Vaccination Delay Research Articles

Mathematical approach for impact of media awareness on measles disease

During the recent pandemic caused by COVID‐19, media awareness played a crucial role in educating people about social distancing, wearing masks, quarantine, vaccination, and medication. Media awareness brought individual behavioral changes among the people, which in turn helped reduce the infection rate. Motivated by this, we have formulated a mathematical model introducing a media compartment to mitigate measles disease transmission. In this paper, the SEIR model is used to study measles disease in three cases: one with a delay in vaccination, the second with regular vaccination, and the third with the impact of media awareness on the spreading of measles disease. Further, the dynamical behavior of the models is studied in terms of positivity, boundedness, equilibrium, and basic reproduction number (BRN). The sensitivity analysis of the models is conducted, which verifies the importance of the BRN ( ) to be less than one for disease eradication. The numerical study confirms the impact of media awareness on exposed and infected populations.

Assessing the impact of the 2018 Changchun Changsheng vaccine incident on childhood vaccination in China

BackgroundThe 2018 Changchun Changsheng vaccine incident is an emergent public health event in China with reports of DTaP vaccines with compromised efficacy. This study aimed to estimate the impact of the vaccine incident on real-world vaccination behaviors in China.MethodsA cross-sectional survey was conducted in ten provinces in 2019. Vaccination records were collected from 5294 children aged 6-59 months, with information on 75,579 vaccine doses for seven National Immunization Program (NIP) vaccines and two non-NIP vaccines received from 2014 to 2019. Chi-square test, interrupted time series, and logistic regression were used to evaluate the impacts of vaccine incident on vaccination delay, measured as the proportion of delayed doses out of total doses in schedule.ResultsHere we show significant increases in doses delayed ≤ 3 months (19.12% to 22.51%, p = 0.000) and > 3 months (7.17% to 11.82%, p = 0.000) for DTaP vaccine after the incident. By scaling nationally, there will be extra 2.1 million doses delayed ≤ 3 months and 2.8 million doses delayed > 3 months in the year following this incident. More guardians choose expensive private-market substitutes containing DTaP elements over government-funded DTaP vaccines. Controlling for socio-demographic factors, doses scheduled after the incident have higher odds of delays for DTaP vaccine (OR: 3.49, 95% CI: 3.08–3.96) and other NIP vaccines (OR: 2.76, 95% CI: 2.55–2.99), but not for non-NIP vaccines.ConclusionsThe observed delays in the incident-involved DTaP vaccine immunization reflect the negative effects of the vaccine incident on vaccination behaviors under the NIP. However, its effects seem minimal for non-NIP vaccines.

Timeliness of childhood vaccination in England: A population-based cohort study

IntroductionVaccine surveillance for children in England focuses on coverage at ages 1, 2, and 5 years. Previous studies exploring vaccine timeliness have used different arbitrary categories to define whether vaccines were received ‘late’ or ‘on time’. This paper aims to provide more detailed and holistic information on timing and patterns of vaccine uptake across the childhood immunisation schedule in England. MethodsWe included all children born in England between 2006 and 2014 and registered in the Clinical Practice Research Datalink (CPRD) Aurum, a primary care electronic health record. We described vaccine uptake for representative antigens (pertussis, pneumococcus, measles) by age in days and stratified by ethnicity, region and birth cohort. Alluvial diagrams were used to illustrate common journeys through the vaccination schedule, and we applied survival analysis using accelerated failure time models (AFT) to predict age of vaccine receipt based on timing of previous doses. Results573,015 children were followed up until their fifth birthday, when they had 90.16 % coverage for two doses of measles, mumps, rubella (MMR) vaccine and 88.78% coverage for four doses of diphtheria, tetanus, pertussis (DTP) vaccine. Overall, the later the age at which a vaccine was due, the more delay in vaccination. Children of Black Ethnicity or from London showed deviating uptake patterns. If a child received their third DTP dose more than a year later than recommended, they would receive the next dose 2.7 times later than a child who was vaccinated on time. A smaller delay was found for children who did not receive first MMR dose on time. DiscussionWe showed that the risk of vaccination delay increased with the age of the child and significant delay of previous doses. Primary care data can help to promptly identify children at higher risk of delayed vaccination.

Factors Contributing to the Delayed Vaccination Among Children in Riyadh City, Saudi Arabia: A Cross-Sectional Study.

Background Immunizations protect children from deadly infectious diseases. The timeliness of vaccinating children is crucial to ensure effective immunization and to decrease the burden of many infectious diseases. Therefore, this study assessed the prevalence and determinants of vaccination delay among children in Riyadh City, Saudi Arabia. Methods This cross-sectional study was conducted at the primary healthcare centers in Riyadh City, Saudi Arabia, on 593 parents with children of two years of age or below. It used a self-administered questionnaire inquiring about socio-demographic characteristics and assessing the vaccination statuses of their children and the causes of delayed vaccinations. Results The results showed that 7.1% of children had a delay in the previous vaccination. Of those delays, collectively, 77.5% were delays in inactivated poliovirus vaccine (IPV), oral poliovirus vaccine (OPV), and meningococcal vaccine (MCV) vaccines. The delay was mostly caused by an illness of the child on vaccination day, carelessness of parents, or long postponement. After adjusting for confounders, the father's high school or bachelor's education level (OR = 1.18, 95% CI: 1.03, 1.36) (p<0.05), child's mix-type nutrition (OR = 1.06, 95% CI: 1.02, 1.10) (p=0.001), and the belief that multiple vaccines are harmful to the child (POR = 1.03, 95% CI: 1.01, 1.06) (p=0.005) were positively associated with vaccination delay, while prematurity was negatively associated with vaccination delay (OR = 0.96, 95% CI: 0.93, 0.99) (p=0.031). Conclusion The study found the prevalence of vaccination delay was lower than in previous COVID-19-era studies. The child's illness was the main reason for the delay. Factors like parental education, nutrition type, and vaccine beliefs contributed to delays, while prematurity reduced delays. Measures should be strengthened to increase vaccination coverage for children.

The association between vaccine hesitancy and pertussis: a systematic review and meta-analysis

BackgroundRobust routine immunization schedules for pertussis-containing vaccines have been applied for years, but pertussis outbreaks remain a worldwide problem. This study aimed to investigate the association between vaccine hesitancy and pertussis in infants and children.MethodsWe searched PubMed, Cochrane, Web of Science, Embase, and China National Knowledge Internet for studies published between January 2012 and June 2022. This study included case–control and cohort studies that assessed the association between childhood/maternal vaccine hesitancy and odds ratios (ORs), risk ratios (RRs), and vaccine effectiveness (VE) related to pertussis in infants and children le 9 years old. ORs/VEs with a 95% confidence interval (CI) were calculated. Random-effects meta-analysis models were used for appropriate pooled estimates, and heterogeneity was assessed using {I}^{2}. Cumulative meta-analysis and subgroup analyses stratified by study characteristics were performed.ResultsTwenty-two studies were included, with a mean quality score of 7.0 (range 6.0–9.0). Infants and children with pertussis were associated with higher vaccine hesitancy to all doses (OR = 4.12 [95% CI: 3.09–5.50]). The highest OR was between children who were unvaccinated over four doses and children who were fully vaccinated (OR = 14.26 [95%CI: 7.62–26.70]); childhood vaccine delay was not statistically significantly associated with pertussis risk (OR = 1.18 [95% CI: 0.74–1.89]). Maternal vaccine hesitancy was associated with significantly higher pertussis risk in infants aged 2 and 3 months old, with higher pertussis ORs in infants le 2 months old (OR = 6.02 [95%CI: 4.31–8.50], OR = 5.14 [95%CI: 1.95–13.52] for infants le 2 and le 3 months old, respectively). Maternal and childhood VEs were high in reducing pertussis infection in infants and children. The administration time of maternal vaccination had little effect on VE.ConclusionVaccine hesitancy increased pertussis risks in infants and children. Ensuring that children receive up-to-date pertussis vaccines is essential; short delays in receiving childhood vaccinations may be unimportant. Maternal vaccinations for pertussis should be encouraged.

The Importance of Mapping Determinants, Attitudes and Beliefs of Vaccine Hesitancy in the Great Challenge of Compulsory Childhood Vaccination Comment on "Convergence on Coercion: Functional and Political Pressures as Drivers of Global Childhood Vaccine Mandates".

Vaccine hesitancy (VH) has risen significantly during the COVID-19 pandemic, becoming a major global health concern. VH is characterized by the delay or refusal of vaccination despite its availability. Various frameworks have been developed to understand the complex factors influencing VH, with attitudes, beliefs, and external influences being the most significant. The surge in VH has reignited the debate on the best approach to address it: persuasive/ educational or coercive. Attwell and Hannah studied the political and social reasons behind the adoption of mandatory vaccination in four jurisdictions (Italy, France, Australia, and California) due to declining vaccine coverage below the safety threshold. However, these methods may foster parental disbeliefs and opposition to vaccination campaigns. To combat VH, it is crucial to systematically assess its determinants within specific contexts and population groups. Increasing awareness about vaccination benefits, engaging with social media, and employing tailored strategies can foster spontaneous adherence to vaccination programs, eliminating the need for coercive measures.

Nurses’ perceptions, experiences, and practices regarding human papillomavirus vaccination: results from a cross-sectional survey in Montana

BackgroundNationally, much of the focus on improving human papillomavirus (HPV) vaccine uptake has been on effective strategies that physicians use to promote vaccination. However, in large, predominately rural states like Montana, nurses and medical assistants play critical roles in immunization services delivery, and their viewpoints are imperative in designing strategies to increase vaccination rates. We conducted a cross-sectional, descriptive study to determine nurses’ perceptions, experiences, and practices regarding human papillomavirus vaccination in a rural and medically underserved region of the United States.MethodsWe designed, pilot-tested, and disseminated an online survey instrument to nurses and medical assistants working in clinics participating in the Vaccines for Children program in Montana. The online surveys were administered from November 2020 to March 2021. Survey questions focused on clinic vaccination practices, respondents’ perceptions of the HPV vaccine, perceived barriers to vaccine uptake, and general opinions on potential strategies to improve HPV vaccination rates.ResultsWe analyzed data from 227 respondents. Overall, 90% of nurses strongly agreed or agreed that the HPV vaccine is important and had confidence in the vaccine’s safety. More nurses reported experiencing greater parental vaccine refusal or delay for male patients regardless of age. About 53.7% of nurses reported that their clinics had reminder/recall systems to encourage parents to bring their children for vaccination. Nurses identified misinformation from social media, infrequent wellness visits, and vaccine safety concerns as barriers to HPV vaccine uptake.ConclusionsStudy findings identified several promising initiatives to accelerate vaccination in primarily rural states like Montana, including promoting widespread adoption of reminder/recall systems, training nurses in evidence-based techniques to provide strong vaccine recommendations, and leveraging social media to disseminate consistent messages about the HPV vaccine recommendations for both sexes and its role in cancer prevention.

Pushed to the Fringe – The Impact of Vaccine Hesitancy on Children and Families

ABSTRACT Vaccine hesitancy has been described as any delay or refusal of vaccines despite their availability and is increasing in Australia and other middle to high-income countries. The aim of this study is to gain a deep understanding of the experiences and influences on vaccine hesitant children and their families. A qualitative interview approach was undertaken with vaccine hesitant parents and pregnant women (n = 12). Semi-structured interviews were conducted by telephone. Inductive thematic analysis was undertaken on data obtained using the guidelines of Braun and Clarke. Three main themes were identified in this study, including Pushed to the fringe; A culture of Distrust; and Coerced choices. The study revealed that vaccine hesitant parents felt isolated and pushed to the fringe of society. They also expressed dissatisfaction with the Australian “No Jab – No Pay” and “No Jab – No Play” legislation. This contributed to feelings of marginalization. Participants also cited a breakdown in the therapeutic relationships, which impacted their child’s health. Additionally, a lack of sufficient information was received to achieve informed consent. These results suggest that there is a need for enhanced education for some health-care professionals, many of whom have reported being confronted by conversations with vaccine hesitant parents.

How Facebook's newsfeed algorithm shapes childhood vaccine hesitancy: An algorithmic fairness, accountability, and transparency (FAT) perspective

Vaccine hesitancy is the delay or refusal of vaccination when vaccines are available. Over the last decade, many reports have suggested that the proliferation of vaccine disinformation and misinformation on social media has aggravated the vaccine-hesitancy problem. Access to vaccine dis(mis)information on social media is deemed partly responsible for the resurfacing of vaccine-preventable diseases (e.g., measles). Although studies have examined social media dis(mis)information, including that related to vaccines, the newsfeed algorithm, which determines the content social media users see, has received scant attention in the literature. We examine how people's perceptions of the fairness, accountability, and transparency (FAT) of the Facebook newsfeed algorithm influence their intention to vaccinate their children. We find that people's perceptions of the Facebook newsfeed algorithm's FAT increase their negative attitudes toward vaccination (fairness and transparency). However, they decrease users' perceptions of antivaccination norms on Facebook (fairness, accountability, and transparency). Negative attitudes toward vaccination decrease the intention to vaccinate, as do perceptions of Facebook antivaccination norms. Our findings demonstrate that to decrease the effectiveness of vaccine dis(mis)information, it is critical to educate the public about how social media newsfeed algorithms make content-display decisions.

Incomplete Childhood Vaccination and Associated Factors Among Children Aged 12–23 Months; Assessment of Time-To-Corrected Missed Opportunity for Vaccination for Routine Immunization: Evidence from The Cameroon Demographic and Health Survey 2018

Background: Complete childhood vaccination remains poor in Sub-Saharan African countries. Although missed opportunity for vaccination (MOV) was found responsible for low coverage, median time-to-corrected is useful to assess delay in vaccination. We explored incomplete vaccination coverage, describe characteristics of children who experienced corrected MOV for all antigens, and estimate median survival time. Method: Secondary analyses of a sample of 1285 (total weights=1315.91) children aged 12 to 23 months with at least one vaccination date, was performed. A weighted survival Kaplan-meier curve was use to estimate median time-to-corrected MOV for for each vaccine. Multiple correspondance analysis (MCA) was called to describe characteristics of children with corrected MOV and incomplete vaccination. We used the YFV corrected MOV status in the MCA analysis as it had the highest probability of outcome. A binary logistic regression analysis was used to identify factors associated to both outcomes. Results: Median survival time ranged from 5 (OPV0) to 96 days (Penta3). For the YFV, it was 22 days, and 65 days for MCV1. MCA analysis revealed two main dimensions characterized mainly by: first, by children who experienced MOV for simultaneous vaccines, born to uneducated mothers with no occupation, who were in contact with health facility within 2 months after birth; second, by first of third bird order children, born to caregivers less than 24 years or more than 31 years, who either had an occupation skill, or were not working. Probability of corrected MOV decreases among caregivers less than 24 years, those who delivered at home and had no antenatal care. Factors associated to incomplete vaccination revealed a decrease in the odds: in children whose mothers attended health facility within 2 months after birth, mother’s age more than 31 years than less than 24 years and, an increase in the odds with children who had less than 5 contacts with the health facility. Conclusion: Enhance effort on strategies targetting mothers during their stay in the maternity, heads of households, and younger mothers, is needed to increase vaccination coverage among children. Caregivers should pay attention to child’s vaccination schedule, and complete each vaccine ontime.

VACCINE HESITANCY IN BRAZIL: CAUSES AND CONSEQUENCES

Vaccine refusal or delay is an old and increasingly prevalent phenomenon. The effectiveness of vaccines has been proven, for example, by eliminating human smallpox. However, some of the population questions this resource. Vaccine hesitancy can be caused by personal beliefs, the spread of fake news, political positioning, and growth of anti-vaccine movements. Despite personal freedom, public health needs to be prioritized. Instead, it ends up suffering consequences. Among these, low vaccine coverage and economic impact.

Gambaran Karakteristik dan Status Gizi Anak yang Melakukan Vaksinasi Covid-19 di UPT Puskesmas Kayon Kota Palangka Raya

Achievement of the COVID 19 vaccination target, especially for children who received dose 2, has only reached 58.7%. One of the obstacles to achieving the vaccination target is the delay in vaccination because the child is sick. Health conditions at the time of vaccination are sought to be healthy and optimal. Nutritional status has an important role in determining the body's immune response. The purpose of this study was to determine the characteristics and nutritional status of children vaccinated against COVID-19 at UPT Puskesmas Kayon, Palangka Raya City. This type of research is a descriptive method, with a cross-sectional design, using a purposive sampling technique, for 3 months from July to September 2022. The research instruments used were a questionnaire and examination of nutritional status. The results showed that the number of respondents was 40 people, 52.5% female and 47.5% male. Age distribution from 6-11 years. Vaccination history at dose 1 20% and dose 2 80%. The nutritional status of the dominant respondents had a normal nutritional status of 67.5%, 20% less nutrition and 12.5% more nutritional status. The conclusion of this study shows that the age distribution of the most respondents is 11 years with the dominant nutritional status of respondents with normal nutritional status.

Dynamic analysis of delayed vaccination process along with impact of retrial queues

Abstract An unprecedented and precise time-scheduled rollout for the vaccine is needed for an effective vaccination process. This study is based on the development of a novel mathematical model considering a delay in vaccination due to the inability to book a slot in one go for a system. Two models are proposed which involve a delay differential equation mathematical model whose dynamical analysis is done to show how the delay in vaccination can destabilize the system. Further, this delay led to the formulation of a queuing model that accounts for the need to retry for the vaccination at a certain rate as delay in vaccination can have negative repercussions. The transition rates from one stage to another follow an exponential distribution. The transient state probabilities of the model are acquired by applying the Runge-Kutta method and hence performance indices are also obtained. These performance measures include the expected number of people in various states. Finally, numerical analysis is also provided to validate both models. Our results would specifically focus on what happens if the delay time increases or if the retrial rate increases (delay time decreases). The results reveal that a delay in being vaccinated by the first dose (i.e., 80 days) leads to an unstable system whereas there exists a delay simultaneously in getting vaccinated by both doses that destabilize the system early (i.e., 80 and 120 days for dose one and two, respectively). The system destabilizes faster in the presence of a delay for slot booking for both doses as compared to one dose delay. Further, the numerical results of queuing models show that if the retrial rate increases in this delay time to book the slots, it not only increases in the vaccinated class but also increases the recovered population.

Stability analysis of an epidemic model with vaccination and time delay

This paper presents an epidemic model with varying population, incorporating a new vaccination strategy and time delay. It investigates the impact of vaccination with respect to vaccine efficacy and the time required to see the effects, followed by determining how to control the spread of the disease according to the basic reproduction ratio of the disease. Some numerical simulations are provided to illustrate the theoretical results.

Spatial distribution and determinants of childhood vaccination refusal in the United States.

Parental refusal and delay of childhood vaccination has increased in recent years in the United States. This phenomenon challenges maintenance of herd immunity and increases the risk of outbreaks of vaccine-preventable diseases. We examine US county-level vaccine refusal for patients under five years of age collected during the period 2012-2015 from an administrative healthcare dataset. We model these data with a Bayesian zero-inflated negative binomial regression model to capture social and political processes that are associated with vaccine refusal, as well as factors that affect our measurement of vaccine refusal. Our work highlights fine-scale socio-demographic characteristics associated with vaccine refusal nationally, finds that spatial clustering in refusal can be explained by such factors, and has the potential to aid in the development of targeted public health strategies for optimizing vaccine uptake.

Determinants of vaccine refusal, delay and reluctance in parents of 2-year-old children in Canada: Findings from the 2017 Childhood National Immunization Coverage Survey (cNICS)

Vaccine hesitancy is a barrier to improving childhood vaccination rates in Canada, but the scope of this problem is unclear due to inconsistent measurement of vaccine uptake indicators. Using 2017 data from a Canadian national vaccine coverage survey, this study analyzed the impact of demographics and parental knowledge, attitudes and beliefs (KAB) on vaccine decisions (refusal, delay and reluctance) in parents of 2-year-old children who had received at least one vaccine. The findings show that 16.8% had refused a vaccine, specifically influenza (73%), rotavirus (13%) and varicella (9%); female parents or those from Quebec or the Territories more likely to refuse. 12.8% were reluctant to accept a vaccine, usually influenza (34%), MMR (21%) and varicella (19%), but eventually accepted them upon advice from a health care provider. 13.1% had delayed a vaccine, usually because their child had health issues (54%) or was too young (18.6%) and was predicted by five or six person households. Recent immigration to Canada decreased likelihood of refusal, delay, or reluctance; however, after 10 years in Canada, these parents were as likely to refuse or be reluctant as parents born in Canada. Poor KAB increased likelihood of refusal and delay by 5 times, and reluctance by 15 times, while moderate KAB increased likelihood of refusal (OR 1.6), delay (OR 2.3) and reluctance (OR 3.6). Future research into vaccine decisions by female and/or single parents, and predictors of vaccine KAB would provide valuable information and help protect our children from vaccine preventable diseases.

COVID-19 Vaccine Refusal and Delay among Adults in Italy: Evidence from the OBVIOUS Project, a National Survey in Italy.

Vaccine hesitancy was defined by the World Health Organization (WHO) in 2019 as a major threat to global health. In Italy, reluctance to receive vaccines is a widespread phenomenon that was amplified during the COVID-19 pandemic by fear and mistrust in government. This study aims to depict different profiles and characteristics of people reluctant to vaccinate, focusing on the drivers of those who are in favor of and those who are opposed to receiving the COVID-19 vaccine. A sample of 10,000 Italian residents was collected. A survey on COVID-19 vaccination behavior and possible determinants of vaccine uptake, delay, and refusal was administered to participants through a computer-assisted web interviewing method. In our sample, 83.2% stated that they were vaccinated as soon as possible ("vaccinators"), 8.0% delayed vaccination ("delayers"), and 6.7% refused to be vaccinated ("no-vaccinators"). In general, the results show that being female, aged between 25 and 64, with an education level less than a high school diploma or above a master's degree, and coming from a rural area were characteristics significantly associated with delaying or refusing COVID-19 vaccination. In addition, it was found that having minimal trust in science and/or government (i.e., 1 or 2 points on a scale from 1 to 10), using alternative medicine as the main source of treatment, and intention to vote for certain parties were characteristics associated with profiles of "delayers" or "no-vaccinators". Finally, the main reported motivation for delaying or not accepting vaccination was fear of vaccine side effects (55.0% among delayers, 55.6% among no-vaccinators). In this study, three main profiles of those who chose to be vaccinated are described. Since those who are in favor of vaccines and those who are not usually cluster in similar sociodemographic categories, we argue that findings from this study might be useful to policy makers when shaping vaccine strategies and choosing policy instruments.

'I'm provax': Pro-vaccination personal histories and socialities of older Australians in the COVID-19 pandemic.

Vaccination scholarship often explores how social networks foster vaccine refusal and delay, revealing how social and institutional relations produce refusing or delaying parents and un- or under-vaccinated children. It is likewise critical to understand the development of pro-vaccination orientations by researching those who want to be vaccinated since such attitudes and associated practices underpin successful vaccination programmes. This article explores pro-vaccination sociality, personal histories and self-understandings during the COVID-19 pandemic in Australia. We draw upon 18 in-depth interviews with older Western Australians, documenting how they articulate 'provax' identities in opposition to those they depict as 'antivax' others. Provax identities were clearly anchored in and solidified through social relations and personal histories, as interviewees spoke of 'likeminded' friends and families who facilitated each other's vaccinations and referenced childhood experiences of epidemics and vaccinations. Access barriers relating to the vaccine programme drove interviewees to reimagine their provax status in light of not yet being vaccinated. Thus, interviewees' moral and ideological understandings of themselves and others were interrelated with supply-side constraints. We examine the development of self-proclaimed 'provaxxers' (in a context of limited access); how they imagine and enact boundaries between themselves and those they deem 'antivax'; and possibilities for public health research.

Optimal time for COVID-19 vaccination in rituximab-treated dermatologic patients.

By depleting circulating B lymphocytes, rituximab time-dependently suppresses coronavirus disease 2019 (COVID-19) vaccines' humoral immunogenicity for a prolonged period. The optimal time to vaccinate rituximab-exposed immune-mediated dermatologic disease (IMDD) patients is currently unclear. To estimate the vaccination timeframe that equalized the occurrence of humoral immunogenicity outcomes between rituximab-exposed and rituximab-naïve IMDD patients. This retrospective cohort study recruited rituximab-exposed and age-matched rituximab-naïve subjects tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific immunity post-vaccination. Baseline clinical and immunological data (i.e., immunoglobulin levels, lymphocyte immunophenotyping) and SARS-CoV-2-specific immunity levels were extracted. The outcomes compared were the percentages of subjects who produced neutralizing antibodies (seroconversion rates, SR) and SARS-CoV-2-specific IgG levels among seroconverters. The outcomes were first analyzed using multiple regressions adjusted for the effects of corticosteroid use, steroid-spearing agents, and pre-vaccination immunological status (i.e., IgM levels, the percentages of the total, naïve, and memory B lymphocytes) to identify rituximab-related immunogenicity outcomes. The rituximab-related outcome differences with a 95% confidence interval (CI) between groups were calculated, starting by including every subject and then narrowing down to those with longer rituximab-to-vaccination intervals (≥3, ≥6, ≥9, ≥12 months). The desirable cut-off performances were <25% outcome inferiority observed among rituximab-exposed subgroups compared to rituximab-naïve subjects, and the positive likelihood ratio (LR+) for the corresponding outcomes ≥2. Forty-five rituximab-exposed and 90 rituximab-naive subjects were included. The regression analysis demonstrated a negative association between rituximab exposure status and SR but not with SARS-CoV-2-specific IgG levels. Nine-month rituximab-to-vaccination cut-off fulfilled our prespecified diagnostic performance (SR difference between rituximab-exposed and rituximab-naïve group [95%CI]: -2.6 [-23.3, 18.1], LR+: 2.6) and coincided with the repopulation of naïve B lymphocytes in these patients. Nine months of rituximab-to-vaccination interval maximize the immunological benefits of COVID-19 vaccines while avoiding unnecessary delay in vaccination and rituximab treatment for IMDD patients.

Public decisions about COVID-19 vaccines: A UK-based qualitative study.

To explore UK public decisions around whether or not to get COVID-19 vaccines, and the facilitators and barriers behind participants' decisions. This qualitative study consisted of six online focus groups conducted between 15th March and 22nd April 2021. Data were analysed using a framework approach. Focus groups took place via online videoconferencing (Zoom). Participants (n = 29) were a diverse group (by ethnicity, age and gender) UK residents aged 18 years and older. We used the World Health Organization's vaccine hesitancy continuum model to look for, and explore, three main types of decisions related to COVID-19 vaccines: vaccine acceptance, vaccine refusal and vaccine hesitancy (or vaccine delay). Two reasons for vaccine delay were identified: delay due to a perceived need for more information and delay until vaccine was "required" in the future. Nine themes were identified: three main facilitators (Vaccination as a social norm; Vaccination as a necessity; Trust in science) and six main barriers (Preference for "natural immunity"; Concerns over possible side effects; Perceived lack of information; Distrust in government;; Conspiracy theories; "Covid echo chambers") to vaccine uptake. In order to address vaccine uptake and vaccine hesitancy, it is useful to understand the reasons behind people's decisions to accept or refuse an offer of a vaccine, and to listen to them and engage with, rather than dismiss, these reasons. Those working in public health or health communication around vaccines, including COVID-19 vaccines, in and beyond the UK, might benefit from incorporating the facilitators and barriers found in this study.