COVID-19 Vaccine Research Articles

Humoral response 24 months after the first COVID-19 vaccination in people with HIV with and without diabetes

People with HIV (PWH) and people with diabetes mellitus have increased risk of severe COVID-19, but little is known about humoral response to COVID-19 vaccines in PWH with DM. We investigated SARS-CoV-2 antireceptor-binding domain (anti-RBD) immunoglobulin G (IgG) geometrical concentrations and neutralizing antibody capacity (nAB) in PWH with and without diabetes mellitus. Anti-RBD IgG and nAB in COVID-19-vaccinated PWH were not associated with diabetes mellitus-status or HbA1c 24 months after the initial COVID-19 vaccination.

Health care workers hospitalized for COVID-19 in Liberia: who were they, and what were their outcomes?

Background Sustaining a ‘fit-for-purpose’ health workforce requires a better understanding of the health care worker cadres that are affected during pandemics and their outcomes. In hospitalized health care workers with confirmed COVID-19 between March 2020 and May 2023 in Liberia, we determined the hospitalization and case fatality rates, type of health care worker cadres affected, their demographic and clinical characteristics and hospital exit outcomes. Methods This was a cohort study using routine data extracted from hospitalization forms for health care workers in 24 designated COVID-19 treatment facilities. Results Of the 424 health care workers with COVID-19, hospitalization rates progressively declined between 2020 and 2023, (P<0.001) with the highest rates in 2020 (24/1,000 health care workers) and 2021 (14/1,000 health care workers). Case fatality was 2% in both 2020 and 2021 with no deaths thereafter. Among those hospitalized, the highest proportions were nursing cadres with 191(45%), physicians with 63 (15%) and laboratory technicians with 42 (10%). The most frequent reported site for COVID-19 infection was the health facility (326, 89%). COVID-19 vaccination coverage in health care workers was 20%. The majority (91%) of hospitalizations were for mild symptomatic infections. Even in referral centres (n-52), 18 (35%) were for mild infections. Of the 424 who were hospitalized, 412 (97%) recovered, 9 (2%) died and 3 (1%) either left against medical advice or absconded. Of the nine deaths, none were vaccinated, seven had moderate-to-severe disease but were not referred to specialized COVID-19 treatment centers. Conclusions The hospitalized health care workers for COVID-19 were predominantly clinical and laboratory personnel who were mostly unvaccinated, and health facilities were hot-spots for contracting infections. The triage and referral system was weak with unnecessary hospitalization of mild infections. This study provides useful insights for outbreak preparedness including priority vaccination and improving health care worker safety in Liberia.

The Platform Trial In COVID-19 priming and BOOsting (PICOBOO): the immunogenicity, reactogenicity, and safety of licensed COVID-19 vaccinations administered as a second booster in BNT162b2 primed individuals aged 18-

PICOBOO is a randomised, adaptive trial evaluating the immunogenicity, reactogenicity, and safety of COVID-19 booster strategies. Here, we data for second boosters among individuals aged 18-<50 and 50-<70 years old primed with BNT162b2 until Day (D) 84. Immunocompetent adults who had received two doses of BNT162b2 and any licensed COVID-19 booster at least three months prior were eligible. Participants were randomly allocated to BNT162b2, mRNA-1273 or NVX-CoV2373 1:1:1. The log10 concentration of anti-spike Ig Total was summarised as the geometric mean concentration (GMC). Reactogenicity and safety outcomes were captured. Between Mar 2022 and Aug 2023, 743 participants recruited to the trial had D28 samples available. Of these, 120 and 103 belonged to the 18-<50y and 50-<70y strata, respectively. The mean adjusted GMCs (95% credible intervals) peaked at D28; these were 41 262 (31 611, 51 105), 45 585 (34 194, 57 441) and 25 281 (20 021, 31 234) U/mL in the 18-<50y stratum and 30 753 (25 071, 36 704), 35 132 (27 523, 42 239) and 17 322 (13 983, 20 641) U/mL in the 50-<70y stratum following BNT162b2, mRNA-1273 and NVX-CoV2373, respectively. Limited neutralisation against Omicron subvariants was found following boosting with all vaccines. There were 4 possibly or probably-related adverse events in the 18-<50y stratum and 5 events in the 50-<70y stratum, and severe reactogenicity events were <10% and <11% in these strata, respectively. Vaccines targeting Ancestral virus elicited boosted antibody responses to Ancestral virus but minimal neutralising antibody against Omicron variants.

Union Responses to Workplace COVID-19 Vaccine Mandates in Canada

This article explores union responses to workplace-based covid-19 vaccine mandates in Canada. Specifically, the authors examine the complex interplay of factors that drove unions to adopt their respective positions on vaccine mandates and to frame those positions in particular ways for the benefit of their members and the wider public. Interviews with key informants, along with analysis of documents and arbitration decisions, reveal a disjuncture between the discursive quality of certain unions’ positions and their actual positions. In particular, media framing of unions as either “for” or “against” vaccine mandates oversimplified or misrepresented the actual positions adopted. In response, the article introduces a typology of union positions that distinguishes between support for mandatory-vaccination policies and support for voluntary-vaccination policies and reveals that the vast majority of unions favoured the latter. The authors further reveal that workplace vaccine mandates were both internally divisive and disorienting for unions, given the central role labour organizations play in managing workplace disputes and representing the interests of workers, both individually and collectively.

Does the COVID-19 Vaccines Effect on the Menstrual Cycle, Cross-Sectional Study Among Adult Females at King Saud University

COVID-19 vaccinations have been associated with irregularities in the menstrual cycle and symptoms occurring pre and post-menstruation, affecting women’s reproductive health. This study aimed to demonstrate the impact of COVID-19 vaccines on women’s reproductive health by examining the association between COVID-19 vaccines and disturbed menstrual cycles. This cross-sectional survey-based study was conducted among adult females at King Saud University, Saudi Arabia, from April 2022 to August 2022. A total of 380 participants were selected through a stratified random sampling technique. Ethical approval was obtained from the Deanship of Scientific Research at King Saud University. The data were analysed using descriptive statistics and appropriate statistical tests. The results revealed that 53.9% of the participants experienced disturbances in the menstrual cycle after receiving the COVID-19 vaccination. Adult females aged 18-25 showed the highest rate of disorders. Menstrual disruptions were substantially correlated with marital status (p = 0.05), with a significant association between the number of COVID-19 vaccine doses and the occurrence of menstrual disturbances (p = 0.001). The administration of the vaccination during menstruation was linked to a notable occurrence of menstrual disturbances, although the p-value showed no statistical significance. A significant correlation was examined (p &lt; 0.05) between pre-existing menstrual problems and the occurrence of disorders after receiving the COVID-19 vaccine (p &lt; 0.05). The study emphasised the importance of tailored healthcare treatments for women following COVID-19 vaccination and the need for regular evaluation of reproductive health outcomes post-COVID-19 vaccination.

Association of mRNA COVID-19 vaccination and reductions in Post-COVID Conditions following SARS-CoV-2 infection in a US prospective cohort of essential workers.

While there is evidence that COVID-19 vaccination protects against development of post-COVID conditions (PCC) after severe infection data are limited on whether vaccination reduces the risk after cases of less-severe non-hospitalized COVID-19 disease with more recent SARS-CoV-2 variant viruses. This study assessed whether COVID-19 vaccination was protective against subsequent development of PCC in persons with predominantly mild initial infections during both Delta and Omicron variant predominance. This study utilized a case-control design, nested within the HEROES-RECOVER cohort. Participants aged ≥18 years with PCR-confirmed SARS-CoV-2 infection between 6/28/2021 and 9/14/2022 were surveyed for PCC, defined by symptoms lasting >1 month after initial infection Cases were participants self-reporting PCC and controls were participants that did not self-report PCC. The exposure was mRNA COVID-19 vaccination (2 or 3 monovalent doses) versus no COVID-19 vaccination. Logistic regression was used to compare the odds of PCC among vaccinated and unvaccinated persons; additional analyses evaluating PCC subtypes were also performed. A total of 936 participants with documented SARS-CoV-2 infection were included; of these 23.6% (221) reported PCC and 83.3% (779) were vaccinated. Participants who received a 3rd COVID-19 monovalent mRNA dose prior to infection had lower odds of PCC-related gastrointestinal, neurological, and other symptoms compared to unvaccinated participants (aOR: 0.37; 95% CI: 0.16-0.85; aOR: 0.56; 95% CI: 0.32-0.97; aOR:0.48; 95% CI: 0.25-0.91). COVID-19 vaccination protected against development of PCC among persons with mild infection during both Delta and Omicron variant predominance, supporting vaccination as an important tool for PCC prevention.

Postural orthostatic tachycardia syndrome after COVID-19 vaccination: A systematic review.

The global COVID-19 vaccination campaign, with 13.53billion doses administered by early 2024, has significantly reduced severe illness and mortality. However, potential adverse effects, such as Postural Orthostatic Tachycardia Syndrome (POTS), have raised concerns. This systematic review evaluates the incidence, mechanisms, and clinical implications of POTS following COVID-19 vaccination. A systematic search of PubMed, EMBASE, and Web of Science was conducted up to June 7, 2024, following PRISMA guidelines to identify studies related to COVID-19 vaccines and POTS. Eligible studies included randomized controlled trials, cohort studies, cross-sectional studies, case-control studies, case series, and case reports. Screening, data extraction, and quality assessment were independently performed by two reviewers using the Joanna Briggs Institute Checklists and the Newcastle-Ottawa Scale. Of the 1,531 articles identified, 10 met the inclusion criteria, encompassing a total of 284,678 participants. These studies included five case reports, two case series, one cross-sectional study, one prospective observational study, and one cohort study. The cohort study reported that the odds of new POTS diagnoses post-vaccination were 1.33 (95% CI: 1.25-1.41) compared to the 90 days prior. In contrast, the post-infection odds were 2.11 (95% CI: 1.70-2.63), and the risk of POTS was 5.35 times higher (95% CI: 5.05-5.68) post-infection compared to post-vaccination. Diagnostic findings across studies included elevated norepinephrine levels and reduced heart rate variability. Reported management strategies involved ivabradine, intravenous therapies, and lifestyle modifications. The risk of POTS following COVID-19 vaccination is lower than that observed post-SARS-CoV-2 infection; however, existing studies are limited by small sample sizes and methodological variability. Further research is needed to clarify the incidence, mechanisms, and long-term outcomes of vaccine-related POTS to inform effective clinical management strategies.

Public health and economic impact of COVID-19 vaccination with the Pfizer-BioNTech COVID-19 Vaccine, KP.2, among adults in 2024/2025 in the United States

ABSTRACT Objectives To assess the public health and economic impact of vaccination with the Pfizer-BioNTech COVID-19 vaccine, KP.2, in 2024/2025 in the United States. Methods A combined cohort Markov-decision tree model was used to estimate the cost-effectiveness and budget impact of vaccination versus no vaccination in adults aged ≥18 years. The adult population was further stratified into 18-64 years and ≥65 years age groups. Public health surveillance data informed the annual proportion of individuals infected with and vaccinated against SARS-CoV-2 and the proportion of those infected who were hospitalized, stratified by age. Other age-stratified clinical, cost, and vaccine effectiveness parameters were informed by literature. The budget impact analysis was based on a hypothetical 1-million-member plan and used a payer perspective. Parameter uncertainty was tested in sensitivity analyses. Results Without vaccination, the model projected 21.4 million new symptomatic cases, 15,793 deaths, 629,098 hospitalizations, $115.5 billion in total costs, and 1 million QALYs lost among adults aged ≥18 years, with the greatest health burden observed among older adults aged ≥65 years (72% of hospitalizations and 86% of deaths) and the greatest economic burden in adults aged 18 to 64 years (62% of total costs). Vaccination was projected to prevent 915,501 cases, 1,057 deaths, and 37,489 hospitalizations, resulting in cost savings of $513 million, 9,173 LYs gained, 56,482 QALYs gained, and a dominant ICER. In the budget impact analysis, vaccination was estimated to result in total incremental cost savings for the population aged ≥ 65 years and a modest budget increase for the population aged 18 to 64 years. Conclusions Vaccination with the Pfizer BioNTech COVID-19 vaccine, KP.2, is a cost-effective measure from the societal perspective at a willingness-to-pay threshold of $50,000 that could reduce the health and economic burden of COVID-19.

Caregivers’ hesitancy and outright refusal toward children’s COVID-19 vaccination in the Democratic Republic of Congo: A community-based cross-sectional study

ABSTRACT Data from the global South show higher COVID-19-related mortality in children compared to the North. Parents’ willingness to vaccinate their children once COVID-19 vaccines are available is poorly documented. We assessed parents’ willingness to vaccinate their children in the DRC. A year after the vaccination program started, we conducted a population and online-based cross-sectional study, using the WHO modified Behavior and Social Drivers questionnaire among parents and caregivers in the eastern DRC. We performed Modified Poisson regressions to determine factors associated with vaccine hesitancy and outright refusal, focusing on the intention to vaccinate one’s children as our primary outcome. Of the 1709 respondents aged 38 years, 82.56% were unwilling to vaccinate their children, of which 26.80% were hesitant and 55.76% were outright refusals. Drivers of hesitancy were religious refusal of vaccine, non-healthcare status, and caregiver beliefs about vaccine unsafety. Independent predictors of refusal were religious refusal of vaccine, neither healthcare nor student status and belief about vaccine effectiveness, unsafety, and distrust. In addition, both hesitancy and refusal to vaccinate one’s children were driven by not being ready to get vaccinated if recommended or mandated. In contrast, parents’ and caregivers’ trust in the government and readiness to vaccinate themselves reduced hesitancy and outright refusal to vaccinate one’s children, respectively. Briefly, COVID-19 vaccine hesitancy and outright refusal in eastern DRC are influenced by individual (subjective convictions) and system-level factors (government confidence, mandate trust). It is important to address these issues to improve vaccine coverage during disease outbreaks and mitigate public health risks.

Design and development of mRNA and self-amplifying mRNA vaccine nanoformulations.

The rapid evolution of mRNA vaccines, highlighted by Pfizer-BioNTech and Moderna's COVID-19 vaccines, has transformed vaccine development and therapeutic approaches. Self-amplifying mRNA (saRNA) vaccines, a groundbreaking advancement in RNA-based vaccines, offer promising possibilities for disease prevention and treatment, including potential applications in cancer and neurodegenerative diseases. This review explores the complex design and development of these innovative vaccines, with a focus on their nanoscale formulations that utilize nanotechnology to improve their delivery and effectiveness. It articulates the fundamental principles of mRNA and saRNA vaccines, their mechanisms of action, and the role of synthetic mRNA in eliciting immune responses. The review further elaborates on various nanoscale delivery systems (e.g., lipid nanoparticles, polymeric nanoparticles and other nanocarriers), emphasizing their advantages in enhancing mRNA stability and cellular uptake. It addresses advanced nanoscale delivery techniques such as microfluidics and discusses the challenges in formulating mRNA and saRNA vaccines. By incorporating the latest technologies and current research, this review provides a thorough overview of recent mRNA and saRNA nanovaccines advancements, highlighting their potential to revolutionize vaccine technology and broaden clinical applications.

Monovalent XBB.1.5 COVID-19 vaccine effectiveness against hospitalisations and deaths during the omicron BA.2.86/JN.1 period among older adults in seven European countries: a VEBIS-EHR network study

ABSTRACT Background We aimed to estimate XBB.1.5 vaccine effectiveness (VE) against COVID-19-related hospitalizations and deaths during BA.2.86/JN.1 predominance, among EU/EEA individuals with ≥ 65-years. Research design and methods We linked electronic health records to create historical cohorts in Belgium, Denmark, Italy, Navarre (Spain), Norway, Portugal and Sweden. We included individuals aged ≥ 65-years eligible for the autumnal 2023 COVID-19 vaccine. Follow-up started when ≥ 80% of country-specific sequenced viruses were BA.2.86/JN.1 (4/dec/23 to 08/jan/24) and ended 25 February 2024. At study site level, we estimated the vaccine confounder-adjusted hazard ratio (aHR) of COVID-19 hospitalizations and deaths between individuals with ≥14 days after vaccination versus unvaccinated in autumn 2023, overall, by time since vaccination and age groups. VE was estimated as (1-pooled aHR)x100 with a random-effects model. Results XBB.1.5 VE against COVID-19 hospitalizations was 50% (95%CI: 45 to 55) and 41% (95%CI: 35 to 46) in 65-79-year-olds and in ≥ 80-year-olds respectively. VE against COVID19-related-death was 58% (95%CI: 42 to 69) and 48% (95%CI: 38 to 57), respectively, in both age groups. VE estimates against each outcome declined in all age groups over time. Conclusion Monovalent XBB.1.5 vaccine had a moderate protective effect against severe and fatal COVID-19 likely caused by BA.2.86/JN.1 during the 2023/2024 winter, among persons aged ≥ 65.

Preclinical development of lyophilized self-replicating RNA vaccines for COVID-19 and malaria with improved long-term thermostability.

Messenger RNA (mRNA) vaccines against COVID-19 have demonstrated high efficacy and rapid deployment capability to target emerging infectious diseases. However, the need for ultra-low temperature storage made the distribution of LNP/mRNA vaccines to regions with limited resources impractical. This study explores the use of lyophilization to enhance the stability of self-replicating mRNA (repRNA) vaccines, allowing for their storage at non-freezing temperatures such as 2-8 °C or room temperature (25 °C). We lyophilized repRNA molecules complexed to a novel cationic emulsion delivery system, LION™, with different sugar-based lyoprotectants to identify candidates that provided the best vaccine integrity and effectiveness after being thermally stressed. For screening, we used repRNA encoding the reporter protein secreted embryonic alkaline phosphatase (SEAP) and for proof-of-concept, we used repRNA vaccines encoding SARS-CoV-2 full-length spike (WA-1 isolate) or full-length surface protein circumsporozoite (CS) of Plasmodium yoelii (Py). We found that lyophilization of LION/repRNA with sucrose provided the best colloidal stability, preserved in vitro expression, and induced equivalent antigen-specific antibody responses in mice compared to freshly prepared liquid LION/repRNA. Furthermore, lyophilized vaccines were stable for at least one week at 25 °C and at least one year at 2-8 °C. The cumulative analysis of stability-determining physicochemical data, in vitro potency, and in vivo immunogenicity in mice enabled the selection of a lead lyophilized composition containing 10 % w/v sucrose as the lyoprotectant. The data presented here provide a foundation for the clinical evaluation of next-generation thermostable repRNA vaccines that will enable more equitable vaccine access globally.

Antibody dynamics for heterologous boosters with aerosolized Ad5-nCoV following inactivated COVID-19 vaccines

ABSTRACT The COVID-19 pandemic has underscored vaccination as a crucial strategy for reducing disease severity and preventing hospitalizations. Heterologous boosters using aerosolized Ad5-nCoV following two doses of inactivated vaccine have demonstrated superior antibody responses. However, the comprehensive dynamics of this antibody boost and the optimal timing for heterologous boosters are still not fully understood. In this study, we investigated the dynamics of neutralizing antibody (nAb) responses in recipients of heterologous booster vaccinations with aerosolized Ad5-nCoV following either two (I-I-A) or three (I-I-I-A) doses of COVID-19 inactivated vaccines. The findings indicate that a booster dose of aerosolized Ad5-nCoV vaccine induced robust and durable nAb responses comparable to those elicited in BA.5 breakthrough infections with similar doses of inactivated vaccine. Notably, group I-I-A showed higher peak nAb titers against the WT strain, BA.5, and XBB.1 variants compared to group I-I-I-A, inversely correlating with the prior nAb levels. This suggesting the possible efficacy of the heterologous aerosolized Ad5-nCoV booster and indicates that pre-boost antibody levels may be related to the outcomes of booster vaccination.

Incidence of severe and non-severe SARS-CoV-2 infections in children and adolescents: a population-based cohort study using six healthcare databases from Italy, Spain, and Norway.

Severe COVID-19 was rare across databases, but up to 3 to 4 times higher in children with comorbidities during the predominance of Omicron BA.1-2 variant in winter 2021-2022. COVID-19 vaccination coverage was slightly lower in children with comorbidities in ARS (Tuscany) and SIDIAP (Catalonia) data sources. Our findings will inform future public policies aimedto protect the pediatric population, both within these countries and globally. • Pediatric population is susceptible to SARS-CoV-2 infection. • COVID-19 severity rates in children vary across study settings and context. • This study confirms the low severity rates of COVID-19 in the pediatric population based on a large cohort of children and adolescents residing in Spain, Italy, and Norway. • Incidence of severe COVID-19 in children and adolescents with comorbidities was up to 3 to 4 times higher than in the general pediatric population during the SARS-CoV-2 high transmission wave of Omicron BA.1-2 variant in winter 2021-2022 in Italy and Spain.

Burden and Risk Factors for Coinfections in Patients with a Viral Respiratory Tract Infection

Which patients should be monitored for coinfections or should receive empirical antibiotic treatment, in patients with an acute viral respiratory infection, is largely unknown. We evaluated the prevalence, characteristics, outcomes of coinfected patients, and risk factors associated with a coinfection among patients with an acute viral infection. A retrospective, single-center study recruited consecutive patients from October 2022 to March 2023 presenting to the emergency department with signs of a respiratory tract infection. Patients were screened for respiratory viruses and bacterial/fungal secondary infections according to local standard procedures. Outcomes included severe disease, in-hospital complications, all-cause in-hospital and ICU-related mortality, time to death, time to discharge, and time to coinfection. The analysis included 652 patients. A viral infection and a secondary bacterial/fungal infection were detected in 39.1% and 40% of cases. Compared with the rest of the cohort, coinfected patients had more frequently severe disease (88.3%, p &lt; 0.001; 51% in patients with SARS-CoV-2) and higher in-hospital mortality (16.5%, p = 0.010). Nephropathy (OR 3.649, p = 0.007), absence of COVID-19 vaccination (OR 0.160, p &lt; 0.001), SARS-CoV-2 infection (OR 2.390, p = 0.017), and lower blood pressure at admission (OR 0.980, p = 0.007) were independent risk factors for coinfection. Multidrug-resistant pathogens were detected in 30.8% of all coinfections. Patients with a viral infection are at high risk of bacterial coinfections, which carry a significant morbidity and mortality burden.

Heterogeneous Associations Between Pandemic-Induced Socioeconomic Hardships and COVID-19 Vaccine Uptake by Sexual Orientation and Gender Identity: A Nationally Representative Analysis in the United States

Background/Objectives: Socioeconomic hardship during the COVID-19 pandemic was associated with lower vaccine uptake. Since the pandemic has exacerbated socioeconomic challenges faced by sexual and gender minority populations, including employment income loss, housing instability, food insufficiency, and household expense difficulty, this study investigated the disparities in COVID-19 vaccine uptake among these populations. Methods: Using the U.S. Census Bureau Household Pulse Survey, a nationally representative sample of 1,767,966 individuals (6% gay or lesbian, 4.2% bisexual, 1.6% something else, and 90.6% heterosexual respondents), we quantified the COVID-19 vaccine uptakes among sexual and gender minorities, as well as the effect measure modifications by socioeconomic hardships. Results: Despite higher vaccine uptake rates among sexual and gender minorities compared to their heterosexual counterparts, socioeconomic hardships triggered by the pandemic among these populations were associated with decreased vaccine uptake. Importantly, the effect measure modifications by socioeconomic hardships were more pronounced among sexual and gender minority status compared to heterosexual individuals. Conclusions: These results highlight the critical need to address socioeconomic hardships among sexual and gender minorities to enhance vaccine uptake, along with the pre-existing and exacerbated social and economic disadvantages during the COVID-19 pandemic.

Design of logistics indicators for monitoring the COVID-19 vaccination process in Colombia : Logistic indicators for vaccination process.

The vaccine supply chain (VSC) integrates all activities from production to dispensing, characterized by complexity and low responsiveness. This study aims to define key performance indicators (KPIs) to evaluate the logistic and operational performance during the COVID-19 National Vaccination Plan in Colombia. This study employed the design science research (DSR) methodology to develop a dashboard for monitoring COVID-19 vaccination progress. DSR is a problem-solving paradigm focused on conceiving, testing, and evaluating artifacts to tackle specific challenges. The dashboard integrated a set of Key Performance Indicators (KPIs) that incorporated three dimensions: epidemiological, humanitarian, and logistical. Both, the dashboard and the KPIs underwent validation through three iterative DSR cycles, in collaboration with both private and public health stakeholders. A set of 38 validated KPIs, grouped into eight categories, was consolidated into an online dashboard. This tool enabled real-time tracking of the National Vaccination Plan at both national and departmental levels, providing stakeholders with a comprehensive view of the vaccine supply chain. It also allowed for the assessment and comparison of the execution and effectiveness of public policies. These KPIs supported decision-making from a logistical standpoint, enhancing the planning, preparation, and continuous improvement of mass vaccination processes, thereby increasing their potential impact even further.

The New Era of mRNA Vaccines: The Success of the Covid-19 Vaccines and the Safety Concerns in Adolescents

Abstract A remarkable scientific achievement during the Covid pandemic is the rapid development and deployment of the mRNA vaccines which played a crucial role in reducing the Covid-related morbidity and mortality. The first-time safe use of the mRNA vaccine platform in humans opened up a new era in vaccinology. In the near future, the mRNA vaccine platform is likely to be used for other diseases as well. Though the Covid mRNA vaccine has been found to be safe in children, a matter of concern is the rare adverse event myocarditis, which was mostly observed among male adolescents. In this setting, we briefly discuss mRNA vaccine-related myocarditis and suggest that the safety concerns need to be alleviated by larger studies with long-term follow-up. We also stress the need for the generation of safety data from children in lower- and middle-income countries as there is limited experience with mRNA vaccines in such settings. The underlying mechanisms need to be understood well as the mRNA vaccine platform holds enormous promise for the future development of vaccines for several diseases.

Simultaneous Protein Quantitation and Glycosylation Profiling of Antigen-Specific Immunoglobulin G1 in Large Clinical Studies.

Antibodies have a key role in the immune system, making their characterization essential to biomedical, biopharmaceutical, and clinical research questions. Antibody effector functions are mainly controlled by quantity, subclass, and Fc glycosylation. We describe an integrated method to measure these three critical dimensions simultaneously. The subclass-specific immunoglobulin G (IgG) Fc glycosylation analysis combines immunosorbance with glycopeptide-centered LC-MS detection. For integrated IgG1-specific quantitation, a commercial, stable isotope labeled IgG1 protein standard was spiked into the immunosorbent eluates. Robust quantitation was achieved, relying on a combination of a proteotypic peptide and the most abundant glycopeptides, generated through proteolytic cleavage from a mixture of natural IgG1 and the recombinant IgG1 standard. Method performance was demonstrated in a large coronavirus vaccination cohort at a throughput of 100 samples/day. LC-MS-derived, anti-SARS-CoV-2 spike protein IgG1 concentrations ranged from 100 to 10000 ng/mL and correlated well with a clinically relevant immunoassay. Technical variation was 200 times lower than biological variation; intermediate precision was 44%. In conclusion, we present a method capable of robustly and simultaneously assessing quantity, subclass, and Fc glycosylation of antigen-specific IgG in large clinical studies. This method will facilitate a broader understanding of immune responses, especially the important interplay among the three dimensions.

Experiences and perceptions of migrant populations in South Africa on COVID-19 immunization: an interpretative phenomenological analysis.

Migrant populations (asylum seekers, permit holders, refugees, and undocumented migrants) living in South Africa face various individual, social, and physical circumstances that underpin their decisions, motivation, and ability to receive the COVID-19 vaccine. We conducted a qualitative study to explore the experiences and perceptions of migrant populations in South Africa on COVID-19 vaccines to inform recommendations for improved COVID-19 immunization. We conducted an Interpretative Phenomenological Analysis (IPA) with 20 asylum seekers, permit holders, refugees, and undocumented migrants living in South Africa. We applied a maximum variation purposive sampling approach to capture all three categories of migrants in South Africa. Semi-structured interviews were conducted and recorded electronically with consent and permission from the study participants. The recordings were transcribed and analyzed thematically following the IPA using Atlas.ti version 9. Four major reflective themes emanated from the data analysis. (1) While some migrants perceived being excluded from the South African national immunization program at the level of advertisement and felt discriminated against at the immunization centers, others felt included in the program at all levels. (2) Skepticism, myths, and conspiracy theories around the origin of SARS-CoV-2 and the COVID-19 vaccine are pervasive among migrant populations in South Africa. (3) There is a continuum of COVID-19 vaccine acceptance/hesitancy ranging from being vaccinated through waiting for the chance to be vaccinated to refusal. (4) Accepting the vaccine or being hesitant follows the beliefs of the participant, knowledge of the vaccine's benefits, and lessons learned from others already vaccinated. COVID-19 vaccine inclusiveness, awareness, and uptake should be enhanced through migrant-aware policies and actions such as community mobilization, healthcare professional training, and mass media campaigns.