Vaccines

African swine fever (ASF) is a highly lethal and contagious disease of domestic pigs and wild boars. There is still no credible commercially available vaccine. The only existing one, issued in Vietnam, is actually used in limited quantities in limited areas, for large-scale clinical evaluation. ASF virus is a large complex virus, not inducing full neutralizing antibodies, with multiple genotypes and a lack of comprehensive research on virus infection and immunity. Since it was first reported in China in August 2018, ASF has spread rapidly across the country. To prevent, control, further purify and eradicate ASF, joint scientific and technological research on ASF vaccines has been carried out in China. In the past 4 years (2018–2022), several groups in China have been funded for the research and development of various types of ASF vaccines, achieving marked progress and reaching certain milestones. Here, we have provided a comprehensive and systematic summary of all of the relevant data regarding the current status of the development of ASF vaccines in China to provide a reference for further progress worldwide. At present, the further clinical application of the ASF vaccine still needs a lot of tests and research accumulation. Full article

Background: Vaccination rates are known to be low in patients with autoimmune inflammatory rheumatic diseases (AIIRD). We therefore aimed to determine current vaccination rates against influenza, Streptococcus pneumoniae and herpes zoster in a cohort of patients with AIIRD in Germany. Methods: Consecutive adult patients with an AIIRD were recruited from our outpatient clinic during their regular consultations. The individual vaccination status regarding influenza, Streptococcus pneumoniae and herpes zoster was obtained by reviewing the vaccination documents. Results: A total of 222 AIIRD patients (mean age 62.9 ± 13.9 years) were included. In total, 68.5% were vaccinated against influenza, 34.7% against Streptococcus pneumoniae and 13.1% against herpes zoster (HZ). The pneumococcal vaccination was outdated in 29.4% of the vaccinated patients. Vaccination rates were significantly higher in patients ≥60 years old (odds ratio (OR) 2.167, 95% confidence interval (CI) 1.213–3.870, p = 0.008 for influenza, OR 4.639, 95% CI 2.555–8.422, p < 0.0001 for pneumococcal and OR 6.059, 95% CI 1.772–20.712, p = 0.001 for HZ vaccination). Ages >60 years, female sex, glucocorticoid use and influenza vaccination were all independently associated with a pneumococcal vaccination. Regarding influenza vaccination, only a positive pneumococcal vaccination history remained independently associated. In patients with HZ vaccination, glucocorticoid use and a preceding pneumococcal vaccination were independently associated with HZ protection. Conclusions: The frequencies of vaccinations against influenza, Streptococcus pneumoniae and HZ have increased during recent years. While this can be partly explained by continuous efforts in patient education during the outpatient visits, the COVID-19 pandemic might also have contributed. Nevertheless, the persistently high incidence and mortality of these preventable diseases in patients with AIIRDs mandates further efforts to increase vaccination coverage, particularly in SLE patients. Full article

Background: The outbreak of monkeypox was declared a global public health emergency by the World Health Organization on 23 July 2022. There have been 60,000 cases reported worldwide, most of which are in places where monkeypox has never been seen due to the travel of people who have the virus. This research aims to evaluate the general Arabic population in regard to the monkeypox disease, fears, and vaccine adoption after the WHO proclaimed a monkeypox epidemic and to compare these attitudes to those of the COVID-19 pandemic. Methods: This cross-sectional study was performed in some Arabic countries (Syria, Egypt, Qatar, Yemen, Jordan, Sudan, Algeria, and Iraq) between 18 August and 7 September 2022. The inclusion criteria were the general public residing in Arabic nations and being older than 18. This questionnaire has 32 questions separated into three sections: sociodemographic variables, prior COVID-19 exposure, and COVID-19 vaccination history. The second portion assesses the knowledge and anxieties about monkeypox, while the third section includes the generalized anxiety disorder (GAD7) scale. Logistic regression analyses were performed to compute the adjusted odds ratios (aOR) and their confidence intervals (95%CI) using STATA (version 17.0). Results: A total of 3665 respondents from 17 Arabic countries were involved in this study. Almost two-thirds (n = 2427, 66.2%) of the participants expressed more worry about COVID-19 than monkeypox diseases. Regarding the major cause for concern about monkeypox, 39.5% of participants attributed their anxiety to the fear that they or a member of their family may contract the illness, while 38.4% were concerned about monkeypox becoming another worldwide pandemic. According to the GAD 7 score, 71.7% of the respondents showed very low anxiety toward monkeypox and 43.8% of the participants scored poor levels of knowledge about monkeypox disease. Participants with previous COVID-19 infection showed a 1.206 times greater acceptance to receive the monkeypox vaccine than those with no previous infection. A 3.097 times higher concern for monkeypox than COVID-19 was shown by the participants who perceived monkeypox as dangerous and virulent than those who did not. Participants who have a chronic disease (aOR: 1.32; 95%CI: 1.09–1.60); participants worried about monkeypox (aOR: 1.21; 95%CI: 1.04–1.40), and perceived monkeypox as a dangerous and virulent disease (aOR: 2.25; 95%CI: 1.92–2.65); and excellent knowledge level (aOR: 2.28; 95%CI: 1.79–2.90) have emerged as significant predictors. Conclusions: Our study reported that three-fourths of the participants were more concerned about COVID-19 than monkeypox disease. In addition, most of the participants have inadequate levels of knowledge regarding monkeypox disease. Hence, immediate action should be taken to address this problem. Consequently, learning about monkeypox and spreading information about its prevention is crucial. Full article

In this study, we provide a fractional-order mathematical model that considers the effect of vaccination on COVID-19 spread dynamics. The model accounts for the latent period of intervention strategies by incorporating a time delay $\tau$. A basic reproduction number, $R_0$, is determined for the model, and prerequisites for endemic equilibrium are discussed. The model’s endemic equilibrium point also exhibits local asymptotic stability (under certain conditions), and a Hopf bifurcation condition is established. Different scenarios of vaccination efficacy are simulated. As a result of the vaccination efforts, the number of deaths and those affected have decreased. COVID-19 may not be effectively controlled by vaccination alone. To control infections, several non-pharmacological interventions are necessary. Based on numerical simulations and fitting to real observations, the theoretical results are proven to be effective. Full article

HPV is the most common cause of sexually-transmitted infections the world over. The aim of this study was to assess the impact of a healthcare quality improvement strategy designed to increase the rate of vaccination against HPV in women diagnosed with cervical lesions graded as CIN2 or higher (CIN2+) during routine screening. The Veneto Regional Health Service developed a 22-item questionnaire to measure the gap between ideal procedure and real practice regarding the offer of vaccination against HPV for women undergoing routine cervical screening. The questionnaire was administered to nine expert doctors, one at each of the region’s Local Health Units (LHUs). An additional specific assessment concerned the quality of the related web pages available on the LHU websites. Strategies to close the gap between ideal procedure and real practice were decided collegially, and a checklist to support good practices was developed and shared with operators at the LHUs. Changes in practice were measured using data relating to women diagnosed with CIN2+ lesions extracted from the regional oncological screening database before and after the publication of a Regional Procedure on the topic. The LHUs differed considerably in how they managed each step, in terms of training for healthcare personnel, organization and assessment of the pathway from cervical screening to HPV vaccination, and in dedicated website communication. After implementing the quality improvement strategy, the proportion of women given a first dose of HPV vaccine within 3 months of being diagnosed with CIN2+ lesions at 1st-level screening rose to 50% (compared with 30.85% beforehand), and the median time elapsing between a diagnosis of CIN2+ lesion and a first dose of HPV vaccine dropped from 158 to 90 days. These findings underscore the importance of providing training to promote vaccination for general practitioners and other clinicians. The study also confirms the need for more efforts in communication to ensure that any citizen has the opportunity to access preventive healthcare. Full article

Rabies is a disease of antiquity and has a history spanning millennia ever since the first interactions between humans and dogs. The alarming fatalities caused by this disease have triggered rabies prevention strategies since the first century BC. There have been numerous attempts over the past 100 years to develop rabies vaccineswith the goal of preventing rabies in both humans and animals. Thepre-Pasteurian vaccinologists, paved the way for the actual history of rabies vaccines with the development of first generation vaccines. Further improvements for less reactive and more immunogenic vaccines have led to the expansion of embryo vaccines, tissue culture vaccines, cell culture vaccines, modified live vaccines, inactivated vaccines, and adjuvanted vaccines. The adventof recombinant technology and reverse genetics have given insight into the rabies viral genome and facilitated genome manipulations, which in turn led to the emergence of next-generation rabies vaccines, such as recombinant vaccines, viral vector vaccines, genetically modified vaccines, and nucleic acid vaccines. These vaccines were very helpful in overcoming the drawbacks of conventional rabies vaccines with increased immunogenicity and clinical efficacies. The path traversed in the development of rabies vaccines from Pasteur to the modern era vaccines, though, faced numerous challenges;these pioneering works have formed the cornerstone for the generation of thecurrent successful vaccines to prevent rabies. In the future, advancements in the scientific technologies and research focus will definitely lay the path for much more sophisticated vaccine candidates for rabies elimination. Full article

Monoclonal antibodies (mAb) against the envelope (E) protein of Zika virus (ZIKV) have shown great potential as therapeutics against the Zika epidemics. However, their use as a therapy may predispose treated individuals to severe infection by the related dengue virus (DENV) via antibody-dependent enhancement of infection (ADE). Here, we generated a broadly neutralizing flavivirus mAb, ZV1, with an identical protein backbone but different Fc glycosylation profiles. The three glycovariants, produced in wild-type (WT) and glycoengineered ΔXF Nicotiana benthamiana plants and in Chinese hamster ovary cells (ZV1^WT, ZV1^ΔXF, and ZV1^CHO), respectively, showed equivalent neutralization potency against both ZIKV and DENV. By contrast, the three mAb glycoforms demonstrated drastically different ADE activity for DENV and ZIKV infection. While ZV1^CHO and ZV1^ΔXF showed ADE activity upon DENV and ZIKV infection, ZV1^WT totally forwent its ADE. Importantly, all three glycovariants exhibited antibody-dependent cellular cytotoxicity (ADCC) against virus-infected cells, with increased potency by the fucose-free ZV1^ΔXF glycoform. Moreover, the in vivo efficacy of the ADE-free ZV1^WT was demonstrated in a murine model. Collectively, we demonstrated the feasibility of modulating ADE by Fc glycosylation, thereby establishing a novel approach for improving the safety of flavivirus therapeutics. Our study also underscores the versatile use of plants for the rapid expression of complex human proteins to reveal novel insight into antibody function and viral pathogenesis. Full article

Human papillomavirus (HPV) vaccines effectively prevent cervical cancer, most of which results from undetected long-term HPV infection. HPV vaccine introduction is particularly sensitive and complicated given widespread misinformation and vaccination of young girls before their sexual debut. Research has examined HPV vaccine introduction in lower- and middle-income countries (LMICs), but almost no studies attend to HPV vaccine attitudes in central Asian countries. This article describes the results of a qualitative formative research study to develop an HPV vaccine introduction communication plan in Uzbekistan. Data collection and analysis were designed using the Capability, Opportunity, and Motivation for Behaviour change (COM-B) mode for understanding health behaviours. This research was carried out with health workers, parents, grandparents, teachers, and other social influencers in urban, semi-urban, and rural sites. Information was collected using focus group discussions (FGDs) and semi-structured in-depth interviews (IDIs), and data in the form of participants’ words, statements, and ideas were thematically analysed to identify COM-B barriers and drivers for each target group’s HPV vaccine-related behaviour. Represented through exemplary quotations, findings were used to inform the development of the HPV vaccine introduction communication plan. Capability findings indicated that participants understood cervical cancer was a national health issue, but HPV and HPV vaccine knowledge was limited among non-health professionals, some nurses, and rural health workers. Results on an opportunity for accepting the HPV vaccine showed most participants would do so if they had access to credible information on vaccine safety and evidence. Regarding motivation, all participant groups voiced concern about the potential effects on young girls’ future fertility. Echoing global research, the study results highlighted that trust in health workers and the government as health-related information sources and collaboration among schools, municipalities, and polyclinics could support potential vaccine acceptance and uptake. Resource constraints precluded including vaccine target-aged girls in research and additional field sites. Participants represented diverse social and economic backgrounds reflective of the country context, and the communication plan developed using research insights contributed to the Ministry of Health (MoH) of the Republic of Uzbekistan HPV vaccine introduction efforts that saw high first dose uptake. Full article

Individuals aged 65 years and above are at increased risk of complications and death from influenza compared with any other age group. Enhanced vaccines, as the MF59^®-adjuvanted quadrivalent influenza vaccine (aQIV) and the high-dose quadrivalent influenza vaccine (HD-QIV), provide increased protection for older adults in comparison to the traditional standard-dose quadrivalent influenza vaccines (SD-QIV). This study aimed to assess the cost-effectiveness of aQIV compared to SD-QIV and HD-QIV in Denmark, Norway, and Sweden for adults aged ≥65 years. A static decision tree model was used to evaluate costs and outcomes of different vaccination strategies from healthcare payer and societal perspectives. This model projects that compared to SD-QIV, vaccination with aQIV could prevent a combined total of 18,772 symptomatic influenza infections, 925 hospitalizations, and 161 deaths in one influenza season across the three countries. From a healthcare payer perspective, the incremental costs per quality adjusted life year (QALY) gained with aQIV versus SD-QIV were EUR 10,170/QALY in Denmark, EUR 12,515/QALY in Norway, and EUR 9894/QALY in Sweden. The aQIV was cost saving compared with HD-QIV. This study found that introducing aQIV to the entire population aged ≥65 years may contribute to reducing the disease and economic burden associated with influenza in these countries. Full article

Substantial progress in maternal and neonatal tetanus elimination has been made in the past 40 years, with dramatic reductions in neonatal tetanus incidence and mortality. However, twelve countries have still not achieved maternal and neonatal tetanus elimination, and many countries that have achieved elimination do not meet key sustainability thresholds to ensure long-lasting elimination. As maternal and neonatal tetanus is a vaccine-preventable disease (with coverage of the infant conferred by maternal immunization during and prior to pregnancy), maternal tetanus immunization coverage is a key metric for monitoring progress towards, equity in, and sustainability of tetanus elimination. In this study, we examine inequalities in tetanus protection at birth, a measure of maternal immunization coverage, across 76 countries and four dimensions of inequality via disaggregated data and summary measures of inequality. We find that substantial inequalities in coverage exist for wealth (with lower coverage among poorer wealth quintiles), maternal age (with lower coverage among younger mothers), maternal education (with lower coverage among less educated mothers), and place of residence (with lower coverage in rural areas). Inequalities existed for all dimensions across low- and lower-middle-income countries, and across maternal education and place of residence across upper-middle-income countries. Though global coverage changed little over the time period 2001–2020, this obscured substantial heterogeneity across countries. Notably, several countries had substantial increases in coverage accompanied by decreases in inequality, highlighting the need for equity considerations in maternal and neonatal tetanus elimination and sustainability efforts. Full article

The footprint of human endogenous retroviruses (HERV), specifically HERV-K, has been found in malignancies, such as melanoma, teratocarcinoma, osteosarcoma, breast cancer, lymphoma, and ovary and prostate cancers. HERV-K is characterized as the most biologically active HERV due to possession of open reading frames (ORF) for all Gag, Pol, and Env genes, which enables it to be more infective and obstructive towards specific cell lines and other exogenous viruses, respectively. Some factors might contribute to carcinogenicity and at least one of them has been recognized in various tumors, including overexpression/methylation of long interspersed nuclear element 1 (LINE-1), HERV-K Gag, and Env genes themselves plus their transcripts and protein products, and HERV-K reverse transcriptase (RT). Therapies effective for HERV-K-associated tumors mostly target invasive autoimmune responses or growth of tumors through suppression of HERV-K Gag or Env protein and RT. To design new therapeutic options, more studies are needed to better understand whether HERV-K and its products (Gag/Env transcripts and HERV-K proteins/RT) are the initiators of tumor formation or just the disorder’s developers. Accordingly, this review aims to present evidence that highlights the association between HERV-K and tumorigenicity and introduces some of the available or potential therapies against HERV-K-induced tumors. Full article

This research paper examines the adoption of digital services for the vaccination during the COVID-19 pandemic in Germany. Based on a survey in Germany’s federal state with the highest vaccination rate, which used digital vaccination services, its platform configuration and adoption barriers are analyzed to understand existing and future levers for optimizing vaccination success. Though technological adoption and resistance models have been originally developed for consumer-goods markets, this study gives empirical evidence especially for the applicability of an adjusted model explaining platform adoption for vaccination services and for digital health services in general. In this model, the configuration areas of personalization, communication, and data management have a remarkable effect to lower adoption barriers, but only functional and psychological factors affect the adoption intention. Above all, the usability barrier stands out with the strongest effect, while the often-cited value barrier is not significant at all. Personalization is found to be the most important factor for managing the usability barrier and thus for addressing the needs, preferences, situation, and, ultimately, the adoption of the citizens as users. Implications are given for policy makers and managers in such a pandemic crisis to focus on the click flow and server-to-human interaction rather than emphasizing value messages or touching traditional factors. Full article

Background: Myocarditis and pericarditis cases following Coronavirus 2019 (COVID-19) vaccination were reported worldwide. In Thailand, COVID-19 vaccines were approved for emergency use. Adverse event following immunization (AEFI) surveillance has been strengthened to ensure the safety of the vaccines. This study aimed to describe the characteristics of myocarditis and pericarditis, and identify the factors associated with myocarditis and pericarditis following COVID-19 vaccination in Thailand. Method: We carried out a descriptive study of reports of myocarditis and pericarditis to Thailand’s National AEFI Program (AEFI-DDC) between 1 March and 31 December 2021. An unpaired case–control study was conducted to determine the factors associated with myocarditis and pericarditis after the CoronaVac, ChAdOx1-nCoV, BBIBP-CorV, BNT162b2, and mRNA-1273 vaccines. The cases consisted of COVID-19 vaccine recipients who met the definition of confirmed, probable, or suspected cases of myocarditis or pericarditis within 30 days of vaccination. The controls were people who underwent COVID-19 vaccination between 1 March and 31 December 2021, with no adverse reactions documented after vaccination. Results: Among the 31,125 events recorded in the AEFI-DDC after 104.63 million vaccinations, 204 cases of myocarditis and pericarditis were identified. The majority of them were male (69%). The median age was 15 years (interquartile range (IQR): 13–17). The incidence was highest following the BNT162b2 vaccination (0.97 cases per 100,000 doses administered). Ten deaths were reported in this study; no deaths were reported among children who received the mRNA vaccine. Compared with the age-specific incidence of myocarditis and pericarditis in Thailand before the introduction of the COVID-19 vaccination, the incidence of myocarditis and pericarditis after the BNT162b2 vaccine was greater in the 12–17 and 18–20 age groups in both males and females. It was higher after the second dose in 12- to 17-year-olds (2.68 cases per 100,000 doses administered) and highest after the second dose in male 12- to 17-year-olds (4.43 cases per 100,000 doses administered). Young age and a mRNA-based vaccination were associated with myocarditis and pericarditis following administration of the COVID-19 vaccine after multivariate analysis. Conclusions: Myocarditis and pericarditis following vaccination against COVID-19 were uncommon and mild, and were most likely to affect male adolescents. The COVID-19 vaccine offers the recipients enormous benefits. The balance between the risks and advantages of the vaccine and consistent monitoring of AEFI are essential for management of the disease and identification of AEFI. Full article

The burden of all-cause community-acquired pneumonia (CAP), including pneumococcal pneumonia, is typically estimated using ICD codes where pneumonia is coded as the most responsible diagnosis (MRDx). Pneumonia may also be coded as other than most responsible diagnosis (ODx) based on administrative and reimbursement criteria. Analyses including pneumonia as MRDx only likely underestimate hospitalized CAP incidence. The aim of this study was to estimate the burden of hospitalized all-cause CAP in Canada and to assess the contribution of ODx-coded cases to the overall disease burden. This longitudinal retrospective study obtained data from the Canadian Institutes of Health Information (CIHI) for adults 50+ years hospitalized for CAP between 1 April 2009 and 31 March 2019. Cases were identified as those where pneumonia was either diagnosis code type M (MRDx) or pre-admit comorbidity type 1 (ODx). Reported outcomes include pneumonia incidence rate, in-hospital mortality, hospital length of stay, and cost. Outcomes were stratified by age group, case coding, and comorbidity. Between 2009–2010 and 2018–2019, CAP incidence increased from 805.66 to 896.94 per 100,000. During this time, 55–58% of cases had pneumonia coded as ODx. Importantly, these cases had longer hospital stays, higher in-hospital mortality, and higher cost of hospitalization. The burden of CAP remains substantial and is significantly greater than that estimated by solely focusing on MRDx-coded cases. Our findings have implications for policy decision making related to current and future immunization programs. Full article

Each injection of any known vaccine results in a strong expression of pro-inflammatory cytokines. This is the result of the innate immune system activation, without which no adaptive response to the injection of vaccines is possible. Unfortunately, the degree of inflammation produced by COVID-19 mRNA vaccines is variable, probably depending on genetic background and previous immune experiences, which through epigenetic modifications could have made the innate immune system of each individual tolerant or reactive to subsequent immune stimulations.We hypothesize that we can move from a limited pro-inflammatory condition to conditions of increasing expression of pro-inflammatory cytokines that can culminate in multisystem hyperinflammatory syndromes following COVID-19 mRNA vaccines (MIS-V). We have graphically represented this idea in a hypothetical inflammatory pyramid (IP) and we have correlated the time factor to the degree of inflammation produced after the injection of vaccines. Furthermore, we have placed the clinical manifestations within this hypothetical IP, correlating them to the degree of inflammation produced. Surprisingly, excluding the possible presence of an early MIS-V, the time factor and the complexity of clinical manifestations are correlated to the increasing degree of inflammation: symptoms, heart disease and syndromes (MIS-V). Full article

Given their occupational risk profile, HCWs were the first to receive anti-SARS-CoV-2 vaccination. However, breakthrough infections remained common, mainly sustained by new SARS-CoV-2 variants of concern (VOCs) that rapidly spread one after another in Italy. Evidence suggests that the measured level of anti-SARS-CoV-2 antibodies does not clearly predict the level of protection conferred by either natural infection or vaccine-induced immunization, highlighting the need for further study on the diversity in susceptibility to SARS-CoV-2 infection. The present study aimed to characterize different risk profiles for SARS-CoV-2 infection in HCWs who had recently received the booster dose, and who were classified according to their immunization profile. The very small number of workers infected during the 8 months following the primary-cycle administration represents proof of the vaccine’s effectiveness against non-omicron strains. The comparison among different immunization profiles showed that hybrid immunization (vaccine plus natural infection) elicits higher antibody levels. However, hybrid immunization does not always provide better protection against reinfection, thus suggesting that the immunization profile plays a major role as a virus–host interaction modifier. Despite the high resistance to the reinfection, the peri-booster infection had a not-neglectable infection rate (5.6%), this further reinforcing the importance of preventive measures. Full article

The Republic of Guatemala’s reported COVID-19 vaccination coverage is among the lowest in the Americas and there are limited studies describing the disparities in vaccine uptake within the country. We performed a cross-sectional ecological analysis using multi-level modeling to identify sociodemographic characteristics that were associated with low COVID-19 vaccination coverage among Guatemalan municipalities as of 30 November 2022. Municipalities with a higher proportion of people experiencing poverty (β = −0.25, 95% CI: −0.43–0.07) had lower vaccination coverage. Municipalities with a higher proportion of people who had received at least a primary education (β = 0.74, 95% CI: 0.38–1.08), children (β = 1.07, 95% CI: 0.36–1.77), people aged 60 years and older (β = 2.94, 95% CI: 1.70–4.12), and testing for SARS-CoV-2 infection (β = 0.25, 95% CI: 0.14–0.36) had higher vaccination coverage. In the simplified multivariable model, these factors explained 59.4% of the variation in COVID-19 vaccination coverage. Poverty remained significantly associated with low COVID-19 vaccination coverage in two subanalyses restricting the data to the time period of the highest national COVID-19-related death rate and to COVID-19 vaccination coverage only among those aged 60 years or older. Poverty is a key factor associated with low COVID-19 vaccination and focusing public health interventions in municipalities most affected by poverty may help address COVID-19 vaccination and health disparities in Guatemala. Full article

Background: To date, little is known about the salivary mucosal immune response following different COVID-19 vaccine types or after a booster (3rd) dose of the BNT162b2 (BNT) vaccine. Methods: A total of 301 saliva samples were collected from vaccinated individuals and arranged into two cohorts: cohort 1 (n = 145), samples from individuals who had received two doses against SARS-CoV-2; cohort 2 (n = 156), samples from individuals who had received a booster of BNT vaccine. Cohorts 1 and 2 were sub-stratified into three groups based on the types of first and second doses (homologous BNT/BNT, homologous ChAdOx1/ChAdOx1, or heterologous BNT/ChAdOx1vaccinations). Salivary immunoglobulin G (IgG) response to SARS-CoV-2 spike glycoprotein was measured by ELISA, and clinical demographic data were collected from hospital records or questionnaires. Results: Salivary IgG antibody responses against different vaccines, whether homologous or heterogeneous vaccination regimens, showed similar levels in cohorts 1 and 2. Compiling all groups in cohort 1 and 2 showed significant, albeit weak, negative correlations between salivary IgG levels and time (r = −0.2, p = 0.03; r = −0.27, p = 0.003, respectively). In cohort 2, the durability of salivary IgG after a booster dose of BNT162b2 significantly dropped after 3 months compared to the <1 month and 1–3 months groups. Conclusions: Different COVID-19 vaccine types and regimens elicit similar salivary anti-SARS-CoV-2 IgG with modest waning over time. Boosting with BNT162b2 vaccine did not produce an evident increase in mucosal IgG response whereby COVID-19 recovered subjects show higher salivary IgG than naive, post-vaccination subjects. The ChAdOx1/ChAdOx1 regimen showed better correlation between salivary IgG levels and durability. These findings highlight the importance of developing oral or intra-nasal vaccines to induce stronger mucosal immunity. Full article