Comparison of medium-term adverse reactions induced by the first and second dose of mRNA BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine: a post-marketing Italian study conducted between 1 January and 28 February 2021

Medical occurrence and safety of SARS-CoV-2 vaccination outside of the hospital setting

During COVID-19 pandemic, vaccination has been strongly recommended and advocated to prevent COVID-19 infection and adverse outcomes, particularly among at-risk populations. The vaccination against SARS-CoV-2 (COVAC) occurred at off-site locations capable of accommodating large crowds, distinct from the hospital setting, where a team of intensivists, emergency physicians, and nurses, ensuring prompt medical attention (medical occurrences, MO) in cases of adverse event following immunization. Our aims were to estimate the incidence of MO, and to assess its association with demographics, and vaccine characteristics. Our retrospective cohort study included all subject aged 12 years and older who received vaccinations at two large out-of-hospital vaccination hubs (Fiera Milano City, Palazzo delle Scintille), between April 12th and August 31st, 2021. Nine hundred and ninety-five thousand and twenty-eight vaccinations were administrated. MOs incidence rate was 278/100,000 doses (95% confidence interval (CI) 268-289). Most MOs were mild (86.27%) and mainly observed in subjects who received the Comirnaty vaccine; 92 MOs (3.32%) were severe and mostly occurred in recipients of the Vaxzeria vaccine. The incidence rate for hospital transfers following vaccination was 4.7/100,000 doses (95% CI 3.5-6.2) and any level of anaphylaxis occurred in 0.4 cases per 100,000 administrated doses (95% CI 0.3.-0.7). Sex, age, type of vaccine and first dose were associated with incidence of MO. Our results showed a low incidence rate in MOs after COVAC, mainly mild and support the feasibility, effectiveness and safety of vaccinations administered in hubs with a dedicated SEU located outside of the hospital setting.

Safety monitoring of precautionary third dose of COVID-19 vaccines in a district in Northern India

Background

The World Health Organization (WHO) declared Coronavirus disease-19 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) a pandemic on March 11, 2020. On 16th January 2021, India began its vaccination programme using two COVID-19 vaccines (Covishield and Covaxin). Precautionary dose (booster shots) was administered to health and front-line workers in the beginning and then to all eligible populations.

Material and Methods

This was a descriptive observational study conducted in the COVID-19 vaccination centres of Karnal district and the ADR monitoring centre, KCGMC, Karnal. During the visits to vaccination centres, all beneficiaries of the precautionary third dose of COVID-19 vaccines as well as healthcare workers were sensitized to report in case of any adverse event following vaccination as part of the policy of the vaccination programme run by the government and Pharmacovigilance Programme of India. The data were collected in suspected adverse drug reaction (ADR) reporting form version 1.4, and causality assessment was done as per the WHO-UMC scale. The data were analysed as simple proportions and percentages.

Results

The booster dose was administered to 72,853 individuals, while the 1st dose and 2nd dose were given to 13,30,042 and 10,73,050, respectively. Only three ADRs were reported with the booster dose in 34 vaccination centres in the Karnal district. These three ADRs were classified as unlikely on causality assessment and hence not included in the analysis.

Conclusion

The booster dose administered for the prevention of COVID-19 has been found to be reasonably safe. The population who received COVID-19 booster doses was significantly less than the populations who received the first and second doses, which suggests a low acceptance rate.

The immunobiology of SARS-CoV-2 infection and vaccine responses: potential influences of cross-reactive memory responses and aging on efficacy and off-target effects

Immune responses to both SARS-CoV-2 infection and its associated vaccines have been highly variable within the general population. The increasing evidence of long-lasting symptoms after resolution of infection, called post-acute sequelae of COVID-19 (PASC) or "Long COVID," suggests that immune-mediated mechanisms are at play. Closely related endemic common human coronaviruses (hCoV) can induce pre-existing and potentially cross-reactive immunity, which can then affect primary SARS-CoV-2 infection, as well as vaccination responses. The influence of pre-existing immunity from these hCoVs, as well as responses generated from original CoV2 strains or vaccines on the development of new high-affinity responses to CoV2 antigenic viral variants, needs to be better understood given the need for continuous vaccine adaptation and application in the population. Due in part to thymic involution, normal aging is associated with reduced naïve T cell compartments and impaired primary antigen responsiveness, resulting in a reliance on the pre-existing cross-reactive memory cell pool which may be of lower affinity, restricted in diversity, or of shorter duration. These effects can also be mediated by the presence of down-regulatory anti-idiotype responses which also increase in aging. Given the tremendous heterogeneity of clinical data, utilization of preclinical models offers the greatest ability to assess immune responses under a controlled setting. These models should now involve prior antigen/viral exposure combined with incorporation of modifying factors such as age on immune responses and effects. This will also allow for mechanistic dissection and understanding of the different immune pathways involved in both SARS-CoV-2 pathogen and potential vaccine responses over time and how pre-existing memory responses, including potential anti-idiotype responses, can affect efficacy as well as potential off-target effects in different tissues as well as modeling PASC.

Association of the Magnitude of Anti-SARS-CoV-2 Vaccine Side Effects with Sex, Allergy History, Chronic Diseases, Medication Intake, and SARS-CoV-2 Infection

Vaccination provides the best protection against the increasing infections of SARS-CoV-2. The magnitude and type of anti-SARS-CoV-2 vaccine side effects (SEs) depend on parameters that are not fully understood. In this cross-sectional study, the associations between different anti-SARS-CoV-2 vaccine SEs and age, sex, the presence of chronic diseases, medication intake, history of allergies, and infections with SARS-CoV-2 were investigated. Our survey used the Google platform and had 866 participants, contacted through e-mails, social media and chain referral sampling (margin of error ≈ 4.38%, 99% confidence). More than 99% of the participants received the BNT162b2 and ChAdOx1-S vaccines. Being female, having chronic diseases, taking medicines routinely and the presence of a SARS-CoV-2 infection (p < 0.05) were associated with strong SEs after the BNT162b2 vaccine second dose. Having a history of allergies and a female sex (p < 0.01) were associated with strong SEs after the ChAdOx1-S vaccine second dose. Furthermore, the results reveal, for the first time, the associations between having a history of allergies, chronic diseases, medication usage, and SEs of a strong magnitude for the BNT162b2 and ChAdOx1-S vaccines. Additionally, this study supports the association of the female sex and infection with SARS-CoV-2 with an increased potential of developing stronger SEs with certain anti-SARS-CoV-2 vaccines.

AstraZeneca COVID-19 Vaccine and Diabetes Mellitus: A Prospective Clinical Study Regarding Vaccine Side Effects

Background Coronavirus disease 2019 (COVID-19) is a major public health problem worldwide, and vaccination is currently the most effective way to control its spread and reduce its severity. Diabetes mellitus (DM) is a prevalent chronic disease that poses a significant health risk and is a frequent comorbidity in COVID-19 patients. Therefore, this study aimed to assess the frequency of local and systemic side effects of the AstraZeneca vaccine among diabetic and non-diabetic participants. Methodology This multicenter study was designed as a cross-sectional prospective study and was conducted in Pakistan using a non-probability consecutive sampling method. The study duration was eight months from August 1, 2022, to March 31, 2023. A total of 700 participants who received both (first and second) doses of the AstraZeneca immunization were included in the study. An independent t-test was applied to determine the association between the means and standard deviations of age, height, weight, and duration of DM and hypertension. The chi-square test was used to evaluate the association between local and systemic side effects. Results Among the 700 participants, 173 (49.4%) males and 177 (50.6%) females had diabetes, whereas 183 (52.3%) males and 167 (47.7%) females did not have DM; their mean ages were 46.95 ± 12.73 years (diabetics) and 38.10 ± 14.14 years (non-diabetics). The most frequent adverse effects of the AstraZeneca vaccine after the first dose were pain at the injection site, reported by 259 (74.0%) diabetics and 226 (64.6%) non-diabetic participants; however, after the second dose, injection site swelling in 170 (48.6%) diabetic and 163 (46.6%) non-diabetic recipients was the most commonly reported local side effects. Conclusions This study concluded that concurrent medical conditions such as DM had substantially more local and systemic side effects than those without the disease. After receiving both doses of the AstraZeneca vaccine, the most frequently reported local side effects in both diabetic and non-diabetic participants were pain, swelling, and burning at the injection site, followed by systemic side effects such as fever.

Deciphering the Immunogenicity of Monkeypox Proteins for Designing the Potential mRNA Vaccine

The Monkeypox virus (MPXV), an orthopox virus, is responsible for monkeypox in humans, a zoonotic disease similar to smallpox. This infection first appeared in the 1970s in humans and then in 2003, after which it kept on spreading all around the world. To date, various antivirals have been used to cure this disease, but now, MPXV has developed resistance against these, thus increasing the need for an alternative cure for this deadly disease. In this study, we devised a reverse vaccinology approach against MPXV using a messenger RNA (mRNA) vaccine by pinning down the antigenic proteins of this virus. By using bioinformatic tools, we predicted prospective immunogenic B and T lymphocyte epitopes. Based on cytokine inducibility score, nonallergenicity, nontoxicity, antigenicity, and conservancy, the final epitopes were selected. Our analysis revealed the stable structure of the mRNA vaccine and its efficient expression in host cells. Furthermore, strong interactions were demonstrated with toll-like receptors 2 (TLR2) and 4 (TLR4) according to the molecular dynamic simulation studies. The in silico immune simulation analyses revealed an overall increase in the immune responses following repeated exposure to the designed vaccine. Based on our findings, the vaccine candidate designed in this study has the potential to be tested as a promising novel mRNA therapeutic vaccine against MPXV infection.

Adrenal Crisis Associated With COVID-19 Vaccination in Patients With Adrenal Insufficiency

Vaccination is generally recommended for patients with adrenal insufficiency receiving glucocorticoid replacement therapy because they are at risk of experiencing adrenal crisis during infections. Conventional vaccinations, such as those for influenza virus, have rarely been associated with adrenal crisis in patients with adrenal insufficiency; therefore, increasing the glucocorticoid dose during vaccination is not necessarily recommended. The COVID-19 mRNA vaccines exhibit a higher degree of adverse reactions, including fever and general fatigue, than those of conventional vaccines. Here, we present 3 cases of adrenal crisis associated with mRNA COVID-19 (BNT162b2) vaccination in patients with secondary adrenal insufficiency. Two patients presented with adrenal crisis after the second dose, whereas 1 presented with adrenal crisis after the first dose. Within 24 hours of vaccination, all patients presented with fatigue and appetite loss, and 2 patients were febrile. None of them increased their glucocorticoid dosage at the time of vaccination, leading to an adrenal crisis. To date, 9 cases of adrenal crisis, including ours, associated with COVID-19 vaccination have been reported. Considering the high degree of adverse reactions to COVID-19 vaccination, administration of prophylactic stress dose of glucocorticoids is strongly recommended, particularly in patients with symptomatic adverse reactions, to protect them from adrenal crisis.

Adverse events following immunisation (AEFI) of COVISHIELD vaccination among healthcare workers in Ghana

OBJECTIVE

To describe the incidence of adverse events following immunisation (AEFI) and determine the factors that affect the onset and duration of AEFI after COVISHIELD vaccination among healthcare workers.

DESIGN

Prospective cohort study.

SETTING

Tertiary healthcare, Korle-Bu, Ghana.

PARTICIPANT

Three thousand and twenty-two healthcare workers at least 18 years of age were followed up for 2 months after receiving two doses of the COVISHIELD vaccine.

PRIMARY OUTCOME

The occurrence of the AEFI was identified by self-reporting to the AEFI team members.

RESULTS

A total of 3022 healthcare workers had at least one AEFI (incidence rate of 706.0 (95% CI 676.8 to 736.1) per 1000 doses) with an incidence rate of 703.0 (95% CI 673.0 to 732.0) per 1000 doses for non-serious AEFI and an incidence rate of 3.3 (95% CI 1.6 to 6.1) per 1000 doses for serious AEFI. The most commonly reported systemic adverse events were headache (48.6%), fever (28.5%), weakness (18.4%) and body pains (17.9%). The estimated median time to onset of the AEFI following the first-dose vaccination was 19 hours and the median AEFI duration was 40 hours or 2 days. Delayed-onset AEFI occurred in 0.3% after first dose and 0.1% after second dose. Age, sex, previous SARS-CoV-2 infection, history of allergies and comorbidity were not significantly associated with the onset and duration of AEFI. However, participants who used paracetamol seemed to be significantly protected (HR 0.15; 95% CI 0.14, 0.17) from having a long duration of AEFI.

CONCLUSION

The results of our study indicate a high incidence of non-serious AEFI and the rare occurrence of serious AEFI after COVISHIELD vaccination in healthcare workers. The rate of AEFI was higher after the first dose than after the second dose. Sex, age, previous SARS-CoV-2 infection, allergies and comorbidity were not significantly associated with the onset and duration of AEFI.

Prevalence and risk factors of adverse effects after the first COVID-19 booster dose: evidence from Greece

Background

In general, COVID-19 vaccines are safe and effective, but minor adverse effects are common. However, adverse effects have not been measured in several countries including Greece.

Objective

To estimate the prevalence of adverse effects after the first COVID-19 booster dose, and to identify possible risk factors.

Material and methods

We conducted a cross-sectional study with a convenience sample in Greece during November 2022. We measured several adverse effects after the booster dose, such as fatigue, headaches, fever, chills, nausea, etc. We considered gender, age, chronic disease, self-assessment of health status, COVID-19 diagnóstico, and self-assessment of COVID-19 course as possible predictors of adverse effects.

Results

In our sample, 96% developed at least one adverse effect. Half of the participants (50.2%) developed one to five adverse effects, 35.9% developed six to ten adverse effects, and 9.5% developed 11 to 16 adverse effects. Mean number of adverse effects was 5.5. The most frequent adverse effects were pain at the injection site (84.3%), fatigue (70.8%), muscle pain (61%), swelling at the injection site (55.2%), headache (49.8%), fever (42.9%), and chills (41%). Females developed more adverse effects than males (p < 0.001). The prevalence of adverse effects of COVID-19 vaccines was statistically significant and positively associated with the severity of COVID-19 among COVID-recovered individuals (p < 0.05). Moreover, younger age was associated with increased adverse effects (p < 0.001).

Conclusions

Almost all participants in our study developed minor adverse effects after the booster dose. Female gender, COVID-19 patients with worse clinical course, and younger individuals experienced more often adverse effects.

Lysosomal nanotoxicity: Impact of nanomedicines on lysosomal function

Although several nanomedicines got clinical approval over the past two decades, the clinical translation rate is relatively small so far. There are many post-surveillance withdrawals of nanomedicines caused by various safety issues. For successful clinical advancement of nanotechnology, it is of unmet need to realize cellular and molecular foundation of nanotoxicity. Current data suggest that lysosomal dysfunction caused by nanoparticles is emerging as the most common intracellular trigger of nanotoxicity. This review analyzes prospect mechanisms of lysosomal dysfunction-mediated toxicity induced by nanoparticles. We summarized and critically assessed adverse drug reactions of current clinically approved nanomedicines. Importantly, we show that physicochemical properties have great impact on nanoparticles interaction with cells, excretion route and kinetics, and subsequently on toxicity. We analyzed literature on adverse reactions of current nanomedicines and hypothesized that adverse reactions might be linked with lysosomal dysfunction caused by nanomedicines. Finally, from our analysis it becomes clear that it is unjustifiable to generalize safety and toxicity of nanoparticles, since different particles possess distinct toxicological properties. We propose that the biological mechanism of the disease progression and treatment should be central in the optimization of nanoparticle design.

Side effects of Pfizer/BioNTech (BNT162b2) COVID-19 vaccine reported by the Birzeit University community

BACKGROUND

The Pfizer BioNTech COVID-19 vaccine was the first to receive emergency authorization and approval from the FDA. Therefore, it is preferred by most recipients; however, many people are concerned about the vaccine's side effects. At the time of the study, December 2021, Palestine lacked a national reporting system for monitoring adverse vaccine effects. Therefore, this study investigates the post-vaccine adverse events following the Pfizer/BioNTech COVID-19 Vaccine administration in Palestine and identifies the occurrence, extent, and severity among university staff, employees, and students at Birzeit University.

METHOD

A questionnaire-based retrospective cross-sectional study was conducted using a university website (Ritaj), social media platforms (e.g., Facebook and Telegram), and in-person interviews. The Chi-square, Fisher's exact, and McNemar's tests were used to investigate significant relationships. Data were analyzed using SPSS version 22.

RESULTS

In total, 1137 participants completed the questionnaire, 33.2% were males, and the mean age was 21.163 years. All participants received at least one dose of the Pfizer-BioNTech COVID-19 vaccine. Approximately one-third of participants reported no adverse effects after receiving the first, second, or third doses (34%, 33.6%, and 32.5%, respectively). The most commonly reported adverse events were fever, chills, headache, fatigue, pain and swelling at the injection site, muscle pain, and joint pain. Allergic reactions were reported by 12.7% of the participants; furthermore, participants with a history of allergy or anaphylaxis before vaccination had a significantly higher tendency for post-vaccination allergic reactions. Eight participants reported rare side effects, including 7 (0.6%) cases of thrombocytopenia and one (0.1%) case of myocarditis. Males aged less than 20 years and smokers were significantly less likely to complain of adverse events. The number of reported side effects was significantly higher after the second vaccine dose than after the first dose. Finally, participants infected with COVID-19 before vaccination was significantly associated with side effects such as fever, chills, shortness of breath, and persistent cough.

CONCLUSION

In this study, the most common post- BNT162b2 Vaccination reported self-limiting side effects similar to those reported by Pfizer/BioNTech Company. However, higher rates of allergic reactions were reported in this sample. Rare side effects, such as thrombocytopenia and myocarditis, were reported by 8 participants. COVID vaccines have been developed at an accelerated pace, and vaccine safety is a top priority; therefore, standard monitoring through a national adverse event reporting system is necessary for safety assurance. Continuous monitoring and long-term studies are required to ensure vaccine safety.

Covid-19 vaccination reported side effects and hesitancy among the Syrian population: a cross-sectional study

INTRODUCTION

Studying post-vaccination side effects and identifying the reasons behind low vaccine uptake are pivotal for overcoming the pandemic.

METHODS

This cross-sectional study was distributed through social media platforms and face-to-face interviews. Data from vaccinated and unvaccinated participants were collected and analyzed using the chi-square test, multivariable logistic regression to detect factors associated with side effects and severe side effects.

RESULTS

Of the 3509 participants included, 1672(47.6%) were vaccinated. The most common reason for not taking the vaccine was concerns about the vaccine's side effects 815(44.4). The majority of symptoms were mild 788(47.1%), followed by moderate 374(22.3%), and severe 144(8.6%). The most common symptoms were tiredness 1028(61.5%), pain at the injection site 933(55.8%), and low-grade fever 684(40.9%). Multivariable logistic regression analysis revealed that <40 years (vs. ≥40; OR: 2.113, p-value = 0.008), females (vs. males; OR: 2.245, p-value< .001), did not receive influenza shot last year (vs. did receive Influenza shot last year OR: 1.697, p-value = 0.041), AstraZeneca (vs. other vaccine brands; OR: 2.799, p-value< .001), co-morbidities (vs. no co-morbidities; OR: 1.993, p-value = 0.008), and diabetes mellitus (vs. no diabetes mellitus; OR: 2.788, p-value = 0.007) were associated with severe post-vaccine side effects. Serious side effects reported were blood clots 5(0.3%), thrombocytopenia 2(0.1%), anaphylaxis 1(0.1%), seizures 1(0.1%), and cardiac infarction 1(0.1%).

CONCLUSION

Our study revealed that most side effects reported were mild in severity and self-limiting. Increasing the public's awareness of the nature of the vaccine's side effects would reduce the misinformation and improve the public's trust in vaccines. Larger studies to evaluate rare and serious adverse events and long-term side effects are needed, so people can have sufficient information and understanding before making an informed consent which is essential for vaccination.

COVID-19 vaccination and liver disease

Various vaccines against severe acute respiratory syndrome coronavirus 2 have been developed in response to the coronavirus disease 2019 (COVID-19) global pandemic, several of which are highly effective in preventing COVID-19 in the general population. Patients with chronic liver diseases (CLDs), particularly those with liver cirrhosis, are considered to be at a high risk for severe COVID-19 and death. Given the increased rates of disease severity and mortality in patients with liver disease, there is an urgent need to understand the efficacy of vaccination in this population. However, the data regarding efficacy and safety of COVID-19 vaccination in patients with CLDs is limited. Indeed, several organ-specific or systemic immune-mediated side effects following COVID-19 vaccination, including liver injury similar to autoimmune hepatitis, have been recently reported. Although the number of cases of vaccine-related liver injury is increasing, its frequency, clinical course, and mechanism remain unclear. Here, we review the current findings on COVID-19 vaccination and liver disease, focusing on: (1) The impact of COVID-19 in patients with CLD; (2) The efficacy, safety, and risk-benefit profiles of COVID-19 vaccines in patients with CLD; and (3) Liver injury following COVID-19 vaccination.

Health Consequences of University Employees Post-COVID-19 Vaccination at Palestinian Universities

Introduction

The control of vaccine hesitancy comes with key protective measures against coronavirus disease (COVID-19) and excellent efficacy in clinical trials and effectiveness in real-world data. However, some people believe that vaccination is ineffective and it causes health problems. This study aimed to assess the health consequences of university employees' post-COVID-19 vaccination at Palestinian universities.

Method

A cross-sectional study was conducted between February and June 2021. A total of 310 university employees participated from six universities in Palestine. A self-reported questionnaire was used for data collection and included the following: personal characteristics of university employees, knowledge about COVID-19 vaccination, medical background of the participant, and their perception regarding receiving the COVID-19 vaccination.

Results

The results revealed that 32.6% and 43.2%of the participants had fever post the first and second doses, respectively. Also, 49.0% and 39.4% of them complained of exhaustion or fatigue and headache post the first dose and 58.1% and 46.1% had exhaustion or fatigue and pain in their muscles post the second dose, respectively. In addition, 29.2% and 16.7% of them had respiratory and digestive problems post the first dose and 38.9% and 19.0% had problems in respiratory and digestive respectively post the second dose. Furthermore, the analysis revealed that fever, symptoms at (the injection site), and exposure to physical symptoms have significant differences between the first dose and second doses of the vaccine (p < .001).

Conclusion

This study confirmed that the respiratory and digestive problems are the main problems post-COVID-19 vaccination. Also, this study confirmed that fever, symptoms at (the injection site), and exposure to physical symptoms have significant differences between the first dose and second dose of the vaccine.

Prevalence of side-effects associated with the booster dose of Pfizer-BioNTech (BNT162b2) of COVID-19 Vaccine among vaccinated adults in the Eastern province of Saudi Arabia

Background

Reports of local and systemic side-effects of COVID-19 vaccination may play an important role in public confidence in the acceptance of the COVID-19 vaccine booster dose.

Methods

We conducted a retrospective cross-sectional study among adults living in Eastern Province of Saudi Arabia. A link to the survey was distributed to community members via WhatsApp, SMS, or e-mail. Participants' general and demographic information was also collected, as well as information about any local and systemic side-effects reported following vaccination.

Results

A total of 370/390 (94.87%) of respondents reported one or more side-effects. Pain or redness at the site of injection (88.92%), fatigue (43.78%), body pain fever (37.84%), and headache (15.95%) were the most commonly reported side-effects. Moreover, 2.43% of the participants reported side-effects needed to see a physician; only four were admitted to the hospital. The non-healthcare respondents (n=273 (97.15%), OR (95% CI) = 5.22 (2.02, 13.48, P <0.001) were more likely to report side-effects compared to the healthcare related respondents (n=36 (85.71%), OR (95% CI) = 0.25 (0.10, 0.70), P=0.013).

Conclusion

According to this study, the Pfizer-BioNTech (BNT162b2) COVID-19 vaccine was safe when given to Saudi Arabian adults. All reported side-effects were mild to moderate. The findings will likely persuade vaccine-hesitant individuals and pessimists to accept booster dose of COVID-19 vaccine.

A retrospective evaluation of side-effects associated with the booster dose of Pfizer-BioNTech/BNT162b2 COVID-19 vaccine among females in Eastern Province, Saudi Arabia

BACKGROUNDS

The development of several types of vaccines to avert COVID-19 has taken place. Despite several reports of undesirable reactions noted post-COVID-19 vaccine administration, later remains one of the best prevention and management tools in fighting the spread of the virus and its variants and reducing the harshness of this viral attack. The purpose of the current paper was to explore the side-effects experienced by the females in the Eastern Province of Saudi Arabia directly after receiving the booster dose of the Pfizer-BioNTech/BNT162b2 COVID-19 vaccine.

METHODS

A descriptive cross-sectional study among adults living in the East-ern Province, Saudi Arabia was applied. A survey link was, distributed through WhatsApp, SMS, or e-mail to community members. Respondent's demographic information was acquired, as well as information about any local and systemic side-effects reported following booster dose of BioNTech/BNT162b2 COVID-19 vaccine.

RESULTS

A total of 72.36% (432/597) of the respondents who participated in this study reported at least one side-effect. Pain and redness at the injection site (75.93%), myalgia (71.99%), headache (53.24%), fever (33.56%), and fatigue (43.78%) were the highest frequently stated side-effects. Furthermore, 9.25% of the respondents had to see a physician due to side effects, plus merely four participants were admitted to the hospital. The respondents working in the non-healthcare-related sector had a 1.677-fold more possibility of side effects in comparison with the other respondents (adjusted odds ratio = 1.677; 95% CI = 1.363, 2.064).

CONCLUSIONS

All reported side-effects were mild to moderate. These findings might persuade pessimists and refusers to get the COVID-19 vaccine. Myalgia and pain or redness at the site of injection were the most common reported side-effects in our study.

A systemic review and recommendation for an autopsy approach to death followed the COVID 19 vaccination

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) started in December 2019. An immediate prevention approach for the outbreak is the development of a vaccination program. Despite a growing number of publications showing the effectiveness of vaccination in preventing SARS-CoV-2 outbreak and reducing the mortality rate, substantial fatal adverse effects were reported after vaccination. Confirmation of the causal relationship of death is required to reimburse under the national vaccination program and could provide a reference for the selection of vaccination. However, a lack of guidelines in the laboratory study and autopsy approach hampered the investigation of post-vaccination death. In this paper, we performed a systematic electronic search on scientific articles related to severe Covid-19 vaccination adverse effects and approaches in identifying the severe side effects using PubMed and Cochrane libraries. A summary on the onset, biochemistry changes and histopathological analyzes of major lethally side effects post-vaccination were discussed. Ultimately, a checklist is suggested to improve the quality of investigation.

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.

Common adverse events following immunization with the COVID-19 comirnaty vaccine (Pfizer-BioNTech) among adult population in Hanoi, Vietnam, 2021

Rationale

To prevent and control the COVID-19 pandemic, the biggest immunization campaign in history had been deployed worldwide. Therefore, it is important to inform the adverse events following immunization (AEFI) to populations.

Objectives

To prevent vaccine hesitancy, this study focused on finding the common AEFI with the COVID-19 Comirnaty vaccine (Pfizer-BioNTech) among participants aged 18 and above and related factors in Hanoi, Vietnam.

Methods

A cross-sectional study was carried out to collect participants’ data and AEFI after being vaccinated at Hanoi Medical University, Vietnam, in 2021. Logistic regression was utilized for analyzing the correlated factors of AEFI.

Results

We recruited a random sample of 820 participants who received both basic doses of Pfizer vaccine in September and October 2021. The proportion of AEFI after the first dose, second dose, and both doses of Pfizer vaccine was 24.4%, 64.2%, and 18.5%, respectively. AEFI mostly appeared within 1 day and lasted for 1 to 2 days. The AEFI were more common in females (OR=1.7; 95%CI=1.25–2.29) and younger age groups (OR=1.9; 95%CI=1.37–2.58). History of allergy, allergic diseases, chronic diseases, and occupations were not statistically significant with AEFI.

Conclusion

Our findings indicated that the COVID-19 Comirnaty vaccine is safe to be injected. Gender and age group are important factors influencing AEFI.

Evaluation of Prevalence of Side-Effects Associated with Booster Dose of mRNA-Based COVID-19 Vaccine Among Healthcare Workers in Eastern Province, Saudi Arabia: A Descriptive Cross-Sectional Study

Background

The purpose of this study was to examine the mild and moderate side-effects experienced by the healthcare workers (HCWs) in the Eastern Province of Saudi Arabia after receiving the booster dose of the Pfizer-BioNTech/BNT162b2 COVID-19 vaccine.

Methods

We directed a descriptive cross-sectional study among adults living in the Eastern Province of Saudi Arabia. A survey link was distributed through WhatsApp, SMS, or e-mail to HCWs. Participants' general and demographic information were also collected, as well as information about any local and systemic side-effects reported following vaccination.

Results

The results of this study showed that 81.84% (401/490) of the HCWs who contributed to this study reported the minimum COVID-19 post-vaccination side-effect. Body pain (89%) and pain at the site of injection (88.73%) were the most frequent frequently reported side-effects, followed by headache (28.68%), joint or bone pain (27.18%), muscle pain (26.43%), nausea or vomiting (21.2%), fever (18.95%), skin rashes (10.22%). History of chronic diseases had a 0.44-fold increased risk of side-effects compared to no history of chronic diseases HCWs (adjusted odds ratio (aOR) = 0.44; 95% CI = 0.224, 0.880), and significant association of occupation with side-effects was also 1.61-fold increased risk compared to nonmedical ((aOR) = 1.61; 95% CI = 1.037, 2.513).

Conclusion

According to this study, the Pfizer-BioNTech/BNT162b2 COVID-19 vaccine was safe when given to Saudi Arabian HCWs. All reported side-effects were mild to moderate. The outcomes indicated that most participants had body pain and pain at the site of injection and fatigue is among the least reported side-effect post-booster dose. Healthcare was highly connected with more reporting of side-effects.

Adverse reactions to the first and second doses of Pfizer-BioNTech COVID-19 vaccine among healthcare workers

INTRODUCTION

In the current coronavirus infection 2019 (COVID-19) pandemic, the messenger RNA vaccines have been shown to help protect high-risk groups from COVID-19. Among healthcare workers vaccinated with Pfizer-BioNTech COVID-19 vaccine, a survey was conducted to analyze the relationship between the incidence and severity of adverse reactions after vaccination.

METHODS

We conducted a prospective self-reported survey of adverse reactions among healthcare workers vaccinated with the Pfizer-BioNTech COVID-19 vaccine (Comirnaty®) in Japan. After the first and second dose of vaccine, local and systemic reactions for 8 days after vaccination were reported by volunteer participants using a website. After receiving vaccination, 374 respondents participated in this matched-pair study.

RESULTS

Both the incidence and severity of adverse reactions tended to be higher after the second vaccine dose than after the first dose. However, the incidence and numeric rating scale (NRS) score of muscle and skin pain were nearly the same after the first and second doses. In a comparison by sex, women had significantly higher incidence and NRS scores for adverse reactions such as headache, skin pain, erythema, and itching. The results also showed that younger age groups had higher incidence rates and NRS scores for all adverse reactions investigated, except for muscle pain, compared with older age groups.

CONCLUSION

Some adverse reactions to the Pfizer-BioNTech Comirnaty® COVID-19 vaccine showed gender and age differences. However, generally speaking, all side reactions disappear within a week. Therefore, these side reactions are not a significant concern in recommending vaccination.

Adverse effect investigation using application software after vaccination against SARS-CoV-2 for healthcare workers

INTRODUCTION

The usefulness of smartphone-based application software as a way to manage adverse events (AEs) after vaccination is well known. The purpose of this study is to clarify the usefulness and precautions of employing a smartphone application for collecting AEs after the administration of Comirnaty®️.

METHODS

Healthcare workers (HCWs) who were vaccinated with Comirnaty®️ were asked to register for the application software and to report AEs for 14 days after vaccination. AEs were self-reported according to severity. The software was set to output an alert in case of fever.

RESULTS

The number of HCWs who received the first dose was 2,551, and 2,406 (94.3%) reported their vaccinations. 2,547 received the second dose, and 2,347 (92.1%) reported their vaccinations. With the first dose, the reporting rate stayed above 83.3% until the final day. On the other hand, that of the second dose decreased rapidly after 6 days. The most frequent symptom was "pain at injection site" (more than 70%). Severe AEs were 6.6% after the second dose, with 0.6% visiting a clinic. Many AEs peaked on the day after administration and disappeared within 1 week. There were few reports of fever.

CONCLUSION

Smartphone applications can be used to collect information on AEs after vaccination. Application settings and dissemination are necessary to maintain the reporting rate of HCWs.

Vaccines and myasthenia gravis: a comprehensive review and retrospective study of SARS-CoV-2 vaccination in a large cohort of myasthenic patients

Introduction

Myasthenia gravis (MG) is an autoimmune disease, for which the risk of exacerbation after vaccines is debated. The aim of this study is to review the available literature concerning safety and efficacy of vaccines in MG. In addition, we also conducted a retrospective research of MG exacerbations and new onset MG after anti-SARS-CoV-2 vaccination in a large cohort of patients.

Methods

A study of the available literature regarding vaccines and MG was carried out through research in the online database “Pubmed”. We also retrospectively collected data from 80 MG patients, who were followed at the Treviso Hospital and completed an anti-SARS-CoV-2 vaccination cycle. For each patient, we recorded MG exacerbations between first and second doses and within a window period of 1 day – 6 weeks after the second dose.

Results

We found 26 relevant articles about influenza, SARS-CoV-2 and other vaccines. No clear associations between most vaccines and MG exacerbations were found. Moreover, cases of new onset post-vaccine MG are mostly anecdotal, except for Japanese encephalitis virus vaccine. Concerning our cohort, 4/80 (5%) MG patients experienced an exacerbation within the post-vaccine window period. In addition, we report a case of new onset post-vaccine MG.

Discussion

Inactivated and subunit vaccines are safe and effective in MG. Although some of them, such as anti-SARS-CoV-2 vaccine, might uncommonly cause MG exacerbations, data from our review suggest that benefits still outweigh by far the potential risks, thus they should be recommended to these patients. Nevertheless, large prospective studies are needed for further investigations.

Headache onset after vaccination against SARS-CoV-2: a systematic literature review and meta-analysis

Background

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are used to reduce the risk of developing Coronavirus Disease 2019 (COVID-19). Despite the significant benefits in terms of reduced risk of hospitalization and death, different adverse events may present after vaccination: among them, headache is one of the most common, but nowadays there is no summary presentation of its incidence and no description of its main features.

Methods

We searched PubMed and EMBASE covering the period between January 1^st 2020 and August 6^th, 2021, looking for record in English and with an abstract and using three main search terms (with specific variations): COVID-19/SARS-CoV-2; Vaccination; headache/adverse events. We selected manuscript including information on subjects developing headache after injection, and such information had to be derived from a structured form (i.e. no free reporting). Pooled estimates and 95% confidence intervals were calculated. Analyses were carried out by vaccine vs. placebo, by first vs. second dose, and by mRNA-based vs. “traditional” vaccines; finally, we addressed the impact of age and gender on post-vaccine headache onset.

Results

Out of 9338 records, 84 papers were included in the review, accounting for 1.57 million participants, 94% of whom received BNT162b2 or ChAdOx1. Headache was generally the third most common AE: it was detected in 22% (95% CI 18–27%) of subjects after the first dose of vaccine and in 29% (95% CI 23–35%) after the second, with an extreme heterogeneity. Those receiving placebo reported headache in 10–12% of cases. No differences were detected across different vaccines or by mRNA-based vs. “traditional” ones. None of the studies reported information on headache features. A lower prevalence of headache after the first injection of BNT162b2 among older participants was shown.

Conclusions

Our results show that vaccines are associated to a two-fold risk of developing headache within 7 days from injection, and the lack of difference between vaccine types enable to hypothesize that headache is secondary to systemic immunological reaction than to a vaccine-type specific reaction. Some descriptions report onset within the first 24 h and that in around one-third of the cases, headache has migraine-like features with pulsating quality, phono and photophobia; in 40–60% of the cases aggravation with activity is observed. The majority of patients used some medication to treat headache, the one perceived as the most effective being acetylsalicylic acid.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01400-4.

Adverse Events Following BNT162b2 mRNA COVID-19 Vaccine Immunization among Healthcare Workers in a Tertiary Hospital in Johor, Malaysia

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), or 2019 coronavirus disease (COVID-19), was declared as pandemic in early 2020. While several studies reported the short-term adverse events (AE) of the mRNA COVID-19 vaccines, medium-term AE have not been extensively evaluated. This study aimed to evaluate the 6-month side effect profiles of the BNT162b2 mRNA vaccine. Methods: This was a descriptive cross-sectional study conducted in a tertiary hospital. Hospital workers who received two doses of the Cominarty (BNT162b2) mRNA vaccine, six months post-vaccination, were invited to participate in this study. All participants completed a self-reported survey assessing AEs occurrence and severity, duration of onset and recovery and if they previously reported these AEs. Results: Of the 670 respondents who completed the survey, 229 (34.2%) experienced at least one AEs, with a total of 937 AEs reported during the 6-month period. After the first dose, the most common reported localized symptoms were pain (n = 106, 27.2%), swelling (n = 38, 9.8%) and erythematous (n = 12, 3.1%) at injection site. Systemic symptoms reported include fatigue (n = 72, 18.5%), fever (n = 55, 14.1%) and headache (n = 46, 11.8%). After the second dose, pain at site of injection (n = 112, 20.4%), swelling (n = 42, 7.7%) and erythematous (n = 14, 2.6%) were among the localized AE reported, while fever (n = 121, 22.1%), fatigue (n = 101, 18.4%) and headache (n = 61, 11.1%) were the most common systemic AE. The proportion of respondents who experienced moderate (first dose: 156 events; second dose: 272 events) and severe (1st dose: 21 events; 2nd dose: 30 events) AEs were higher after the second dose. Most AEs commonly resolved within 1–2 days, and none required hospitalization. No new onset of AE was observed 7 days post-vaccination. A total of 137 (59.8%) participants did not proceed to formal AE reporting. Conclusion: Most of the AEs reported were of mild to moderate intensity and short-term, consistent with those reported in previous studies. No medium-term finding was detected in the survey. AE reporting was not routinely performed, necessitating the attention of health authorities in order to enhance pharmacovigilance.

Impact of a delayed second dose of mRNA vaccine (BNT162b2) and inactivated SARS-CoV-2 vaccine (CoronaVac) on risks of all-cause mortality, emergency department visit, and unscheduled hospitalization

BACKGROUND

Safety after the second dose of the SARS-CoV-2 vaccine remains to be elucidated, especially among individuals reporting adverse events after their first dose. This study aims to evaluate the impact of a delayed second dose on all-cause mortality and emergency services.

METHODS

A territory-wide, retrospective cohort of people who had completed two doses of mRNA (BNT162b2) or inactivated SARS-CoV-2 (CoronaVac) vaccine between February 23 and July 3, 2021, in Hong Kong was analyzed, with linkage to electronic health records retrieved from the Hong Kong Hospital Authority. Vaccine recipients were classified as receiving a second dose within recommended intervals (21-28 days for BNT162b2; 14-28 days for CoronaVac) or delayed. Study outcomes were all-cause mortality, emergency department (ED) visits, and unscheduled hospitalizations within 28 days after the second dose of vaccination.

RESULTS

Among 417,497 BNT162b2 and 354,283 CoronaVac second dose recipients, 3.8% and 28.5% received the second dose beyond the recommended intervals (mean 34.4 and 31.8 days), respectively. During the study period, there were < 5 daily new cases of COVID-19 infections in the community. Delaying the second dose was not associated with all-cause mortality (hazard ratio [HR] = 1.185, 95% CI 0.478-2.937, P = 0.714), risk of ED visit (HR = 0.966, 95% CI 0.926-1.008, P = 0.113), and risk of unscheduled hospitalization (HR = 0.956, 95% CI 0.878-1.040, P = 0.294) compared to that within the recommended interval for CoronaVac recipients. No statistically significant differences in all-cause mortality (HR = 4.438, 95% CI 0.951-20.701, P = 0.058), ED visit (HR = 1.037, 95% CI 0.951-1.130, P = 0.411), and unscheduled hospitalization (HR = 1.054, 95% CI 0.867-1.281, P = 0.597) were identified between people who received a second dose of BNT162b2 within and beyond the recommended intervals.

CONCLUSIONS

No significant association between delayed second dose of BNT162b2 or CoronaVac and all-cause mortality, ED visit, and unscheduled hospitalization was observed in the present cohort. Regardless of the recommended or delayed schedule for SARS-CoV-2 vaccination, a second dose of both vaccines should be administered to obtain better protection against infection and serious disease. The second dose should be administered within the recommended interval following the manufacturer's product information, until further studies support the benefits of delaying vaccination outweighing the risks.

Reported Adverse Effects and Attitudes among Arab Populations Following COVID-19 Vaccination: A Large-Scale Multinational Study Implementing Machine Learning Tools in Predicting Post-Vaccination Adverse Effects Based on Predisposing Factors

Background: The unprecedented global spread of coronavirus disease 2019 (COVID-19) has imposed huge challenges on the healthcare facilities, and impacted every aspect of life. This has led to the development of several vaccines against COVID-19 within one year. This study aimed to assess the attitudes and the side effects among Arab communities after receiving a COVID-19 vaccine and use of machine learning (ML) tools to predict post-vaccination side effects based on predisposing factors. Methods: An online-based multinational survey was carried out via social media platforms from 14 June to 31 August 2021, targeting individuals who received at least one dose of a COVID-19 vaccine from 22 Arab countries. Descriptive statistics, correlation, and chi-square tests were used to analyze the data. Moreover, extensive ML tools were utilized to predict 30 post vaccination adverse effects and their severity based on 15 predisposing factors. The importance of distinct predisposing factors in predicting particular side effects was determined using global feature importance employing gradient boost as AutoML. Results: A total of 10,064 participants from 19 Arab countries were included in this study. Around 56% were female and 59% were aged from 20 to 39 years old. A high rate of vaccine hesitancy (51%) was reported among participants. Almost 88% of the participants were vaccinated with one of three COVID-19 vaccines, including Pfizer-BioNTech (52.8%), AstraZeneca (20.7%), and Sinopharm (14.2%). About 72% of participants experienced post-vaccination side effects. This study reports statistically significant associations (p < 0.01) between various predisposing factors and post-vaccinations side effects. In terms of predicting post-vaccination side effects, gradient boost, random forest, and XGBoost outperformed other ML methods. The most important predisposing factors for predicting certain side effects (i.e., tiredness, fever, headache, injection site pain and swelling, myalgia, and sleepiness and laziness) were revealed to be the number of doses, gender, type of vaccine, age, and hesitancy to receive a COVID-19 vaccine. Conclusions: The reported side effects following COVID-19 vaccination among Arab populations are usually non-life-threatening; flu-like symptoms and injection site pain. Certain predisposing factors have greater weight and importance as input data in predicting post-vaccination side effects. Based on the most significant input data, ML can also be used to predict these side effects; people with certain predicted side effects may require additional medical attention, or possibly hospitalization.

Impact of age, sex and medical history on adverse reactions to the first and second dose of BNT162b2 mRNA COVID-19 vaccine in Japan: a cross-sectional study

BACKGROUND

Vaccines for coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are being promoted worldwide. In this study, we analyzed the relationship between adverse reactions and the profile of vaccinated recipients.

METHODS

Vaccinated subjects who received two doses of BNT162b2 between May 17 and June 11, 2021, at Osaka University Dental Hospital were included in this study. Adverse reactions and profiles were collected by questionnaires, and the relationship between the presence of adverse reactions and the profiles of the vaccinated persons was analyzed by logistic regression analysis. The correlation between the severity of adverse reactions and age was analyzed by Spearman's rank correlation.

RESULTS

Logistic regression analysis showed that, for many kinds of adverse reactions, the incidence was significantly higher in females than in males and in younger than in older people. There was a very weak but significant negative correlation between age and the severity of many kinds of adverse reactions. The relationship between sex and the incidence of each adverse reaction was significant for injection site reactions and fatigue in the first vaccination, whereas significant relationships were found for fatigue, chills, fever, arthralgia, myalgia and headache in the second vaccination, all of which were clearly more likely to occur in females.

CONCLUSION

Adverse reactions to BNT162b2 were found to be more frequent and more intense in females and younger people in Japan, especially after the second vaccination.

Adverse Reactions to Anti-SARS-CoV-2 Vaccine: A Prospective Cohort Study Based on an Active Surveillance System

To date, Coronavirus disease (COVID-19) has caused high morbidity and mortality worldwide. To counteract the pandemic scenario, several vaccines against the etiological factor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were developed and tested. At the end of December 2020, BNT162b2 (Comirnaty, Pfizer-BioNTech) was the first and only authorized vaccine in Italy for selected categories, such as healthcare workers, fragile patients and people aged over 80 years old. To master our knowledge about BNT162b2 adverse reactions (ARs), an active surveillance system based on instant messaging was realized for voluntary participants who had been vaccinated at COVID-19 Vaccination Center of the Palermo University Hospital. Overall, 293 vaccinated persons were included in this study, which were more frequently healthcare workers (n = 207, 70.6% with a median age of 36 years, IQR = 29−55) followed by health professional students (n = 31, 10.6% with a median age of 27 years, IQR = 25−29), reporting 82.6% of at least one local or systemic AR. In details, the frequency of at least one local or systemic AR after the second dose of Comirnaty (n = 235, 80.2%) was statistically significant with higher value in comparison to the first one (n = 149, 50.9%; p < 0.001). However, local pain, swelling, joint pain and muscular pain after the second dose were the symptom causing a statistically significant working limitation. The youngest persons showed a higher risk to have either local or systemic ARs (aOR = 7.5, CI 95% = 2.9−18.9), while females had a higher risk of having systemic ARs (aOR = 1.8, CI 95% = 1.1−3.0). Despite the small sample examined, this active surveillance system by instant messaging seems to detect a higher ARs prevalence with respect to data obtained by the passive surveillance. Further studies could be required in order to optimize this clinical monitoring that could be considered an efficient and timely active surveillance.

Acute pancreatitis soon after COVID-19 vaccination: A case report

RATIONALE

In response to the global coronavirus infectious disease 2019 (COVID-19) pandemic, several vaccines against severe acute respiratory syndrome coronavirus 2 have been developed. Although many infrequent side effects of COVID-19 mRNA vaccine have been reported, only a few cases of pancreatitis have been reported.

PATIENT CONCERNS

A 71-year-old woman was presented to the hospital with upper abdominal pain and vomiting. She had no history of alcohol consumption, pancreatitis, or allergic reactions to vaccines. She had received the first dose of the Pfizer/BioNTech COVID-19 mRNA vaccine 2 days prior to her current presentation. Laboratory tests revealed elevated serum pancreatic enzymes. An abdominal computed tomography scan showed diffuse enlargement of the pancreas with fat stranding extending to below the kidneys bilaterally.

DIAGNOSIS

The patient was diagnosed with acute pancreatitis.

INTERVENTIONS

The patient was treated with the administration of intravenous antimicrobials, proteolytic enzyme inhibitors, and proton pump inhibitors.

OUTCOMES

The patient had an uneventful recovery with no complications.

LESSONS

Acute pancreatitis can develop shortly after COVID-19 mRNA vaccination. Therefore, of great importance to differentiate acute pancreatitis when abdominal pain occurs after COVID-19 mRNA vaccination.

Perceptions and Experiences of COVID-19 Vaccine Side-Effects Among Healthcare Workers in Southern Ethiopia: A Cross-Sectional Study

Background

We examined the perceptions of healthcare workers about the side-effects of COVID-19 vaccine and the types of side-effects they experienced in the post-vaccination period.

Methods

An institutional-based cross-sectional survey research design was used in which a semi-structured questionnaire was distributed to collect quantitative data from healthcare workers in Southern Ethiopia that were selected on the basis of a multi-stage cluster sampling technique. After inserting the completed cases into SPSS software, descriptive statistical techniques, such as frequencies, percentages, charts and inferential statistical tool, particularly binary logistic regression analysis, were used to analyze and present the data.

Results

Majority (43.6%) of respondents perceive that COVID-19 vaccine will have muscle pain around the injection site, followed by fever (39.9%), problems of blood clots (37.8%), headache (35.6%), fatigue (33.5%), and aching limbs (16%). And 63.6%) of them reported that they have experienced muscle pain around the injection site after receiving the COVID-19 vaccine, followed by fatigue (42%), headache (37.2%), fever (34.2%), redness around the injection site (21.6%), and swelling around the injection site (17.8%). Moreover, 25% reported that the fear of potential side-effects of COVID-19 vaccine inhibited them from taking the vaccine. Above all, it is found that respondents’ expectation of COVID-19 vaccine to have such serious side-effects is significantly associated to their educational status (OR = 0.229; P < 0.01; 95%C.I.: 0.080–0.651).

Conclusion

While the expectations of most of the healthcare workers regarding the side-effects of the vaccine are parallel to the normal reactions of the vaccine, a significant proportion of the study participants have reported that they perceive COVID-19 vaccine will have life-threatening side-effects. Such fears have also played a role in affecting vaccine uptake. Therefore, the Ministry of Health, and other concerned government bodies should create further awareness on COVID-19 vaccine and related safety issues.

Side Effects of COVID-19 Pfizer-BioNTech mRNA Vaccine in Children Aged 12-18 Years in Saudi Arabia

Background: Massive vaccination campaigns have been undertaken globally to combat the spread of the Coronavirus Disease 2019 (COVID-19). While most COVID-19 vaccines have shown excellent efficacy and safety profiles in clinical studies, real-world monitoring of vaccine safety is still important. In this study, we aimed to investigate the early side effects of Pfizer-BioNTech (BNT162b2) mRNA vaccine in children between 12–18 years old in Saudi Arabia. Method: To investigate the side effects in children in this age range following the administration of either one or two doses of Pfizer-BioNTech (BNT162b2) mRNA vaccine, we conducted a retrospective, cross-sectional study using a self-administered online survey. General and demographic data were collected, and vaccine-associated side effects following vaccination were evaluated. Results: The study recruited a total of 965 eligible participants. Overall, 571 (60%) of the study participants reported at least one side effect following Pfizer-BioNTech (BNT162b2) mRNA vaccination. The most frequently reported side effects were pain or redness at the site of injection (90%), fatigue (67%), fever (59%), headache (55%), nausea or vomiting (21%), and chest pain and shortness of breath (20%). Joint or bone pain were reported less frequently among our participants (2%). Our data showed that more female participants reported side effects compared to male participants, with 52% and 48%, respectively. Side effects were more common after the second dose compared to the first dose in our study cohort. Conclusions: While 60% of the children (12–18 years old) who received Pfizer-BioNTech (BNT162b2) mRNA vaccine reported side effects, our data showed that these side effects were not different from those that were reported in the clinical trials which lasted only for a few days. Side effects were more common after the second dose. Larger epidemiological and molecular studies are needed to evaluate the safety and the effectiveness of COVID-19 vaccine in protection of children against SARS-CoV-2 reinfections.

Active Surveillance of Adverse Events in Healthcare Workers Recipients After Vaccination with COVID-19 BNT162b2 Vaccine (Pfizer-BioNTech, Comirnaty): A Cross-Sectional Study

In this cross-sectional study, adverse events after the first and second dose of BNT162b2 mRNA (Pfizer-BioNTech, Comirnaty) vaccine against coronavirus disease 2019 were investigated among employees of clinics in central Italy. A 42-items questionnaire was administrated to vaccine recipients. Adverse events were classified based on severity and occurrence as reported in the literature. A descriptive/univariate analysis using Chi-square or Fisher’s Exact tests was performed. Odds ratio (OR) and 95% confidence intervals were calculated to assess risk factors. 340 individuals (61.5% females; median age 49 years) participated. Adverse events were reported by 279 (82%) and 281 (82.6%) individuals as induced by the first and second dose, respectively. Mild reactions were mainly reported (80.9% and 80.3%), followed by moderate (11.8% and 37.1%) and severe (3.8% and 4.7%). Adverse events were identical to those already described as very common (81.8% and 80.6%), although vaccine-coincidental events not cited in the literature were reported by 6% and 15.6% following each dose. Age ≤ 55 years was a risk factor for any adverse event after each injection (ORs: 2.942 and 2.818), as well as female sex for those mild (ORs: 1.856 and 2.818) and common (ORs: 3.452 and 2.145). Findings were consistent with national reports as most of the adverse events were mild and associated with female sex and young age, while investigations are needed for reactions not described elsewhere. Data are useful to support the vaccine safety profile, also because largely targeted healthcare personnel more skilled than general population in self-diagnosis of health-related issues.

Adverse Events Following One Dose of mRNA COVID-19 Vaccination Among US Nursing Home Residents With and Without a Previous SARS-CoV-2 Infection

OBJECTIVES

To compare rates of adverse events following Coronavirus Disease 2019 (COVID-19) vaccination among nursing home residents with and without previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

DESIGN

Prospective cohort.

SETTING AND PARTICIPANTS

A total of 20,918 nursing home residents who received the first dose of messenger RNA COVID-19 vaccine from December 18, 2020, through February 14, 2021, in 284 facilities within Genesis Healthcare, a large nursing home provider spanning 24 US states.

METHODS

We screened the electronic health record for adverse events, classified by the Brighton Collaboration, occurring within 15 days of a resident's first COVID-19 vaccine dose. All events were confirmed by physician chart review. To obtain risk ratios, multilevel logistic regression model that accounted for clustering (variability) across nursing homes was implemented. To balance the probability of prior SARS-CoV-2 infection (previous positive test or diagnosis by the International Classification of Diseases, 10^th Revision, Clinical Modification) more than 20 days before vaccination, we used inverse probability weighting. To adjust for multiplicity of adverse events tested, we used a false discovery rate procedure.

RESULTS

Statistically significant differences existed between those without (n = 13,163) and with previous SARS-CoV-2 infection [symptomatic (n = 5617) and asymptomatic (n = 2138)] for all baseline characteristics assessed. Only 1 adverse event was reported among those with previous SARS-CoV-2 infection (asymptomatic), venous thromboembolism [46.8 per 100,000 residents 95% confidence interval (CI) 8.3-264.5], which was not significantly different from the rate reported for those without previous infection (30.4 per 100,000 95% CI 11.8-78.1). Several other adverse events were observed for those with no previous infection, but were not statistically significantly higher than those reported with previous infection after adjustments for multiple comparisons.

CONCLUSIONS AND IMPLICATIONS

Although reactogenicity increases with preexisting immunity, we did not find that vaccination among those with previous SARS-CoV-2 infection resulted in higher rates of adverse events than those without previous infection. This study stresses the importance of monitoring novel vaccines for adverse events in this vulnerable population.

To Be or Not To Be Vaccinated: That Is a Question in Myasthenia Gravis

Myasthenia gravis (MG) is an autoimmune disease characterized by muscle weakness and abnormal fatigability due to the antibodies against postsynaptic receptors. Despite the individual discrepancy, patients with MG share common muscle weakness, autoimmune dysfunction, and immunosuppressive treatment, which predispose them to infections that can trigger or exacerbate MG. Vaccination, as a mainstay of prophylaxis, is a major management strategy. However, the past years have seen growth in vaccine hesitancy, owing to safety and efficacy concerns. Ironically, vaccines, serving as an essential and effective means of defense, may induce similar immune cross-reactivity to what they are meant to prevent. Herein, we outline the progress in vaccination, review the current status, and postulate the clinical association among MG, vaccination, and immunosuppression. We also address safety and efficacy concerns of vaccination in MG, in relation to COVID-19. Since only a handful of studies have reported vaccination in individuals with MG, we further review the current clinical studies and guidelines in rheumatic diseases. Overall, our reviews offer a reference to guide future vaccine clinical decision-making and improve the management of MG patients.