Herd Immunity and Implications for SARS-CoV-2 Control

COVID-19 vaccine intentions and attitudes in Black American emerging adults with asthma

BACKGROUND

Emerging adults (aged 18-29) are less likely to receive the COVID-19 vaccine than any other adult age group. Black Americans are less likely than non-Hispanic white Americans to be fully vaccinated against COVID-19. This study explored factors which affect vaccine intention and attitudes in Black American emerging adults with asthma.

METHODS

Participants were recruited from an NHLBI-funded clinical trial to improve asthma control. Fifty-nine Black American emerging adults completed a Qualtrics survey that assessed asthma control, intention to vaccinate, and factors which may affect the decision to vaccinate. Twenty-five participants also completed a semi-structured interview via Zoom. Bivariate correlations and descriptive statistics, including Chi Square analyses, were run using SPSS. Interview thematic analyses were conducted via QDA Miner.

RESULTS

Of the 59 Black American emerging adults with asthma who completed surveys, 32.2% responded that they were highly unlikely to receive the COVID-19 vaccine, while 50.8% responded that they were highly likely to receive it. Increased asthma control was significantly correlated with a higher likelihood to discuss the COVID-19 vaccine with their healthcare provider (ρ = 0.339, α = 0.011). Concerns about immediate (ρ= -0.261, α = 0.050) and long-term (ρ= -0.280, α = 0.035) side effects were inversely correlated with intention to vaccinate. Only 17% of the participants who were unemployed stated that they were highly likely to receive the vaccines compared to 65% of the participants who were employed; however, interview participants who were unemployed stated not needing the vaccine because they were protecting themselves by social distancing. When deciding whether to receive the vaccine, safety, efficacy, and immediate side effects were the top three factors for 91%, 54%, and 49% of the participants, respectively. Beliefs about the vaccines' safety and efficacy, information gathering, personal factors, and societal factors emerged as important themes from the interviews.

CONCLUSION

Only half of the surveyed Black American emerging adults with asthma were highly likely to receive the COVID-19 vaccine. Safety and efficacy were important for the majority of the participants, regardless of vaccine intention. Greater asthma control, but not access to asthma-related healthcare, was correlated with intention to discuss the vaccine with their healthcare provider.

College students' COVID-19 vaccine beliefs and intentions: Implications for interventions

On college campuses, effective management of vaccine-preventable transmissible pathogens requires understanding student vaccination intentions. This is necessary for developing and tailoring health messaging to maximize uptake of health information and vaccines. The current study explored students' beliefs and attitudes about vaccines in general, and the new COVID-19 vaccines specifically. This study provides insights into effective health messaging needed to rapidly increase COVID-19 vaccination on college campuses-information that will continue to be informative in future academic years across a broad scope of pathogens. Data were collected from 696 undergraduate students ages 18-29 years old enrolled in a large public university in the Northeast during fall 2020. Data were collected via an online survey. Overall, we found COVID-19 vaccine hesitancy in college students correlated strongly with some concerns about vaccines in general as well as with concerns specific to COVID-19 vaccines. Taken together, these results provide further insight for message development and delivery and can inform more effective interventions to advance critical public health outcomes on college campuses beyond the current pandemic.

Leveraging the CORE Group Partners Project Polio Infrastructure to Integrate COVID-19 Vaccination and Routine Immunization in South Sudan

INTRODUCTION

Countries with fragile health systems like South Sudan experienced significant impacts on routine immunization during the COVID-19 pandemic. Routine immunization in children aged younger than 1 year declined due to pandemic-related constraints and was compounded by the introduction of the COVID-19 vaccine, which was met with hesitancy and reluctance. When South Sudan reported the first COVID-19 case in March 2020, the CORE Group Partners Project (CGPP) rapidly integrated the COVID-19 outbreak response into its ongoing polio eradication activities, leveraging the existing polio infrastructure and human resources. We describe the integration process, results, and challenges and detail the impact of the integration on coverage for both routine immunization and COVID-19 vaccinations.

METHODS

Efforts to integrate COVID-19 vaccination and routine immunization service delivery were implemented in 5 phases: assessing the need, developing multisector collaborations, developing a service delivery plan, assessing implementation readiness, and implementing and evaluating the service delivery plan. Integration efforts prioritized coordination, training vaccinators and volunteers, development of microplans, data management, and last-mile vaccine delivery. Integrated service delivery was implemented through "one-stop shop" sessions where communities accessed routine immunizations for children, COVID-19 vaccinations for adults, and other primary health services.

RESULTS

Integrating health service delivery contributed to improved routine immunization coverage among children, improved COVID-19 vaccination coverage among adults, reduced cost for service delivery, and increased access to more comprehensive health services in hard-to-reach communities. COVID-19 vaccinations were delivered at US$4.70 per dose, a cost substantially lower than other reported delivery mechanisms.

CONCLUSION

Integration can yield positive results and improve access to vaccination and other health services for communities. However, it requires clear policy guidelines, commitment, and strong collaboration. Challenges included resistance from stakeholders, overstretched human resources, and diversion of funding and attention from program areas, which were overcome through deliberate high-level advocacy, partnership, and intensified community engagement.

Knowledge of and Self-Expressed Stigma for COVID-19 Vaccination among Pre-University Students in a College in South India: A Cross-Sectional Study

Background

Coronavirus disease 2019 (COVID-19) is a contagious infection characterized by severe acute respiratory syndrome (SARS-CoV-2). Safe and effective vaccines are game-changers in the global vision of marking an end to the challenges posed by the COVID-19 pandemic. However, vaccine hesitancy due to perceived stigma and misinformation is a grave cause of concern.

Objectives

To assess pre-university students' self-expressed stigma regarding COVID-19 vaccination and its association with their knowledge.

Materials and Methods

A cross-sectional study was adopted for this research. A structured questionnaire approach was used to gather data from 384 students purposively at the selected pre-university college. The structured questionnaire consisted of three sections that explored the socio-demographic characteristics of the study participants, knowledge of vaccination, and self-expressed stigma, respectively. A total of 384 respondents took part in the study.

Results

The study observes a low positive relationship (r = 0.25, P < 0.01) between knowledge and self-expressed stigma toward vaccination. Further, it was observed that participants from rural backgrounds had lower knowledge and self-expressed stigma scores than participants from urban settings. It is pertinent to note that participants with other sources of information had higher knowledge than those who used the internet, friends/peers, or newspapers. Both of the aforementioned findings are statistically significant.

Conclusion

The interventions should revive trust in national health authorities, structured awareness campaigns by government agencies, and media coverage about the safety and efficacy of vaccines. In addition, it is also important to support citizens in ensuring that they have access to the right information from authentic sources in times of crisis.

Nanovaccines for Advancing Long-Lasting Immunity against Infectious Diseases

Infectious diseases, particularly life-threatening pathogens such as small pox and influenza, have substantial implications on public health and global economies. Vaccination is a key approach to combat existing and emerging pathogens. Immunological memory is an essential characteristic used to evaluate vaccine efficacy and durability and the basis for the long-term effects of vaccines in protecting against future infections; however, optimizing the potency, improving the quality, and enhancing the durability of immune responses remains challenging and a focus for research involving investigation of nanovaccine technologies. In this review, we describe how nanovaccines can address the challenges for conventional vaccines in stimulating adaptive immune memory responses to protect against reinfection. We discuss protein and nonprotein nanoparticles as useful antigen platforms, including those with highly ordered and repetitive antigen array presentation to enhance immunogenicity through cross-linking with multiple B cell receptors, and with a focus on antigen properties. In addition, we describe how nanoadjuvants can improve immune responses by providing enhanced access to lymph nodes, lymphnode targeting, germinal center retention, and long-lasting immune response generation. Nanotechnology has the advantage to facilitate vaccine induction of long-lasting immunity against infectious diseases, now and in the future.

If Long-Term Suppression is not Possible, how do we Minimize Mortality for Infectious Disease Outbreaks?

OBJECTIVE

For any emerging pathogen, the preferred approach is to drive it to extinction with non-pharmaceutical interventions (NPI) or suppress its spread until effective drugs or vaccines are available. However, this might not always be possible. If containment is infeasible, the best people can hope for is pathogen transmission until population level immunity is achieved, with as little morbidity and mortality as possible.

METHODS

A simple computational model was used to explore how people should choose NPI in a non-containment scenario to minimize mortality if mortality risk differs by age.

RESULTS

Results show that strong NPI might be worse overall if they cannot be sustained compared to weaker NPI of the same duration. It was also shown that targeting NPI at different age groups can lead to similar reductions in the total number of infected, but can have strong differences regarding the reduction in mortality.

CONCLUSIONS

Strong NPI that can be sustained until drugs or vaccines become available are always preferred for preventing infection and mortality. However, if people encounter a worst-case scenario where interventions cannot be sustained, allowing some infections to occur in lower-risk groups might lead to an overall greater reduction in mortality than trying to protect everyone equally.

Examining health sciences students' intention to uptake COVID-19 vaccination using the theory of planned behavior

To examine the association between the theory of planned behavior (TPB) constructs and Health Sciences students' intentions to receive COVID-19 vaccination. A cross-sectional study was conducted in Saudi Arabia by recruiting Health Sciences students as participants. Using Structural Equation Modeling (SEM), the proposed TPB model was evaluated. The sample of 505 individuals consisted of more males (n = 275; 54.5%) than females and was relatively young (88% were between the ages of 18 and 30). The suggested TPB model explained 78.2% of the variation in intention to get COVID-19 immunization. We found that greater levels of perceived behavioral control (β = 1.58, p < .001) and attitude (β = .44, p < .001) strongly predicted increased vaccination intentions. The subjective norm construct was not a significant predictor of vaccination intentions (β = 0.06, p = .34). The findings of this study indicate that the TPB can be utilized effectively to obtain insight into the factors associated with COVID-19 adherence and help in the development of effective COVID-19 intervention strategies.

Community perception and acceptability of COVID-19 vaccine in South-West Nigeria: an online cross-sectional study

Background

The development of COVID-19 vaccines holds great potential for controlling the spread of SARS-CoV-2. Vaccines, irrespective of the disease are generally fraught with hesitancy, and Nigeria has a history of vaccine hesitancy.

Objective

This study aimed at determining the perception of community members about the COVID-19 vaccine and their readiness to accept the vaccine in South West, Nigeria.

Methods

A descriptive cross-sectional study design was employed to collect data from consenting adults using a structured online questionnaire for a period of three weeks. Data were subjected to a Chi-square test and logistic regression for bivariate and multivariate analysis, respectively.

Results

A total of 807 respondents participated in the survey with 57.7% males and 42.3% females. Forty-five respondents (5.6%) had previously been diagnosed with COVID-19 while 11.5% of the respondents had co-morbidity. The overall perception of COVID-19 vaccines was good. Fifty-nine (59%) percent of the respondents were willing to accept the vaccine and will also encourage their family members to take the vaccine. Vaccine origin and cost were determinants of vaccine acceptability. Nonacceptability of the vaccine (61.6%) was based on possible adverse effects of the vaccine and mistrust of the government. Educational level, skill status, type of employment, and sector of employment were associated (P<0.001) with the acceptability of the COVID-19 vaccine.

Conclusions

Citizens were willing to take COVID-19 vaccines, however, a lack of trust in government programs might undermine the vaccine campaign. Hence, the government needs to rebuild trust with the citizens towards achieving a high vaccination rate for COVID-19.

The effect of private self-consciousness on the intention to receive the COVID-19 vaccine

<b>Background:</b> Although COVID-19 vaccines have been developed, the number of people willing to receive the vaccine has not yet reached the level for herd immunity. Using the health belief model with governmental information support, this study examined private self-consciousness in combination with other factors that influence the intention to receive the COVID-19 vaccine.<br /> <b>Materials and methods:</b> The perceived susceptibility to and perceived seriousness of COVID-19, perceived benefits of and perceived barriers to the COVID-19 vaccine, governmental information support, private self-consciousness, and the intention to receive the vaccine were examined in 523 adults. The data were analyzed with partial least squares regression.<br /> <b>Results:</b> The results indicate that private self-consciousness reduces the effect of perceived susceptibility on the intention to receive the vaccine and the negative effect of the perceived barriers to receiving it on intention.<br /> <b>Conclusion:</b> The information provided by the public health department should focus on perceived seriousness and perceived benefits because they are not affected by private self-consciousness.

Variation in antibody titers determined by Abbott and Roche Elecsys SARS-CoV-2 assays in vaccinated healthcare workers

SARS-CoV-2-specific antibody measurement is important for evaluating COVID-19 vaccine efficacy. We quantified and compared anti-spike (S) antibodies using different commercial immunoassays. We tested serum samples from 70 SARS-CoV-2-naive health care workers 2 weeks after vaccination with a single dose of BNT162b2, 2 and 4 weeks, and 3 months after the second dose of BNT162b2. The following quantitative assays were used: Roche Elecsys Anti-SARS-CoV-2 S (Roche-S), Abbott SARS-CoV-2 IgG II Quant [Abbott-IgG(S)], and Abbott SARS-CoV-2 IgM (Abbott-IgM). All samples tested positive for Roche-S and Abbott-IgG antibodies after the second dose, with 83.6% Abbott-IgM positive rate. Roche-S and Abbott-IgG(S) correlated significantly in all samples (r = 0.920, p < 0.0001), and the Roche-S and Abbott-IgG(S) assay showed a strong correlation with each other at each time point after vaccination. Roche-S and Abbott-IgG(S) antibody titers were correlated with age; their rate of decline was age-dependent in males but not in females. Abbott-IgG(S) antibody titers decreased from 2 weeks after the second dose. Roche-S antibody titers peaked 2 weeks after the second dose in 76.2% of the participants; the titers recovered 3 months post-vaccination after declining at week 4 in 40.7% of the participants. The concordance between Roche-S and Abbott-IgG(S) antibody titers over time was 47.5%. Most participants presented significantly high Roche-S and Abbott-IgG(S) antibody titers after immunization. Some measurements were inconsistent with titer changes between these assays, possibly because of differences in the immunoglobulin-specificity of the kits.

Integrated factors affecting intention of COVID-19 preventive behaviours including vaccination in Korea

AIM

The aim of the study was to determine the multiple potential contributing factors in preventive behaviours, including COVID-19 vaccination for an effective campaign strategy.

DESIGN

This is a descriptive correlation study to examine the effects of the behavioural outcome, attitude, subjective norm, perceived behavioural control, optimistic bias and social stigma on the intention of preventive behaviour, based on Ajen's Theory of Planned Behaviour.

METHODS

The survey was performed by a professional research company online from 16-19 July 2021. Two hundred and thirty-three participants who had not been vaccinated against COVID-19 at the time of data collection completed the survey.

RESULTS

Perceived benefit, perceived behavioural control and social stigma are significantly associated with intention of preventive behaviours. The factors engaging in preventive behaviour presents us that our society is strongly influenced by social groups. Social groups influence decision-making in intention of preventing behaviour. Public education using social networks can increase such desirable behaviour.

Deliberation, context, emotion and trust - understanding the dynamics of adults' COVID-19 vaccination decisions in Germany

BACKGROUND

Willingness to vaccinate against coronavirus disease 2019 (COVID-19), which is vital to successful vaccination campaigns, is wavering and suboptimal. In Germany, quantitative research highlighted concerns regarding the safety and efficacy of COVID-19 vaccines as barriers to uptake, but qualitative insights regarding individuals' decisions about COVID-19 vaccines and how personal perceptions reflect or refute existing behavioral theories are lacking.

METHODS

To identify how individuals make COVID-19 vaccination decisions within real-life contexts, we conducted 33 semi-structured, in-depth qualitative interviews with individuals in Germany between March and April 2021 using maximum variation sampling, focusing on perceptions of COVID-19 vaccines. Analysis, informed by a framework approach, began in the field via debriefings and was amplified upon the conclusion of data collection.

RESULTS

Four interconnected themes (deliberation, context, emotion, trust) shaped respondents' decisions about vaccination. Personal deliberation regarding benefits and risks of vaccines and perceptions of the broader social and political context sparked a spectrum of emotions that underpinned vaccination decisions. Trust in science and researchers emerged as a powerful protective factor facilitating the decision to get vaccinated even amidst a rapidly changing context and disconcerting information.

CONCLUSIONS

Our findings add to ongoing debates about the breadth of vaccination decisions by highlighting how respondents are influenced by their perceptions of the political context and the emotional heft of their decisions. The role of cognitive evaluation, context, and emotions mirrors other decision-making frameworks, particularly the Risk as Feelings Theory. We extend on the elements of this theory by highlighting trust as a protective factor when making decisions particularly in highly uncertain contexts. Success of vaccination campaigns, more important than ever as new variants of COVID-19 emerge, is interwoven with an ability to bolster trust in science. Communicating public-health decisions and information about vaccines transparently without instilling fear offers promising chances to strengthen public trust in COVID-19 vaccines.

TRIAL REGISTRATION

German Clinical Trials Register ( DRKS00024505 ).

Diné teachings and public health students informing peers and relatives about vaccine education: Providing Diné (Navajo)-centered COVID-19 education materials using student health messengers

Introduction/background

On 9 April 2021, the Centers for Disease Control and Prevention (CDC) reported that only 19. 9% of United States (US) adults were fully vaccinated against COVID-19. In that same week, the Navajo Nation (NN) reported that 37.4% of residents were fully vaccinated, making the NN a leader in the uptake of COVID-19 vaccines. Despite high vaccination rates, vaccine hesitancy exists within the NN. The Diné (Navajo) Teachings and Public Health Students Informing Peers and Relatives about Vaccine Education (RAVE) intervention was designed to utilize trusted health messengers as an effective means to address adults' vaccine concerns and hesitancy.

Methods

The research team used COVID-19 vaccine materials developed in a previous collaboration with non-Navajo tribal communities and publicly available materials. Diné Traditional Knowledge Holders (TKHs) were interviewed to develop and incorporate Diné-specific information on individual and collective health behaviors into the RAVE materials. These drafted health education materials were presented to NN community health representatives (CHRs) and Diné public health students using a consensus panel approach. NN residents who participated in the intervention completed a 16-element retrospective pretest.

Results

The adaptation and tailoring process of materials yielded 4 health education materials. The students recruited 46 adults for health education sessions. These participants then completed the retrospective pretest. Changes in the 16 elements were in the desired direction, although only six were significant: four related to attitudes and two concerned with vaccination intention. Participants were more likely to consider vaccination and to try to get vaccinated after the education session.

Discussion

Trusted messengers and culturally centered materials have been identified as effective means of health behavior education with Native American audiences. RAVE applied these intervention elements by (1) training Diné College public health students to leverage their cultural knowledge and social relationships (cultural and social capital) to recruit vaccine-hesitant adults and provide education; (2) building on previous understanding of Native American communities' vaccine concerns; and (3) integrating Diné perspectives on individual and collective health into the adaptation of materials designed for general audiences; this knowledge was gained from interviews with TKHs.

Examining COVID-19 vaccine attitude using SEM-Artificial Neural Networks approach: a case from Reddit community

As new coronavirus variants continue to emerge, in order to better address vaccine-related concerns and promote vaccine uptake in the next few years, the role played by online communities in shaping individuals’ vaccine attitudes has become an important lesson for public health practitioners and policymakers to learn. Examining the mechanism that underpins the impact of participating in online communities on the attitude toward COVID-19 vaccines, this study adopted a two-stage hybrid structural equation modeling (SEM)-artificial neural networks (ANN) approach to analyze the survey responses from 1037 Reddit community members. Findings from SEM demonstrated that in leading up to positive COVID-19 vaccine attitudes, sense of online community mediates the positive effects of perceived emotional support and social media usage, and perceived social norm mediates the positive effect of sense of online community as well as the negative effect of political conservatism. Health self-efficacy plays a moderating role between perceived emotional support and perceived social norm of COVID-19 vaccination. Results from the ANN model showed that online community members’ perceived social norm of COVID-19 vaccination acts as the most important predictor of positive COVID-19 vaccine attitudes. This study highlights the importance of harnessing online communities in designing COVID-related public health interventions and accelerating normative change in relation to vaccination.

Perception and willingness to accept COVID-19 Vaccines: A cross-sectional survey of the general population of Sokoto State, Nigeria

The number of confirmed cases of COVID-19 globally is well over 400 million, however, the number of cases is showing a downward trend especially in developed countries largely as a result of effective vaccination against COVID-19. In developing countries, vaccination coverage is still very low as a result of vaccine hesitancy, which could be attributed to misconceptions about COVID-19 itself and its newly developed vaccines. This study assessed COVID-19 vaccine acceptance and perception amongst the adult population in Sokoto state, Nigeria. A cross-sectional study was conducted in Sokoto state among 854 respondents selected via a multi-stage sampling technique. Data was collected electronically using a set of structured questionnaire and analysis was done using IBM SPSS version 25. Respondents' perception was assessed using a 5-point Likert scale ranging from strongly disagree (1) to strongly agree (5). Respondents having a score of 3 and below were graded as having poor perception and those having scores above 3 were graded as having good perception. Respondents' ages ranged from 17 to 76 years, with a mean of 34.8±12.07; more than half [474(53.7%)] of the respondents were males, 667(75.5%) were married and 539(61.0%) had formal education. The majority [839(95.0%)] of the respondents had a good perception of COVID -19 vaccine; 49.9% agreed enough research would be required on the safety of the vaccine. The majority, (72.4%) expressed their willingness to accept the COVID- 19 vaccine (male 38.4% vs. female 34.0%); 410(47.4%) said they can spend more than one hour to get the vaccine. Significant predictors of willingness to accept COVID 19 vaccine include age (p = 0.006; aOR = 0.223; 95% CI = 0.077-0.645), education (p<0.001; aOR = 1.720; 95% CI = 1.274-2.321) and perception of COVID 19 vaccine (p<0.001; aOR = 0.020; 95% CI = 0.009-0.044). The majority of the respondents had a good perception of COVID- 19 vaccine and more than two-thirds were willing to be vaccinated with the vaccine. Government should make the vaccine available for vaccination since a significant proportion of the respondents expressed their willingness to accept the vaccine.

Spatial modeling of vaccine deserts as barriers to controlling SARS-CoV-2

Background

COVID-19 vaccine distribution is at risk of further propagating the inequities of COVID-19, which in the United States (US) has disproportionately impacted the elderly, people of color, and the medically vulnerable. We sought to measure if the disparities seen in the geographic distribution of other COVID-19 healthcare resources were also present during the initial rollout of the COVID-19 vaccine.

Methods

Using a comprehensive COVID-19 vaccine database (VaccineFinder), we built an empirically parameterized spatial model of access to essential resources that incorporated vaccine supply, time-willing-to-travel for vaccination, and previous vaccination across the US. We then identified vaccine deserts—US Census tracts with localized, geographic barriers to vaccine-associated herd immunity. We link our model results with Census data and two high-resolution surveys to understand the distribution and determinates of spatially accessibility to the COVID-19 vaccine.

Results

We find that in early 2021, vaccine deserts were home to over 30 million people, >10% of the US population. Vaccine deserts were concentrated in rural locations and communities with a higher percentage of medically vulnerable populations. We also find that in locations of similar urbanicity, early vaccination distribution disadvantaged neighborhoods with more people of color and older aged residents.

Conclusion

Given sufficient vaccine supply, data-driven vaccine distribution to vaccine deserts may improve immunization rates and help control COVID-19.

Effectiveness of Bacille Calmette-Guerin vaccination policies in reducing infection and mortality of COVID-19: a systematic review

BACKGROUND

COVID-19 vaccination has been advocated as the most effective way to curb the pandemic. But with its inequitable distribution and slow rollout, especially in low- to middle- income countries, it will still take a long time before herd immunity is achieved. Alternative measures must therefore be explored to bolster current COVID-19 vaccination efforts. In particular, the Bacille Calmette-Guerin vaccine has been studied extensively as to its proposed conferment of non-specific immunity against different infections, including COVID-19. The aim of this study, therefore, is to evaluate the current evidence on the effectiveness of national BCG vaccination policies in reducing infection and mortality of COVID-19.

METHODS

A systematic review was conducted between April to August 2021 following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA-P) guidelines. Literature was retrieved from PubMed, Cochrane, HERDIN, Web of Science, EBSCO, and Western Pacific Region Index Medicus (WPRIM). Studies conducted from January 2020 to August 2021 that fell within Level 1A to 2C of the Oxford Center for Evidence-Based Medicine were included in the review. Quality assessment was performed using the appropriate Joanna Briggs Institute critical appraisal tool and a quality assessment checklist for ecological studies adapted from Betran et al. RESULTS: A total of 13 studies were included in this review. Nine studies reported significant association between BCG vaccination policies and COVID-19 outcomes, even when controlling for confounding variables. In addition, among other mandated vaccines, such as pneumococcal, influenza, diphtheria-tetanus-pertussis, and measles, only BCG vaccination showed significant association with decreased COVID-19 adverse outcomes. However, other factors also showed positive association with COVID-19 outcomes, particularly markers of high economic status of countries, higher median age, and greater population densities.

CONCLUSION

The lower incidence and mortality of COVID-19 in countries with mandated BCG vaccination may not solely be attributable to BCG vaccination policies, but there is still some evidence that demonstrates a possible protective effect. Clinical trials must be continued before recommendations of BCG vaccinations are to be used as an alternative or booster vaccine against COVID-19.

Knowledge, attitudes, and practices of pregnant women regarding COVID-19 vaccination in pregnancy in 7 low- and middle-income countries: An observational trial from the Global Network for Women and Children's Health Research

OBJECTIVES

We sought to determine the knowledge, attitudes and practices of pregnant women regarding COVID-19 vaccination in pregnancy in seven low- and middle-income countries (LMIC).

DESIGN

Prospective, observational, population-based study.

SETTINGS

Study areas in seven LMICs: Bangladesh, India, Pakistan, Guatemala, Democratic Republic of the Congo (DRC), Kenya and Zambia.

POPULATION

Pregnant women in an ongoing registry.

METHODS

COVID-19 vaccine questionnaires were administered to pregnant women in the Global Network's Maternal Newborn Health Registry from February 2021 through November 2021 in face-to-face interviews.

MAIN OUTCOME MEASURES

Knowledge, attitude and practice regarding vaccination during pregnancy; vaccination status.

RESULTS

No women were vaccinated except for small proportions in India (12.9%) and Guatemala (5.5%). Overall, nearly half the women believed the COVID-19 vaccine is very/somewhat effective and a similar proportion believed that the COVID-19 vaccine is safe for pregnant women. With availability of vaccines, about 56.7% said they would get the vaccine and a 34.8% would refuse. Of those who would not get vaccinated, safety, fear of adverse effects, and lack of trust predicted vaccine refusal. Those with lower educational status were less willing to be vaccinated. Family members and health professionals were the most trusted source of information for vaccination.

CONCLUSIONS

This COVID-19 vaccine survey in seven LMICs found that knowledge about the effectiveness and safety of the vaccine was generally low but varied. Concerns about vaccine safety and effectiveness among pregnant women is an important target for educational efforts to increase vaccination rates.

COVID-19 Vaccine Acceptance and Its Determinants among Myanmar Migrant Workers in Southern Thailand

Success in eradicating COVID-19 will rely on the rate of vaccination adoption worldwide. Vaccine acceptance among vulnerable groups is critical for preventing the spread of COVID-19 and decreasing unnecessary deaths. The purpose of this study was to report on the willingness to obtain COVID-19 immunization and the factors related to its acceptance among Myanmar migrant workers in southern Thailand. This cross-sectional study consisted of 301 samples collected between October and November 2021 and analyzed using multiple logistic regression. Thirty-nine percent of workers intended to receive the COVID-19 vaccine within a year. The following factors were associated with obtaining the COVID-19 vaccine: a high level of perception of COVID-19 (AOR = 5.43), income less than or equal to 10,000 baht/month (AOR = 6.98), financial status at a sufficient level (AOR = 7.79), wearing a face mask in the previous month almost all the time (AOR =4.26), maintaining 1-2 m of distance from anyone in the last month (AOR =2.51), and measuring temperature in the previous month (AOR = 5.24). High reluctance to accept the COVID-19 vaccine among Myanmar migrant workers can influence efforts to eliminate COVID-19. Collaboration with all stakeholders is critical to helping Myanmar workers understand COVID-19, social measures, and preventive beliefs to increase vaccine uptake.

The impact of vaccination upon dental clinic avoidance and the cessation of individual protection measures

The aim of this study was to analyze the evolution of germ aversion, to perceived infectability and to the fear of COVID-19 from the beginning of the pandemic until the arrival of the vaccines. A repeated measures design was used with three time points during the pandemic. The survey consisted of: Scale of perceived vulnerability to disease; Scale of fear of COVID-19; They were asked if they were vaccinated and if that vaccination is complete. They were asked if they would avoid the dental clinic through fear of COVID-19; and if they have reduced preventive practice in response to COVID-19. A T0-T1 increase in perceived infectability and germ aversion was reported. However, fear of COVID-19 decreased at T1-T2. The vaccinated experienced a greater reduction than the unvaccinated and a greater relaxation of their preventive practice. The frequency of dental avoidance decreased in the vaccinated group from T1 to T2 by 68.3% while in the non-vaccinated this reduction was only 4.9%; X ² = 18.58 (p < 0.01). In summary, vaccination has had an impact in the reduction of perceived infectability and in reducing fear of COVID-19. Nevertheless, germ aversion has remained stable and independent of vaccination. Empirical support is found for the affirmation that vaccination can reduce certain preventive behavior and dental avoidance.

Acceptance of coronavirus disease 2019 (COVID-19) vaccines among healthcare workers: A meta-analysis

Background

The coronavirus disease 2019 (COVID-19) pandemic has posed increasing challenges to global health systems. Vaccination against COVID-19 can effectively prevent the public, particularly healthcare workers (HCWs), from being infected by this disease.

Objectives

We aim to understand the factors influencing HCWs' acceptance of COVID-19 vaccines.

Methods

We searched PubMed, Embase and Web of Science to collect literature published before May 15, 2022, about HCWs' acceptance of COVID-19 vaccines. The Newcastle-Ottawa quality assessment scale was used to assess the risk of bias and the quality of the included studies. We utilized Stata 14.0 software for this meta-analysis with a random-effects model, and odds ratios (ORs) with 95% confidence intervals (CIs) were reported. This meta-analysis was conducted in alignment with the preferred reporting items for systematic review and meta-analysis (PRISMA) guideline.

Results

Our meta-analysis included 71 articles with 93,508 HCWs involved. The research showed that the acceptance of vaccines had significantly increased among HCWs compared to non-HCWs (OR = 1.91, 95% CI: 1.16-3.12). A willingness to undergo COVID-19 vaccination was observed in 66% (95% CI: 0.61-0.67) of HCWs. Among the HCWs involved, doctors showed a generally increased intention to be vaccinated compared with nurses (OR = 2.22, 95% CI: 1.71-2.89). Additionally, males were found to hold more positive attitudes toward vaccination than females (OR = 1.81, 95% CI: 1.55-2.12). When the effectiveness of COVID-19 vaccines was improved, the vaccination acceptance of HCWs was greatly increased accordingly (OR = 5.03, 95% CI: 2.77-9.11). The HCWs who were willing to vaccinate against seasonal influenza showed an increased acceptance of COVID-19 vaccines (OR = 3.52, 95% CI: 2.34-5.28). Our study also showed that HCWs who were willing to be vaccinated against COVID-19 experienced a reduced rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (OR = 0.78, 95% CI: 0.66-0.92).

Conclusions

Our analysis revealed that the five factors of occupation, gender, vaccine effectiveness, seasonal influenza vaccines, and SARS-CoV-2 infection presumably affected the acceptance of COVID-19 vaccines among HCWs. It is essential to boost the confidence of HCWs in COVID-19 vaccines for the containment of the epidemic.

The emergence, spread and vanishing of a French SARS-CoV-2 variant exemplifies the fate of RNA virus epidemics and obeys the Mistigri rule

The nature and dynamics of mutations associated with the emergence, spread, and vanishing of SARS-CoV-2 variants causing successive waves are complex. We determined the kinetics of the most common French variant ("Marseille-4") for 10 months since its onset in July 2020. Here, we analyzed and classified into subvariants and lineages 7453 genomes obtained by next-generation sequencing. We identified two subvariants, Marseille-4A, which contains 22 different lineages of at least 50 genomes, and Marseille-4B. Their average lifetime was 4.1 ± 1.4 months, during which 4.1 ± 2.6 mutations accumulated. Growth rate was 0.079 ± 0.045, varying from 0.010 to 0.173. Most of the lineages exhibited a bell-shaped distribution. Several beneficial mutations at unpredicted sites initiated a new outbreak, while the accumulation of other mutations resulted in more viral heterogenicity, increased diversity and vanishing of the lineages. Marseille-4B emerged when the other Marseille-4 lineages vanished. Its ORF8 gene was knocked out by a stop codon, as reported in SARS-CoV-2 of mink and in the Alpha variant. This subvariant was associated with increased hospitalization and death rates, suggesting that ORF8 is a nonvirulence gene. We speculate that the observed heterogenicity of a lineage may predict the end of the outbreak.

Methodology to estimate natural- and vaccine-induced antibodies to SARS-CoV-2 in a large geographic region

Accurate estimates of natural and/or vaccine-induced antibodies to SARS-CoV-2 are difficult to obtain. Although model-based estimates of seroprevalence have been proposed, they require inputting unknown parameters including viral reproduction number, longevity of immune response, and other dynamic factors. In contrast to a model-based approach, the current study presents a data-driven detailed statistical procedure for estimating total seroprevalence (defined as antibodies from natural infection or from full vaccination) in a region using prospectively collected serological data and state-level vaccination data. Specifically, we conducted a longitudinal statewide serological survey with 88,605 participants 5 years or older with 3 prospective blood draws beginning September 30, 2020. Along with state vaccination data, as of October 31, 2021, the estimated percentage of those 5 years or older with naturally occurring antibodies to SARS-CoV-2 in Texas is 35.0% (95% CI = (33.1%, 36.9%)). This is 3× higher than, state-confirmed COVID-19 cases (11.83%) for all ages. The percentage with naturally occurring or vaccine-induced antibodies (total seroprevalence) is 77.42%. This methodology is integral to pandemic preparedness as accurate estimates of seroprevalence can inform policy-making decisions relevant to SARS-CoV-2.

Evaluation of an Emergency Department Influenza Vaccination Program: Uptake Factors and Opportunities

Introduction: Influenza vaccines are commonly provided through community health events and primary care appointments. However, acute unscheduled healthcare visits such as emergency department (ED) visits are increasingly viewed as important vaccination opportunities. Emergency departments may be well-positioned to complement broader public health efforts with integrated vaccination programs. Methods: We studied an ED-based influenza vaccination initiative in an urban hospital and examined patient-level factors associated with screening and vaccination uptake. Our analyses included patient visits to the ED from October 1, 2019-April 1, 2020. Results: The influenza screening and vaccination program proved feasible. Of the 20,878 ED visits that occurred within the study period, 3,565 (17.1%) included a screening for influenza vaccine eligibility; a small proportion (11.5%) of the patients seen had multiple screenings. Among the patients screened eligible for the vaccine, 916 ultimately received an influenza vaccination while in the ED (43.7% of eligible patients). There was significant variability in the characteristics of patients who were and were not screened and vaccinated. Age, gender, race, preferred language, and receipt of a flu vaccine in prior years were associated with screening and/or receiving a vaccine in the ED. Conclusion: Vaccination programs in the ED can boost community vaccination rates and play a role in both preventing and treating current and future vaccine-preventable public health crises, although efforts must be made to deliver services equitably.

The effect of herd immunity thresholds on willingness to vaccinate

Throughout the COVID-19 pandemic, media and policymakers openly speculated about the number of immune citizens needed to reach a herd immunity threshold. What are the effects of such numerical goals on the willingness to vaccinate? In a large representative sample (N = 1540) of unvaccinated Swedish citizens, we find that giving a low (60%) compared to a high (90%) threshold has direct effects on beliefs about reaching herd immunity and beliefs about how many others that will get vaccinated. Presenting the high threshold makes people believe that herd immunity is harder to reach (on average about half a step on a seven-point scale), compared to the low threshold. Yet at the same time, people also believe that a higher number of the population will get vaccinated (on average about 3.3% more of the population). Since these beliefs affect willingness to vaccinate in opposite directions, some individuals are encouraged and others discouraged depending on the threshold presented. Specifically, in mediation analysis, the high threshold indirectly increases vaccination willingness through the belief that many others will get vaccinated (B = 0.027, p = 0.003). At the same time, the high threshold also decreases vaccination willingness through the belief that the threshold goal is less attainable (B = -0.053, p < 0.001) compared to the low threshold condition. This has consequences for ongoing COVID-19 vaccination and future vaccination campaigns. One message may not fit all, as different groups can be encouraged or discouraged from vaccination.

A disproportionality analysis for the association of central nervous system demyelinating diseases with COVID-19 vaccination using the World Health Organization pharmacovigilance database

BACKGROUND

Limited information is available on associations between COVID-19 vaccines and central nervous system (CNS) demyelinating diseases.

OBJECTIVES

We investigated potential safety signals for CNS demyelinating diseases related to COVID-19 vaccines using the World Health Organization pharmacovigilance database.

METHODS

Disproportionality analyses of CNS demyelinating disease following COVID-19 vaccination were performed by calculating the information component (IC) or the reporting odds ratio (ROR) compared with those for the entire database and for all other viral vaccines.

RESULTS

We identified 715 cases of optic neuritis, 515 of myelitis, 220 of acute disseminated encephalomyelitis (ADEM), and 2840 total CNS demyelinating events adverse drug reactions from July 2020 through February 2022. For mRNA-based and ChAdOx1 nCoV-19 vaccines, there were no potential safety signals of disproportionality for optic neuritis (IC₀₂₅ = -0.93, ROR₀₂₅ = 0.38; IC₀₂₅ = -1.76, ROR₀₂₅ = 0.26), myelitis (IC₀₂₅ = -0.69, ROR₀₂₅ = 0.50; IC₀₂₅ = -0.63, ROR₀₂₅ = 0.53), ADEM (IC₀₂₅ = -1.05, ROR₀₂₅ = 0.33; IC₀₂₅ = -1.76, ROR₀₂₅ = 0.20), or overall CNS demyelinating disease events (IC₀₂₅ = -0.66, ROR₀₂₅ = 0.52; IC₀₂₅ = -1.31, ROR₀₂₅ = 0.34) compared with other viral vaccines.

CONCLUSION

As with other viral vaccines, our disproportionality analyses indicate that the risk of COVID-19 vaccine-associated CNS demyelinating disease was low.

Application of a data-driven XGBoost model for the prediction of COVID-19 in the USA: a time-series study

OBJECTIVE

The COVID-19 outbreak was first reported in Wuhan, China, and has been acknowledged as a pandemic due to its rapid spread worldwide. Predicting the trend of COVID-19 is of great significance for its prevention. A comparison between the autoregressive integrated moving average (ARIMA) model and the eXtreme Gradient Boosting (XGBoost) model was conducted to determine which was more accurate for anticipating the occurrence of COVID-19 in the USA.

DESIGN

Time-series study.

SETTING

The USA was the setting for this study.

MAIN OUTCOME MEASURES

Three accuracy metrics, mean absolute error (MAE), root mean square error (RMSE) and mean absolute percentage error (MAPE), were applied to evaluate the performance of the two models.

RESULTS

In our study, for the training set and the validation set, the MAE, RMSE and MAPE of the XGBoost model were less than those of the ARIMA model.

CONCLUSIONS

The XGBoost model can help improve prediction of COVID-19 cases in the USA over the ARIMA model.

Associations of Guillain-Barré Syndrome with Coronavirus Disease 2019 Vaccination: Disproportionality Analysis Using the World Health Organization Pharmacovigilance Database

BACKGROUND AND AIMS

Vaccinations against the severe acute respiratory syndrome coronavirus 2 which causes COVID-19 have been administered worldwide. We aimed to investigate associations of COVID-19 vaccination with the occurrence of Guillain-Barré syndrome (GBS).

METHODS

We explored potential safety signals regarding the development of GBS using disproportionality analyses to compare COVID-19 vaccination with all adverse drug reaction (ADR) reports and influenza vaccines reported to VigiBase.

RESULTS

As of October 15, 2021, a total of 2,163 cases (0.13%) of GBS and its variants (including 46 cases of Miller-Fisher syndrome and 13 cases of Bickerstaff's encephalitis) were identified in entire ADR database after vaccination with the ChAdOx1 nCoV-19 (AstraZeneca, Cambridge, England) or the two messenger RNA-based COVID-19 (BNT162b2 ; Pfizer and BioNTech) or mRNA-1273;Moderna) vaccines. The median time to onset of GBS after vaccination was around two weeks. The ChAdOx1 nCoV-19 and two messenger RNA-based COVID-19 vaccines demonstrated a higher risk for GBS against entire database (information component [IC]₀₂₅ =1.73 reporting odds ratio [ROR]₀₂₅ =3.51; IC₀₂₅ =1.07, ROR₀₂₅ =2.22, respectively). When compared with influenza vaccines, neither the ChAdOx1 nCoV-19 nor mRNA-based vaccines were found to be associated with greater risks of GBS (IC₀₂₅ =-1.84, ROR₀₂₅ =0.11; IC₀₂₅ =-1.86, ROR₀₂₅ =0.06, respectively).

INTERPRETATION

Although potential safety signals associated with GBS COVID-19 vaccines have been identified, the risk of GBS from COVID-19 vaccines were low and did not surpass those of influenza vaccines; however, because of the heterogeneity of the sources of information in the WHO pharmacovigilance database, further epidemiological studies are warranted to confirm these observations. This article is protected by copyright. All rights reserved.

Assessment of acceptability of the COVID-19 vaccine based on the health belief model among Malaysians-A qualitative approach

INTRODUCTION

Several countries have started mass vaccination programs to halt the spread of the COVID-19 pandemic. With an R naught value of 2 to 3, about 70% of the population needs to be immunized to achieve herd immunity. This study aimed to investigate the reasons for acceptance or refusal of COVID-19 vaccines among the Malaysian population.

METHODOLOGY

An exploratory, descriptive qualitative design was performed. The cross-sectional survey used a non-probability convenient sampling technique to recruit the respondents, who were required to answer an open-ended question: Either "If you are willing to get the vaccine, please state your reason" or "If you are not willing to get vaccinated, please state your reason." The survey also included questions on demography such as age, gender, and place of residence. According to the Health Belief Model, the data was transcribed, translated, and analyzed: perceived susceptibility, perceived severity, perceived barrier, and cues for action.

RESULTS

A total of 1091 respondents who completed the online survey comprised 685 (62.8%) females, 406 (37.2%) males, with a mean age of 38.16 (SD = 16.44). The majority (81.1%) were willing to get vaccinated. Thematic analysis showed that most respondents perceived that the vaccine is safe, effective, protective and will provide herd immunity. Barriers to vaccination include unknown long-term side effects, rapid vaccine production, inadequate information and concerns regarding halal status. Cues to vaccination included individual desire, social responsibility, economic concerns and wait-and-see behavior.

CONCLUSIONS

The public should be well informed about the vaccine, its efficacy, side effects, and halal status to increase vaccine acceptability and achieve herd immunity.

COVID-19 Vaccination Strategies and Their Adaptation to the Emergence of SARS-CoV-2 Variants

About one year after the identification of the first cases of pneumonia due to a novel coronavirus in Wuhan, several vaccines against SARS-CoV-2/COVID-19 started to be approved for emergency use or authorized for early or limited use. The rapid development of effective vaccines based on different technological platforms represents an unprecedented success for vaccinology, providing a unique opportunity for a successful public health intervention. However, it is widely known that only a limited number of vaccine doses are usually available at the beginning of vaccination campaigns against an emerging virus; in this phase, protecting health care workers and reducing mortality rates is the priority. When a larger number of vaccines become available, the identification of the drivers of virus circulation coupled with the use of transmission blocking vaccines are key to achieve epidemic control through population immunity. However, as we learned during the vaccination campaigns against the pandemic coronavirus, several factors may hamper this process. Thus, flexible plans are required to obtain the best sustainable result with available tools, modulating vaccination strategies in accordance with improved scientific knowledge, and taking into account the duration of protective immune response, virus evolution, and changing epidemic dynamics.

Persistently low readiness to vaccinate young children against COVID among vaccine adherent mothers in Vermont, USA

Young children (0-4 years) represent the next population in whom the SARS-CoV-2 (COVID) vaccine will be available. Addressing parental feelings about vaccination will be important to optimize uptake. In this study, online surveys were administered in 78 perinatal women in the Northeast United States (Vermont) between January and July 2021. Women reported vaccine intention by indicating their plans to have their child vaccinated. Response choices included vaccinate as soon as possible, vaccinate but not immediately, or no intention to vaccinate. Subsequently, women rated their readiness to vaccinate children if offered the COVID vaccine tomorrow on an 11-point scale from 0 (definitely not get the vaccine) to 10 (definitely get the vaccine). Factors influencing ratings were measured categorically. General vaccine hesitancy was measured with the Parent Attitudes about Childhood Vaccinations scale. While many individual participants changed readiness to vaccinate children between baseline and follow-up; readiness in the study cohort remained unchanged. Approximately 50% of participants were likely to have their young children vaccinated. Concerns about vaccine safety was the largest driver of hesitancy. Importantly, even in a cohort highly adherent to childhood vaccines, hesitancy toward general childhood vaccines predicted decreased readiness for young children to receive the COVID vaccine. Our data provide evidence that maternal attitudes about the COVID vaccine are not fixed but overall readiness remains low, that prior adherence to childhood vaccine schedules will not predict vaccine behavior related to the COVID vaccine, and that public health messaging should emphasize messaging targeting vaccine safety in children.

A Disproportionality Analysis for Association of Systemic Capillary Leak Syndrome with COVID-19 Vaccination Using the World Health Organization Pharmacovigilance Database

Systemic capillary leak syndrome (SCLS) is a rare and potentially life-threatening disorder characterized by reversible plasma extravasation and vascular collapse. This study aimed to investigate the association between different types of COVID-19 vaccine and SCLS in a real-world setting. We used individual case safety reports of SCLS after COVID-19 vaccination from the WHO pharmacovigilance database, VigiBase. A disproportionality analysis of ChAdOx1 nCoV-19 and mRNA-based vaccines was performed. The information component (IC) and reporting odds ratio (ROR) were calculated from the entire database and viral vaccines data subset. A positive 95% lower end of the IC (IC025) value (>0) using Bayesian neural network analysis and lower end of the ROR 95% confidence interval (ROR025) ≥1 were defined as the ADR signal detection threshold. A total of 101 (0.004%) events of SCLS were identified. A significant potential signal of disproportionality of SCLS was noted in ChAdOx1 nCoV-19 when applied as the denominator for entire database (IC025 = 0.24, ROR025 = 1.23) and all viral vaccines (IC025 = 0.41, ROR025 = 1.59). No significant potential signal was noted for two mRNA-based vaccines as denominators for the entire database (IC025 = −0.49, ROR025 = 0.71) and all viral vaccines (IC025 = −0.32, ROR025 = 0.77). Contrary to ChAdOx1 nCoV-1, no safety signal for developing SCLS was identified for mRNA-based vaccines.

Association of Cerebral Venous Thrombosis with mRNA COVID-19 Vaccines: A Disproportionality Analysis of the World Health Organization Pharmacovigilance Database

Cerebral venous thrombosis (CVT), a rare thrombotic event that can cause serious neurologic deficits, has been reported after some ChAdOx1 nCoV-19 vaccinations against coronavirus disease 2019 (COVID-19). However, there are few reports of associations between COVID-19 mRNA vaccination and CVT. We retrospectively analyzed CVT occurrence, time of onset after vaccination, outcomes (recovered/not recovered), and death after COVID-19 vaccination from adverse drug reactions (ADR) reports in VigiBase. A disproportionality analysis was performed regarding COVID-19 mRNA vaccines (BNT162b2 and mRNA-1273) and the ChAdOx1 nCoV-19 vaccine. We identified 756 (0.07%) CVT cases (620 (0.05%) after BNT162b2 and 136 (0.01%) after mRNA-1273) of 1,154,023 mRNA vaccine-related ADRs. Significant positive safety signals were noted for COVID-19 mRNA vaccines (95% lower end of information component = 1.56; reporting odds ratio with 95% confidence interval (CI) = 3.27). The median days to CVT onset differed significantly between the BNT162b2 and ChAdOx1 nCoV-19 vaccines (12 (interquartile range, 3−22) and 11 (interquartile range, 7−16), respectively; p = 0.02). Fewer CVT patients died after receiving mRNA vaccines than after receiving the ChAdOx1 nCoV-19 vaccine (odds ratio, 0.32; 95% CI, 0.22−0.45; p < 0.001). We noted a potential safety signal for CVT occurrence after COVID-19 mRNA vaccination. Therefore, awareness about the risk of CVT, even after COVID-19 mRNA vaccination, is necessary.

Machine learning-based model for prediction of clinical deterioration in hospitalized patients by COVID 19

Despite the publication of great number of tools to aid decisions in COVID-19 patients, there is a lack of good instruments to predict clinical deterioration. COVID19-Osakidetza is a prospective cohort study recruiting COVID-19 patients. We collected information from baseline to discharge on: sociodemographic characteristics, comorbidities and associated medications, vital signs, treatment received and lab test results. Outcome was need for intensive ventilatory support (with at least standard high-flow oxygen face mask with a reservoir bag for at least 6 h and need for more intensive therapy afterwards or Optiflow high-flow nasal cannula or noninvasive or invasive mechanical ventilation) and/or admission to a critical care unit and/or death during hospitalization. We developed a Catboost model summarizing the findings using Shapley Additive Explanations. Performance of the model was assessed using area under the receiver operating characteristic and prediction recall curves (AUROC and AUPRC respectively) and calibrated using the Hosmer–Lemeshow test. Overall, 1568 patients were included in the derivation cohort and 956 in the (external) validation cohort. The percentages of patients who reached the composite endpoint were 23.3% vs 20% respectively. The strongest predictors of clinical deterioration were arterial blood oxygen pressure, followed by age, levels of several markers of inflammation (procalcitonin, LDH, CRP) and alterations in blood count and coagulation. Some medications, namely, ATC AO2 (antiacids) and N05 (neuroleptics) were also among the group of main predictors, together with C03 (diuretics). In the validation set, the CatBoost AUROC was 0.79, AUPRC 0.21 and Hosmer–Lemeshow test statistic 0.36. We present a machine learning-based prediction model with excellent performance properties to implement in EHRs. Our main goal was to predict progression to a score of 5 or higher on the WHO Clinical Progression Scale before patients required mechanical ventilation. Future steps are to externally validate the model in other settings and in a cohort from a different period and to apply the algorithm in clinical practice.

Registration: ClinicalTrials.gov Identifier: NCT04463706.

Decoupling between SARS-CoV-2 transmissibility and population mobility associated with increasing immunity from vaccination and infection in South America

All South American countries from the Southern cone (Argentina, Brazil, Chile, Paraguay and Uruguay) experienced severe COVID-19 epidemic waves during early 2021 driven by the expansion of variants Gamma and Lambda, however, there was an improvement in different epidemic indicators since June 2021. To investigate the impact of national vaccination programs and natural infection on viral transmission in those South American countries, we analyzed the coupling between population mobility and the viral effective reproduction number [Formula: see text]. Our analyses reveal that population mobility was highly correlated with viral [Formula: see text] from January to May 2021 in all countries analyzed; but a clear decoupling occurred since May-June 2021, when the rate of viral spread started to be lower than expected from the levels of social interactions. These findings support that populations from the South American Southern cone probably achieved the conditional herd immunity threshold to contain the spread of regional SARS-CoV-2 variants circulating at that time.

Factors associated with COVID-19 vaccine intent among Latino SNAP participants in Southern California

Background

COVID-19 is significantly impacting the health and well-being of the country, particularly for ethnic minority populations and low-income groups. Our goal was to determine COVID-19 vaccination intent in a low-income, Latino population receiving aid from the Supplemental Nutrition Assistance Program (SNAP) in Southern California, and identify contributing factors and concerns.

Methods

A cross-sectional, mixed-methods survey was conducted among participants in the Southern California Nutrition Incentives Program (¡Más Fresco! More Fresh). Only Latino respondents were included in this analysis. Primary outcome was vaccine intent trichotomized into: “definitely/likely yes”, “not sure/don’t know”, and “definitely/likely not.”

Results

The majority of participants (n = 486) were female (93%), Spanish speaking (74%), with a median age of 40 years (IQR = 13). Approximately half (48%) reported they would get a COVID-19 vaccine, 39% were unsure, and 13% reported “definitely/likely not”. In the multivariable multinomial logistic regression model, participants with a household member with a COVID-19 health risk factor were more likely to be unsure about getting the vaccine. Participants who were primarily English speaking, did not receive the influenza vaccine last season, and reported not reading or talking about COVID-19 were more likely to report not intending to receive the vaccine. Many respondents were concerned about “side effects and ingredients”, and did not trust the vaccine development process, particularly with how fast it happened.

Conclusion

Low-income Latinos in Southern California were generally hesitant to get a COVID-19 vaccine. Culturally sensitive vaccine promotion campaigns need to address the concerns of minority populations who experience increased morbidity and mortality from COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13027-w.

Modelling the Effect of the Interaction between Vaccination and Nonpharmaceutical Measures on COVID-19 Incidence

Since December 2019, the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly from Wuhan (China) across the globe, affecting more than 200 countries by mid-2021, with over 190 M reported cases and around 4 M fatalities. During the first year of the pandemic, affected countries implemented a variety of nonpharmaceutical interventions to control virus transmission. In December 2020, countries started administering several authorised vaccines under a limited supply scenario. In this context, the aim of this study was to develop a SEIR-type continuous-time deterministic disease model, to determine the impact of interaction between different vaccination scenarios and levels of protection measures on disease incidence. For this, the model incorporates (i) a protection measure including low (self-protection), medium (mobility limitation), high (closure of indoor facilities), and very high (lockdown) protection levels, (ii) quarantine for confirmed cases, and (iii) vaccination rate and efficacy of four types of vaccines (Pfizer, Moderna, Astra Zeneca, and Janssen). The model was verified and evaluated using the response timeline and vaccination strategies and rates in the Basque Country (N. Spain). Once the model performance was validated, different initial phase (when 30% of the population is vaccinated) vaccination scenarios were simulated, including (i) a realistic vaccine limited supply scenario and (ii) four potential full vaccine supply scenarios where a unique vaccine type is administered. Significant differences in disease prevalence and cumulative mortality were found between vaccination scenarios for low and medium-level protection measures. For high-level protection measures, any vaccine scenario is effective at limiting the virus transmission and disease mortality. The results obtained here may vary in further studies since there may be some unpredictable factors/covariates. With this in mind, the model here could be easily applied to other regions or countries, modifying the strategies implemented and initial conditions.

Understanding the influence of political orientation, social network, and economic recovery on COVID-19 vaccine uptake among Americans

The COVID-19 pandemic poses unprecedented risks to the well-being of Americans. To control the pandemic, a sufficient proportion of the population needs to be vaccinated promptly. Despite the proven efficacy and widespread availability, vaccine distribution and administration rates remain low. Thus, it is important to understand the public behavior of COVID-19 vaccination. This study aims to identify determinants at multiple levels that promote or inhibit one's vaccine uptake. We combine individual-level data from a national survey conducted in the summer of 2021 with corresponding state-level indicators. Findings of multilevel logistic regression show that political orientation, social network, and economic recovery altogether have significant influence. We articulate that individual decision to take the vaccine are a function of their personal characteristics and are also rooted in their home state's political, public health, and economic contexts. These findings contribute to the literature and have policy implications. Knowledge of the profiles among people who take/refuse the vaccine provides essential information to leverage certain factors and maximize vaccine uptake to mitigate the pandemic's devastating impact.

A Case Report of Thrombotic Thrombocytopenia After ChAdOx1 nCov-19 Vaccination and Heparin Use During Hemodialysis

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but life-threatening complication. VITT strongly mimics heparin-induced thrombocytopenia (HIT) and shares clinical features. Heparin is commonly used to prevent coagulation during hemodialysis. Therefore, nephrologists might encounter patients needing dialysis with a history of heparin exposure who developed thrombotic thrombocytopenia after vaccination. A 70-year-old male presented with acute kidney injury and altered mental status due to lithium intoxication. He needed consecutive hemodialysis using heparin. Deep vein thrombosis of left lower extremity and accompanying severe thrombocytopenia of 15,000/µL on 24 days after vaccination and at the same time, nine days after heparin use. Anti-platelet factor 4 antibody test was positive. Anticoagulation with apixaban and intravenous immunoglobulin (IVIG) infusion resolved swelling of his left calf and thrombocytopenia. There were no definitive diagnostic tools capable of differentiating between VITT and HIT in this patient. Although VITT and HIT share treatment with IVIG and non-heparin anticoagulation, distinguishing between VITT and HIT will make it possible to establish a follow-up vaccination plan in a person who has had a thrombocytopenic thrombotic event. Further research is needed to develop the tools to make a clear distinction between the clinical syndromes.

Older Adults' Perceived Risk Regarding COVID-19 and Intention to Vaccinate: Role of Health-Related Literacy

The current cross-sectional descriptive study aimed to explore the association between coronavirus disease 2019 (COVID-19)-related health literacy, perceived risk, and intention to receive a COVID-19 vaccine. A sample of 414 older adults completed several questionnaires regarding COVID-19 risk perception, intention to vaccinate, and health literacy. Results revealed that more than one half of older adults demonstrated perceived high risk related to COVID-19 infection. Moreover, 31.6% of older adults noted their unwillingness to get vaccinated, and 39.4% demonstrated low health literacy regarding COVID-19. A significant positive correlation was found among older adults' perceived risk regarding COVID-19 infection, intention toward vaccination against COVID-19, and COVID-19-related health literacy. Findings serve to aid the Ministry of Health in planning proactive steps to increase COVID-19 vaccine uptake in older adults. [Research in Gerontological Nursing, 15(2), 57-67.].

High Incidence of SARS-CoV-2 Within Incarcerated Populations and Possible Implications for Herd Immunity

Controlling the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been challenging in the community and prison systems. Where herd immunity lies for this virus is unknown, although estimates have ranged from 60% to 80%. Since the start of the pandemic, there have been multiple SARS-CoV-2 outbreaks within U.S. prison systems, which may provide more insight on where true herd immunity lies. We reviewed data from the California Department of Corrections and Rehabilitation to investigate the cumulative incidence of infection and found levels in 14 (40%) of 35 prisons were >60%. These data and existing literature suggest that in prison environments, prevalence of immunity often needs to reach >70% before transmission slows. Similar levels may be needed in the general population before transmission is suppressed.

Anti-SARS-CoV-2 antibodies among indigenous populations of the Brazilian Amazon: a cross-sectional study

OBJECTIVES

The emergence of SARS-CoV-2 and its pandemic spread generated serious concern about the impact of the infection on vulnerable indigenous populations of the Brazilian Amazon. Thus, this study aimed to perform a seroepidemiological survey of anti-SARS-CoV-2 antibodies in those populations.

SETTING

Six indigenous ethnic groups living in the State of Pará (Northern Brazil) were investigated. The villages of Xikrin do Bacajá, Assurini, Araweté, Parakanã, Munduruku and Kararaô were visited from October 2020 to January 2021.

DESIGN AND PARTICIPANTS

We performed a cross-sectional study to investigate the prevalence of anti-spike (S1) IgG antibodies. Plasma was tested for the presence of anti-SARS-CoV-2 IgM and IgG antibodies using two assays (a lateral flow rapid test and an ELISA). A total of 1185 individuals of both sexes were enrolled in the study.

RESULTS

The prevalences of IgM and IgG antibodies were 6.9% and 68.1%, respectively, ranging from 0% to 79.6%, with significant differences (p<0.001) between age groups in three communities (Araweté, Xikrin and Munduruku) and a virulence rate of 0.86%. The overall IgG prevalence obtained by rapid tests and ELISAs were similar, and the agreement of the results between the two tests was 80%, which was classified as good (kappa=0.4987; p<0.001; sensitivity of 82.1% and specificity of 71.6%). Herd immunity was probably attained, similar to that found in other communities of the Amazon.

CONCLUSIONS

SARS-CoV-2 spread rapidly among the indigenous populations investigated, but it had a low mortality rate. It is necessary to expand serological investigations to other communities in the Amazon region of Brazil.

Associations among political voting preference, high-risk health status, and preventative behaviors for COVID-19

BACKGROUND

We investigate the relationships among political preferences, risk for COVID-19 complications, and complying with preventative behaviors, such as social distancing, quarantine, and vaccination, as they remain incompletely understood. Since those with underlying health conditions have the highest mortality risk, prevention strategies targeting them and their caretakers effectively can save lives. Understanding caretakers' adherence is also crucial as their behavior affects the probability of transmission and quality of care, but is understudied. Examining the degree to which adherence to prevention measures within these populations is affected by their health status vs. voting preference, a key predictor of preventative behavior in the U. S, is imperative to improve targeted public health messaging. Knowledge of these associations could inform targeted COVID-19 campaigns to improve adherence for those at risk for severe consequences.

METHODS

We conducted a nationally-representative online survey of U.S. adults between May-June 2020 assessing: 1) attempts to socially-distance; 2) willingness/ability to self-quarantine; and 3) intention of COVID-19 vaccination. We estimated the relationships between 1) political preferences 2) underlying health status, and 3) being a caretaker to someone with high-risk conditions and each dependent variable. Sensitivity analyses examined the associations between political preference and dependent variables among participants with high-risk conditions and/or obesity.

RESULTS

Among 908 participants, 75.2% engaged in social-distancing, 94.4% were willing/able to self-quarantine, and 60.1% intended to get vaccinated. Compared to participants intending to vote for Biden, participants who intended to vote for Trump were significantly less likely to have tried to socially-distance, self-quarantine, or intend to be vaccinated. We observed the same trends in analyses restricted to participants with underlying health conditions and their caretakers Underlying health status was independently associated with social distancing among individuals with obesity and another high-risk condition, but not other outcomes.

CONCLUSION

Engagement in preventative behavior is associated with political voting preference and not individual risk of severe COVID-19 or being a caretaker of a high-risk individual. Community based strategies and public health messaging should be tailored to individuals based on political preferences especially for those with obesity and other high-risk conditions. Efforts must be accompanied by broader public policy.

The association between coronaphobia and attitude towards COVID-19 Vaccine: A sample in the east of Turkey

PURPOSE

This study was conducted to examine the association between coronaphobia and attitude towards COVID-19 vaccine in the society.

METHODS

This cross-sectional descriptive study was conducted with snowball sampling method between December 30, 2020 and January 10, 2021. The survey form was sent online to individuals who were 18 years of age and older. 1252 individuals who responded to the surveys were included in the study. The data were collected by using "Descriptive Information Form", "Attitudes towards the Covid-19 vaccine scale" and "Coronavirus 19 Phobia Scale (CP19-S)". Descriptive statistics and Pearson Correlation analysis were used in the evaluation of data.

RESULTS

In the study, it was found that the participants had a mean ATV-COVID-19 scale positive attitude sub-dimension score of 2.81±1.04, while they had a mean negative attitude sub-dimension score of 2.95±0.78 and a mean total score of 2.89±0.78. It was found that the participants had a mean C19P-S psychological sub-dimension score of 21.03±5.36, a mean psychosomatic sub-dimension score of 10.30±4.11, a mean social sub-dimension score of 15.04±4.71, a mean economic sub-dimension score of 8.89±3.46 and a mean total scale score of 55.28±15.00. It was found in the study that there was a positive association between the participants' C19P-S and social sub-dimension and ATV-COVID-19 and positive attitude sub-dimension, while there was a negative association between ATV-COVID-19 and negative attitude sub-dimension (p<0.05).

CONCLUSIONS

It was found that the participants had a moderate level of coronavirus phobia and positive attitudes towards the vaccine. It was found that positive attitudes towards COVID-19 vaccine increased as the coronavirus phobia increased.

Impact of corona-phobia on attitudes and acceptance towards COVID-19 vaccine among cancer patients: a single-center study

Aim: This study aimed to assess the impact of COVID-19 phobia and related factors on attitude towards COVID-19 vaccine in cancer patients. Methods: A prospective cross-sectional descriptive study was conducted with 300 adult patients using a validated COVID-19 Phobia Scale (C19P-S) and related survey to determine the factors affecting vaccine acceptance between May-June 2021. Results: Regarding the COVID-19 vaccine willingness, 86.7% accepted vaccination, 6.3% were hesitant and 7% refused vaccination. Patients that accepted vaccination had significantly higher C19P-S scores in general, and in psychological and psychosomatic subdivisions. Univariate analysis revealed that increased age, being retired, and being married were significantly associated with willingness to be vaccinated against COVID-19. Conclusion: The majority of patients had high 'coronophobia' levels which were associated with increased willingness for the COVID-19 vaccines. Minimizing negative attitudes towards vaccines will most likely be achieved by raising awareness in the cancer population about COVID-19 vaccine.

Investigating vaccine-induced immunity and its effect in mitigating SARS-CoV-2 epidemics in China

BACKGROUND

To allow a return to a pre-COVID-19 lifestyle, virtually every country has initiated a vaccination program to mitigate severe disease burden and control transmission. However, it remains to be seen whether herd immunity will be within reach of these programs.

METHODS

We developed a compartmental model of SARS-CoV-2 transmission for China, a population with low prior immunity from natural infection. Two vaccination programs were tested and model-based estimates of the immunity level in the population were provided.

RESULTS

We found that it is unlikely to reach herd immunity for the Delta variant given the relatively low efficacy of the vaccines used in China throughout 2021 and the lack of prior natural immunity. We estimated that, assuming a vaccine efficacy of 90% against the infection, vaccine-induced herd immunity would require a coverage of 93% or higher of the Chinese population. However, even when vaccine-induced herd immunity is not reached, we estimated that vaccination programs can reduce SARS-CoV-2 infections by 50-62% in case of an all-or-nothing vaccine model and an epidemic starts to unfold on December 1, 2021.

CONCLUSIONS

Efforts should be taken to increase population's confidence and willingness to be vaccinated and to develop highly efficacious vaccines for a wide age range.

A single mRNA vaccine dose in COVID-19 patients boosts neutralizing antibodies against SARS-CoV-2 and variants of concern

The urgent need for, but limited availability of, SARS-CoV-2 vaccines worldwide has led to widespread consideration of dose-sparing strategies. Here, we evaluate the SARS-CoV-2-specific antibody responses following BNT162b2 vaccination in 150 previously SARS-CoV-2-infected individuals from a population-based cohort. One week after first vaccine dose, spike protein antibody levels are 27-fold higher and neutralizing antibody titers 12-fold higher, exceeding titers of fully vaccinated SARS-CoV-2-naive controls, with minimal additional boosting after the second dose. Neutralizing antibody titers against four variants of concern increase after vaccination; however, overall neutralization breadth does not improve. Pre-vaccination neutralizing antibody titers and time since infection have the largest positive effect on titers following vaccination. COVID-19 severity and the presence of comorbidities have no discernible impact on vaccine response. In conclusion, a single dose of BNT162b2 vaccine up to 15 months after SARS-CoV-2 infection offers higher neutralizing antibody titers than 2 vaccine doses in SARS-CoV-2-naive individuals.

Challenges in Engendering Herd Immunity to SARS-CoV-2 infection: Possibly Impossible but Plausibility with Hope

Herd immunity scaled to the population level is what gives rise to herd immunity. When a sufficiently significant fraction of immune individuals exist in a group, it confers indirect protection from infection to vulnerable individuals. This population-level effect is frequently considered in the context of vaccination programs, which attempt to build herd immunity so that people who cannot be vaccinated, such as the very young or those with impaired immune systems, are nonetheless protected from disease. Clinical signs are a poor predictor of transmissibility for some infections, such as COVID-19, because asymptomatic hosts can be extremely infectious and contribute to the spread of the virus. COVID-19 is a quickly evolving issue that has been widely circulated throughout the world. The concept of herd immunity is frequently stated during this time, although it is readily misconstrued. The concept of herd immunity is frequently stated during this time, although it is readily misconstrued. This article elaborates on the idea and goal of herd immunity, the necessary conditions for realizing herd immunity, the restrictive requirements for applying herd immunity, and the obstacles experienced in achieving herd immunity in the context of COVID-19. This mini article explains the concept and purpose of herd immunization in the context of COVID-19.

Hesitancy in COVID-19 vaccine uptake and its associated factors among the general adult population: a cross-sectional study in six Southeast Asian countries

Background

Vaccines are effective and reliable public health interventions against viral outbreaks and pandemics. However, hesitancy regarding the Coronavirus disease (COVID-19) vaccine is evident worldwide. Therefore, understanding vaccination-related behavior is critical in expanding the vaccine coverage to flatten the infection curve. This study explores the public perception regarding COVID-19 vaccination and identifies factors associated with vaccine hesitancy among the general adult populations in six Southeast Asian countries.

Methods

Using a snowball sampling approach, we conducted a descriptive cross-sectional study among 5260 participants in Indonesia, Malaysia, Myanmar, Philippines, Thailand, and Vietnam between February and May 2021. Binary logistic regression analysis with a backward conditional approach was applied to identify factors associated with COVID-19 vaccine hesitancy.

Results

Of the total, 50.6% were female, and the median age was 30 years (range: 15–83 years). The majority of the participants believed that vaccination effectively prevents and controls COVID-19 (81.2%), and 84.0% would accept COVID-19 vaccines when they become available. They agreed that health providers’ advice (83.0%), vaccination convenience (75.6%), and vaccine costs (62.8%) are essential for people to decide whether to accept COVID-19 vaccines. About half (49.3%) expressed their hesitancy to receive the COVID-19 vaccines. After adjustment for other covariates, COVID-19 vaccine hesitancy was significantly associated with age, residential area, education levels, employment status, and family economic status. Participants from Indonesia, Myanmar, Thailand, and Vietnam were significantly more likely to express hesitancy in receiving COVID-19 vaccines than those from Philippines.

Conclusions

In general, participants in this multi-country study showed their optimistic perception of COVID-19 vaccines’ effectiveness and willingness to receive them. However, about half of them still expressed their hesitancy in getting vaccinated. The hesitation was associated with several socioeconomic factors and varied by country. Therefore, COVID-19 vaccination programs should consider these factors essential for increasing vaccine uptake in the populations.