Safety of COVID-19 Vaccines Among the Paediatric Population: Analysis of the European Surveillance Systems and Pivotal Clinical Trials.

BACKGROUND AND OBJECTIVES: The European Medicine Agency extended the use of Comirnaty, Spikevax, and Nuvaxovid in paediatrics; thus, these vaccines require additional real-world safety evidence. Herein, we aimed to monitor the safety of COVID-19 vaccines through Covid-19 Vaccine Monitor (CVM) and EudraVigilance surveillance systems and the published pivotal clinical trials. METHODS: In a prospective cohort of vaccinees aged between 5 and 17 years, we measured the frequency of commonly reported (local/systemic solicited) and serious adverse drug events (ADRs) following the first and second doses of COVID-19 vaccines in Europe using data from the CVM cohort until April 2022. The results of previous pivotal clinical trials and data in the EudraVigilance were also analysed. RESULTS: The CVM study enrolled 658 first-dose vaccinees (children aged 5-11 years; n = 250 and adolescents aged 12-17 years; n = 408). Local/systemic solicited ADRs were common, whereas serious ADRs were uncommon. Among Comirnaty first and second dose recipients, 28.8% and 17.1% of children and 54.2% and 52.2% of adolescents experienced at least one ADR, respectively; injection-site pain (29.2% and 20.7%), fatigue (16.1% and 12.8%), and headache (22.1% and 19.3%) were the most frequent local and systemic ADRs. Results were consistent but slightly lower than in pivotal clinical trials. Reporting rates in Eudravigilance were lower by a factor of 1000. CONCLUSIONS: The CVM study showed high frequencies of local solicited reactions after vaccination but lower rates than in pivotal clinical trials. Injection-site pain, fatigue, and headache were the most commonly reported ADRs for clinical trials, but higher than spontaneously reported data.

Preliminary results of COVID-19 vaccination among Taiwanese pregnant women: A single-center, prospective, case-control study.

OBJECTIVE: To evaluate the impacts of messenger RNA coronavirus disease 2019 (COVID-19) vaccines in Taiwanese pregnant women in terms of obstetrical and neonatal outcomes. METHODS: The authors prospectively followed up 450 pregnant women receiving vaccination at a single center. Patients recorded prespecified adverse reactions via a mobile application up to 30 days after the first and second doses. Obstetrical and neonatal outcomes were compared with those of pregnant women, during the same period, who did not undergo vaccination. RESULTS: Among the 387 women who received the first dose and were followed up for 30 days, injection site pain, fatigue, injection site swelling, muscle ache, and headache were the most prevalent side effects. There were 4.7-, 5.7-, 7.1-, and 9.3-fold increases in fatigue, injection site swelling, muscle ache, and headache, respectively, among the 231 women who received the second dose. Most of the side effects resolved by 14 days and all resolved by 30 days after each doses. There were no significant differences (P > 0.05) in obstetrical and neonatal morbidity or mortality between the vaccinated and unvaccinated cohorts. CONCLUSION: No serious adverse reactions were noted among pregnant women receiving messenger RNA vaccinations with comparable obstetrical and neonatal outcomes to unvaccinated pregnant women.

Post-vaccination headache reporting: Trends according to the Vaccine Adverse Events Reporting System.

OBJECTIVE: To assess the characteristics and associated disability of headache as an adverse event following vaccination. BACKGROUND: According to clinical trials and post-licensure surveillance, headache is a common symptom of vaccines, yet systematic investigations of post-licensure reports of this adverse event are lacking. METHODS: This was a retrospective database analysis study. We searched the Vaccine Adverse Events Reporting System (VAERS) database completed from July 1990 to June 2020 (a 30-year period prior to the start of COVID-19 pandemic) to identify reports of headache. We evaluated epidemiological features, including event characteristics, patient demographics, and vaccine type. RESULTS: In those aged 3 years or older, headache was the fifth most reported adverse symptom, present in 8.1% (43,218/536,120) of all reports. Of headache reports, 96.3% (41,635/43,218) included the code "headache" not further specified. Migraine was coded in 1973 cases, although almost one-third (12,467/41,808; 29.8%) of headache reports without a migraine code mention nausea or vomiting. The onset of symptoms was within 1 day of vaccination in over two-thirds of cases. The majority of reports were classified as not serious; about one-third involved emergency room or office visits. Of the 43,218 total headache reports, only a minority involved hospitalizations (2624; 6.1%) or permanent disability (1091; 2.5%), females accounted for 68.9% (29,771) and males for 29.5% (12,725), patients aged 6 to 59 years represented 67.3% (29,112), and over one-third of cases were reported after herpes zoster (8665; 20.1%) and influenza (6748; 15.6%) vaccinations. CONCLUSION: In a national surveillance system, headache was a commonly reported post-vaccination adverse event; a small subset of reports was considered serious. The development of standardized vaccine-related case definitions could be useful for better evaluating headache as an adverse event during vaccine development, and may reduce vaccine hesitancy especially in headache-prone individuals.

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.

Adverse events following immunization with ChAdOx1 nCoV-19 and BBIBP-CorV vaccine: A comparative study among healthcare professionals of Nepal.

BACKGROUND: Adverse events following immunization (AEFI) against SARS-CoV-2 are common as reported by clinical trials and contemporary evidence. The objective of the present study was to evaluate the local and systemic adverse events following vaccination with ChAdOx1 nCoV-19 and BBIBP-CorV among the healthcare professionals (HCPs) of Nepal. METHODS: This cross-sectional study was conducted among 606 vaccinated HCPs of Kathmandu, Nepal. Data was collected from June 15 to 30, 2021 using a self-administered online survey tool. Multiple binary logistic regression models were used to predict the adverse events according to the vaccine types and doses after adjusting for age, sex, comorbidity and previous SARS-CoV-2 infection. RESULTS: The mean (SD) age of the participants was 35.6 (13.2) years and 52% of them were female. Almost 59% of participants were vaccinated with two doses and around 54% of total of them took the ChAdOx1 nCoV-19 vaccine. At least one local and systemic adverse event was reported by 54% and 62% of participants after the first dose and 37% and 49% after the second dose of ChAdOx1 nCoV-19 and by 37% and 43% after the first dose and 42% and 36% after the second dose of BBIBP-CorV vaccine respectively. Injection site pain, swelling and tenderness at the injection site were the most frequently reported local AEFI while, fatigue, headache, fever and myalgia were the most frequently reported systemic AEFI. The logistic model demonstrated that the risk of both local and systemic adverse events was higher among the ChAdOx1 nCoV-19 vaccine recipients compared to the BBIBP-CorV vaccine. Almost 10% of individuals reported a post-vaccination SARS-CoV-2 infection and most of them occurred after taking the first dose of vaccine. CONCLUSIONS: Recipients of both the ChAdOx1 nCoV-19 and BBIBP-CorV vaccine among the HCPs of Nepal reported only mild and constitutional symptoms including injection site pain and tenderness, headache, fever, fatigue, etc. after vaccination.

Side-effects of COVID-19 vaccines among the Saudi population: A cross-sectional study.

OBJECTIVES: To measure and assess the side-effects of Pfizer/BioNTech and AstraZeneca vaccines on residents of Saudi Arabia, as well as provide a database that gives insight into the relative safety of these 2 COVID-19 vaccines. METHODS: A community-based cross-sectional study was conducted to determine the side-effects of the two COVID-19 vaccines. The study was initiated on the 5th of June 2021 at Hail University, Hail, Saudi Arabia. The information was collected through an online survey designed on Google forms. The questionnaire was pre-tested for validity, with all information carefully reviewed. RESULTS: The study included 2,530 participants from different regions of Saudi Arabia, with a mean age of 26.9 ± 12.4 years old. The most common vaccine among the study group was Pfizer, which 73.8% of the population were provided; the remaining 26.2% received the AstraZeneca vaccine. Regarding the Pfizer vaccine, the common systemic side-effects followed the first dose, included headaches, followed by muscle pain, fever, and joint pain. Those who had the AstraZeneca vaccine reported a few more side-effects. For example, during the first dose fever was reported as the most common side-effect, followed by headache, muscle pain and fatigue. CONCLUSION: The present study confirmed that vaccine side-effects are more frequently reported by smokers and those who received the AstraZeneca vaccine. Further studies are needed to acquire a better understanding of the association between risk factors and the experiencing of post-vaccine side-effects.

Timing of headache after COVID-19 vaccines and its association with cerebrovascular events: An analysis of 41,700 VAERS reports.

BACKGROUND: Delayed-onset of headache seems a specific feature of cerebrovascular events after COVID-19 vaccines. METHODS: All consecutive events reported to the United States Vaccine Adverse Reporting System following COVID-19 vaccines (1 January to 24 June 2021), were assessed. The timing of headache onset post-vaccination in subjects with and without concomitant cerebrovascular events, including cerebral venous thrombosis, ischemic stroke, and intracranial haemorrhage was analysed. The diagnostic accuracy in predicting concurrent cerebrovascular events of the guideline- proposed threshold of three-days from vaccination to headache onset was evaluated. RESULTS: There were 314,610 events following 306,907,697 COVID-19 vaccine doses, including 41,700 headaches, and 178/41,700 (0.4%) cerebrovascular events. The median time between the vaccination and the headache onset was shorter in isolated headache (1 day vs. 4 (in cerebral venous thrombosis), 3 (in ischemic stroke), or 10 (in intracranial hemorrhage) days, all P < 0.001). Delayed onset of headache had an area under the curve of 0.83 (95% CI: 0.75-0.97) for cerebral venous thrombosis, 0.70 (95% CI: 0.63-76) for ischemic stroke and 0.76 (95% CI: 0.67-84) for intracranial hemorrhage, and >99% negative predictive value. CONCLUSION: Headache following COVID-19 vaccination occurs within 1 day and is rarely associated with cerebrovascular events. Delayed onset of headache 3 days post-vaccination was an accurate diagnostic biomarker for the occurrence of a concomitant cerebrovascular events.

Long-term adverse events of three COVID-19 vaccines as reported by vaccinated physicians and dentists, a study from Jordan and Saudi Arabia.

Assessment of safety of COVID-19 vaccines is an ongoing process. This study aims to explore long-term adverse events reported by physicians and dentists who received at least two COVID-19 vaccine doses. A group of physicians and dentists were invited to complete a validated questionnaire that was composed of items on: socio-demographics, medical history, administered vaccines, and long-term adverse events (LTAE). Data of a total of 498 practitioners were included. Age ranged from 22 to 71 years (mean age= 35.75 ± 11.74) with a female majority (N = 348, 69.9%). The most frequently administered vaccines were Pfizer-BioNtech, Sinopharm and AstraZeneca vaccines. A total of 80 (16.0%) participants reported LTAEs which were mainly fatigue, menstrual disturbances, myalgia, arthralgia, dizziness, and headache (N = 32, 15, 8, 6, 4, and 4, respectively). There was no statistically significant association between LTAEs and: age, gender, or medical history (P > .05). The collective symptoms of fatigue, myalgia, arthralgia, dizziness, and headache were significantly associated with Sinopharm vaccine (P = .04). This was further confirmed by general linear multivariate model analysis. Less than 20% of COVID-19 vaccine recipients may complain of LTAEs that are mostly fatigue-related. It seems that factors such as age, gender, and medical status play a negligible role in development of these AEs. On the other hand, Sinopharm vaccine showed the highest significant association with these AEs followed by AstraZeneca vaccine.

Reactogenicity and immunogenicity of heterologous prime-boost immunization with COVID-19 vaccine.

BACKGROUND: The objective of the present work was to assess the reactogenicity and immunogenicity of heterologous COVID-19 vaccination regimens in clinical trials and observational studies. METHODS: PubMed, Cochrane Library, Embase, MedRxiv, BioRxiv databases were searched in September 29, 2021. The PRISMA instruction for systemic review was followed. Two reviewers independently selected the studies, extracted the data and assessed risk of bias. The quality of studies was evaluated using the New Castle-Ottawa and Cochrane risk of instrument. The characteristics and study outcome (e.g., adverse events, immune response, and variant of concern) were extracted. RESULTS: Nineteen studies were included in the final data synthesis with 5 clinical trials and 14 observational studies. Heterologous vaccine administration showed a trend toward more frequent systemic reactions. However, the total reactogenicity was tolerable and manageable. Importantly, the heterologous prime-boost vaccination regimens provided higher immunogenic effect either vector/ mRNA-based vaccine or vector/ inactivated vaccine in both humoral and cellular immune response. Notably, the heterologous regimens induced the potential protection against the variant of concern, even to the Delta variant. CONCLUSIONS: The current findings provided evidence about the higher induction of robust immunogenicity and tolerated reactogenicity of heterologous vaccination regimens (vector-based/mRNA vaccine or vector-based/inactivated vaccine). Also, this study supports the application of heterologous regimens against COVID-19 which may provide more opportunities to speed up the global vaccination campaign and maximize the capacity to control the pandemic.

A snapshot global survey on side effects of COVID-19 vaccines among healthcare professionals and armed forces with a focus on headache.

BACKGROUND: New messenger RNA (mRNA) and adenovirus-based vaccines (AdV) against Coronavirus disease 2019 (COVID-19) have entered large scale clinical trials. Since healthcare professionals (HCPs) and armed forces personnel (AFP) represent a high-risk category, they act as a suitable target population to investigate vaccine-related side effects, including headache, which has emerged as a common complaint. METHODS: We investigated the side-effects of COVID-19 vaccines among HCPs and AFP through a 38 closed-question international survey. The electronic link was distributed via e-mail or via Whatsapp to more than 500 contacts. Responses to the survey questions were analyzed with bivariate tests. RESULTS: A total of 375 complete surveys have been analyzed. More than 88% received an mRNA vaccine and 11% received AdV first dose. A second dose of mRNA vaccine was administered in 76% of individuals. No severe adverse effects were reported, whereas moderate reactions and those lasting more than 1 day were more common with AdV (P=0.002 and P=0.024 respectively). Headache was commonly reported regardless of the vaccine type, but less frequently, with shorter duration and lower severity that usually experienced by participants, without significant difference irrespective of vaccine type. CONCLUSIONS: Both mRNA and AdV COVID-19 vaccines were safe and well tolerated in a real-life subset of HCPs and AFP subjects.

The characteristics of COVID-19 vaccine-related headache: Clues gathered from the healthcare personnel in the pandemic.

INTRODUCTION: Headache is a frequent adverse event after viral vaccines. We aimed to investigate the frequency and clinical associations of COVID-19 vaccine-related headache. METHODS: The characteristics, associations of this headache, main comorbidities, headache history following the influenza vaccine and during COVID-19 were investigated using a web-based questionnaire. RESULTS: A total of 1819 healthcare personnel (mean age: 44.4 ± 13.4 years, 1222 females), vaccinated with inactivated virus, contributed to the survey; 209 (11.4%) had been infected with COVID-19. A total of 556 participants (30.6%) reported headache with significant female dominance (36.1% vs. 19.3%), 1.8 ± 3.5 (median: 1; IQR: 0-2) days following vaccination. One hundred and forty-four participants (25.9%) experienced headache lasting ≥3 days. Headache was mostly bilateral without accompanying phenomena, less severe, and shorter than COVID-19-related headache. The presence of primary headaches and migraine were significantly associated with COVID-19 vaccine-related headache (ORs = 2.16 [95% CI 1.74-2.68] and 1.65 [1.24-2.19], respectively). Headache during COVID-19 or following influenza vaccine also showed significant association with headache following COVID-19 vaccine (OR = 4.3 [95% CI 1.82-10.2] and OR = 4.84 [95% CI 2.84-8.23], respectively). Only thyroid diseases showed a significant association (OR = 1.54 [95% CI 1.15-2.08]) with vaccine-related headache among the common comorbidities. CONCLUSION: Headache is observed in 30.6% of the healthcare workers following COVID-19 vaccine and mostly experienced by females with pre-existing primary headaches, thyroid disorders, headache during COVID-19, or headache related to the influenza vaccine.

First-in-Human Study of Bamlanivimab in a Randomized Trial of Hospitalized Patients With COVID-19.

Therapeutics for patients hospitalized with coronavirus disease 2019 (COVID-19) are urgently needed during the pandemic. Bamlanivimab is a potent neutralizing monoclonal antibody that blocks severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) attachment and entry into human cells, which could potentially lead to therapeutic benefit. J2W-MC-PYAA was a randomized, double-blind, sponsor unblinded, placebo-controlled, single ascending dose first-in-human trial (NCT04411628) in hospitalized patients with COVID-19. A total of 24 patients received either placebo or a single dose of bamlanivimab (700 mg, 2,800 mg, or 7,000 mg). The primary objective was assessment of safety and tolerability, including adverse events and serious adverse events, with secondary objectives of pharmacokinetic (PK) and pharmacodynamic analyses. Treatment-emergent adverse event (TEAE) rates were identical in the placebo and pooled bamlanivimab groups (66.7%). There were no apparent dose-related increases in the number or severity of TEAEs. There were no serious adverse events or deaths during the study, and no discontinuations due to adverse events. PKs of bamlanivimab is linear and exposure increased proportionally with dose following single i.v. administration. The half-life was ~ 17 days. These results demonstrate the favorable safety profile of bamlanivimab, and provided the initial critical evaluation of safety, tolerability, and PKs in support of the development of bamlanivimab in several ongoing clinical trials.

Integrated Safety Analysis of Abrocitinib for the Treatment of Moderate-to-Severe Atopic Dermatitis From the Phase II and Phase III Clinical Trial Program.

BACKGROUND: Pivotal phase III studies demonstrated that abrocitinib, an oral, once-daily, JAK1-selective inhibitor, is effective treatment for moderate-to-severe atopic dermatitis (AD) as monotherapy and in combination with topical therapy. OBJECTIVE: The aim of this study was to evaluate the long-term safety of abrocitinib 200 mg and 100 mg in an integrated analysis of a phase IIb study, four phase III studies, and one long-term extension study. METHODS: Two cohorts were analyzed: a placebo-controlled cohort from 12- to 16-week studies and an all-abrocitinib cohort including patients who received one or more abrocitinib doses. Adverse events (AEs) of interest and laboratory data are reported. RESULTS: Total exposure in the all-abrocitinib cohort (n = 2856) was 1614 patient-years (PY); exposure was ≥ 24 weeks in 1248 patients and ≥ 48 weeks in 606 (maximum 108 weeks). In the placebo-controlled cohort (n = 1540), dose-related AEs (200 mg, 100 mg, placebo) were nausea (14.6%, 6.1%, 2.0%), headache (7.8%, 5.9%, 3.5%), and acne (4.7%, 1.6%, 0%). Platelet count was reduced transiently in a dose-dependent manner; 2/2718 patients (200-mg group) had confirmed platelet counts of < 50 × 103/mm3 at week 4. Incidence rates (IRs) were 2.33/100PY and 2.65/100 PY for serious infection, 4.34/100PY and 2.04/100PY for herpes zoster, and 11.83/100PY and 8.73/100PY for herpes simplex in the 200-mg and 100-mg groups, respectively. IRs for nonmelanoma skin cancer, other malignancies, and major adverse cardiovascular events were < 0.5/100PY for both doses. Five venous thromboembolism events occurred (IR 0.30/100PY), all in the 200-mg group. There were three deaths due to gastric carcinoma (diagnosed at day 43), sudden death, and COVID-19. CONCLUSION: Abrocitinib, with proper patient and dose selection, has a manageable tolerability and longer-term safety profile appropriate for long-term use in patients with moderate-to-severe AD. TRIAL REGISTRIES: ClinicalTrials.gov: NCT02780167, NCT03349060, NCT03575871, NCT03720470, NCT03627767, NCT03422822.

A single dose of ChAdOx1 Chik vaccine induces neutralizing antibodies against four chikungunya virus lineages in a phase 1 clinical trial.

Chikungunya virus (CHIKV) is a reemerging mosquito-borne virus that causes swift outbreaks. Major concerns are the persistent and disabling polyarthralgia in infected individuals. Here we present the results from a first-in-human trial of the candidate simian adenovirus vectored vaccine ChAdOx1 Chik, expressing the CHIKV full-length structural polyprotein (Capsid, E3, E2, 6k and E1). 24 adult healthy volunteers aged 18-50 years, were recruited in a dose escalation, open-label, nonrandomized and uncontrolled phase 1 trial (registry NCT03590392). Participants received a single intramuscular injection of ChAdOx1 Chik at one of the three preestablished dosages and were followed-up for 6 months. The primary objective was to assess safety and tolerability of ChAdOx1 Chik. The secondary objective was to assess the humoral and cellular immunogenicity. ChAdOx1 Chik was safe at all doses tested with no serious adverse reactions reported. The vast majority of solicited adverse events were mild or moderate, and self-limiting in nature. A single dose induced IgG and T-cell responses against the CHIKV structural antigens. Broadly neutralizing antibodies against the four CHIKV lineages were found in all participants and as early as 2 weeks after vaccination. In summary, ChAdOx1 Chik showed excellent safety, tolerability and 100% PRNT50 seroconversion after a single dose.

Emergency Department Utilization by In-hospital Healthcare Workers after COVID-19 Vaccination.

BACKGROUND: This is an observational study to analyze an emergency department (ED) utilization pattern of coronavirus disease 2019 (COVID-19) vaccinated in-hospital healthcare workers (HCWs). METHODS: We included 4,703 HCWs who were administered the first dose of the COVID-19 vaccine between March 4 and April 2, 2021, in a tertiary hospital in Korea where fast-track and post-vaccination cohort zone (PVCZ) were introduced in ED. We analyzed data of participants' age, sex, occupation, date and type of vaccination, and their clinical information using SPSS v25.0. RESULTS: The sample comprised HCWs, who received either the ChAdOx1 (n = 4,458) or the BNT162B2 (n = 245) vaccines; most participants were female (73.5%), and 81.1% were under 50 years old. Further, 153 (3.3%) visited the ED and reported experiencing fever (66.9%) and myalgia (56.1%). Additionally, 91 (59.5%) of them were in their 20s, and 106 (67.5%) were assigned to the PVCZ. Lastly, 107 (68.2%) of the patients received parenteral management. No patient required hospitalization. CONCLUSION: In conclusion, vaccinated HCWs who visited the ED with adverse events had a high incidence of fever and a low likelihood of developing serious illnesses. As the COVID-19 vaccination program for Korean citizens continues to expand, strategies to minimize unnecessary ED overcrowding should be put into effect.

COVID-19 vaccines: concerns beyond protective efficacy and safety.

INTRODUCTION: Several vaccine candidates have been developed using different platforms, including nucleic acids (DNA and RNA), viral vectors (replicating and non-replicating), virus-like particles, peptide-based, recombinant proteins, live attenuated, and inactivated virus modalities. Although many of these vaccines are undergoing pre-clinical trials, several large clinical trials investigating the clinical efficacy and safety of coronavirus disease 2019 (COVID-19) vaccines have produced promising findings. AREAS COVERED: In this review, we provide a status update on COVID-19 vaccines currently undergoing clinical trials and discuss issues of concern beyond vaccine efficacy and safety, including dosing regimens, the mixed vaccine strategy, prior severe acute respiratory syndrome coronavirus-2 infection, antibody levels, cellular immunity and protection, variants of concern, COVID-19 vaccine distribution, vaccination willingness, herd immunity, immunity passports, and vaccine indications. EXPERT OPINION: Four vaccines have obtained emergency use authorization, 87 are at the clinical development stage, and 186 are in pre-clinical development. While the knowledge and development of COVID-19 vaccines is rapidly expanding, the benefits of COVID-19 vaccines must outweigh the potential risks of adverse events. To combat the COVID-19 pandemic, clinicians should consistently update COVID-19-associated information, and healthcare authorities and manufacturers should work together to provide adequate and appropriate vaccinations for the prevention of COVID-19. PLAIN LANGUAGE SUMMARY: What is the context?Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) caused a global pandemic: the coronavirus disease 2019 (COVID-19) outbreak. The development and implementation of the COVID-19 vaccine could be an important measure to control the COVID-19 pandemic.What is new?Several phase 3 clinical trials have demonstrated the effectiveness and safety of COVID-19 vaccines for the prevention of SARS-CoV-2 infections. Several COVID-19 vaccines have obtained emergency use authorization and been implemented in many countries. Although concerns regarding unusual blood clots and low platelet counts have been raised, the benefits of COVID-19 vaccines outweigh the potential risks of adverse events.What is the impact?Except for children, the COVID-19 vaccine is recommended for all people, including those pregnant or immunocompromised. Healthcare authorities should advise people receiving the vaccine that they must seek medical attention if they have associated thromboembolism and thrombocytopenia symptoms. More studies are necessary to determine the appropriate vaccine dose and regimen strategy, as well as the effectiveness of COVID-19 vaccines against variants of concerns. A global effort must be made to achieve widespread vaccination and herd immunity.

Hydroxychloroquine safety: A meta-analysis of randomized controlled trials.

BACKGROUND: Hydroxychloroquine (HCQ) is currently being examined for COVID-19. No previous meta-analysis has evaluated its side effects versus placebo. We conducted this meta-analysis to compare the safety of HCQ versus placebo. METHODS: Two authors independently searched PubMed and EMBASE databases for randomized controlled trials (RCTs) of adults comparing the adverse events (AEs) of HCQ versus placebo for any indication. Peto odds ratios (Peto ORs) and 95% confidence intervals (CIs) were calculated based on random-effects models. The heterogeneity (I2) was assessed using Cochran's Q test. RESULTS: Nine RCTs (eight were double-blind) with a total of 916 patients were included. HCQ caused significantly more skin pigmentation than placebo (Peto OR, 4.64; 95% CI, 1.13 to 19.00; P-value = 0.033; I2 = 0%). The increase in other AEs did not reach statistical significance: rash (Peto OR, 1.11; 95% CI, 0.3 to 3.77; P-value = 0.03; I2 = 0%); gastrointestinal AEs (Peto OR, 1.43; 95% CI, 0.55 to 3.72; P-value = 0.46; I2 = 15.17%); headache (Peto OR, 1.94; 95% CI, 0.65 to 5.78; P-value = 0.23; I2 = 9.99%); dizziness (Peto OR, 1.32; 95% CI, 0.49 to 3.52; P-value = 0.58; I2 = 0%); fatigue (Peto OR, 2.13; 95% CI, 0.76 to 5.98; P-value = 0.15; I2 = 0%); and visual AEs (Peto OR, 1.61; 95% CI, 0.76 to 3.41; P-value = 0.22; I2 = 0%). Cardiac toxicity was not reported. CONCLUSIONS: This meta-analysis of RCTs found a significantly higher risk of skin pigmentation in HCQ users versus placebo. More data are needed to evaluate HCQ in the context of COVID-19 treatment.