asian countries.MethodsFrom February 2014-July 2017, we conducted a prospective case-control study in ten hospitals in Taiwan. Case-patients included children aged 8–59 months, and hospitalized with laboratory-confirmed rotavirus acute gastroenteritis (AGE). For each case patient, up to four controls, rotavirus-negative AGE or non-AGE illnesses, respectively, were matched by gender, age and enrolled date. Vaccination history was confirmed through vaccination card or hospital record. VE was calculated as (1 − odds ratio of vaccination) × 100%.ResultsTotally 4248 AGE patients and 2242 non-AGE controls were enrolled. A total of 330 case-patients with rotavirus AGE, 1226 rotavirus-negative AGE controls and 1122 non-AGE controls were included for analysis. Unvaccinated rate was 85.15% for rotavirus-positive cases, 42.9% for rotavirus-negative controls, and 34.31% for non-AGE controls. VE of two-dose RV1 was 84.9% (95% confidence interval [CI]:77.7%, 90.1%) for rotavirus-negative AGE and 88.9% (95% CI: 83.4%, 92.8%) for non-AGE controls, while VE of three-dose RV5 was 92.5% (95% CI: 85.1%, 96.7%) and 96.4% (95% CI: 91.9%, 98.6%), respectively. For respective vaccine, VEs were not significantly different in term of rotavirus genotypes. VEs of both vaccines declined <80% in children aged three years by combined controls.ConclusionsBoth vaccines provided excellent and sustained protection against rotavirus AGE hospitalization in children in Taiwan, but the effectiveness declined slightly in children aged three years.     

Relative effectiveness of a 2nd booster dose of COVID-19 mRNA vaccine up to four months post administration in individuals aged 80 years or more in Italy: A retrospective matched cohort study

Several countries started a 2nd booster COVID-19 vaccination campaign targeting the elderly population, but evidence around its effectiveness is still scarce. This study aims to estimate the relative effectiveness of a 2nd booster dose of COVID-19 mRNA vaccine in the population aged ≥ 80 years in Italy, during predominant circulation of the Omicron BA.2 and BA.5 subvariants.We linked routine data from the national vaccination registry and the COVID-19 surveillance system. On each day between 11 April and 6 August 2022, we matched 1:1, according to several demographic and clinical characteristics, individuals who received the 2nd booster vaccine dose with individuals who received the 1st booster vaccine dose at least 120 days earlier. We used the Kaplan-Meier method to compare the risks of SARS-CoV-2 infection and severe COVID-19 (hospitalisation or death) between the two groups, calculating the relative vaccine effectiveness (RVE) as (1 – risk ratio)X100.Based on the analysis of 831,555 matched pairs, we found that a 2nd booster dose of mRNA vaccine, 14–118 days post administration, was moderately effective in preventing SARS-CoV-2 infection compared to a 1st booster dose administered at least 120 days earlier [14.3 %, 95 % confidence interval (CI): 2.2–20.2]. RVE decreased from 28.5 % (95 % CI: 24.7–32.1) in the time-interval 14–28 days to 7.6 % (95 % CI: ?14.1 to 18.3) in the time-interval 56–118 days. However, RVE against severe COVID-19 was higher (34.0 %, 95 % CI: 23.4–42.7), decreasing from 43.2 % (95 % CI: 30.6–54.9) to 27.2 % (95 % CI: 8.3–42.9) over the same time span.Although RVE against SARS-CoV-2 infection was much reduced 2–4 months after a 2nd booster dose, RVE against severe COVID-19 was about 30 %, even during prevalent circulation of the Omicron BA.5 subvariant. The cost-benefit of a 3rd booster dose for the elderly people who received the 2nd booster dose at least four months earlier should be carefully evaluated.     

Safety and immunogenicity of a pichia pastoris-expressed bivalent human papillomavirus (types 16 and 18) L1 virus-like particle vaccine in healthy Chinese women aged 9–45 years: A randomized,double-blind,placebo-controlled phase 1 clinical trial

BackgroundWe evaluated the safety and immunogenicity of high and low doses of a novel pichia pastoris-expressed bivalent (types 16 and 18) human papillomavirus (HPV) virus-like particle vaccine.MethodsIn this randomized, double-blind, placebo-controlled phase 1 trial, we enrolled 160 healthy females aged 9–45 years in Guangxi, China who were randomized (1:1:2) to receive either low (0.5 mL) or high (1.0 mL) dosages of bivalent HPV vaccine, or placebo (aluminum adjuvant) in a 0, 2, 6 months schedule. Adverse events and other significant conditions that occurred within 30 days after each vaccination were recorded throughout the trial. Sera were collected at days 0, 60, 180 and 210 to measure anti-HPV 16/18 neutralizing antibodies.ResultsA total of 160 participants received at least one dose of the HPV vaccine and 152 completed the three dose vaccination series. Reporting rates of adverse events in placebo, low dose (0.5 mL) and high dose (1.0 mL) groups were 47.5 %, 55.0 % and 55.0 %, respectively. No serious adverse events occurred during this trial. 100 % of the participants who received three doses of the HPV vaccine produced neutralizing antibodies against HPV 16/18 vaccine. For HPV 16 and HPV 18, the geometric mean titers (GMTs) were similar between the low dose group (GMT_{HPV 16} = 10816 [95 % CI: 7824–14953]), GMT_{HPV 18} = 3966 [95 % CI: 2693–5841]) and high dose group (GMT _{HPV 16} = 14482 [95 % CI: 10848–19333], GMT _{HPV 18} = 3428 [95 % CI: 2533–4639]).ConclusionThe pichia pastoris-expressed bivalent HPV vaccine was safe and immunogenic in Chinese females aged 9–45 years. The low dosage (0.5 mL) was selected for further immunogenicity and efficacy study.