Post-vaccination Adverse Events Research Articles

2022 AAHA Canine Vaccination Guidelines (2024 Update).

Vaccination is a cornerstone of canine preventive healthcare and one of the most cost-effective ways of maintaining a dog's health, longevity, and quality of life. Canine vaccination also serves a public health function by forming a barrier against several zoonotic diseases affecting dogs and humans. Canine vaccines are broadly categorized as containing core and noncore immunizing antigens, with administration recommendations based on assessment of individual patient risk factors. The guidelines include a comprehensive table listing canine core and noncore vaccines and a recommended vaccination and revaccination schedule for each vaccine. The guidelines explain the relevance of different vaccine formulations, including those containing modified-live virus, inactivated, and recombinant immunizing agents. Factors that potentially affect vaccine efficacy are addressed, including the patient's prevaccination immune status and vaccine duration of immunity. Because animal shelters are one of the most challenging environments for prevention and control of infectious diseases, the guidelines also provide recommendations for vaccination of dogs presented at or housed in animal shelters, including the appropriate response to an infectious disease outbreak in the shelter setting. The guidelines explain how practitioners can interpret a patient's serological status, including maternally derived antibody titers, as indicators of immune status and suitability for vaccination. Other topics covered include factors associated with postvaccination adverse events, vaccine storage and handling to preserve product efficacy, interpreting product labeling to ensure proper vaccine use, and using client education and healthcare team training to raise awareness of the importance of vaccinations.

Haemorrhagic intracranial complications associated with vaccine-induced thrombocytopenia or central venous thrombosis after COVID-19 vaccination: postulated underlying mechanisms with literature and case review.

Despite the unequivocal medical and social advantages of introducing vaccines against the novel coronavirus SARS-CoV-2, there were also some concerns regarding possible post-vaccination adverse events. Most of these are mild. But in rare cases, severe neurological symptoms including ischaemic stroke, intracranial haemorrhage (ICH), cerebral venous and sinus thrombosis (CVT), and thrombosis with thrombocytopenia (TTS) have been observed. Literature data suggests that thrombosis with thrombocytopenia was the major underlying cause of the ICH; dural venous sinuses/cerebral veins were indicated as the primarily affected sites of thrombosis. Our review confirms the previously documented suspicion that CVT and TTS are most likely to occur following vector-type, rather than mRNA, vaccine administration. The postulated mechanism of TTS is similar to heparin-induced thrombocytopenia (HIT) both clinically and serologically. Although ICH and VITT are very rare side effects of the COVID-19 vaccine, for patients with risk factors for thrombosis (e.g. pregnancy), physicians should carefully consider the benefit/risk ratio of vaccination.

Side effects and perceptions among young adults in Bangladesh following COVID-19 vaccination: a single center study

Background and objectives: COVID-19, caused by SARS-CoV-2, has led to a global pandemic with severe health, economic, and social impacts. Vaccination has emerged as a crucial mitigation strategy. Despite the pivotal role of COVID-19 vaccines in controlling the pandemic, vaccine hesitancy remains a significant concern globally, particularly among young adults. This study aimed to explore the side effects and perceptions of the young adults in Bangladesh following COVID-19 vaccination. Materials and methods: The study, conducted in April 2021 among 325 young Bangladeshi adults who received two doses of Sinopharm (BBIBP-CorV) vaccine against SAR-CoV-2. Participants completed a self-administered online questionnaire covering demographics, health history, post-vaccination adverse events, and perceptions about COVID-19 vaccine. A symptom scoring system, based on the interquartile range (IQR), was used to categorize the severity of the side effects. Data analysis utilized SPSS version 26.0, with appropriate tests for significance. Result: Total 325 participants (male - 64.6%, female - 68.9%) were enrolled. The mean age was 22 ± 1.6 years. Social media (43·1%) was the primary source of information about COVID-19. Vaccine related side effects were experienced by 40.9% and 47.1% participants following 1st and 2nd dose of vaccination respectively. Side effects were more prevalent after the second dose of vaccine, particularly in females (31·3% vs. 8·2%, p<0·001). Common side effects included fatigue (41·6%), injection site pain/swelling (36·7%) and headache (32·6%). In over 50% of participants, symptoms appeared within 8 hours following both doses. Symptoms resolved by taking rest at home in majority of participants. Participants with comorbidity reported significantly higher rate of side effects after the first dose (61.8% vs. 37·3%, p <0.05). Despite side effects, 69·8% felt reassured post-vaccination, 63·7% believed in its long-term safety, and 98·8% recommended vaccination to others. Conclusion: The Sinopharm COVID-19 vaccine was well-tolerated among young adults in Bangladesh. Though higher side effects after the second dose were observed in female participants, yet most maintained a positive perception, underscoring its acceptability and recommended vaccination to others. July 2024; Vol. 18(2):011. DOI:https://doi.org/10.55010/imcjms.18.023 *Correspondence: Md. Faizul Ahasan, Department of Pharmacology, Ibrahim Medical College, 1/A Ibrahim Sarani, Segunbagicha, Dhaka 1000, Bangladesh. Email: arronnoo_shuvro@live.com

Omicron XBB.1.16-Adapted Vaccine for COVID-19: Interim Immunogenicity and Safety Clinical Trial Results.

(1) Background: The global coronavirus disease 2019 vaccination adapts to protect populations from emerging variants. This communication presents interim findings from the new Omicron XBB.1.16-adapted PHH-1V81 protein-based vaccine compared to an XBB.1.5-adapted mRNA vaccine against various acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains. (2) Methods: In a Phase IIb/III pivotal trial, adults previously vaccinated with a primary scheme and at least one booster dose of an EU-approved mRNA vaccine randomly received either the PHH-1V81 or BNT162b2 XBB.1.5 vaccine booster as a single dose. The primary efficacy endpoint assessed neutralization titers against the Omicron XBB.1.16 variant at day 14. Secondary endpoints evaluated neutralization titers and cellular immunity against different variants. Safety endpoints comprised solicited reactions up to day 7 post-vaccination and serious adverse events until the cut-off date of the interim analysis. Changes in humoral responses were assessed by pseudovirion-based or virus neutralization assays. (3) Results: At the cut-off date, immunogenicity assessments included 599 participants. Both boosters elicited neutralizing antibodies against XBB.1.16, XBB.1.5, and JN.1, with PHH-1V81 inducing a higher response for all variants. The PHH-1V8 booster triggers a superior neutralizing antibody response against XBB variants compared to the mRNA vaccine. A subgroup analysis consistently revealed higher neutralizing antibody responses with PHH-1V81 across age groups, SARS-CoV-2 infection history, and the number of prior vaccination shots. A safety analysis (n = 607) at the day 14 visit revealed favorable safety profiles without any serious vaccine-related adverse events. (4) Conclusions: PHH-1V81 demonstrates superiority on humoral immunogenicity compared to the mRNA vaccine against XBB variants and non-inferiority against JN.1 with a favorable safety profile and lower reactogenicity, confirming its potential as a vaccine candidate.

New Russian Trivalent Hepatitis B Vaccine (Bubo®­-Unigep): Reactogenicity, Safety and Immunological Efficacy

Relevance. In Russia, phase III of clinical trials of the domestic trivalent vaccine Bubo®-Unigep, containing protective antigens that provide protection against “wild” forms of the hepatitis B virus subtypes ay and ad, as well as the determinant of serotype ay with the G145R mutation, has been completed. Аim. Evaluation of the effect of the new recombinant polyvaccine against hepatitis B «Bubo-Unigep» on vital functions and laboratory parameters in previously unvaccinated individuals in an adult healthy population. Materials and methods. A randomized multicenter clinical study was conducted to assess the reactogenicity, safety and immunogenicity of Bubo®-Unigep (CJSC NPC «COMBIOTECH») in previously unvaccinated healthy adults (n = 166). The study performed according to the protocol developed by the contract research organization «R&D Pharma» at eight clinical centers located in Russian Federation. Results and discussion. Analysis of the studied parameters throughout the study (frequency and severity of adverse events, physical examination data of volunteers with assessment of vital signs, laboratory test results, etc.) made it possible to establish a high safety profile of Bubo®-Unigep vaccine, which turned out to be virtually areactogenic without causing development of targeted local and systemic post-vaccination adverse events. Conclusion. The wide range of specificity of the immune response, along with the high safety and reactogenicity of the Bubo®-Unigep vaccine, the production of which can be carried out through a full technological cycle without the use of imported substances, will increase the effectiveness of hepatitis B prevention.

Data quality and timeliness analysis for post-vaccination adverse event cases reported through healthcare data exchange to FDA BEST pilot platform.

This study is part of the U.S. Food and Drug Administration (FDA)'s Biologics Effectiveness and Safety (BEST) initiative, which aims to improve the FDA's postmarket surveillance capabilities by using real-world data (RWD). In the United States, using RWD for postmarket surveillance has been hindered by the inability to exchange clinical data between healthcare providers and public health organizations in an interoperable format. However, the Office of the National Coordinator for Health Information Technology (ONC) has recently enacted regulation requiring all healthcare providers to support seamless access, exchange, and use of electronic health information through the interoperable HL7 Fast Healthcare Interoperability Resources (FHIR) standard. To leverage the recent ONC changes, BEST designed a pilot platform to query and receive the clinical information necessary to analyze suspected AEs. This study assessed the feasibility of using the RWD received through the data exchange of FHIR resources to study post-vaccination AE cases by evaluating the data volume, query response time, and data quality. The study used RWD from 283 post-vaccination AE cases, which were received through the platform. We used descriptive statistics to report results and apply 322 data quality tests based on a data quality framework for EHR. The volume analysis indicated the average clinical resources for a post-vaccination AE case was 983.9 for the median partner. The query response time analysis indicated that cases could be received by the platform at a median of 3 min and 30 s. The quality analysis indicated that most of the data elements and conformance requirements useful for postmarket surveillance were met. This study describes the platform's data volume, data query response time, and data quality results from the queried postvaccination adverse event cases and identified updates to current standards to close data quality gaps.

Assessing clinical benefits of live-attenuated vaccination in post-liver transplant patients: Analysis of breakthrough infections and natural boosters

Recently, live-attenuated measles, rubella, varicella, and mumps vaccines have been administered to carefully selected post-liver transplant patients. Although attention has been focused on post-vaccination antibody titers and adverse events, the real-life clinical benefits remain unclear. A comprehensive analysis of breakthrough infections and natural boosters (asymptomatic cases with significant elevation in virus antibody titers) following immunization post-liver transplantation was conducted from 2002-2023, exploring the timing, frequency, correlation with domestic outbreaks, and degree of antibody elevation. During the median 10-year observation period among 68 post-liver transplant patients, breakthrough infections occurred only in chickenpox, with 7 mild cases (1 episode/64 person-years). A total of 59 natural booster episodes (1, 5, 20, and 33 for measles, rubella, chickenpox, and mumps, respectively) were observed, with incidence rates of 1 per 569, 110, 22, and 17 person-years, respectively. The timing of natural boosters closely correlated with domestic outbreaks (P < .05 in chickenpox and mumps), influenced by local vaccine coverage. The degree of antibody elevation was significantly higher in individuals with breakthrough infections than in those with natural boosters (P < .05). These findings suggest that immunization with live-attenuated vaccines for post-liver transplant patients has demonstrated clinical benefits. Furthermore, mass vaccination has a positive impact on post-transplant patient outcomes.

Adverse reactions following COVID-19 immunization in children of elementary school age

Purpose: Due to the low rate of parent acceptance of vaccines, this study was conducted to evaluate post-vaccination adverse events among elementary school students.&#x0D; Methods: This survey took place in the Manggala Subdistrict of Makassar City. The study was conducted from September to October 2022 by distributing a paper-based questionnaire regarding the COVID-19 vaccines.&#x0D; Results: Of 129 respondents, the age range was 7-12 years. Sixty-five percent of respondents received the first vaccine shot in January or February, with a 4-week interval of the second dose among 46.5% of children. The vaccine administered was CoronaVac from Sinovac. The most common adverse events were injection pain (45-48%) and fever (15-17%). The other side effects were itching, swelling, fever, and shortness of breath. Around 17-18 % of respondents did not have any adverse reactions. There is no increase in the risk for younger children (years 1-3) compared with older children (years 4-6). &#x0D; Conclusion: The children reported only mild adverse events such as injection pain, weakness, and fever. The CoronaVac has minimal side effects among elementary school children.

Headache as the most prevalent post-vaccination adverse event after Covid-19 vaccination

Context: In 2020, the first vaccines were approved, according to the WHO. However, speculations have arisen regarding its efficacy and post-vaccination adverse events (AEFI). Objective: To evaluate the prevalence of headache as AEFI from the SARSCoV-2 vaccine in Piauí, Brazil.Methods: This is a quantitative, observational, cross-sectional and prevalence study. The data were provided by the Post-Vaccination Adverse Events Information System (SI-AEFV), of cases reported in the period from January to September 2021. The data were analyzed and the research was approved by the Research Ethics Committee of the UFPI. Results: 2,008 cases were analyzed. Headache was reported in 752 cases (27.99%) as AEFI after vaccination against SARS-CoV-2. In most cases, the patients were from Teresina (67.62%), of mixed race/ethnicity (52.67%), female (79.00%) and the majority were not healthcare professionals (54. 27%). The most common age of patients, with the original data, was 33 years old. After correcting the data, the most common age was 28 years old. The majority of these cases were not serious (96.44%) and the majority of cases were associated with the first dose of the Covid-19-Covishield-Oxford/AstraZeneca vaccine (43.18%). Conclusion: Thus, it is concluded from the partial analysis of the results that headache is the most common adverse event after vaccination against SARS-CoV-2. The profile of patients with the most notifications was mixed-race women aged between 30 and 40 years who received the first dose of the Covid-19-Covishield-Oxford/AstraZeneca vaccine. Regarding the severity of the events, the vast majority were considered non-serious and no deaths were mentioned, demonstrating the safety of immunobiologicals.

Comparative analysis of efficacy and safety of ChAdOx1 nCov-19 and AD26.COV2.S

Vaccine technology has been going through some radical and incremental advancement over the years for its importance as the most crucial tool in the prevention and elimination of transmissive diseases. Since the outbreak of COVID-19, several vaccine platforms were being studied, developed, and entered the market. Among the platforms, vector viral vaccines attracted particular attention for the cooperation of viral vectors to deliver genetic material of the pathogens. While the mechanism has improved the flexibility of vaccine design and efficacy, the adverse events after vaccination were worth attention at the same time. Taking ChAdOx12 nCov-19 and AD26.COV2.S. as the subjects, the efficacy and safety of the two vaccine platforms were compared and analyzed. In this paper, the initial vaccine efficacy, the resistances against virus variants, and various post vaccination adverse events were looked in more detail to identify the different factors that could affect the performance of viral vector vaccines.

A retrospective cohort study: vaccination status and safety analysis of SARS-CoV-2 vaccine in patients with Wilson’s disease

ABSTRACT Background Wilson’s disease (WD) is a rare hepatic and neurological disorder, which can dramatically worsen by traumatic injuries, surgeries, and infections. No studies have reported safety data of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in WD patients. We aimed to investigate the SARS-CoV-2 vaccination status and post-vaccination adverse events in WD patients. Methods This is a multicenter, retrospective, observational study. We investigated the vaccination rates, the type of vaccine, subjective reasons for non-vaccination, and the adverse events following vaccination. Logistic regression analysis was used to assess the correlation between vaccination status and increased Unified Wilson’s Disease Rating Scale (UWDRS) scores. Results A total of 554 WD patients with a mean (SD) age of 25.3 (10.85) years were included in this study, of whom 336 (60.6%) were males and 218 (39.4%) were females. 368 (66.4%) patients received at least one dose of the SARS-CoV-2 vaccine.186 (33.6%) patients were unvaccinated. Logistic regression analysis showed that vaccination against SARS-CoV-2 was not significantly associated with increased UWDRS scores. The safety analysis demonstrated that 21.2% had post-vaccination adverse events. Conclusions In this study, vaccination against SARS-CoV-2 was safe in WD patients, providing evidence for the safety of vaccination in WD patients.

Effect of Secukinumab and Tumor Necrosis Factor Inhibitors on Humoral Response to BNT162b2 mRNA Vaccine in Patients With Spondyloarthritis Compared to Immunocompetent Controls.

To assess the humoral response to the BNT162b2 mRNA vaccine among patients with spondyloarthritis (SpA) receiving secukinumab (SEC) compared to those receiving tumor necrosis factor inhibitors (TNFi) and immunocompetent controls. Consecutive patients with psoriatic arthritis or axial SpA receiving SEC (n = 37) or TNFi (monotherapy, n = 109; + methotrexate [MTX], n = 16), immunocompetent controls (n = 122), and patients with rheumatoid arthritis (RA) receiving TNFi therapy (controls, n = 50) were vaccinated with 2 or 3 doses of the BNT162b2 vaccine. We evaluated humoral response, adverse events, and disease activity, and monitored for breakthrough coronavirus disease 2019 (COVID-19) postvaccination. The 2-dose vaccine regimen induced a comparable seropositive response in all study groups. S1/S2 antibody titers (in binding antibody units/mL; mean [SD]) were higher in the SEC group vs the TNFi + MTX-SpA and TNFi-RA groups (192.5 [68.4] vs 104.6 [46.9], P < 0.001, and 143.1 [81.9], P = 0.004). After 6 months, 96.3%, 96.6%, and 80.9% of the SEC, immunocompetent, and TNFi monotherapy-SpA groups (P = 0.10), respectively; 66.7% of the TNFi + MTX-SpA group (P = 0.03); and 63% of the TNFi-RA group (P = 0.004) remained seropositive. S1/S2 antibody titer decline was steeper in the TNFi groups than the SEC group. After the third dose, 100% of the SpA and immunocompetent and 88.9% of the TNFi-RA (P = 0.25) groups were seropositive. Rate of breakthrough COVID-19 infection was higher in the TNFi groups than in the SEC group (36-37.5% vs 10.8%). No significant between-group differences were observed for postvaccination disease activity and adverse events. SEC did not interfere with the immunogenic response to BNT162b2 vaccine in patients with SpA; however, TNFi therapy was associated with lower S1/S2-antibody titers, faster decline, and higher rate of breakthrough infections.

Providing compensation for patients with diseases who cannot be given the COVID-19 Vaccine

This study aims to describe the procedures and barriers associated with compensating disease sufferers who are not eligible to receive the COVID-19 vaccine. The research method used is normative research, which focuses on analyzing legal aspects based on legal regulations, including Presidential Regulation Number 99 of 2020, concerning Procurement of Vaccines and Implementation of Vaccinations in the Context of Overcoming the 2019 Coronavirus Disease (COVID-19) Pandemic, as well as regulations other relevant matters. Research data was obtained through literature study and document analysis, including primary and secondary legal materials. Data analysis was carried out descriptively and qualitatively with a deductive approach, which refers to general legal principles. The research results identified various obstacles, including technical problems such as a lack of public discipline in undergoing health checks before receiving vaccination and a lack of compliance from medical personnel who manage vaccination procedures per established guidelines. As a result, some groups of people who should not receive the COVID-19 vaccine still receive vaccination, which can ultimately cause side effects. The research also highlights Presidential Regulation Number 14 of 2021 concerning Procurement of Vaccines and Implementation of Vaccinations in the Context of Overcoming the COVID-19 Pandemic, which provides compensation guarantees following applicable regulations if a Post-Vaccination Adverse Event (AEFI) occurs which has the potential to cause disability or death in sufferers of the disease who are not eligible to receive the COVID-19 vaccine. The results of this research provide a deeper understanding of the challenges and obstacles in implementing COVID-19 vaccination, especially in the context of disease sufferers who do not meet the requirements to receive the vaccine, as well as the importance of guaranteeing compensation in AEFI situations that have the potential to have profound impacts.

Adverse Events Following COVID-19 Vaccination in Anambra State, South East Nigeria

The use of safe and effective vaccination is critical to control of pandemics. Vaccines remain the bedrock in management of infectious diseases outbreaks. There has always been hesitancy to vaccination due to the fear of adverse events. It is therefore necessary that post vaccination adverse events be studied for effective enlightenment of the general populace.&#x0D; Objective: We aimed to investigate the adverse reactions following COVID-19 vaccination in Anambra state, South East Nigeria.&#x0D; Methods: Using a cross-sectional study design, 433 subjects aged 18years or older who had received any dose of the four COVID-19 vaccines (Moderna, Astra Zeneca, Pfizer and J&amp;J (Janssen) were selected using a multi-stage sampling technique. The subjects were interviewed about COVID-19 vaccine related adverse reactions using self-administered questionnaire. Descriptive statistics (mean, standard deviation) and analytical statistics were performed and level of significance set at &lt; 0.5 using SPSS V24.&#x0D; Results: Of the 433 subjects finally studied, 62.8% were females and 22.4% were married. About 69% of them had tertiary education. Those who received the second dose of their respective vaccines were 44.8% while 11.5% had received a booster dose. Approximately half (50.3%) of the COVID-19 vaccines had adverse events. The most common types of adverse events (AEs) were local pain at injection site (62.1%) followed by headache (54.3%) and then fatigue (50.1%). Majority of the adverse events were mild to moderate in severity. Those who had only local adverse events were 70.2% while 45% had systemic adverse events.&#x0D; Conclusion: In this study, severe adverse events were rare, even after the second dose. Most of the adverse events were mild to moderate in severity and therefore awareness campaign should be created to enlighten the community about the adverse effects of COVID-19 vaccines.

Prevalence of Adverse Events of Pneumococcal and Influenza Vaccines among People with Diabetes

Abstract Background: People with diabetes have an increased risk of contracting influenza and pneumonia compared to healthy individuals. In addition, people with diabetes often have comorbidities that increase this risk. Vaccinations are an effective prophylaxis against these infections. The overall vaccination status is still low due to the fear of adverse events. Hence, it is important to analyze the risk of adverse vaccination events. The study aims to find the adverse events and tolerance of influenza and pneumococcal vaccines among people with diabetes who visited a tertiary diabetes care center. Methods: The study is a retrospective analysis of 5423 people with diabetes who received routine influenza and pneumococcal vaccinations. Postvaccination adverse events were collected from Diabetes Tele Management System®. Analysis was carried out using R program version 4.3.2 at a level of significance of 5%. Results: Among 5423 study participants, 2459 (45.34%) received the pneumococcal vaccine, while 2964 (54.65%) received the influenza vaccine. The majority of vaccine recipients, 3591 (66.21%), were male. Among the 2459 people who received the pneumococcal vaccine, 3.17% reported adverse events. Among the influenza group, 8.22% of people reported adverse events. Common adverse events experienced by the pneumococcal group included body pain, fever, tiredness, and pain at the injection site. The influenza group experienced cough, throat pain, sneezing, and asthma. These adverse events were treatable and self-limiting. Conclusion: The pneumococcal and influenza vaccinations were well tolerated by people with diabetes. A very small population reported adverse events, which were self-limiting, and treatable, resulting in a rapid recovery. Vaccinations are, therefore, highly recommended among people with diabetes and must be a part of their routine diabetes care. Vaccination is important to prevent infections and their complications.

A framework for nationwide COVID-19 vaccine safety research in the Republic of Korea: the COVID-19 Vaccine Safety Research Committee.

With the introduction of coronavirus disease 2019 (COVID-19) vaccines, the Korea Disease Control and Prevention Agency (KDCA) commissioned the National Academy of Medicine of Korea to gather experts to independently assess post-vaccination adverse events. Accordingly, the COVID-19 Vaccine Safety Research Committee (CoVaSC) was launched in November 2021 to perform safety studies and establish evidence for policy guidance. The CoVaSC established 3 committees for epidemiology, clinical research, and communication. The CoVaSC mainly utilizes pseudonymized data linking KDCA's COVID-19 vaccination data and the National Health Insurance Service's claims data. The CoVaSC's 5-step research process involves defining the target diseases and organizing ad-hoc committees, developing research protocols, performing analyses, assessing causal relationships, and announcing research findings and utilizing them to guide compensation policies. As of 2022, the CoVaSC completed this research process for 15 adverse events. The CoVaSC launched the COVID-19 Vaccine Safety Research Center in September 2022 and has been reorganized into 4 divisions to promote research including international collaborative studies, long-/short-term follow-up studies, and education programs. Through these enhancements, the CoVaSC will continue to swiftly provide scientific evidence for COVID-19 vaccine research and compensation and may serve as a model for preparing for future epidemics of new diseases.

Adverse events following immunization with COVID-19 vaccines

Objective: The purpose of this study was to identify Post-Vaccination Adverse Events (PVAE) with Moderna vaccine, locally systemically, and other reactions. Methods: A quantitative descriptive research method with a retrospective approach was used in this study. The study was carried out at RSUD Cicalengka Bandung with a population of employees who had received the Moderna vaccine after two complete doses of Sinovac from August to September 2021. Purposive sampling was used, with a total of 162 respondents calculated using the Yamane formula.

Recommended Adult Immunization Schedule, United States, 2023.

Recommended Adult Immunization Schedule, United States, 2023.

Adverse events following the first, second and third doses of a COVID-19 vaccine in hemodialysis patients

Background This study aimed to identify adverse events following the first three doses of COVID-19 vaccines in hemodialysis (HD) patients. Risk factors associated with postvaccination adverse events were explored. Methods Postvaccination adverse events in 438 HD patients who received 3 doses of COVID-19 vaccines were prospectively assessed. The adverse events among three doses were compared using generalized linear mixed models. Factors associated with adverse events were assessed with multivariate analyses. Results The vast majority of participants received Oxford/AstraZeneca ChAdOx1 as their first two doses and Moderna mRNA-1273 as their third dose. Overall, 79%, 50% and 84% of the participants experienced at least one adverse event after their first, second, and third doses, respectively. These adverse events were mostly minor, short-lived and less than 5% reported daily activities being affected. Compared with the first dose, the second dose caused a lower rate of adverse events. Compared with the first dose, the third dose elicited a higher rate of injection site reactions and a lower rate of systemic reactions. Multivariate analyses showed that every 10-year increase of age (odds ratio 0.67, 95% confidence intervals 0.57-0.79) was associated with decreased risk of adverse events, while female sex (2.82, 1.90-4.18) and arteriovenous fistula (1.73, 1.05–2.84) were associated with increased risk of adverse events. Compared with Oxford/AstraZeneca ChAdOx1, Moderna mRNA-1273 was associated with an increased risk of injection site reactions. Conclusions COVID-19 vaccination was well tolerated in HD patients. Age, sex, dialysis vascular access and vaccine types were associated with postvaccination adverse events.

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

To assess the characteristics and associated disability of headache as an adverse event following vaccination. 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. 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. 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. 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.