COVID-19 vaccines: Considering sex differences in efficacy and safety

Physiological Response to the COVID-19 Vaccine: Insights From a Prospective, Randomized, Single-Blinded, Crossover Trial

BACKGROUND

Rapid development and implementation of vaccines constituted a crucial step in containing the COVID-19 pandemic. A comprehensive understanding of physiological responses to these vaccines is important to build trust in medicine.

OBJECTIVE

This study aims to investigate temporal dynamics before and after COVID-19 vaccination in 4 physiological parameters as well as the duration of menstrual cycle phases.

METHODS

In a prospective trial, 17,825 adults in the Netherlands wore a medical device on their wrist for up to 9 months. The device recorded their physiological signals and synchronized with a complementary smartphone app. By means of multilevel quadratic regression, we examined changes in wearable-recorded breathing rate, wrist skin temperature, heart rate, heart rate variability, and objectively assessed the duration of menstrual cycle phases in menstruating participants to assess the effects of COVID-19 vaccination.

RESULTS

The recorded physiological signals demonstrated short-term increases in breathing rate and heart rate after COVID-19 vaccination followed by a prompt rebound to baseline levels likely reflecting biological mechanisms accompanying the immune response to vaccination. No sex differences were evident in the measured physiological responses. In menstruating participants, we found a 0.8% decrease in the duration of the menstrual phase following vaccination.

CONCLUSIONS

The observed short-term changes suggest that COVID-19 vaccines are not associated with long-term biophysical issues. Taken together, our work provides valuable insights into continuous fluctuations of physiological responses to vaccination and highlights the importance of digital solutions in health care.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1186/s13063-021-05241-5.

Sex differences in airway disease: estrogen and airway surface liquid dynamics

Biological sex differences exist for many airway diseases in which females have either worse or better health outcomes. Inflammatory airway diseases such as cystic fibrosis (CF) and asthma display a clear male advantage in post-puberty while a female benefit is observed in asthma during the pre-puberty years. The influence of menstrual cycle stage and pregnancy on the frequency and severity of pulmonary exacerbations in CF and asthma point to a role for sex steroid hormones, particularly estrogen, in underpinning biological sex differences in these diseases. There are many ways by which estrogen may aggravate asthma and CF involving disturbances in airway surface liquid (ASL) dynamics, inappropriate hyper-immune and allergenic responses, as well as exacerbation of pathogen virulence. The deleterious effect of estrogen on pulmonary function in CF and asthma contrasts with the female advantage observed in airway diseases characterised by pulmonary edema such as pneumonia, acute respiratory distress syndrome (ARDS) and COVID-19. Airway surface liquid hypersecretion and alveolar flooding are hallmarks of ARDS and COVID-19, and contribute to the morbidity and mortality of severe forms of these diseases. ASL dynamics encompasses the intrinsic features of the thin lining of fluid covering the airway epithelium which regulate mucociliary clearance (ciliary beat, ASL height, volume, pH, viscosity, mucins, and channel activating proteases) in addition to innate defence mechanisms (pathogen virulence, cytokines, defensins, specialised pro-resolution lipid mediators, and metabolism). Estrogen regulation of ASL dynamics contributing to biological sex differences in CF, asthma and COVID-19 is a major focus of this review.

When Should I Get My Next COVID-19 Vaccine? Data From the Surveillance of Responses to COVID-19 Vaccines in Systemic Immune-Mediated Inflammatory Diseases (SUCCEED) Study

OBJECTIVE

To determine how serologic responses to coronavirus disease 2019 (COVID-19) vaccination and infection in immune-mediated inflammatory disease (IMID) are affected by time since last vaccination and other factors.

METHODS

Post-COVID-19 vaccination, data, and dried blood spots or sera were collected from adults with rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, ankylosing spondylitis and spondylarthritis, and psoriasis and psoriatic arthritis. The first sample was collected at enrollment, then at 2 to 4 weeks and 3, 6, and 12 months after the latest vaccine dose. Multivariate generalized estimating equation regressions (including medications, demographics, and vaccination history) evaluated serologic response, based on log-transformed anti-receptor-binding domain (RBD) IgG titers; we also measured antinucleocapsid (anti-N) IgG.

RESULTS

Positive associations for log-transformed anti-RBD titers were seen with female sex, number of doses, and self-reported COVID-19 infections in 2021 to 2023. Negative associations were seen with prednisone, anti-tumor necrosis factor agents, and rituximab. Over the 2021-2023 period, most (94%) of anti-N positivity was associated with a self-reported infection in the 3 months prior to testing. From March 2021 to February 2022, anti-N positivity was present in 5% to 15% of samples and was highest in the post-Omicron era, with antinucleocapsid positivity trending to 30% to 35% or higher as of March 2023. Anti-N positivity in IMID remained lower than Canada's general population seroprevalence (> 50% in 2022 and > 75% in 2023). Time since last vaccination was negatively associated with log-transformed anti-RBD titers, particularly after 210 days.

CONCLUSION

Ours is the first pan-Canadian IMID assessment of how vaccine history and other factors affect serologic COVID-19 vaccine responses. These findings may help individuals personalize vaccination decisions, including consideration of additional vaccination when > 6 months has elapsed since last COVID-19 vaccination/infection.

Sex and gender differences in adverse events following influenza and COVID-19 vaccination

INTRODUCTION

Active and passive surveillance studies have found that a greater proportion of females report adverse events (AE) following receipt of either the COVID-19 or seasonal influenza vaccine compared to males. In a predominately young adult female population of healthcare workers, we sought to determine the intersection of biological sex and sociocultural gender differences in prospective active reporting of vaccine outcomes, which remains poorly characterized.

METHODS

This cohort study enrolled Johns Hopkins Health System healthcare workers (HCWs) who were recruited from the mandatory annual fall 2019-2022 influenza vaccine and the fall 2022 COVID-19 bivalent vaccine campaigns. Vaccine recipients were enrolled the day of vaccination and AE surveys were administered two days post-vaccination for bivalent COVID-19 and influenza vaccine recipients. Data were collected regarding the presence of a series of solicited local and systemic AEs. Open-ended answers about participants' experiences with AEs also were collected for the COVID-19 vaccine recipients.

RESULTS

Females were more likely to report local AEs after either influenza (OR = 2.28, p = 0.001) or COVID-19 (OR = 2.57, p = 0.008) vaccination compared to males, regardless of age or race. Males and females had comparable probabilities of reporting systemic AEs after either influenza (OR = 1.18, p = 0.552) or COVID-19 (OR = 0.96, p = 0.907) vaccination. Hormonal birth control use did not impact the rates of reported AEs following influenza vaccination among reproductive-aged female HCWs. Women reported more interruptions in their daily routine following COVID-19 vaccination than men and were more likely to seek out self-treatment. More women than men scheduled their COVID-19 vaccination before their days off in anticipation of AEs.

CONCLUSIONS

Our findings highlight the need for sex- and gender-inclusive policies to inform more effective mandatory occupational health vaccination strategies. Further research is needed to evaluate the potential disruption of AEs on occupational responsibilities following mandated vaccination for healthcare workers, a predominately female population, and to more fully characterize the post-vaccination behavioral differences between men and women.

Longitudinal Follow-Up Study on the Side Effects of COVID-19 Vaccines: A Telephonic Questionnaire Approach

BACKGROUND

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has prompted urgent efforts to develop and deploy effective vaccines. Covishield and Covaxin are two prominent COVID-19 vaccines authorized for emergency use; however, concerns regarding their safety persist.

OBJECTIVE

This longitudinal follow-up study aimed to comprehensively assess and compare the demographic characteristics, frequencies, severities of reported side effects, and associations between vaccine type and demographic factors among individuals vaccinated with Covishield and Covaxin.

METHODS

A telephonic questionnaire was used to collect data from individuals who attended COVID-19 vaccination programs between January 1, 2021, and January 1, 2022. Logistic regression analysis was performed to investigate the associations between vaccine type, demographic factors, and likelihood of experiencing side effects.

RESULTS

Covaxin recipients exhibited a lower incidence of mild flu-like illness (16 cases) and post-vaccination infection (55 cases) than Covishield recipients (110 and 98 cases, respectively). However, Covaxin recipients reported more cases of soreness at the injection site (139 cases) than did Covishield recipients (172 cases). Logistic regression analysis revealed significantly higher odds of experiencing side effects among Covaxin recipients than among Covishield recipients (OR = 1.687, p < 0.001). Age was inversely associated with the likelihood of experiencing side effects (OR = 0.982, p < 0.001), while sex and ethnicity also exhibited significant associations.

CONCLUSION

This study provides valuable insights into the safety profiles of the Covishield and Covaxin COVID-19 vaccines. These findings underscore the importance of ongoing surveillance and evaluation of vaccine safety and tolerability to inform public health policies and vaccination strategies.

An Analysis of Antibody Response to COVID-19 Vaccination Among Medicos in a Predominantly Tribal State in India: A Comparative Study

Introduction Global health is still being impacted by the coronavirus disease 2019 (COVID-19) pandemic. Objectives We evaluated the antibody response in this study in individuals who received two doses of the COVID-19 vaccination, both with and without a history of SARS-CoV-2 infection. Methodology It was a hospital-based cross-sectional study conducted among healthcare personnel at a tertiary institution of a predominantly tribal state in India. Results A total of 187 medical students made up the vaccinee group; the majority (152; 81.3%) were between the ages of 18 and 23; 128 (68.4%) of the students were female; and 104 (55.6%) had received the Covishield (AstraZeneca plc, England, UK) vaccination. Of the subjects, 51 (27.3%) had a history of COVID-19 infection. For those who were infected, the antibody titer peaked after six months, whereas it took twice as long for those who were not. Up to a year later, the antibody titers for Covaxin (Bharat Biotech, Hyderabad, India) and Covishield remained equal; however, Covishield titers drastically decreased while Covaxin stayed constant when an infection history was present. Conclusion The study's findings show that immunization in individuals who have previously contracted COVID-19 induces a higher level of antibody response than immunization in individuals who have not previously contracted the virus.

The clinical and immunological features of alopecia areata following SARS-CoV-2 infection or COVID-19 vaccines

INTRODUCTION

Alopecia areata (AA) is an autoimmune disease induced by viral infection or vaccination. With the increased incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the incidence of AA has also increased. Recently the incidence was found to be 7.8% from a previously reported rate of 2.1%. The physical and psychological damage caused by AA could seriously affect patients' lives, while AA is a challenging dermatological disease owing to its complex pathogenesis.

AREAS COVERED

This paper presents a comprehensive review of the prevalence, pathogenesis and potential therapeutic targets for AA after infection with SARS-CoV-2 or SARS-CoV-2 vaccine.

EXPERT OPINION

The treatment of AA remains challenging because of the complexity of its pathogenesis. For patients with AA after SARS-CoV-2 infection or vaccination, the use of sex hormones and alternative regenerative therapies may be actively considered in addition to conventional treatments. For preexisting disease, therapeutic agents should be adjusted to the patient's specific condition.

SARS-CoV-2 specific antibody response after an mRNA vaccine as the third dose: Homologous versus heterologous boost

The aim of this study was to evaluate immunogenicity and longevity of the humoral immune response within six months after the homologous (BNT162b2/BNT162b2) or heterologous (BBIBP-CorV/BNT162b2) third dose, and to assess breakthrough infections among vaccinees during the Omicron wave in Serbia. Serum samples were analyzed at four timepoints: five months after the primary series; three weeks, three months, and six months after the boost. IgG antibodies against the receptor-binding domain of the spike protein were detected using enzyme-linked fluorescence assay. Both homologous (n = 55) and heterologous group (n = 36) showed a highly significant increase in antibody concentrations (p < 0.001) three weeks after the boost. A moderate inverse correlation between the age of recipients and the antibody levels at three weeks post-boost was observed in the homologous group (p = 0.02, r = -0.37), while the same correlation was not significant for heterologous group (p = 0.55, r = -0.15). Heterologous group had significantly higher antibody concentrations than homologous group at three weeks (Median 851.4(IQR 766.6-894.1); 784.3(676.9-847.4); p = 0.03) and three months post-boost (766.6(534.8-798.9); 496.8(361.6-664.0); p < 0.001). However, a significant decline in antibody response over time was noted for both strategies. The overall incidence of breakthrough cases was estimated at 36.36% (20/55) for homologous, and 16.67% (6/36) for heterologous group, but none of them required hospitalization. Although observed incidence in the homologous group was more than double when compared to the heterologous group, this difference was not statistically significant, most likely due to the small sample size. In conclusion, waning immunity after inactivated vaccine can be recovered by BNT162b2 heterologous boost regardless of the age of recipients, and both boost strategies induced potent humoral immune response and protection against severe COVID-19 during the Omicron wave. However, as the observed incidence of breakthrough infections was higher in the homologous group, although non-significant, this finding could indicate an advantage of heterologous approach.

The Role of Biological Sex in Pre-Clinical (Mouse) mRNA Vaccine Studies

In this study, we consider the influence of biological sex-specific immune responses on the assessment of mRNA vaccines in pre-clinical murine studies. Recognising the established disparities in immune function attributed to genetic and hormonal differences between individuals of different biological sexes, we compared the mRNA expression and immune responses in mice of both biological sexes after intramuscular injection with mRNA incorporated within lipid nanoparticles. Regarding mRNA expression, no significant difference in protein (luciferase) expression at the injection site was observed between female and male mice following intramuscular administration; however, we found that female BALB/c mice exhibit significantly greater total IgG responses across the concentration range of mRNA lipid nanoparticles (LNPs) in comparison to their male counterparts. This study not only contributes to the scientific understanding of mRNA vaccine evaluation but also emphasizes the importance of considering biological sex in vaccine study designs during pre-clinical evaluation in murine studies.

Gendering the Pandemic: Women's Health Disparities From a Human Rights Perspective

As COVID-19 keeps impacting the world, its impact is felt differently by people of different sexes and genders. International guidelines and research on gender inequalities and women's rights during the pandemic have been published. However, data from Taiwan is lacking. This study aims to fill the gap to increase our knowledge regarding this issue and provide policy recommendations. This study is part of a more extensive project in response to the fourth state report concerning the implementation of the Convention on the Elimination of All Forms of Discrimination against Women in Taiwan in 2022. We have drawn on the guidelines and documents published by the United Nations human rights bodies, conducted interviews with advocacy and professional practitioners, and hosted a study group comprising students and teachers from the National Taiwan University College of Public Health to supplement the interview data. The data were analyzed thematically. The results include five themes: (1) particular health risks to carers (primarily women); (2) COVID-related measures' impact on women's health and health behaviors; (3) highly gendered psychological maladjustment; (4) increase in gender-based violence and domestic violence; and (5) mental health inequities and intersectionality. The study has global implications for societies of similar sociopolitical contexts and developmental statuses. To truly live up to the standard of CEDAW and other international human rights principles, we ask that central and local government be more aware of these lived experiences and adjust their policies accordingly, accounting for gender sensitivity.

Sex and gender differences in adverse events following receipt of influenza and COVID-19 vaccination among healthcare workers

Introduction

Active and passive surveillance studies have found that a greater proportion of females report adverse events (AE) following receipt of either the COVID-19 or seasonal influenza vaccine compared to males. We sought to determine the intersection of biological sex and sociocultural gender differences in prospective active reporting of vaccine outcomes, which remains poorly characterized.

Methods

This cohort study enrolled Johns Hopkins Health System healthcare workers (HCWs) who were recruited from the annual fall 2019-2022 influenza vaccine and the fall 2022 COVID-19 bivalent vaccine campaigns. Vaccine recipients were enrolled the day of vaccination and AE surveys were administered two days post-vaccination (DPV) for bivalent COVID-19 and Influenza vaccine recipients. Data were collected regarding the presence of a series of solicited local and systemic AEs. Open-ended answers about participants' experiences with AEs also were collected for the COVID-19 vaccine recipients.

Results

Females were more likely to report local AEs after influenza (OR=2.28, p=0.001) or COVID-19 (OR=2.57, p=0.008) vaccination compared to males, regardless of age or race. Males and females had comparable probabilities of reporting systemic AEs after influenza (OR=1.18, p=0.552) or COVID-19 (OR=0.96, p=0.907) vaccination. Exogenous hormones from birth control use did not impact the rates of reported AEs following COVID-19 vaccination among reproductive-aged female HCWs. Women reported more interruptions in their daily routine following COVID-19 vaccination than men and were more likely to seek out self-treatment. More women than men scheduled their COVID-19 vaccination before their days off in anticipation of AEs.

Conclusions

Our findings highlight the need for sex- and gender-inclusive policies to inform more effective occupational health vaccination strategies. Further research is needed to evaluate the potential disruption of AEs on occupational responsibilities following mandated vaccination for healthcare workers and to more fully characterize the post-vaccination behavioral differences between men and women.

KEY MESSAGE

What is already known on this topic: ⇒ Among diversely aged adults 18-64 years, females report more AEs to vaccines, including the influenza and COVID-19 vaccines, than males.⇒ Vaccine AEs play a role in shaping vaccine hesitancy and uptake.⇒ Vaccine uptake related to influenza and COVID-19 are higher among men than women.⇒ Research that addresses both the sex and gender disparities of vaccine outcomes and behaviors is lacking.What this study adds: ⇒ This prospective active reporting study uses both quantitative and qualitative survey data to examine sex and gender differences in AEs following influenza or COVID-19 vaccination among a cohort of reproductive-aged healthcare workers.How this study might affect research, practice, or policy: ⇒ Sex and gender differences in AEs and perceptions relating to vaccination should drive the development of more equitable and effective vaccine strategies and policies in occupational health settings.

The Importance of Gender-Sensitive Health Care in the Context of Pain, Emergency and Vaccination: A Narrative Review

So far, health care has been insufficiently organized in a gender-sensitive way, which makes the promotion of care that meets the needs of women and men equally emerge as a relevant public health problem. The aim of this narrative review was to outline the need for more gender-sensitive medical care in the context of pain, emergency care and vaccinations. In this narrative review, a selective search was performed in Pubmed, and the databases of the World Health Organization (WHO), the European Institute for Gender Equality and the German Federal Ministry of Health were searched. Study data indicate that there are differences between men and women with regard to the ability to bear pain. On the other hand, socially constructed role expectations in pain and the communication of these are also relevant. Studies indicate that women receive adequate pain medication less often than men with a comparable pain score. Furthermore, study results indicate that the female gender is associated with an increased risk of inadequate emergency care. In terms of vaccine provision, women are less likely than men to utilize or gain access to vaccination services, and there are gender-sensitive differences in vaccine efficacy and safety. Sensitization in teaching, research and care is needed to mitigate gender-specific health inequalities.

Association between sex hormones and anti-S/RBD antibody responses to COVID-19 vaccines in healthcare workers

Healthcare workers (HCWs) are the target population for vaccination against coronavirus disease (COVID-19) as they are at a high risk of exposure and transmission of pathogens to patients. Neutralizing antibodies developed after COVID-19 vaccination decline within few months of vaccination. Several factors, including age and sex, can affect the intensity, efficacy, and duration of immune response to vaccines. However, sex-specific analyses of humoral responses to COVID-19 vaccines are lacking. This study aimed to evaluate sex-based differences in anti-S/RBD (Receptor Binding Domain) responses at three different time points after the second dose of mRNA COVID-19 vaccine in HCWs in relation to age, and to investigate the role of sex hormones as potential markers of response. Anti-S/RBD levels after two doses of the mRNA vaccine were collected from 521 HCWs naïve to COVID-19, working at two Italian Clinical Centers. Multiple regression analysis was applied to evaluate the association between anti-S levels and sex, age, and plasma levels of sex hormones. Significantly higher anti-S/RBD response to the COVID-19 vaccination was found in female HCWs, and a significant and more abrupt decline in response with time was observed in women than that in men. A novel, positive association of testosterone plasma levels and higher anti-S levels in male HCWs was found, suggesting its potential role as sex specific marker in males. In conclusion, understanding the sex-based differences in humoral immune responses to vaccines may potentially improve vaccination strategies and optimize surveillance programs for HCWs.

SARS-CoV-2 mRNA vaccination induces an intranasal mucosal response characterized by neutralizing antibodies

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine-induced systemic antibody profiles are well characterized; however, little is known about whether intranasal mucosal antibodies are induced or can neutralize virus in response to mRNA vaccination.

Objective

We sought to evaluate intranasal mucosal antibody production with SARS-CoV-2 mRNA vaccination.

Methods

SARS-CoV-2-specific IgG and IgA concentrations and neutralization activity from sera and nasal mucosa via nasal epithelial lining fluid (NELF) collection were measured in SARS-CoV-2 mRNA-vaccinated healthy volunteers (N = 29) by using multiplex immunoassays. Data were compared before and after vaccination, between mRNA vaccine brands, and by sex.

Results

SARS-CoV-2 mRNA vaccination induced an intranasal immune response characterized by neutralizing mucosal antibodies. IgG antibodies displayed greater Spike 1 (S1) binding specificity than did IgA in serum and nasal mucosa. Nasal antibodies displayed greater neutralization activity against the receptor-binding domain than serum. Spikevax (Moderna)-vaccinated individuals displayed greater SARS-CoV-2-specific IgG and IgA antibody concentrations than did Comirnaty (BioNTech/Pfizer)-vaccinated individuals in their serum and nasal epithelial lining fluid. Sex-dependent differences in antibody response were not observed.

Conclusion

SARS-CoV-2 mRNA vaccination induces a robust systemic and intranasal antibody production with neutralizing capacity. Spikevax vaccinations elicit a greater antibody response than does Comirnaty vaccination systemically and intranasally.

Real-world clinical effectiveness of Tixagevimab/Cilgavimab and Regdanvimab monoclonal antibodies for COVID-19 treatment in Omicron variant-dominant period

Several virus-neutralizing monoclonal antibodies (mAbs) have become new tools in the treatment of the coronavirus disease (COVID-19), but their effectiveness against the rapidly mutating virus is questionable. The present study investigated the effectiveness of Tixagevimab/Cilgavimab and Regdanvimab for mild and moderate COVID-19 treatment in real-world clinical practice during the Omicron variant-dominant period. Patients with known risk factors for disease progression and increasing disease severity were enrolled in the study within the first 7 days of symptom onset. Seventy-seven patients were divided into four groups: first 15 patients received 300 mg Tixagevimab/Cilgavimab intravenously (IV) and 23 patients got the same drug 300 mg intramuscularly (IM), the next 15 patients was on the same combination in dose of 600 mg IV, and 24 patients were on Regdanvimab at a dose of 40 mg/kg IV. By Day 4, 100% of Tixagevimab/Cilgavimab IV patients showed negative polymerase chain reaction results for SARS-CoV-2 Ribonucleic acid (RNA) regardless of the mAbs dose while in the Regdanvimab group 29% of the patients were positive for SARS-CoV-2 virus RNA. The testing for virus neutralizing antibodies (nAbs) to various Omicron sublineages (BA.1, BA.2, and BA.5) showed that an increase in nAb levels was detected in blood serum immediately after the drug administration only in Tixagevimab/Cilgavimab 300 mg and 600 mg IV groups. In the group of intravenous Regdanvimab, a significant increase in the level of nAbs to the Wuhan variant was detected immediately after the drug administration, while no increase in nAbs to different Omicron sublineages was observed.

Clinical trial registration

https://clinicaltrials.gov/, identifier NCT05982704.

Immunologic response and seroconversion following third-dose COVID-19 vaccination in solid organ transplant recipients: A meta-analysis

INTRODUCTION

The immunogenicity and efficacy of COVID-19 vaccination varied by demographic, including solid organ transplant recipients on immunosuppressive therapy.

AIM

This purpose of this study is to assess seropositivity and seroconversion in solid-organ transplant recipients before and after third-dose COVID-19 vaccination.

METHODS

This study is a systematic review and meta-analysis performed using PRISMA guidelines. To analyze clinical and cohort studies reporting immunologic response and seroconversion third-dose vaccination, a systematic search was performed using electronic databases (PubMed, Scopus, Cochrane, Directory of Open Access Journal (DOAJ), and Clinicaltrials.gov).

RESULT

There were 18 full-text papers that could be analyzed qualitatively and quantitatively. After the third vaccination, the pooled rate seropositivity was 67.00% (95% CI 59.511; 74.047, I2 = 93.82%), and the pooled rate seroconversion was 52.51% (95% CI 44.03; 60.91, I2 = 92.15%). The pooled rate of seroconversion after the mRNA-based booster was 52.380% (95% CI 40.988; 63.649, I2 = 94.35%), and after the viral-vector-based booster was 42.478% (95% CI 35.222; 49.900, I2 = 0.00%).

CONCLUSION

Based on the analysis of immunologic responses and seroconversion findings, the third-dose vaccination of solid organ transplant recipients is an effective method in establishing better immunity against COVID-19.

The Safety and Effectiveness of mRNA Vaccines Against SARS-CoV-2

The coronavirus disease 2019 (COVID-19) pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in numerous deaths worldwide, along with devastating economic disruptions, and has posed unprecedented challenges to healthcare systems around the world. In the wake of COVID-19's emergence in 2019, a variety of vaccine technologies were formulated and developed, including those that drew from the technology employed in messenger RNA (mRNA) vaccines, designed to curb the disease's transmission and manage the pandemic. mRNA vaccine has several advantages over traditional ones, and hence its development has received considerable attention recently. Researchers believe the mRNA vaccine technology will emerge as the leading technology because it is potent, inexpensive, rapidly developed, and safe. This article provides an overview of mRNA vaccines with a special focus on the efficacy and safety of the Moderna and Pfizer-BioNTech mRNA vaccines against the different variants of COVID-19 and compare them with the Oxford-AstraZeneca (viral vector) and Sinopharm (inactivated virus) vaccines. The clinical data reviewed in this article demonstrate that the currently authorized Moderna and Pfizer-BioNTech mRNA vaccines are highly safe and potent against different variants of COVID-19, especially in comparison with Oxford-AstraZeneca (viral vector) and Sinopharm (inactivated virus) vaccines.

A qualitative assessment of the adverse effects associated with COVID-19 vaccines: a study from Jordan

OBJECTIVES

The current study aimed to qualitatively explore the side effects reported by participants who received the COVID-19 vaccine among the Jordanian population.

METHODS

Between April 18th and May 12th, 2022, an in-depth interview was conducted with a purposive sample of vaccinated individuals to assess the side effects of the COVID-19 vaccine in this study. Thematic analysis was used to identify themes and sub-themes within the current qualitative data.

RESULTS

A total of 20 participants were interviewed. They had a mean age of 41.3 (SD = 14.3) years. Half of the participants were females (n = 10, 50.0%). The study revealed six main themes: first, most of the respondents believed that COVID-19 vaccines were safe. Second, the vaccines are not equivalent in their safety. The third there showed that participants follow preventive measures to decrease the possibility of experiencing side effects. The fourth theme showed that reporting of side effects by the participants is dependent on the experienced side effects. Moreover, the next theme revealed that participants showed hesitancy to take more than one type of vaccine. Finally, participants were willing to take the vaccine annually, because they believed that the vaccine is better than the disease itself and decreases the aggressive effects of the disease.

CONCLUSIONS

This study found that the majority of participants believed in the safety of the COVID-19 vaccines and emphasized the responsibility of the healthcare providers in increasing awareness among the population about the importance of the vaccines. Enhancing such awareness is essential to improve the acceptance of receiving different types of vaccines.

COVID-19 Vaccination Effectiveness in the General Population of an Italian Province: Two Years of Follow-Up

We carried out a cohort study on the overall population of the province of Pescara, Italy, to assess the real-world effectiveness of SARS-CoV-2 vaccination against infection, severe, or lethal COVID-19, two years after the start of the vaccination campaign. We included all the resident or domiciled subjects, and extracted the official demographic, vaccination, COVID-19, hospital and co-pay exemption datasets from 1 January 2021, up to 15 February 2023. Cox proportional hazards analyses were adjusted for gender, age, diabetes, hypertension, COPD, major cardio- and cerebrovascular events, cancer, and kidney diseases. Throughout the follow-up (466 days on average), 186,676 subjects received greater than or equal to three vaccine doses (of ChAdOx1 nCoV-19, BNT162b2, mRNA-1273, NVX-CoV2373, or JNJ-78436735), 47,610 two doses, 11,452 one dose, and 44,989 none. Overall, 40.4% of subjects were infected with SARS-CoV-2. Of them, 2.74% had severe or lethal (1.30%) COVID-19. As compared to the unvaccinated, the individuals who received greater than or equal to one booster dose showed a ≥85% lower risk of severe or lethal COVID-19. A massive impact of vaccination was found among the elderly: 22.0% of the unvaccinated, infected individuals died, as opposed to less than 3% of those who received greater than or equal to three vaccine doses. No protection against infection was observed, although this finding was certainly influenced by the Italian restriction policies to control the pandemic. Importantly, during the Omicron predominance period, only the group who received at least a booster dose showed a reduced risk of COVID-19-related death.

Baseline Gut Microbiome Signatures Correlate with Immunogenicity of SARS-CoV-2 mRNA Vaccines

The powerful immune responses elicited by the mRNA vaccines targeting the SARS-CoV-2 Spike protein contribute to their high efficacy. Yet, their efficacy can vary greatly between individuals. For vaccines not based on mRNA, cumulative evidence suggests that differences in the composition of the gut microbiome, which impact vaccine immunogenicity, are some of the factors that contribute to variations in efficacy. However, it is unclear if the microbiome impacts the novel mode of immunogenicity of the SARS-CoV-2 mRNA vaccines. We conducted a prospective longitudinal cohort study of individuals receiving SARS-CoV-2 mRNA vaccines where we measured levels of anti-Spike IgG and characterized microbiome composition, at pre-vaccination (baseline), and one week following the first and second immunizations. While we found that microbial diversity at all timepoints correlated with final IgG levels, only at baseline did microbial composition and predicted function correlate with vaccine immunogenicity. Specifically, the phylum Desulfobacterota and genus Bilophila, producers of immunostimulatory LPS, positively correlated with IgG, while Bacteroides was negatively correlated. KEGG predicted pathways relating to SCFA metabolism and sulfur metabolism, as well as structural components such as flagellin and capsular polysaccharides, also positively correlated with IgG levels. Consistent with these findings, depleting the microbiome with antibiotics reduced the immunogenicity of the BNT162b2 vaccine in mice. These findings suggest that gut microbiome composition impacts the immunogenicity of the SARS-CoV-2 mRNA vaccines.

Addressing sociodemographic disparities in COVID-19 vaccine uptake among youth in Zimbabwe

INTRODUCTION

COVID-19 vaccine acceptance research has mostly originated from high-income countries and reasons why youth may not get vaccinated may differ in low-income settings. Understanding vaccination coverage across different population groups and the sociocultural influences in healthcare delivery is important to inform targeted vaccination campaigns.

METHODS

A population-based survey was conducted in 24 communities across three provinces (Harare, Bulawayo and Mashonaland East) in Zimbabwe between October 2021 and June 2022. Youth aged 18-24 years were randomly selected using multistage sampling. Sociodemographic characteristics, COVID-19 vaccination uptake and reasons for non-uptake were collected, and odds of vaccination was investigated using logistic regression.

RESULTS

17 682 youth were recruited in the survey (n=10 742, 60.8% female). The median age of participants was 20 (IQR: 19-22) years. Almost two thirds (n=10 652, 60.2%) reported receiving at least one dose of COVID-19 vaccine. A higher proportion of men than women had been vaccinated (68.9% vs 54.7%), and vaccination prevalence increased with age (<19 years: 57.5%, 20-22: 61.5%, >23: 62.2%). Lack of time to get vaccinated, belief that the vaccine was unsafe and anxiety about side effects (particularly infertility) were the main reasons for not getting vaccinated. Factors associated with vaccination were male sex (OR=1.69, 95% CI 1.58 to 1.80), increasing age (>22 years: OR=1.12, 95% CI 1.04 to 1.21), education level (postsecondary: OR=4.34, 95% CI 3.27 to 5.76) and socioeconomic status (least poor: OR=1.32, 95% CI 1.20 to 1.47).

CONCLUSION

This study found vaccine inequity across age, sex, educational attainment and socioeconomic status among youth. Strategies should address these inequities by understanding concerns and tailoring vaccine campaigns to specific groups.

A cohort study reveals different dynamics of SARS-CoV-2-specific antibody formation after Comirnaty and Vaxzevria vaccination

The Coronavirus (COVID-19) Disease Pandemic, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has affected millions of people worldwide, prompting a collective effort from the global scientific community to develop a vaccine against it. This study purports to investigate the influence of factors such as sex, age, type of vaccination (Comirnaty, BNT162b2, Pfizer Inc. or Vaxzevria, ChAdOx1-S, Oxford/AstraZeneca), and time since vaccine administration on the process of antibody production. Both of them are based on the introduction of SARS-CoV-2 spike protein (S protein) to the body using different mechanisms (mRNA and recombinant adenovirus, respectively). S protein is responsible for host cell attachment and penetration via its receptor-binding domain (RBD domain). The level of anti-RBD IgG antibodies was tested with an ELISA-based immunodiagnostic assay in serum samples from a total of 1395 patients at 3 time points: before vaccination, after the first dose, and after the second dose. Our novel statistical model, the Generalized Additive Model, revealed variability in antibody production dynamics for both vaccines. Interestingly, no discernible variation in antibody levels between men and women was found. A nonlinear relationship between age and antibody production was observed, characterized by decreased antibody levels for people up to 30 and over 60 years of age, with a lack of correlation in the middle age range. Collectively, our findings further the understanding of the mechanism driving vaccine-induced immunity. Additionally, we propose the Generalized Additive Model as a standardized way of presenting data in similar research.

Establishment of reference intervals for complete blood count in times of COVID-19 and vaccination

Introduction

COVID-19 and vaccination may affect some parameters of the complete blood count (CBC). The aim of this study was to determine reference intervals (RI) of CBC in healthy population with different COVID-19 and vaccination backgrounds and compare them with those established previously.

Materials and methods

A cross-sectional study was conducted in donors who attended the Traumatology Hospital "Dr. Victorio de la Fuente Narváez" (HTVFN) from June to September 2021. Reference intervals were established using the non-parametric method on Sysmex XN-1000. For differences between groups with different COVID-19 and vaccination backgrounds, non-parametric tests were used.

Results

The RI were established in 156 men and 128 women. Haemoglobin (Hb), haematocrit (Hct), red blood cells (RBC), platelets (Plt), mean platelets volume (MPV), monocytes and relative neutrophils were higher in men than women (P < 0.001). The percentiles of Hb, Hct, RBC, MPV and relative monocytes showed higher values; Plt, white blood cells (WBC), lymphocytes, monocytes, neutrophils, eosinophils and absolute basophils, the 2.5th was higher and the 97.5th was lower; for lymphocytes and relative neutrophils, both percentiles had a trend toward lower values, compared to previous RI. Differences between groups with different COVID-19 and vaccination backgrounds, in lymphocytes (P = 0.038), neutrophils (P = 0.017) and eosinophils (P = 0.018) in men; Hct (P = 0.014), RDW (P = 0.023) in women and MPV (P = 0.001) in both, were not considered pathological.

Conclusions

The RI for the CBC were established in a Mestizo-Mexican population with different COVID-19 and vaccination backgrounds, so should be updated and validated in different hospitals close to the HTVFN that use the same analyser.

Cytokinopathy with aberrant cytotoxic lymphocytes and profibrotic myeloid response in SARS-CoV-2 mRNA vaccine-associated myocarditis

Rare immune-mediated cardiac tissue inflammation can occur after vaccination, including after SARS-CoV-2 mRNA vaccines. However, the underlying immune cellular and molecular mechanisms driving this pathology remain poorly understood. Here, we investigated a cohort of patients who developed myocarditis and/or pericarditis with elevated troponin, B-type natriuretic peptide, and C-reactive protein levels as well as cardiac imaging abnormalities shortly after SARS-CoV-2 mRNA vaccination. Contrary to early hypotheses, patients did not demonstrate features of hypersensitivity myocarditis, nor did they have exaggerated SARS-CoV-2-specific or neutralizing antibody responses consistent with a hyperimmune humoral mechanism. We additionally found no evidence of cardiac-targeted autoantibodies. Instead, unbiased systematic immune serum profiling revealed elevations in circulating interleukins (IL-1β, IL-1RA, and IL-15), chemokines (CCL4, CXCL1, and CXCL10), and matrix metalloproteases (MMP1, MMP8, MMP9, and TIMP1). Subsequent deep immune profiling using single-cell RNA and repertoire sequencing of peripheral blood mononuclear cells during acute disease revealed expansion of activated CXCR3+ cytotoxic T cells and NK cells, both phenotypically resembling cytokine-driven killer cells. In addition, patients displayed signatures of inflammatory and profibrotic CCR2+ CD163+ monocytes, coupled with elevated serum-soluble CD163, that may be linked to the late gadolinium enhancement on cardiac MRI, which can persist for months after vaccination. Together, our results demonstrate up-regulation in inflammatory cytokines and corresponding lymphocytes with tissue-damaging capabilities, suggesting a cytokine-dependent pathology, which may further be accompanied by myeloid cell-associated cardiac fibrosis. These findings likely rule out some previously proposed mechanisms of mRNA vaccine--associated myopericarditis and point to new ones with relevance to vaccine development and clinical care.

Adverse events following immunization (AEFI): COVID-19 vaccine dose and characteristics in Central Java, Indonesia

Introduction

Vaccination is an effort to control the COVID-19 pandemic. Although vaccines can be effective prevention, they can have potential side effects, or adverse events following immunization (AEFI). CoronaVac, BBIBP-CorV, BNTb262-BioNTech, mRNA-1273, and ChAdOx1NCoV-19 were vaccines used in Indonesia when this study was conducted. This study aimed to analyze the factors associated with AEFI for the COVID-19 vaccines for each dose in the community.

Methods

This study used a cross-sectional design. The study was conducted in Central Java Province, Indonesia from August to October 2021. The variables included respondent characteristics, COVID-19 infection history, COVID-19 vaccine AEFI, dose, and type. Data collection was performed through questionnaires and data was analyzed by a logistic regression test.

Results

The percentage of AEFI was 21.1% after the first dose, 14.1% after the second dose, and 83.9% after the third dose of the vaccine. The factors associated with higher odds of COVID-19 vaccine AEFI were different for each dose, as follows: for the first dose: age group >45 years (p=0.009; OR=2.837; 95%CI: 1.301-6.187) and overweight (p=0.007; OR=3.323; 95%CI: 1.242-8.689); for the second dose: overweight (p=0.007; OR=9.118; 95%CI: 1.827-45.5), female sex (p=0.011; OR=2.885; 95%CI: 1.274-6.531), age group >45 years (p=0.017; OR=3.257; 95%CI: 1.24-8.555) and prior episode of COVID-19 (p=0.044; OR=2.459; 95%CI: 1.026-5.893); and for the third dose: female sex (p=0.040; OR=3.650; 95%CI: 1.062-12.550).

Conclusions

The factors that were associated with AEFI of COVID-19 vaccine were sex, age, nutritional status and prior history of COVID-19.

Factors Influencing Antibody Response to SARS-CoV-2 Vaccination

Vaccination plays a key role in tackling the ongoing SARS-CoV-2 pandemic but data regarding the individual's protective antibody level are still pending. Our aim is to identify factors that influence antibody response following vaccination in healthcare workers. This single-center study was conducted at Evangelische Kliniken Gelsenkirchen, Germany. Healthcare workers were invited to answer a questionnaire about their vaccinations and adverse reactions. Subsequently, the level of anti-receptor binding domain (RBD) IgG antibody against SARS-CoV-2's spike protein through blood samples was measured. For statistics, we used a defined correlation of protection (CoP) and examined risk factors associated with being below the given CoP. A total of 645 employees were included and most were female (n = 481, 77.2%). A total of 94.2% participants had received two doses of vaccines (n = 587) and 12.4% (n = 720) had been infected at least once. Most common prime-boost regimen was BNT162b2 + BNT162b2 (57.9%, n = 361). Age (p < 0.001), days since vaccination (p = 0.007), and the homologous vaccination regimen with ChAdOx + ChAdOx (p = 0.004) were risk factors for the antibody level being below the CoP, whereas any previous COVID-19 infection (p < 0.001), the number of vaccines (p = 0.016), and physical complaints after vaccination (p = 0.01) were associated with an antibody level above the CoP. Thus, age, vaccination regimen, days since vaccination, and previous infection influence the antibody level. These risk factors should be considered for booster and vaccinations guidelines.

A First Report on Side-Effects of COVID-19 Vaccines among General Population in Sudan: A Cross-Sectional Analysis

BACKGROUND

The process of mass immunization against COVID-19 may be impacted by vaccine reluctance despite intense and ongoing efforts to boost vaccine coverage. The COVID-19 vaccine is a crucial component for controlling the pandemic. To the best of our knowledge, we did not come across any study presenting the post-vaccination side-effect profile among the Sudanese population. Developing strategies to improve the vaccine acceptability and uptake necessitate evidence-based reports about vaccine's side effects and acceptance. In this regard, this study aimed at estimating the prevalence of COVID-19 vaccine side-effects among the general population in Sudan.

METHODOLOGY

A cross-sectional web-based quantitative study was conducted among the general population aged ≥18 years and residing in the Khartoum state of Sudan. A 30-item survey tool recorded the demographics, chronic diseases, allergy to other vaccines and COVID-19 vaccine side-effects after the first, second and booster doses. The data on the onset and duration of side-effects after each dose were also recorded. The distribution of side-effect scores after each dose of COVID-19 vaccine was compared using appropriate statistical methods.

RESULTS

A total of 626 participants were approached for this study. There was a preponderance of females (57.7%), and 19% of respondents had chronic diseases. The vaccination rate against COVID-19 was 55.8% (n = 349/626). The prevalence of side-effects after the first, second and booster doses were 79.7, 48 and 69.4%, respectively. Pain at the injection site, headache, fatigue, exhaustion and fever were the common side-effects after the first and second doses, while pain at the injection site, fatigue, headache and muscle pain were frequently reported after the booster dose. Most of these side-effects appeared within 6 h and resolved within one or two days following the administration of the vaccine dose. The average side-effects scores were 4.1 ± 4.4 (n = 349), 2.2 ± 3.6 (n = 202) and 3.5 ± 4.1 (n = 36) after the first, second and booster doses, respectively. The female gender had significantly higher side-effects after primary and booster doses. The age group 18-24 years indicated higher side-effects after the first dose compared to participants with ages ranging from 31 to 40 years (p = 0.014). Patients with chronic disease indicated significantly higher (p = 0.043) side-effects compared to those without any comorbid illness.

CONCLUSIONS

This study showed a high prevalence of transient COVID-19 vaccine-related side-effects after primary and booster doses. However, these side-effects waned within 48 h. Pain at the injection site was the most common local side-effect, while fatigue, fever, headache and muscle pain were frequently reported systemic side-effects. The frequency of side-effects was more profound among females, young adults and those with comorbid conditions. These findings indicate that COVID-19 vaccines are safe and have side-effects as reported in the clinical trials of the vaccines. These results aid in addressing the ongoing challenges of vaccine hesitancy in the Sudanese population that is nurtured by widespread concerns over the safety profile.

Sex-Differential and Non-specific Effects of Vaccines Over the Life Course

Biological sex and age have profound effects on immune responses throughout the lifespan and impact vaccine acceptance, responses, and outcomes. Mounting evidence from epidemiological, clinical, and animal model studies show that males and females respond differentially to vaccination throughout the lifespan. Within age groups, females tend to produce greater vaccine-induced immune responses than males, with sex differences apparent across all age groups, but are most pronounced among reproductive aged individuals. Females report more adverse effects following vaccination than males. Females, especially among children under 5 years of age, also experience more non-specific effects of vaccination. Despite these known sex- and age-specific differences in vaccine-induced immune responses and outcomes, sex and age are often ignored in vaccine research. Herein, we review the known sex differences in the immunogenicity, effectiveness, reactogenicity, and non-specific effects of vaccination over the lifespan. Ways in which these data can be leveraged to improve vaccine research are described.

Sex-disaggregated outcomes of adverse events after COVID-19 vaccination: A Dutch cohort study and review of the literature

Background

Albeit the need for sex-disaggregated results of adverse events after immunization (AEFIs) is gaining attention since the COVID-19 pandemic, studies with emphasis on sexual dimorphism in response to COVID-19 vaccination are relatively scarce. This prospective cohort study aimed to assess differences in the incidence and course of reported AEFIs after COVID-19 vaccination between males and females in the Netherlands and provides a summary of sex-disaggregated outcomes in published literature.

Methods

Patient reported outcomes of AEFIs over a six month period following the first vaccination with BioNTech-Pfizer, AstraZeneca, Moderna or the Johnson&Johnson vaccine were collected in a Cohort Event Monitoring study. Logistic regression was used to assess differences in incidence of 'any AEFI', local reactions and the top ten most reported AEFIs between the sexes. Effects of age, vaccine brand, comorbidities, prior COVID-19 infection and the use of antipyretic drugs were analyzed as well. Also, time-to-onset, time-to-recovery and perceived burden of AEFIs was compared between the sexes. Third, a literature review was done to retrieve sex-disaggregated outcomes of COVID-19 vaccination.

Results

The cohort included 27,540 vaccinees (38.5% males). Females showed around two-fold higher odds of having any AEFI as compared to males with most pronounced differences after the first dose and for nausea and injection site inflammation. Age was inversely associated with AEFI incidence, whereas a prior COVID-19 infection, the use of antipyretic drugs and several comorbidities were positively associated. The perceived burden of AEFIs and time-to-recovery were slightly higher in females.

Discussion

The results of this large cohort study correspond to existing evidence and contribute to the knowledge gain necessary to disentangle the magnitude of the effect sex in response to vaccination. Whilst females have a significant higher probability of experiencing an AEFI than males, we observed that the course and burden is only to a minor extent different between the sexes.

Effects of Biological Sex and Pregnancy on SARS-CoV-2 Pathogenesis and Vaccine Outcomes

SARS-CoV-2 is the causative agent of COVID-19 in humans and has resulted in the death of millions of people worldwide. Similar numbers of infections have been documented in males and females; males, however, are more likely than females to be hospitalized, require intensive care unit, or die from COVID-19. The mechanisms that account for this are multi-factorial and are likely to include differential expression of ACE2 and TMPRSS2 molecules that are required for viral entry into hosts cells and sex differences in the immune response, which are due to modulation of cellular functions by sex hormones and differences in chromosomal gene expression. Furthermore, as comorbidities are also associated with poorer outcomes to SARS-CoV-2 infection and several comorbidities are overrepresented in males, these are also likely to contribute to the observed sex differences. Despite their relative better prognosis following infection with SARS-CoV-2, females do have poorer outcomes during pregnancy. This is likely to be due to pregnancy-induced changes in the immune system that adversely affect viral immunity and disruption of the renin-angiotensin system. Importantly, vaccination reduces the severity of disease in males and females, including pregnant females, and there is no evidence that vaccination has any adverse effects on the outcomes of pregnancy.

Effectiveness of BNT162b2 and CoronaVac COVID-19 vaccination against asymptomatic and symptomatic infection of SARS-CoV-2 omicron BA.2 in Hong Kong: a prospective cohort study

BACKGROUND

COVID-19 vaccines provide protection against symptomatic infection that might require medical attention and against severe outcomes; however, there is a paucity of evidence regarding the effectiveness of the BNT162b2 and CoronaVac vaccines and their booster regimens against asymptomatic or mild omicron infections in the community. We aimed to measure the effectiveness of BNT162b2 and CoronaVac vaccines against asymptomatic and symptomatic SARS-CoV-2 omicron infections, during a period of omicron BA.2 predominance in Hong Kong.

METHODS

In this prospective cohort study in a population that was generally infection-naive before the large omicron BA.2 wave between January and late May, 2022, we established a public health surveillance platform to monitor the evolving activity of SARS-CoV-2 infections in the community. We recruited a cohort of individuals aged 5 years and older between March 1 and March 7, 2022, from the general population. Individuals were enrolled from all 18 districts of Hong Kong, according to a predefined age-stratified quota, primarily by random digit dialing (generating suitable eight-digit local telephone numbers by randomly picking sets of the first four digits from a sampling frame, and randomly generating the last four digits), and supplemented by our existing cohorts (which included cohorts for studying influenza vaccination from school-based vaccination programmes and cohorts for SARS-CoV-2 seroprevalence from the community), to ensure representativeness of the population in Hong Kong. Participants did weekly rapid antigen testing with a self-collected pooled nasal and throat swab, regardless of symptom and exposure status, from March 1 to April 15, 2022. Individuals reporting a history of SARS-CoV-2 infection confirmed by laboratory PCR testing before enrolment were excluded from the vaccine effectiveness analysis to avoid potential bias due to infection-induced immunity. The primary outcomes of the study were the incidence of SARS-CoV-2 infection, including asymptomatic and symptomatic infections, and the vaccine effectiveness of BNT162b2 and CoronaVac vaccines. The effectiveness of one, two, and three doses of vaccination was estimated with a Cox proportional hazards regression model with time-dependent covariates, allowing for changes in vaccination status over time, after adjustment for demographic factors and pre-existing medical conditions.

FINDINGS

Of the 8636 individuals included in the analysis, 7233 (84%) received at least two doses of vaccine, 3993 (46%) received booster doses, and 903 (10%) reported SARS-CoV-2 infection. Among these infections 589 (65·2%) were symptomatic and 314 (34·8%) were asymptomatic at the time of testing. Statistically significant protection against asymptomatic and symptomatic SARS-CoV-2 omicron infection was found only for those who received a BNT162b2 or CoronaVac booster dose, with a vaccine effectiveness of 41·4% (23·2 to 55·2; p=0·0001) and 32·4% (9·0 to 49·8; p=0·0098), respectively. The vaccine effectiveness of BNT162b2 and CoronaVac boosters was further increased to 50·9% (95% CI 31·0-65·0; p<0·0001) and 41·6% (15·0-59·8; p=0·0049), respectively, for symptomatic omicron infections. A similar pattern of vaccine effectiveness (55·8%, 22·9-74·6; p=0·0040) was also conferred after receipt of a BNT162b2 booster by individuals who received a CoronaVac primary vaccination series.

INTERPRETATION

Two doses of either vaccine did not provide significant protection against COVID-19 infection. However, receipt of a BNT162b2 booster or CoronaVac booster was associated with a significantly lower risk of omicron BA.2 infection and symptomatic infection. Our findings confirm the effectiveness of booster doses to protect against mild and asymptomatic infection.

FUNDING

Henry Fok Foundation and Hong Kong Health Bureau.

Surveillance of Side Effects after Two Doses of COVID-19 Vaccines among Patients with Comorbid Conditions: A Sub-Cohort Analysis from Saudi Arabia

Background: Individuals with underlying chronic illnesses have demonstrated considerable hesitancy towards COVID-19 vaccines. These concerns are primarily attributed to their concerns over the safety profile. Real-world data on the safety profile among COVID-19 vaccinees with comorbid conditions are scarce. This study aimed to ascertain the side-effects profile after two doses of COVID-19 vaccines among chronic-disease patients. Methodology: A cross-sectional questionnaire-based study was conducted among faculty members with comorbid conditions at a public educational institute in Saudi Arabia. A 20-item questionnaire recorded the demographics and side effects after the two doses of COVID-19 vaccines. The frequency of side effects was recorded following each dose of vaccine, and the association of the side-effects score with the demographics was ascertained through appropriate statistics. Results: A total of 204 patients with at least one comorbid condition were included in this study. A total of 24 side effects were reported after the first dose and 22 after second dose of the COVID-19 vaccine. The incidence of at least one side effect was 88.7% and 95.1% after the first and second doses of the vaccine, respectively. The frequent side effects after the first dose were pain at the injection site (63.2%), fatigue (58.8%), fever (47.5%), muscle and joint pain (38.7%), and headache (36.3%). However, pain at the injection site (71.1%), muscle and joint pain (62.7%), headache (49.5%), fever (45.6%), and stress (33.3%) were frequent after the second dose. The average side-effects score was 4.41 ± 4.18 (median: 3, IQR: 1, 6) and 4.79 ± 3.54 (median 4, IQR: 2, 6) after the first and second dose, respectively. Female gender, diabetes mellitus, hypertension, hyperlipidemia, comorbidity > 2, family history of COVID-19, and the AstraZeneca vaccine were significantly associated with higher side-effect scores. Only 35.8% of study participants were satisfied with the safety of COVID-19 vaccines. Conclusions: Our analysis showed a high proportion of transient and short-lived side effects of Pfizer and AstraZeneca vaccines among individuals with chronic illnesses. However, the side-effects profile was comparable with the safety reports of phase 3 clinical trials of these vaccines. The frequency of side effects was found to be associated with certain demographics, necessitating the need for further investigations to establish a causal relationship. The current study’s findings will help instill confidence in the COVID-19 vaccines among people living with chronic conditions, overcome vaccine hesitancy, and increase vaccine coverage in this population.

Interim analysis from a phase 2 randomized trial of EuCorVac-19: a recombinant protein SARS-CoV-2 RBD nanoliposome vaccine

BACKGROUND

Numerous vaccine strategies are being advanced to control SARS-CoV-2, the cause of the COVID-19 pandemic. EuCorVac-19 (ECV19) is a recombinant protein nanoparticle vaccine that displays the SARS-CoV-2 receptor-binding domain (RBD) on immunogenic nanoliposomes.

METHODS

Initial study of a phase 2 randomized, observer-blind, placebo-controlled trial to assess the immunogenicity, safety, and tolerance of ECV19 was carried out between July and October 2021. Two hundred twenty-nine participants were enrolled at 5 hospital sites in South Korea. Healthy adults aged 19-75 without prior known exposure to COVID-19 were vaccinated intramuscularly on day 0 and day 21. Of the participants who received two vaccine doses according to protocol, 100 received high-dose ECV19 (20 μg RBD), 96 received low-dose ECV19 (10 μg RBD), and 27 received placebo. Local and systemic adverse events were monitored. Serum was assessed on days 0, 21, and 42 for immunogenicity analysis by ELISA and neutralizing antibody response by focus reduction neutralization test (FRNT).

RESULTS

Low-grade injection site tenderness and pain were observed in most participants. Solicited systemic adverse events were less frequent, and mostly involved low-grade fatigue/malaise, myalgia, and headache. No clinical laboratory abnormalities were observed. Adverse events did not increase with the second injection and no serious adverse events were solicited by ECV19. On day 42, Spike IgG geometric mean ELISA titers were 0.8, 211, and 590 Spike binding antibody units (BAU/mL) for placebo, low-dose and high-dose ECV19, respectively (p < 0.001 between groups). Neutralizing antibodies levels of the low-dose and high-dose ECV19 groups had FRNT₅₀ geometric mean values of 129 and 316, respectively. Boosting responses and dose responses were observed. Antibodies against the RBD correlated with antibodies against the Spike and with virus neutralization.

CONCLUSIONS

ECV19 was generally well-tolerated and induced antibodies in a dose-dependent manner that neutralized SARS-CoV-2. The unique liposome display approach of ECV19, which lacks any immunogenic protein components besides the antigen itself, coupled with the lack of increased adverse events during boosting suggest the vaccine platform may be amenable to multiple boosting regimes in the future. Taken together, these findings motivate further investigation of ECV19 in larger scale clinical testing that is underway.

TRIAL REGISTRATION

The trial was registered at ClinicalTrials.gov as # NCT04783311.

SARS-CoV-2 Specific Humoral Immune Responses after BNT162b2 Vaccination in Hospital Healthcare Workers

BACKGROUND

COVID-19 pandemic has led to a loss of human life in millions and devastating socio-economic consequences worldwide. So far, vaccination is the most effective long-term strategy to control and prevent severe COVID-19 disease. The aim of the current study was to evaluate the humoral immune responses raised against the BNT162b2 vaccine in hospital healthcare workers.

METHODS

Total number of 173 healthcare workers enrolled in the study. Their blood samples were collected in three different time intervals after the second SARS-CoV-2 vaccination and evaluated by the ELISA method to detect anti-spike protein IgM and IgG antibodies. The baseline characteristics of all participants were collected using questionnaires and were evaluated for finding any significant data.

RESULTS

Our results demonstrated that the levels of antibodies were higher in the young group (21-30 years old) and also among male participants. Moreover, the highest levels of antibodies were detected from the group that received the third shot vaccination.

CONCLUSIONS

Our results indicate that age, gender and third-dose vaccination can affect the levels of humoral immune responses against the BNT162b2 vaccine in healthcare workers.

Evaluation of Short-Term Symptoms Associated With COVID-19 Vaccines Used Among Adolescents in Saudi Arabia

Objectives: Several government-sponsored reporting systems have stated mild to moderate side effects of COVID-19 vaccines. However, patient-reported data on COVID-19 vaccine-associated adverse effects in adolescents are lacking. Our objective was to assess the short-term side effects of Pfizer-BioNTech BNT162b2 or Moderna mRNA-1273 vaccinations among teenagers in Saudi Arabia.

Methods: A retrospective, cross-sectional study was conducted among individuals aged 12-18 years old who received one of the two mentioned vaccines between July 2021 and March 2022 in Riyadh, Saudi Arabia.

Results: The most common short-term side effects reported for COVID-19 vaccines among teenagers in our study were fatigue, pain at the site of injection, fever, chills, headache, nausea, and vomiting. Female participants, individuals who had a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and those who received two doses of the vaccine are at higher risk to develop side effects after getting the vaccine. Importantly, asthmatic participants have a higher incidence of COVID-19 vaccine side effects when compared to those with no history of chronic diseases.

Conclusion: Our findings might enhance public trust in the COVID-19 vaccine, which could speed up the immunization procedure.

Alopecia Areata Occurring after COVID-19 Vaccination: A Single-Center, Cross-Sectional Study

Limited data concerning the development of autoimmune skin diseases after COVID-19 vaccination are currently available. Recently, a few reports described the development, worsening or recurrence of alopecia areata after the administration of COVID-19 vaccines. High variability in terms of disease onset following vaccination as well as the heterogeneous topical and/or systemic treatment approaches have been described. Methods: All patient-related data and images were obtained as part of clinical routine. Diagnosis of alopecia areata was established according to clinical and trichoscopic findings, along with the exclusion of common differential diagnoses. Results. Twenty-four patients, 20 females (83.3%) and four males (16.7%), with a mean age of 39.1 years (age range: 14–66 years), were examined for the occurrence of alopecia areata within 16 weeks after COVID-19 vaccination. Out of 24, 14 patients (58.3%) experienced a patchy alopecia areata, while an extensive disease occurred in 10/24 patients (41.7%): six patients with whole scalp involvement (alopecia areata totalis) and four patients with the whole body affected (alopecia areata universalis). Twelve patients reported a history of autoimmune disease (50%). Treatment with topical corticosteroid was performed in almost all patients with patchy alopecia areata, whilst it was associated with systemic drugs (corticosteroids, minoxidil, cyclosporin) in the case of generalized alopecia areata and alopecia areata universalis. Mean baseline values of Severity of Alopecia Tool (SALT) score decreased from 43.4 to 36.6 after 12 weeks of treatment, with evidence of hair regrowth in 16/21 patients. Conclusion. This study described the occurrence of alopecia areata after COVID-19 vaccination and its management that implicates the use of both topical and systemic therapies.

Subacute Thyroiditis Following SARS-CoV-2 Vaccines: Six Cases Report and Review of the Literature

Subacute thyroiditis (SAT) is an inflammatory disease of the thyroid that develops following viral upper respiratory tract infections. SARS-CoV-2 virus, the cause of COVID-19, binds to the Angiotensin-Converting Enzyme-2 (ACE2) molecule expressed on the target cell surface. Thyroid gland shows high levels of ACE2 expression. The cases of SARS-CoV-2-related subacute thyroiditis and Graves' disease have been reported. It has recently been noted that vaccines for SARS-CoV-2 also induce autoimmune and inflammatory reactions. We present six (4 male, 2 female) cases of SAT that developed after mRNA and inactivated SARS-CoV-2 vaccines. And we have reviewed the literature. SAT was seen in 5 patients after mRNA vaccine, in one after inactivated vaccine. Their clinic and laboratory findings suggested to SAT. They were treated with nonsteroid anti-inflamatory drugs and/or methylprednisolone.They recovered within few weeks. Out patients did not have permanent hypothyroidism after SAT. The history of SARS-CoV-2 vaccination should be questioned in patients with subacute thyroiditis in pandemic days.

Surveillance of Post-Vaccination Side Effects of COVID-19 Vaccines among Saudi Population: A Real-World Estimation of Safety Profile

Vaccines are considered to be the most beneficial means for combating the COVID-19 pandemic. Although vaccines against SARS-CoV-2 have demonstrated excellent safety profiles in clinical trials, real-world surveillance of post-vaccination side effects is an impetus. The study investigates the short-term side effects following the administration of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines in Saudi Arabia. A cross-sectional quantitative study was conducted among the general population with age ≥ 18 years, from five regions (Central, Northern, Eastern, Southern, and Western Regions) of Saudi Arabia for a period of 6 months (July to December 2021). A self-administered study instrument was used to record the side effects among the COVID-19 vaccine recipients. Of the total 398 participants (males: 59%), 56.3% received Pfizer and 43.7% were vaccinated with AstraZeneca. Only 22.6% of respondents received the second dose of the COVID-19 vaccines. The most commonly reported side effects were pain at the injection site (85.2%), fatigue (61.8%), bone or joint pain (54.0%), and fever (42.5%). The average side effects score was 3.4 ± 2.2. Females, young people, and Oxford-AstraZeneca recipients had a higher proportion of side effects. The Oxford-AstraZeneca vaccine recipients complained more about fever (p < 0.001), bone and joint pain (p < 0.001), fatigue (p < 0.001), loss of appetite (p = 0.001), headache (p = 0.008), and drowsiness (p = 0.003). The Pfizer-BioNTech vaccinees had more pain and swelling at the injection site (p = 0.001), and sexual disturbance (p = 0.019). The study participants also reported some rare symptoms (<10%) including heaviness, sleep disturbance, fainting, blurred vision, palpitations, osteomalacia, and inability to concentrate. This study revealed that both Pfizer-BioNTech and Oxford-AstraZeneca administration was associated with mild to moderate, transient, short-lived side effects. These symptoms corroborate the results of phase 3 clinical trials of these vaccines. The results could be used to inform people about the likelihood of side effects based on their demographics and the type of vaccine administered. The study reported some rare symptoms that require further validation through more pharmacovigilance or qualitative studies.

A Unique Robust Dual-Promoter-Driven and Dual-Reporter-Expressing SARS-CoV-2 Replicon: Construction and Characterization

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2, SARS2) remains a great global health threat and demands identification of more effective and SARS2-targeted antiviral drugs, even with successful development of anti-SARS2 vaccines. Viral replicons have proven to be a rapid, safe, and readily scalable platform for high-throughput screening, identification, and evaluation of antiviral drugs against positive-stranded RNA viruses. In the study, we report a unique robust HIV long terminal repeat (LTR)/T7 dual-promoter-driven and dual-reporter firefly luciferase (fLuc) and green fluorescent protein (GFP)-expressing SARS2 replicon. The genomic organization of the replicon was designed with quite a few features that were to ensure the replication fidelity of the replicon, to maximize the expression of the full-length replicon, and to offer the monitoring flexibility of the replicon replication. We showed the success of the construction of the replicon and expression of reporter genes fLuc and GFP and SARS structural N from the replicon DNA or the RNA that was in vitro transcribed from the replicon DNA. We also showed detection of the negative-stranded genomic RNA (gRNA) and subgenomic RNA (sgRNA) intermediates, a hallmark of replication of positive-stranded RNA viruses from the replicon. Lastly, we showed that expression of the reporter genes, N gene, gRNA, and sgRNA from the replicon was sensitive to inhibition by Remdesivir. Taken together, our results support use of the replicon for identification of anti-SARS2 drugs and development of new anti-SARS strategies targeted at the step of virus replication.