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Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses

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A special issue of Vaccines (ISSN 2076-393X). This special issue belongs to the section "COVID-19 Vaccines and Vaccination".

Deadline for manuscript submissions: 31 May 2024 | Viewed by 19620

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Special Issue Editors

Dr. Rahul Shekhar

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Guest Editor

University of New Mexico Health Sciences Center, Albuquerque, NM 87106, USA
Interests: COVID-19 vaccination hesitancy; vaccination in special population
Special Issues, Collections and Topics in MDPI journals

Dr. Prabal Chourasia

E-Mail Website
Guest Editor

Mary Washington Hospital, Fredericksburg, VA 22401, USA
Interests: COVID-19 vaccination; COVID-19 vaccination hesitancy; COVID-19 vaccination complication; COVID-19 vaccination efficacy

Dr. Abu Baker Sheikh

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Guest Editor

Department of Internal Medicine, University of New Mexico, Albuquerque, NM 87106, USA
Interests: COVID-19 infection; hospital medicine; COVID-19 complications
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

COVID-19 was declared a pandemic by the WHO on March 11^th, 2020, and since then, it has caused unprecedented morbidity and mortality worldwide, leading to more than 6.5 million deaths, and immense social, economic, personal, and emotional loss. Apart from social distancing, hand hygiene, and mask wearing, the only effective way to curb this pandemic is through effective herd immunity, which can only be achieved through mass immunization of the general population. COVID-19 vaccines were developed at an unimaginable speed and are considered quite safe and effective, representing one of the miracles of modern medicine. Even though their safety and effectiveness are backed up by published scientific data, there is widespread hesitancy towards vaccination due to personal beliefs, religious practices, socioeconomic reasons, or political ideology. Misinformation and conspiracy theories are also widespread and prevalent on social media. This is a major barrier to effectively reaching herd immunity and curtailing the pandemic. People are not only hesitant to take the primary vaccination series, but also the booster doses. Indeed, not many individuals are ready to take the annual recommended COVID-19 booster dose.

In this Special Issue, we aim to invite distinguished authors to publish manuscripts related to knowledge, attitudes, beliefs, and hesitancy toward COVID-19 vaccination in the general population and special population groups. We also invite manuscripts on attitudes and beliefs towards COVID-19 vaccine booster doses in the general population and in special population groups such as cancer patients, immunocompromised patients, and transplant patients.

We look forward to original research articles such as behavior surveys, systemic reviews, meta-analyses, review articles, or opinion pieces.

I am excited to receive your contributions.

Dr. Rahul Shekhar
Dr. Prabal Chourasia
Dr. Abu Baker Sheikh
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Vaccines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

COVID-19 vaccine hesitency
COVID-19 Vaccine booster dose
COVID-19 vaccine in immunocompromised population

Published Papers (11 papers)

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Research

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12 pages, 477 KiB

Open AccessArticle

Anti-SARS-CoV-2 Antibodies Level and COVID-19 Vaccine Boosters among Healthcare Workers with the Highest SARS-CoV-2 Infection Risk—Follow Up Study

by Dagny Lorent, Rafał Nowak, Magdalena Figlerowicz, Luiza Handschuh and Paweł Zmora

Vaccines 2024, 12(5), 475; https://doi.org/10.3390/vaccines12050475 (registering DOI) - 29 Apr 2024

Viewed by 93

Abstract

During the COVID-19 pandemic, several vaccines were developed to limit the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, due to SARS-CoV-2 mutations and uneven vaccination coverage among populations, a series of COVID-19 waves have been caused by different variants of concern (VOCs). Despite the updated vaccine formulations for the new VOC, the benefits of additional COVID-19 vaccine doses have raised many doubts, even among high-risk groups such as healthcare workers (HCWs). We examined the factors underlying hesitancy to receive COVID-19 booster vaccine doses and analysed the anti-SARS-CoV-2 IgG antibody response after booster vaccination among HCWs. Our study found that 42% of the HCWs were hesitant about the second booster dose, while 7% reported no intent to get vaccinated with any additional doses. As reasons for not vaccinating, participants most frequently highlighted lack of time, negative experiences with previous vaccinations, and immunity conferred by past infections. In addition, we found the lowest post-vaccination antibody titres among HCWs who did not receive any vaccine booster dose and the highest among HCWs vaccinated with two booster doses. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

15 pages, 279 KiB

Open AccessArticle

Factors Influencing the Healthcare Workers’ Willingness to Receive the COVID-19 Booster Dose in Tuscany (Italy)

by Giovanni Guarducci, Giovanna Mereu, Davide Golinelli, Giacomo Galletti, Fabrizio Gemmi, Alessandra Cartocci, Nora Holczer, Luca Bacci, Alessandro Sergi, Gabriele Messina, Valerio Mari and Nicola Nante

Vaccines 2023, 11(12), 1751; https://doi.org/10.3390/vaccines11121751 - 24 Nov 2023

Viewed by 1035

Abstract

Background: The World Health Organization has defined vaccine hesitancy as behavior influenced by several factors, including trust in the vaccine itself or its provider or the perceived need for vaccination. The aim of this study was to investigate the factors influencing the willingness to receive the COVID-19 vaccine among the employees and healthcare professionals of the Central Tuscany Local Health Authority (CT-LHA) in Italy. Methods: From July to October 2022, a cross-sectional study was conducted. An online questionnaire was administered to 7000 employees of the CT-LHA. The questionnaire analyzed the factors that influenced receiving the booster dose of the COVID-19 vaccine. The sample was stratified by gender, age, type of occupation (healthcare or non-healthcare workers), and seniority. Incomplete questionnaires were excluded. A chi-squared test was performed through STATA. The significance level was set at 95%. Results: Of the questionnaires administered, 1885 (26.9%) questionnaires were eligible for the study. In the previous vaccination campaign, the healthcare workers (HCWs) considered the vaccine used by CT-LHA as safe, in contrast to non-healthcare workers (N-HCWs), who considered it less secure (p < 0.05). The HCWs showed a higher propensity for vaccine safety to receive the booster dose than N-HCWs. N-HCWs appeared to be less affected by an updated booster dose than HCWs (p < 0.05). Conclusions: The factors studied appear to influence HCWs differently from N-HCWs. Both HCWs and N-HCWs would choose an upgraded mRNA vaccine for the booster dose. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

18 pages, 1285 KiB

Open AccessArticle

The Role of Vaccination Centers in a National Mass Immunization Campaign—Policymaker Insights from the German COVID-19 Pandemic Vaccine Roll-Out

by Stella Danek, Dmitrij Achelrod, Ole Wichmann and Falk Schwendicke

Vaccines 2023, 11(10), 1552; https://doi.org/10.3390/vaccines11101552 - 30 Sep 2023

Viewed by 1191

Abstract

During the COVID-19 vaccination campaign, Germany, like other high-income countries, introduced mass vaccination centers for administering vaccinations. This qualitative study aimed to examine the role that these novel, temporary government healthcare structures played in a mass immunization roll-out and how they can be optimally deployed. In addition, learnings for general emergency preparedness were explored. A total of 27 high-level policymakers responsible for planning and implementing the COVID vaccination campaign at the national and state level in Germany were interviewed in May and June 2022. The semi-structured interviews were analyzed using thematic analysis. Interviewees indicated that mass vaccination structures played an essential role with respect to controllability, throughput, accessibility and openness in line with the key success criteria vaccination coverage, speed and accessibility. In contrast to the regular vaccination structures (private medical practices and occupational health services), public administration has direct authority over mass vaccination centers, allowing for reliable vaccine access prioritization and documentation. The deployment of vaccination centers should be guided by vaccine availability and demand, and vaccine requirements related to logistics, as well as local capacities, i.e., public-health-service strength and the physician density, to ensure effective, timely and equitable access. Improvements to the capacity use, scalability and flexibility of governmental vaccination structures are warranted for future pandemics. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

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10 pages, 265 KiB

Open AccessArticle

COVID-19 Vaccine Booster Hesitancy among Hispanic Adults: A Cross-Sectional Study from the Puerto Rico Community Engagement Alliance against COVID-19 Disparities (PR-CEAL)

by Hérmilis Berríos, Andrea López-Cepero, Cynthia M. Pérez, Stephanie Cameron, Adriana D. Pons Calvo and Vivian Colón-López

Vaccines 2023, 11(9), 1426; https://doi.org/10.3390/vaccines11091426 - 28 Aug 2023

Cited by 1 | Viewed by 1399

Abstract

Hispanic/Latino communities have suffered a disproportionate burden of the COVID-19 pandemic. Although Puerto Rico has one of the highest COVID-19 primary series vaccination rates nationwide, this estimate contrasts with the reported booster doses’ low uptake. This study aimed to assess health belief correlates of COVID-19 vaccine booster uptake. Using a convenience sampling approach, the Puerto Rico-Community Engagement Alliance (PR-CEAL) conducted a cross-sectional study where 787 participants were recruited using online and in-person strategies between December 2021 and February 2022. Participants were adults 18 years or older, Spanish-speaking, and residents of Puerto Rico. The Health Belief Model was used to evaluate attitudes and beliefs. A total of 784 participants were used in this analysis. Adjusted Poisson regression models were used to estimate prevalence ratios (PR) and 95% confidence intervals (CI) of booster refusal. Overall, 22% of participants refused the vaccine booster or had not gotten it yet. Adjusted models showed that (i) participants who disagreed that getting the booster dose either made them feel less worried about COVID-19 or (ii) felt that the vaccine decreased their chances of getting COVID-19 presented higher booster-refusal prevalence ratios (PR = 4.20, 95% CI: 3.00, 5.90; PR = 3.70, 95% CI: 2.64, 5.18). Moreover, participants that (iii) reported having concerns for booster side effects [PR = 2.47; 95% CI = 1.73, 3.51], (iv) booster efficacy [PR = 2.50; 95% CI = 1.75, 3.58], and (v) booster safety [PR = 2.80; 95% CI = 1.96, 3.99] were significantly more likely to refuse the booster. In conclusion, booster vaccination refusal was associated with lower perceived vaccine benefits and greater barriers among adults in Puerto Rico. These results informed the development of PR-CEAL’s targeted community outreach strategies and public health campaigns to increase booster vaccine uptake. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

14 pages, 1886 KiB

Open AccessArticle

SARS-CoV-2 Vaccine Uptake among Patients with Chronic Liver Disease: A Cross-Sectional Analysis in Hebei Province, China

by Yongmei Liu, Wenfang Yuan, Haoting Zhan, Haiyan Kang, Xiaomeng Li, Yongliang Chen, Haolong Li, Xingli Sun, Linlin Cheng, Haojie Zheng, Wei Wang, Xinru Guo, Yongzhe Li and Erhei Dai

Vaccines 2023, 11(8), 1293; https://doi.org/10.3390/vaccines11081293 - 28 Jul 2023

Viewed by 924

Abstract

Chronic liver disease (CLD) patients have higher mortality and hospitalization rates after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to explore SARS-CoV-2 vaccine perceptions, side effects, factors associated with nonvaccination and attitudes toward fourth-dose vaccine among CLD patients. The differences between vaccinated and unvaccinated groups among 1491 CLD patients and the risk factors associated with nonvaccination status were analyzed. In total, 1239 CLD patients were immunized against SARS-CoV-2. CLD patients have a high level of trust in the government and clinicians and were likely to follow their recommendations for vaccination. Reasons reported for nonvaccination were mainly concerns about the vaccines affecting their ongoing treatments and the fear of adverse events. However, only 4.84% of patients reported mild side effects. Risk factors influencing nonvaccination included being older in age, having cirrhosis, receiving treatments, having no knowledge of SARS-CoV-2 vaccine considerations and not receiving doctors’ positive advice on vaccination. Furthermore, 20.6% of completely vaccinated participants refused the fourth dose because they were concerned about side effects and believed that the complete vaccine was sufficiently protective. Our study proved that SARS-CoV-2 vaccines were safe for CLD patients. Our findings suggest that governments and health workers should provide more SARS-CoV-2 vaccination information and customize strategies to improve vaccination coverage and enhance vaccine protection among the CLD population. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

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14 pages, 301 KiB

Open AccessArticle

COVID-19 and Vaccination: Knowledge, Attitudes and Practices of People Working on Illegal Gold Mining Sites in French Guiana

by Pierre Durand, Célia Basurko, Stephen Vreden, Mathieu Nacher and Maylis Douine

Vaccines 2023, 11(7), 1265; https://doi.org/10.3390/vaccines11071265 - 21 Jul 2023

Viewed by 1590

Abstract

Introduction: French Guiana is a French territory bordering Brazil and Suriname where the COVID-19 pandemic has severely strained the French Guianese health system. The people working on illegal gold mining sites in French Guiana, also known as garimpeiros, are mainly of Brazilian origin. Their health conditions are precarious, they live under the radar of the surveillance system and therefore, assessment of their health is quite challenging.. The objective of this study was to describe their knowledge, attitudes and practices regarding COVID-19 and vaccination against this infection. Methods: We conducted an international multicenter cross-sectional survey between 1 March 2022 and 30 April 2022 in French Guiana and Suriname, using a structured questionnaire. Results: Eighty persons were included, 95.0% of whom were Brazilian. Most had good general knowledge of COVID-19. Antibiotic prophylaxis had been practiced by 10.0% of participants. Forty-three people thought they had been infected with COVID-19 (53.8%). Self-medication was frequent, often with antibiotics (32.6%, mostlychloroquine, ivermectin or azithromycin) and most had not consulted a physician for symptoms of COVID-19. A majority (62.5%) had received at least one dose of vaccine. Those who were ever tested for COVID-19 were the most likely to be vaccinated (PR = 1.98, p = 0.009). Conclusions: Garimpeiros have a good level of knowledge about COVID-19 but the high consumption of antibiotics raises concerns about the selection of resistant bacteria. The vaccination rate was higher than that of the Guianese population. The most vaccinated individuals were those who had already taken a COVID test suggesting that these individuals had more exposure to the disease, were more health conscious, or had easier access to health centers. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

22 pages, 5270 KiB

Open AccessArticle

Crisis Communication during COVID-19: English, French, Portuguese, and Spanish Discourse of AstraZeneca Vaccine and Omicron Variant on Social Media

by Daniel Catalan-Matamoros, Ignacio Prieto-Sanchez and Andrea Langbecker

Vaccines 2023, 11(6), 1100; https://doi.org/10.3390/vaccines11061100 - 15 Jun 2023

Cited by 2 | Viewed by 1380

Abstract

Social media have been the arena of different types of discourse during the COVID-19 pandemic. We aim to characterize public discourse during health crises in different international communities. Using Tweetpy and keywords related to the research, we collected 3,748,302 posts from the English, French, Portuguese, and Spanish Twitter communities related to two crises during the pandemic: (a) the AstraZeneca COVID-19 vaccine, and (b) the Omicron variant. In relation to AstraZeneca, ‘blood clot’ was the main focus of public discourse. Using quantitative classifications and natural language processing algorithms, results are obtained for each language. The English and French discourse focused more on “death”, and the most negative sentiment was generated by the French community. The Portuguese discourse was the only one to make a direct reference to a politician, the former Brazilian President Bolsonaro. In the Omicron crisis, the public discourse mainly focused on infection cases follow-up and the number of deaths, showing a closer public discourse to the actual risk. The public discourse during health crises might lead to different behaviours. While public discourse on AstraZeneca might contribute as a barrier for preventive measures by increasing vaccine hesitancy, the Omicron discourse could lead to more preventive behaviours by the public, such as the use of masks. This paper broadens the scope of crisis communication by revealing social media’s role in the constructs of public discourse. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

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Review

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67 pages, 2314 KiB

Open AccessReview

Understanding Low Vaccine Uptake in the Context of Public Health in High-Income Countries: A Scoping Review

by Josephine Etowa, Sheryl Beauchamp, Manal Fseifes, Glory Osandatuwa, Paul Brenneman, Kudirat Salam-Alada, Rasheedaht Sulaiman, Emmanuella Okolie, Ihechi Dinneh, Samora Julmisse and Victoria Cole

Vaccines 2024, 12(3), 269; https://doi.org/10.3390/vaccines12030269 - 04 Mar 2024

Viewed by 1278

Abstract

Although the COVID-19 pandemic has caused the need for the largest mass vaccination campaign ever undertaken to date, African, Caribbean, and Black (ACB) populations have shown both a disproportionately high degree of negative impacts from the pandemic and the lowest willingness to become vaccinated. This scoping review aims to investigate low vaccine uptake in ACB populations relative to public health in high-income countries. A search was conducted in MEDLINE(R) ALL (OvidSP), Embase (OvidSP), CINAHL (EBSCOHost), APA PsycInfo (OvidSP), the Cochrane Central Register of Controlled Trials (OvidSP), the Cochrane Database of Systematic Reviews (OvidSP), the Allied and Complimentary Medicine Database (Ovid SP), and the Web of Science following the Joanna Briggs Institute (JBI) framework for scoping reviews, supplemented by PRISMA-ScR. Theoretical underpinnings of the intersectionality approach were also used to help interpret the complexities of health inequities in the ACB population. The eligibility criteria were based on the population, concept, context (PCC) framework, and publications from 2020–19 July 2022 which discussed vaccine uptake amongst ACB people in high-income countries were included. Analysis was carried out through thematic mapping and produced four main themes: (1) racism and inequities, (2) sentiments and behaviors, (3) knowledge and communication, and (4) engagement and influence. This study has contributed to the identification and definition of the issue of low vaccine uptake in ACB populations and has illustrated the complexity of the problems, as vaccine access is hampered by knowledge, psychological, socioeconomic, and organizational barriers at the individual, organizational, and systemic levels, leading to structural inequities that have manifested as low vaccine uptake. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

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11 pages, 261 KiB

Open AccessReview

Paxlovid (Nirmatrelvir and Ritonavir) Use in Pregnant and Lactating Woman: Current Evidence and Practice Guidelines—A Scoping Review

by Prabal Chourasia, Babu Sriram Maringanti, Morgan Edwards-Fligner, Karthik Gangu, Aniesh Bobba, Abu Baker Sheikh and Rahul Shekhar

Vaccines 2023, 11(1), 107; https://doi.org/10.3390/vaccines11010107 - 01 Jan 2023

Cited by 9 | Viewed by 7228

Abstract

COVID-19 virus, since the detection of the first case in Wuhan in 2019, has caused a worldwide pandemic with significant human, economic and social costs. Fortunately, several vaccines and treatments, both IV and oral, are currently approved against the COVID-19 virus. Paxlovid is an oral treatment option for patients with mild-to-moderate disease, and it effectively reduces disease severity in high-risk patients. Paxlovid is an oral antiviral that consists of a combination of nirmatrelvir and ritonavi. As an oral medication suitable for outpatient treatment, it reduces the cost, hospitalization and mortality associated with COVID-19 infection. The pregnant population is a high-risk category for COVID-19 disease. Given their exclusion in clinical trials, there is limited data regarding Paxlovid use in pregnant and lactating women. Indirect evidence from ritonavir use as part of HAART therapy in the pregnant and lactating population with HIV has shown no significant teratogenicity. Moreover, animal studies on the use of nirmatrelvir do not suggest teratogenicity. This article summarizes the available data on ritonavir and nirmatrelvir use during pregnancy and in ongoing clinical trials. We also review the recommendations of major societies worldwide regarding Paxlovid use in pregnant and breastfeeding patients. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

Other

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11 pages, 532 KiB

Open AccessSystematic Review

Scoping Review on Barriers and Challenges to Pediatric Immunization Uptake among Migrants: Health Inequalities in Italy, 2003 to Mid-2023

by Samina Sana, Elisa Fabbro, Andrea Zovi, Antonio Vitiello, Toluwani Ola-Ajayi, Ziad Zahoui, Bukola Salami and Michela Sabbatucci

Vaccines 2023, 11(9), 1417; https://doi.org/10.3390/vaccines11091417 - 25 Aug 2023

Viewed by 1398

Abstract

In the aftermath of the COVID-19 pandemic, asylum seekers, refugees, and foreign-born migrants are more likely to suffer from physical, mental, and socioeconomic consequences owing to their existing vulnerabilities and worsening conditions in refugee camps around the world. In this scenario, the education of migrants and newcomers about immunization is critical to achieving health equity worldwide. Globally, it is unclear whether government vaccination policies are prioritizing the health information needs of migrants. We searched for studies investigating the vaccination uptake of migrant children settled in Italy that were published between January 2003 and 25 June 2023. Following Arksey and O’Malley’s five-stage method for scoping reviews, all potentially relevant literature published in English was retrieved from SciSearch, Medline, and Embase. This search resulted in 88 research articles, 25 of which met our inclusion criteria. Our findings indicate unequal access to vaccination due to a lack of available information in the native language of the immigrants’ country of origin, vaccine safety concerns or lack of awareness, logistical difficulties, and fear of legal consequences. The findings strongly encourage further government and political discourse to ensure migrants have fair, equitable, ethical, and timely access to essential medicines. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

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8 pages, 1093 KiB

Open AccessBrief Report

Weaker Effects of the Fourth Dose of BNT162b2 SARS-CoV-2 Vaccine on the Elderly Human Population

by Chloé Dimeglio, Isabelle Da-Silva, Marion Porcheron, Marie-Pierre Panero, Laetitia Staes, Pauline Trémeaux, Hélène Villars and Jacques Izopet

Vaccines 2023, 11(6), 1095; https://doi.org/10.3390/vaccines11061095 - 12 Jun 2023

Cited by 1 | Viewed by 1039

Abstract

The vaccines presently available are less effective in older people due to senescence of their immune systems. We measured the antibody responses of 42 adults living in nursing homes after the third and the fourth doses of an mRNA vaccine and found that the strain (BA.2 and BA.2.75: from 64 to 128, BA.5: from 16 to 32, BQ.1.1: from 16 to 64 among the uninfected) influenced the effect of the fourth dose of vaccine on neutralizing antibodies. The fourth dose also increased binding antibodies (from 1036 BAU/mL to 5371 BAU/mL among the uninfected, from 3700 BAU/mL to 6773 BAU/mL among the BA.5 infected). This effect was less significant than that of the third dose of vaccine for both neutralizing (BA.2: from 8 to 128, BA.5: from 2 to 16, BA.2.75: from 8 to 64, BQ.1.1: from 2 to 16) and binding antibodies (from 139.8 BAU/mL to 2293 BAU/mL). However, the fourth dose attained the 5000 BAU/mL threshold conferring approximately 80% protection against a SARS-CoV-2 BA.2 infection in most individuals, unlike the third. Full article

(This article belongs to the Special Issue Knowledge, Attitudes, Beliefs and Hesitancy towards COVID-19 Vaccination and Booster Doses)

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