Willingness to get vaccinated against Covid-19 and attitudes toward vaccination in general

BackgroundHigh uptake of Covid-19 vaccination is required to reach herd immunity.MethodsA representative sample of 2,060 Belgians were surveyed in October 2020. Regression analyses identified the predictors associated with willingness to get vaccinated against Covid-19, and attitudes toward vaccination in general.Results34% of the participants reported that they will definitely get vaccinated against Covid-19 and 39% that they would “probably”. Intended uptake was strongly associated with age, opinion on the government’s dealing with the Covid-19 pandemic, medical risk, spoken language, gender, and to a lesser extent with having known someone who was hospitalised because of Covid-19. Similar predictors were identified for attitudes to vaccination in general. Covid-19 vaccine hesitancy was more marked in age groups below 54 years old. We further analysed a sample of 17% (N = 349) found favourable to vaccination in general but not willing to be vaccinated against Covid-19. They were mainly female, young, French speaking, slightly less educated, working, and did not belong to a Covid-19 risk group. They were very dissatisfied with the government’s dealing with the pandemic, and did not know someone who was hospitalised because of Covid-19.ConclusionsVaccine hesitancy was higher for Covid-19 vaccines than for other vaccines. The part of the population being convinced of the utility of vaccination in general but hesitant about the Covid-19 vaccine is a primary interest group for tailored communication campaigns in order to reach the vaccine coverage needed for herd immunity.     

Covid-19 vaccine immunogenicity in people living with HIV-1

IntroductionCOVID-19 vaccine efficacy has been evaluated in large clinical trials and in real-world situation. Although they have proven to be very effective in the general population, little is known about their efficacy in immunocompromised patients. HIV-infected individuals’ response to vaccine may vary according to the type of vaccine and their level of immunosuppression. We evaluated immunogenicity of an mRNA anti-SARS CoV-2 vaccine in HIV-positive individuals.MethodsHIV-positive individuals (n = 121) were recruited from HIV clinics in Montreal and stratified according to their CD4 counts. A control group of 20 health care workers naïve to SARS CoV-2 was used. The participants’ Anti-RBD IgG responses were measured by ELISA at baseline and 3–4 weeks after receiving the first dose of an mRNA vaccine).ResultsEleven of 121 participants had anti-COVID-19 antibodies at baseline, and a further 4 had incomplete data for the analysis. Mean anti-RBD IgG responses were similar between the HIV negative control group (n = 20) and the combined HIV+ group (n = 106) (p = 0.72). However, these responses were significantly lower in the group with <250 CD4 cells/mm³. (p < 0.0001). Increasing age was independently associated with decreased immunogenicity.ConclusionHIV-positive individuals with CD4 counts over 250 cells/mm³ have an anti-RBD IgG response similar to the general population. However, HIV-positive individuals with the lowest CD4 counts (<250 cells/mm³) have a weaker response. These data would support the hypothesis that a booster dose might be needed in this subgroup of HIV-positive individuals, depending on their response to the second dose.     

Recent MMR vaccination in health care workers and Covid-19: A test negative case-control study

BackgroundIt has been hypothesised that the measles-mumps-rubella (MMR) vaccine may afford cross-protection against SARS-CoV-2 which may contribute to the wide variability in disease severity of Covid-19.MethodsWe employed a test negative case-control study, utilising a recent measles outbreak during which many healthcare workers received the MMR vaccine, to investigate the potential protective effect of MMR against SARS-CoV-2 in 5905 subjects (n = 805 males, n = 5100 females).ResultsThe odds ratio for testing positive for SARS-CoV-2, in recently MMR-vaccinated compared to not recently MMR-vaccinated individuals was 0.91 (95% CI 0.76, 1.09). An interaction analysis showed a significant interaction for sex. After sex-stratification, the odds ratio for testing positive for males was 0.43 (95% CI 0.24, 0.79, P = 0.006), and 1.01 (95% CI 0.83, 1.22, P = 0.92) for females.ConclusionOur results indicate that there may be a protective effect of the MMR vaccine against SARS-CoV-2 in males but not females.     

Safety and effectiveness of BNT162b2 mRNA Covid-19 vaccine in adolescents

In South Korea, all 12th grade students (highs school seniors) were offered BNT162b2 vaccine starting July 19, 2021; while 10^th–11th grade students were not eligible. We conducted a nationwide retrospective cohort study by to determine the safety and effectiveness of BNT162b2 mRNA Covid-19 vaccine in adolescents against SARS-CoV-2 infection. Among 444,313 persons who received the first dose of vaccine, reporting rate for myocarditis and/or pericarditis was 1.8 per 100,000 (95% C.I. 0.8–3.5) among first-dose recipients and 4.3 per 100,000 (95% C.I. 2.6–6.7) in second-dose recipients. Vaccine effectiveness against symptomatic/asymptomatic SARS-CoV-2 infection 14 days post-first dose vaccination was 91.1% (95% C.I. 89.6–92.5), and 14 days post-second dose was 99.1% (95% C.I. 98.5–99.5). In this retrospective cohort study, BNT162b2 vaccination was safe and was associated with a significantly lower risk of SARS-CoV-2 infection, suggesting that vaccination in adolescent may reduce the burden of Covid-19.     

Hesitation of the Tunisian population to COVID-19 vaccination,and its associated factors

Background: Many people are reluctant to be vaccinated against COVID-19. Aim: To determine the intention to accept COVID19 vaccine and its associated factors among Tunisians. Methods: We conducted a cross-sectional study among Tunisians from December 2020 to January 2021 using an online questionnaire. Factors associated with intention to accept coronavirus vaccine were analysed using multinomial logistic regression. Results: In total, 169 Tunisians participated in our study. The majority were female (85.2%). The mean age was 48.3 ± 11.8 years. Only 33.1% intended to accept to be vaccinated when COVID-19 vaccine will be available in Tunisia and 22.5% were still hesitant. In multinomial logistic regression, participants having high or very high perceived personal risk of COVID-19 infection (aOR:3.257, 95% CI :1.204 – 8.815) were more prone to hesitate to accept COVID-19 vaccine rather than those being willing to accept it. Respondents undergoing seasonal influenza vaccination (aOR: 0.091, 95% CI : 0.019 – 0.433)were less prone to refuse COVID-19 vaccine rather than those being willing to accept it. Young ones aged less than 40 years (aOR: 4.324, 95% CI: 1.180 – 15.843) were more prone to refuse COVID-19 vaccine rather than those being willing to accept it. Conclusion: The acceptance rate of coronavirus vaccination was moderate. Therefore, a good communication and health education at a community level are needed.     

Factors associated with COVID-19 vaccination intentions among adults in the deep South

The recent approval of several COVID-19 vaccines signals progress toward controlling the pandemic. Although social distancing and masking have been effective, vaccines are an important additional measure of protection to reduce COVID-19 spread. Adequate uptake is essential to reach herd immunity, estimated to be approximately 67%. However, vaccine hesitancy, the fast-tracked nature of the COVID-19 vaccines, and misinformation circulating through various forms of media have contributed to lower vaccination intention than desired. The current research study developed an online survey conducted via Facebook to explore the attitudes and perceptions of adult Alabama residents about COVID-19 and the COVID-19 vaccines. Of the 3,781 respondents, only 44.3% reported intent to receive a vaccine, with a large proportion reporting they were unsure (28.1%). Lack of intention to vaccinate was associated with low educational attainment, low COVID-19 knowledge levels, low income, and African American race. The current survey also explored participants’ influenza vaccine behavior as this information can also be used to inform successful COVID-19 vaccine distribution. Of the respondents, 56% report receiving the yearly influenza vaccine and the majority receive it at a pharmacy or healthcare provider office. This informs likely successful locations for COVID-19 vaccine distribution. Appropriate education targeted to populations most likely to refuse COVID-19 vaccination is essential to promote uptake. The information collected from the current study should be utilized to inform effective and efficient vaccine distribution strategies.     

Safety signal identification for COVID-19 bivalent booster vaccination using tree-based scan statistics in the Vaccine Safety Datalink

BackgroundTraditional active vaccine safety monitoring involves pre-specifying health outcomes and biologically plausible outcome-specific time windows of concern, limiting the adverse events that can be evaluated. In this study, we used tree-based scan statistics to look broadly for >60,000 possible adverse events after bivalent COVID-19 vaccination.MethodsVaccine Safety Datalink enrollees aged ≥5 years receiving Moderna or Pfizer-BioNTech bivalent COVID-19 vaccine through November 2022 were followed for 56 days post-vaccination. Incident diagnoses in inpatient or emergency department settings were analyzed for clustering within the hierarchical ICD-10-CM diagnosis code “tree” and temporally within post-vaccination follow-up. The conditional self-controlled tree-temporal scan statistic was used, conditioning on total number of cases of each diagnosis and total number of cases of any diagnosis occurring during the scanning risk window across the entire tree. P = 0.01 was the pre-specified cut-off for statistical significance.ResultsAnalysis included 352,509 doses of Moderna and 979,189 doses of Pfizer-BioNTech bivalent vaccines. After Moderna vaccination, no statistically significant clusters were found. After Pfizer-BioNTech, there were clusters of unspecified adverse events (Days 1–3, p = 0.0001–0.0007), influenza (Days 35–56, p = 0.0001), cough (Days 44–55, p = 0.0002), and COVID-19 (Days 52–56, p = 0.0004).ConclusionsFor Pfizer-BioNTech only, we detected clusters of: (1) unspecified adverse effects, as have been observed in other vaccine studies using this method, and (2) respiratory disease toward the end of follow-up. The respiratory clusters were likely due to overlap of follow-up with the spread of respiratory syncytial virus, influenza, and COVID-19, i.e., confounding by seasonality. The untargeted nature of the method and its inherent adjustment for the many diagnoses and risk intervals evaluated are unique advantages. Limitations include susceptibility to time-varying confounding, lower statistical power for assessing risks of specific outcomes than in traditional studies targeting fewer outcomes, and the possibility of missing adverse events not strongly clustered in time or within the “tree.”     

Side effects during the week after first dose vaccination with four Covid-19 vaccines. Results of the ProVaVac Survey Study with 13,837 people in Spain

BackgroundIn 2021, four vaccines against Covid-19 (BNT162b2, mRNA-1273, ChAdOx1nCoV-19, and JNJ-78436735) were employed in the region of Valencia, Spain. We conducted a survey to identify real-world, self-reported frequency and severity of side effects during the week after vaccination.MethodsSurvey data was obtained from April 19, 2021, to October 6, 2021, at three different moments in time: day one, day three and day seven after vaccination. Answers were linked to individual-level, personal and clinical information. Respondents were stratified by the vaccine they received and reported effects were presented over time and stratified by severity. We compared our results per vaccine with the frequencies stated in each Summary of Product Characteristics (SmPC). We used binomial logistic models to identify associations between respondent characteristics and side effects.ResultsNo symptoms were reported by 1,986 respondents (14.35 %), 6,254 informed exclusively mild symptoms (45.20 %), 3,444 up to moderate symptoms (24.89 %), and 2,153 people (15.56 %) notified also severe symptoms. Among the latter, the more frequent were extreme tiredness (7.0 %), and nausea or vomiting (7.1 %). The reported frequency of facial paralysis (0.4 %) was much higher than reflected in SmPCs. Female sex, younger age, previous positive Active Infection Diagnostic Test, chronicity, and vaccination with other than the BNT162b2 vaccine were associated to an increased risk of side effects (p < 0.001).ConclusionsSide effects after vaccination are common in the real-world. However, they are principally mild, and their frequency declines after a few days. Providing patients with dependable, beforehand information about side effects may improve outcomes and reinforce vaccination programs.     

Prenatal maternal COVID-19 vaccination and pregnancy outcomes

BackgroundPrenatal maternal physiological changes may cause severe COVID-19 among pregnant women. The Pfizer-BioNTech COVID-19 vaccine (BNT162b2 mRNA) has been shown to be highly effective and it is recommended for individuals aged ≥16 years, including pregnant women, although the vaccine has not been tested on the latter.ObjectiveTo study the association between prenatal Pfizer-BioNTech COVID-19 vaccination, pregnancy course and outcomes.Study designA retrospective cohort study was performed, including all women who delivered between January and June 2021 at Soroka University Medical Center, the largest birth center in Israel. Excluded were women diagnosed with COVID-19 in the past, multiple gestations or unknown vaccination status. Pregnancy, delivery and newborn complications were compared between women who received 1 or 2-dose vaccines during pregnancy and unvaccinated women. Multivariable models were used to adjust for background characteristics.ResultsA total of 4,399 women participated in this study, 913 (20.8%) of which were vaccinated during pregnancy. All vaccinations occurred during second or third trimesters. As compared to the unvaccinated women, vaccinated women were older, more likely to conceive following fertility treatments, to have sufficient prenatal care, and of higher socioeconomic position. In both crude and multivariable analyses, no differences were found between the groups in pregnancy, delivery and newborn complications, including gestational age at delivery, incidence of small for gestational age and newborn respiratory complications.ConclusionsPrenatal maternal COVID-19 vaccine has no adverse effects on pregnancy course and outcomes. These findings may help pregnant women and health care providers to make informed decision regarding vaccination.     

Optimal non-pharmaceutical intervention policy for Covid-19 epidemic via neuroevolution algorithm

BackgroundNational responses to the Covid-19 pandemic varied markedly across countries, from business-as-usual to complete shutdowns. Policies aimed at disrupting the viral transmission cycle and preventing the overwhelming of healthcare systems inevitably exact an economic toll.MethodologyWe developed an intervention policy model that comprised the relative human, implementation and healthcare costs of non-pharmaceutical epidemic interventions and identified the optimal strategy using a neuroevolution algorithm. The proposed model finds the minimum required reduction in transmission rates to maintain the burden on the healthcare system below the maximum capacity.ResultsWe find that such a policy renders a sharp increase in the control strength during the early stages of the epidemic, followed by a steady increase in the subsequent ten weeks as the epidemic approaches its peak, and finally the control strength is gradually decreased as the population moves towards herd immunity. We have also shown how such a model can provide an efficient adaptive intervention policy at different stages of the epidemic without having access to the entire history of its progression in the population.Conclusions and implicationsThis work emphasizes the importance of imposing intervention measures early and provides insights into adaptive intervention policies to minimize the economic impacts of the epidemic without putting an extra burden on the healthcare system.Lay SummaryWe developed an intervention policy model that comprised the relative human, implementation and healthcare costs of non-pharmaceutical epidemic interventions and identified the optimal strategy using a neuroevolution algorithm. Our work emphasizes the importance of imposing intervention measures early and provides insights into adaptive intervention policies to minimize the economic impacts of the epidemic without putting an extra burden on the healthcare system.     

Health system access challenges of people with disabilities increased during Covid-19 pandemic

BackgroundPeople with disabilities (PWDs) have unequal access to health services compared with the general population and this disparity is worsening during the Covid-19 pandemic. Evidence supports the importance of policy development and legislation for addressing the unmet health needs of PWDs, but little is known about the impact of these efforts in Ghana.ObjectiveThis study examined health system experiences of PWDs in Ghana within the context of existing disability legislation and related policies prior to and during the Covid-19 pandemic.MethodsNarrative analysis of data from qualitative research approaches of focus group discussions, semi-structured interviews, and participant observations were used to examine the experiences of fifty-five PWDs, four staff of the Department of Social Welfare, and six leaders of disability-focused non-governmental organizations in Ghana.ResultsStructural and system barriers hinder PWDs access to health services. Bureaucratic bottlenecks hinder PWDs access to Ghana's free health insurance policy and health workers' disability stigma impedes accessibility to health services.ConclusionsAccess barriers and disability stigma increased accessibility challenges for PWDs in Ghana's health system during the Covid-19 pandemic. My findings support the need for increased efforts toward making Ghana's health system more accessible to address health disparities experienced by PWDs.     

Between nudges and mandates: The drivers of COVID-19 vaccination intentions and subsequent uptake in Russia

Despite high levels of morbidity and mortality, as well as the widespread availability of domestic vaccines, Russia demonstrated significantly low rates of vaccination throughout the COVID-19 pandemic. This research explores vaccination intentions before the start of the immunisation campaign and the consequent uptake in Russia after the introduction of mandatory vaccination policy in certain industries and proof-of-immunisation for social activities. Using a nationally representative panel dataset, we analyse factors behind individual vaccination decisions using binary and multinomial logistic regressions. Special attention is given to the effect of employment in industries with vaccine mandates and personal factors which determine individual “nudgeability” to vaccination (e.g., personality traits, beliefs, vaccine alertness, self-perceived vaccine availability etc.). Our results show that 49 per cent of the population received at least one shot of COVID-19 vaccine by autumn 2021 after the introduction of mandatory vaccination. Vaccination intentions before the rollout of the nationwide immunisation campaign are correlated with the consequent attitudes and uptake, although the prediction is not perfect. 40 percent of vaccine refusers eventually got vaccinated, while 16 percent of vaccine supporters turned into refusers, revealing the lack of promotion of vaccine safety and effectiveness. To a large extent, vaccination refusal and hesitance are explained by vaccine alertness. Vaccine mandates significantly increased the uptake in several affected industries, especially education. These results offer important insights for designing information policy, relevant for future vaccination campaigns.     

Make it or break it: On-time vaccination intent at the time of Covid-19

On-time effective vaccination is critical to curbing a pandemic, but this is often hampered by citizens' hesitancy to get quickly vaccinated. This research concentrates on the hypothesis that, besides traditional factors in the literature, vaccination success would hinge on two dimensions: a) addressing a broader set of risk perception factors than health-related issues only, and b) securing sufficient social and institutional trust at the time of vaccination campaign launch. We test this hypothesis regarding Covid-19 vaccination preferences in six European countries and at the early stage of the pandemic by April 2020. We find that addressing the two roadblock dimensions could further boost Covid-19 vaccination coverage by 22%. The study also offers three extra innovations. The first is that the traditional segmentation logic between vaccine “acceptors”, “hesitants” and “refusers” is further justified by the fact that segments have different attitudes: refusers care less about health issues than they are worried about family tensions and finance (dimension 1 of our hypothesis). In contrast, hesitants are the battlefield for more transparency by media and government actions (dimension 2 of our hypothesis). The second added value is that we extend our hypothesis testing with a supervised non-parametric machine learning technique (Random Forests). Again, consistent with our hypothesis, this method picks up higher-order interaction between risk and trust variables that strongly predict on-time vaccination intent. We finally explicitly adjust survey responses to account for possible reporting bias. Among others, vaccine-reluctant citizens may under-report their limited will to get vaccinated.     

COVID-19 vaccine uptake and its associated factors among Palestinian healthcare workers: Expectations beaten by reality

BackgroundIn response to this extraordinary outbreak, many countries and companies rush to develop an effective vaccine, authorize, and deliver it to all people across the world. Despite these extensive efforts, curbing this pandemic relies highly upon vaccination coverage. This study aimed to determine SARS-COV-2 vaccine uptake among Palestinian healthcare workers, the factors that influence vaccination uptake, and the motivators and barriers to vaccination.MethodsA cross-sectional study was conducted using an online anonymous self-administered questionnaire during April and May 2021, after the Palestinian Ministry of Health launched the COVID-19 vaccination campaign.The questionnaire collected socio-demographic characteristics, vaccination attitude and vaccination uptake status, and motivators and barriers towards vaccination. In addition, multivariate logistic regression was performed to identify the influencing factors of vaccination uptake.ResultsThe study included 1018 participants from different professions, including 560 (55.0%) females. Of the participants, 677 (66.5%; 95% CI: 63.5–69.4%) received the vaccine. Higher uptake was observed among males (aOR = 1.5; 95 %CI: 1.1–2.1), single HCWs (aOR = 1.3; 95 %CI: 1.1–1.8), HCWs working in the non-governmental sector (aOR = 1.6; 95 %CI: 1.2–2.4), higher monthly income (aOR = 1.9; 95 %CI: 1.4–2.8) and smoking (aOR = 1.5; 95 %CI: 1.1–3.5). The lower level of negative vaccination attitudes predicted higher intake; mistrust of vaccine belief (aOR = 1.6; 95 %CI: 1.4–1.7) and worries over unforeseen future effects (aOR = 1.2; 95 %CI: 1.1–1.3).ConclusionIn conclusion, the COVID-19 vaccination uptake was comparable to other studies worldwide but still needs to be improved, especially in the context of this ongoing global pandemic. It is imperative to invest resources to promote vaccination uptake and target all the vaccine misconceptions and fears.     

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.     

Impact of national Covid-19 vaccination Campaign,South Korea

BackgroundWe evaluate the overall effectiveness of the nationwide vaccination campaign using ChAdOx1 nCoV-19, BNT162b2, mRNA-1273, and Ad26.COV2.S vaccines in preventing Covid-19 in South Korea.MethodsThe National Surveillance System with the National Immunization Registry were linked to form a large-linked database for assessment. Age-adjusted incidence of SARS-CoV-2 infection, severe disease, and death by vaccination status are calculated. Weekly vaccine effectiveness was calculated based on incidence rate ratio (IRR) between fully-vaccinated and unvaccinated persons, as: IRR = incidence rate of vaccinated / incidence rate of unvaccinated. We estimate the cumulative SARS-CoV-2 outcome overtime comparing the observed case with predicted cases without vaccination.ResultsAge-adjusted incidence in unvaccinated persons (5.69 per 100,000 person-day) was 2.7 times the rate in fully vaccinated (2.13 per 100,000 person-day) persons, resulting effectiveness against SARS-CoV-2 infection of 63%. Vaccine effectiveness against severe disease and death were 93% and 95%, respectively. Between March and October 2021, estimated Covid-19 related outcomes averted by vaccinations were: 46,508 infections, 3,424 severe diseases, and 718 deaths.ConclusionsWe found significant protection for national Covid-19 vaccination campaign against Covid-19 severe disease, and death in target populations, but there was an unexpected decreased protection against SARS-CoV-2 infection, highlighting the importance of continued surveillance and assessment.