Vaccine Immunization Research Articles

Mumps: A case report

The widespread of mumps and its medical and social significance determine the relevance of further study of the etiology, epidemiology, diagnosis, treatment, and prevention of mumps infection. Despite the lack of mortality, the possible occurrence of complications that affect the suppression of male reproductive function makes mumps a priority. Official statistics show the annual incidence of mumps in the Russian Federation, estimated in hundreds of cases up to several thousand (2017–2018). The continued spread of mumps is associated with violations of immunization regimens, underestimation of the unvaccinated population or unreliability of the reported data, introduction of new viral genotypes capable of bypassing vaccine immunity, and natural weakening of post-vaccination immunity. The presented clinical case refers to an outpatient case of mumps in a 53-year-old man with a delayed diagnosis despite the typical clinical manifestations. The clinical case demonstrates the lack of awareness of outpatient practitioners about the manifestations of mumps. The causes of mumps in older age groups and possible ways to solve the problem are discussed.

A nanoparticle vaccine based on the VP121–26 and VP2 structural proteins of Senecavirus A induces robust protective immune responses

Senecavirus A (SVA) is a causative agent that can cause vesicular disease in swine, which causes a great threat to the swine husbandry in the world. Therefore, it is necessary to develop a vaccine that can effectively prevent the spread of SVA. In this study, we developed a 24-polymeric nano-scaffold using β-annulus peptide from tomato bushy effect virus (TBSV) by coupling this antigen to SVA B cell epitope VP121–26 and VP2 proteins via linkers, respectively. The SVA-based nanoparticle protein of the VP1(B)-β-VP2 was expressed and purified by low-cost prokaryotic system to prepare a SVA nanoparticle vaccine. The immunological protective effect of SVA nanoparticle vaccine was evaluated in mouse and swine models, respectively. The results suggested that both mice and swine could induce high levels SVA neutralizing antibodies and IgG antibodies after two doses immunization. In addition, the swine challenge protection experiment showed that the protection rate of immune SVA nanoparticle vaccine and SVA inactivated vaccine both were 80 %, while the negative control had no protection effect. It demonstrated that SVA nanoparticle vaccine effectively prevented SVA infection in swine. In summary, the preparation of SVA vaccine by using β-annulus peptide is a promising candidate vaccine for prevent SVA transmission, and provides a new idea for the development of novel SVA vaccines.

Investigation of Transmission and Evolution of PEDV Variants and Co-Infections in Northeast China from 2011 to 2022.

Porcine epidemic diarrhea virus (PEDV) is a rapidly evolving virus that causes outbreaks in pig herds worldwide. Mutations in the S protein of PEDV have led to the emergence of new viral variants, which can reduce vaccine immunity against prevalent strains. To understand the infection and variation pattern of PEDV in China, an extensive epidemiological survey was conducted in northeast China from 2015 to 2022. The genetic diversity of enteroviruses co-infected with PEDV and the PEDV S gene was analyzed, common mutation patterns that may have led to changes in PEDV virulence and infectivity in recent years were identified, and structural changes in the surface of the S protein resulting from mutations in the PEDV S gene from 2011 to 2022 were reviewed. Of note, two distinct mutations in the emerging 2022 HEB strain were identified. These findings provide a basis for a better understanding of PEDV co-infection and genetic evolution in northeast China.

Immunotherapies: A Treasure Trove of Alzheimer's Disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease that falls under the umbrella of dementia and is characterized by the presence of enormously neurotoxic amyloid-beta (Aβ) plaques and neurofibrillary tangles (NFTs) of tau protein inside the brain. AD remains an intractable global health challenge with limited therapeutic options. Early diagnosis, enabled by biomarkers and neuroimaging, is pivotal for optimizing treatment outcomes. Immunotherapeutic strategies, including monoclonal antibodies, active vaccination, and passive immunization, have been developed to target hallmark AD pathology, such as amyloid-beta aggregation. Here we summarized the emerging role of immunotherapies in the early stages of AD, shedding light on recent breakthroughs and clinical progress. Challenges, including treatment response variability and safety concerns, are discussed alongside evolving approaches, such as personalized immunotherapy and combinatorial treatments. This concise review underscores the promise of immunotherapies as a transformative approach to AD intervention, offering hope for a brighter future in the quest to combat this devastating neurodegenerative disease.

Pediatric antibody responses to SARS-CoV-2 after infection and vaccination in Calgary, Canada

BackgroundThere are few reports of longitudinal serologic responses in children following Sars-CoV-2 infection and vaccination. This study describes longitudinal SARS-CoV-2 antibody responses following infection, vaccination, or both (hybrid immunity) in a cohort of Canadian children. The objectives of our study were to compare antibody levels following SARS-CoV-2 infection, vaccination, and hybrid immunity and to examine antibody decline after final antigen exposure.MethodsThe Alberta Childhood COVID-19 Cohort (AB3C) study was a prospective longitudinal cohort study conducted from July 2020 to September 2022 with repeat sampling across 5 visits. Children under 18 years of age were enrolled for serial measurement of antibody responses to SARS-CoV-2 virus vaccine and infection.ResultsThe final sample size was 919; participants were 50.5% female, 48.2% were > 12 years and 88.5% were white ethnicity. The median peak spike IgG level of those with only infection was not different from those with no vaccination or infection (233 AU/mL (IQR: 99–944 AU/mL) vs. 3 AU/mL (IQR: 1–5 AU/mL; P = 0.1765). Participants with infections after vaccination had higher IgG levels than those where infection preceded vaccination (median: 36,660 (IQR: 22,084 − 40,000 AU/mL) vs. 17,461 AU/mL (IQR: 10,617 − 33,212 AU/mL); P < 0.0001). In a linear mixed methods model, children with infection-only had low levels of antibody that stayed stable over the study duration without further antigen exposures. Those with infection after vaccination had the slowest rate of antibody decline over time at 4% (95%CI: 2-5%) per week, compared with children where infection preceded vaccine 7% (95%CI: 6-8%) per week.ConclusionsChildren with hybrid immunity conferred through vaccination (2 + doses) followed by a SARS-CoV-2 infection had the highest and longest lasting antibody levels, compared to children who had an infection followed by vaccination, vaccination-only, or infection-only. The longer-term clinical importance of these findings, related to prevention of repeated infections and severe outcomes and need for further vaccine doses, is not yet known.

Analysis of Epidemiological Characteristics of Varicella Before and After the Implementation of the Two-dose Varicella Vaccine Immunization Program in Banan District of Chongqing City

Analysis of Epidemiological Characteristics of Varicella Before and After the Implementation of the Two-dose Varicella Vaccine Immunization Program in Banan District of Chongqing City

Establishment of an A/T-Rich Specifically MGB Probe digital droplet PCR Assays Based on SNP for Brucella wild strains and vaccine strains

In recent years, immunization with the S2 live-attenuated vaccine has been recognized as the most economical and effective strategy for preventing brucellosis in Inner Mongolia, China. However, there are still challenges related to vaccine toxicity and the inability to distinguish between vaccine immunization and natural infection. Therefore, in this study, we developed a digital droplet polymerase chain reaction (ddPCR) assay based on single-nucleotide polymorphism (SNP) loci to identify wild Brucella strains and S2 vaccine strains. The assay demonstrated excellent linearity (R2> 0.99) with a lower detection limit of 10 copies/µL for both wild and vaccine strains. Additionally, the ddPCR assay outperformed the real-time fluorescent quantitative PCR (qPCR) assay in screening 50 clinical samples. We have established an effective and highly sensitive ddPCR assay for Brucella, providing an efficient method for detecting and differentiating wild strains of Brucella from the S2 vaccine strain.

Breast Milk-Derived Antibodies Impair Vaccine Immunity in Suckling Mice.

Breast milk confers multiple benefits to the neonate, including passive immunity against multiple microorganisms via Abs. However, it remains unclear whether breast milk-derived Abs affect vaccine-induced immunity in the neonate. We evaluated in C57BL/6 and BALB/c mice whether breastfeeding from an mRNA-SARS-CoV-2-vaccinated dam affects vaccine-induced immunity in neonate mice. Using an experimental model that allows the distinction of maternal Abs and neonate Abs based on their allotype, we show that breastfeeding from an immune dam is associated with reduced vaccine immunity in the neonate. Importantly, mice that breastfed from an immune dam showed reduced numbers of plasma cells after vaccination, relative to mice that breastfed from a naive dam. Our subsequent studies using an mRNA-luciferase reporter system show that passive transfer of Abs through breastfeeding accelerates the clearance of vaccine Ag in suckling mice, resulting in reduced Ag availability. Altogether, maternal Abs transferred through breast milk can protect against infectious microorganisms, but they may also interfere with the neonate's response to vaccination by accelerating the clearance of vaccine Ag. These findings are important for understanding the effects of maternal Abs on the neonate's response to vaccines and may provide insights for improving neonatal vaccines.

Exosome nanovesicles: biomarkers and new strategies for treatment of human diseases.

Exosomes are nanoscale vesicles of cellular origin. One of the main characteristics of exosomes is their ability to carry a wide range of biomolecules from their parental cells, which are important mediators of intercellular communication and play an important role in physiological and pathological processes. Exosomes have the advantages of biocompatibility, low immunogenicity, and wide biodistribution. As researchers' understanding of exosomes has increased, various strategies have been proposed for their use in diagnosing and treating diseases. Here, we provide an overview of the biogenesis and composition of exosomes, describe the relationship between exosomes and disease progression, and focus on the use of exosomes as biomarkers for early screening, disease monitoring, and guiding therapy in refractory diseases such as tumors and neurodegenerative diseases. We also summarize the current applications of exosomes, especially engineered exosomes, for efficient drug delivery, targeted therapies, gene therapies, and immune vaccines. Finally, the current challenges and potential research directions for the clinical application of exosomes are also discussed. In conclusion, exosomes, as an emerging molecule that can be used in the diagnosis and treatment of diseases, combined with multidisciplinary innovative solutions, will play an important role in clinical applications.

PEMBERIAN EDUKASI TENTANG PENTINGNYA IMUNISASI LENGKAP DAN VAKSINASI POLIO

Immunization is a public health intervention that is very effective in preventing serious infectious diseases. In this context, polio vaccination plays an important role because polio can cause permanent paralysis and even death. The aim of this activity is to increase knowledge, awareness and community participation about the importance of immunization, especially polio vaccination, through providing accurate information and eliminating misinformation, as well as facilitating access to health services. Method: This service begins with preparation and includes monitoring and evaluation. Where the interventions carried out are counseling, distribution of educational materials, door-to-door visits, and mobile posyandu to the community. Results: there has been a significant increase in knowledge, awareness and positive attitudes of the community towards immunization and polio vaccination. The evaluation showed a 45% increase in knowledge and a supportive change in attitudes. Conclusion: Service activities in Bandar Kidul Village succeeded in increasing the community's knowledge and positive attitudes towards polio immunization. This activity could be a model for other regions and is recommended to be held regularly with structured material and developed for maternal and child health (KIA).

Hepatitis B virus in oocytes and embryos: pregnancy outcomes and children’s health

To investigate whether the presence of hepatitis B virus (HBV) in oocytes and embryos affects pregnancy outcomes for invitro fertilization and embryo transfer (ET) as well as is related to the vertical transmission of HBV to children. Retrospective cohort study. A university-affiliated fertility center. This study included 167 couples with at least 1 hepatitis B surface antigen-seropositive partner. These couples underwent invitro fertilization-ET, and the discarded oocytes and embryos had been tested for HBV. Couples with HBV-positive oocytes or embryos were categorized as the positive group, whereas those couples with HBV-negative oocytes and embryos served as the negative group. None. Pregnancy outcomes and the rate of children's HBV infection. The pregnancy outcomes of fresh and frozen ETs were not associated with the presence of HBV in the oocytes and embryos. Of the 106 infants born, 1 child whose mother tested positive for hepatitis B surface antigen but had negative oocytes and embryos was infected with HBV. Additionally, 26.09% of children who had been administered passive immunization and active vaccinations did not reach protective levels of anti-HBV antibodies (hepatitis B surface antibodies) and became nonresponders. The negative rate of children's hepatitis B surface antibody was associated with the presence of HBV in oocytes and embryos (odds ratio, 3.01; 95% confidence interval, 1.04-9.25). The presence of HBV in oocytes and embryos did not affect pregnancy outcomes or result in the vertical transmission of HBV to the offspring of HBV carriers. Follow-up is needed for HBV-vaccinated children with an HBV-infected parent. Booster vaccinations are necessary for continued protection.

Preparation and immunological activity evaluation of an intranasal protein subunit vaccine against ancestral and mutant SARS-CoV-2 with curdlan sulfate/O-linked quaternized chitosan nanoparticles as carrier and adjuvant

Chitosan and its derivatives are ideal nasal vaccine adjuvant to deliver antigens to immune cells. Previously, we successfully used a chitosan derivative, O-(2-Hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (O-HTCC), and a β-glucan derivative, curdlan sulfate (CS), to prepare a nanoparticle adjuvant CS/O-HTCC which could deliver ovalbumin to antigen presenting cells (APCs) through nasal inhalation. In this article, we used SARS-CoV-2 spike receptor binding domain (S-RBD) as the antigen and CS/O-HTCC nanoparticles as the adjuvant to develop a nasal mucosal protein subunit vaccine, CS/S-RBD/O-HTCC. The humoral immunity, cell-mediated immunity and mucosal immunity induced by vaccines were evaluated. The results showed that CS/S-RBD/O-HTCC could induce desirable immunization with single or bivalent antigen through nasal inoculation, giving one booster vaccination with mutated S-RBD (beta) could bring about a broad cross reaction with ancestral and different mutated S-RBD, and vaccination of the BALB/c mice with CS/S-RBD/O-HTCC containing S-RBD mix antigens (ancestral and omicron) could induce the production of binding and neutralizing antibodies against both of the two antigens. Our results indicate that CS/O-HTCC is a promising nasal mucosal adjuvant to prepare protein subunit vaccine for both primary and booster immunization, and the adjuvant is suitable for loading more than one antigen for preparing multivalent vaccines.

The Impact of Vaccination Status on Anthropometric Indices of Growth Among Children: A Cross-Sectional Study.

Background Childhood immunization programs in underdeveloped nations can improve children's growth and nutritional status and prevent growth delays while protecting against infectious diseases and meeting growth norms. This study aimed toassess the impact of vaccination status on the anthropometric indices of children aged 12-18 months at an Expanded Programme on Immunization vaccination center and compare the anthropometric indices of growth in children with complete and incomplete vaccination statuses. Methodology This study was conducted at the rural health center in Kala Shah Kaku, Pakistan, from November 2023 to December 2023. Children aged 12-18 months were enrolled and their vaccination status was recorded. Height and weight were measured using World Health Organization growth charts. The data were analyzed using descriptive statistics and chi-square and Fisher's exact tests. A p-value <0.05 was considered statistically significant. Results The mean age of the 110 children who visited the vaccination site for this study was 16.36 months ± 2.415. There were 28 (25.5%) stunted children. In the study, 17.6 (16%) participants were underweight, and 15.95 (14.5%) were wasted. Of the children, 79% had received all recommended vaccinations. A statistically significant(p < 0.05) association was foundbetween vaccination and nutritional status. Conclusions This study emphasizes the significance of vaccination in promoting child health and nutrition, reducing stunting risk, and ensuring equitable access to vaccination services and comprehensive healthcare interventions. This can help mitigate the malnutrition burden and promote optimal growth, contributing to global health and development goals.

Potential impact of nirsevimab and bivalent maternal vaccine against RSV bronchiolitis in infants: A population-based modelling study

BackgroundA new monoclonal antibody (nirsevimab; Beyfortus®) and a bivalent prefusion RSV vaccine (Abrysvo®) for maternal immunization have been approved recently. This is a modelling study to estimate the potential impact of different immunization programs with these products on RSV-bronchiolitis. MethodsPopulation-based real-world data from primary care and hospitalizations were considered. RSV bronchiolitis dynamics in absence of these immunization scenarios were explained by a multivariate age-structured Bayesian model. Then, the potential impact was simulated under different assumptions including the most recent clinical trial data. Differences in endpoints, populations, and timeframes between trials make the two products’ efficacy difficult to compare. ResultsA seasonal with catch-up program, assuming a constant effectiveness of 79.5 % during the first 5 months followed by a linear decay to 0 by month 10 with nirsevimab, would prevent between 5121 and 8846 RSV bronchiolitis per 100,000 infants-years. Assuming 77.3 % effectiveness with the same decay, between 976 and 1686 RSV-hospitalizations per 100,000 infants-years could be prevented depending on the uptake. A year-round maternal immunization program, with 51 % of effectiveness during the first 6 months followed by a linear decay to 0 by month 10 would prevent between 3246 and 5606 RSV bronchiolitis cases per 100,000 infants-years. Assuming 56.9 % effectiveness with the same decay, between 713 and 1231 RSV-hospitalizations per 100,000 infants-years could be prevented. ConclusionsOur results suggest that each strategy would effectively reduce RSV-bronchiolitis.

Sero-epidemiological study and infection rate evaluation of pertussis in Henan Province

Objective: To analyze the epidemiological distribution characteristics, influencing factors, and infection rates of pertussis in the population of Henan Province. Methods: From 2022 to 2023, a cross-sectional survey was conducted to investigate the permanent population in Henan Province. Enzyme-linked immunosorbent assay (ELISA) was used to detect anti-pertussis toxin IgG (PT-IgG), analyze the antibody positivity rate (≥20 IU/ml) and median concentration (MC), and estimate the pertussis infection rate based on PT IgG ≥40 IU/ml. The rank sum test was used to compare antibody levels among groups, and the χ2 test was used to compare antibody positive rates and infection rates among groups. Results: A total of 4 810 research subjects were included in this study. The overall positive rate of PT-IgG was 12.10% and MC was 3.04 (0.35, 10.36) IU/ml. There were significant differences both in positive rates and antibody levels of PT-IgG among different regions or age groups (region positive rate: χ2=134.06, P<0.001, MC: H=337.74, P<0.001; age group positive rate: χ2=45.27, P<0.001, MC: H=134.49, P<0.001). Both the positive rate of PT-IgG (25.26%) and MC (8.01 IU/ml) were the highest within one year after completing a full course of vaccination. There were significant differences in positive rates and antibody levels among people receiving different types of pertussis vaccines (positive rate: χ2=12.38, P=0.006, MC: H=17.93, P<0.001). The antibody positivity rate (35.71%) and MC (8.88 IU/ml) of the people who received cell-free pertussis inactivated poliomyelitis influenza type b (combined) vaccine throughout the course were higher than those who received other types of vaccines. The natural infection rate of pertussis was evaluated for individuals aged≥3 years who had no history of pertussis vaccine immunization within the year prior to sampling. With a high vaccination rate, the estimated infection rate of pertussis in the population was 5 757.22/100 000. The infection rates in the 3-year-old (1 940.16/100 000) and 4-year-old (1 765.68/100 000) populations were at a low level among the entire population, reaching their peak at the age of 6 (12 656.71/100 000). Subsequently, although the infection rate continued to decline, it remained at a high level and peaked again at the age of 40-49 years (8 740.39/100 000). There was a statistically significant difference in the estimated infection rate of pertussis among different age groups (χ2=53.21, P<0.001). Conclusion: The PT-IgG level of pertussis in the population of Henan Province is generally at a low level. The estimated infection rate of pertussis is much higher than the reported incidence rate. A booster dose of pertussis vaccine is recommended at 6 years old.

Factors Associated with the Giving of Basic Inactivated Poliovirus Vaccine (IPV) Immunisation

Inactivated Poliovirus Vaccine (IPV) immunisation is given starting from 2-3 months of age with three consecutive doses with an interval of 6-8 weeks. IPV immunisation is one of the key steps in polio control efforts. However, there are still challenges in achieving optimal immunisation coverage in some areas. The aim was to determine the factors associated with the provision of IPV basic immunisation. This type of research uses descriptive analytics with a Cross Sectional approach where data on both variables are collected at the same time or at one time. Sampling using simple random sampling using the formula as many as 164 samples. The instruments used in the study were questionnaires and KMS Statistical tests used were chi-square. Results: The results of this study report that there is a significant relationship between knowledge (p value 0.000), work (p value 0.000), posyandu cadres (p value 0.000), posyandu officers (p value 0.000), and family support (p value 0.000) with the provision of IPV Basic Immunisation in the Working Area of Puskesmas Pulau Panggung. There is an influence of knowledge, occupation, posyandu cadres, posyandu officers, and family support on the provision of IPV basic immunisation. This study suggests that health workers should be more active in providing information to local mothers by providing information through counselling and putting up posters, banners and distributing leaflets about the importance of IPV to children or by providing information from house to house.

The immunization questionnaire for understanding unwellness (TIQUU): Fun learning about vaccination using an innovative storytelling approach

BackgroundVaccination is a pivotal tool in public health. In LMICs like Pakistan, challenges hinder high immunization rates. This study addresses gaps in vaccination knowledge among school children through innovative educational interventions. The study aims to enhance vaccination awareness and contribute to health education discourse. MethodologyThis quasi-experimental study was conducted in 4 private schools in Karachi, Pakistan, from February to May 2021. Children aged 8–12 years in grades 2–5 were enrolled. An interactive discussion on vaccine safety and immunization was conducted using a bilingual pictorial storybook. Group-I experienced traditional Urdu book reading, while Group-II engaged with a digital animated video in English. A pre-test was conducted to assess baseline knowledge about immunization followed by an interactive discussion and immediately a post-test. Test scores were analyzed using paired sample t-test using Stata 17.0 version. ResultsThe study enrolled 400 students in Karachi, Pakistan. Both groups exhibited significant knowledge shifts regarding vaccine-related topics. Group-I (Analog Urdu) showed changes in understanding sickness reasons, vaccine timing, newborn protection, sports injury response, and memory impact. Group-II (Digital English) displayed shifts in illness understanding, recommended actions, injection and vaccine knowledge, safety perceptions, measles prevention, and management during sports injury. A statistically significant improvement in mean scores was observed. ConclusionAs a proactive and early strategy to alleviate the societal burden of under-immunization, cost-effective educational interventions can be integrated into school curricula. Our approach through bilingual pictorial storybooks and animated videos has been proven effective and helps one grasp immunization's importance.

Hepatitis-B immune status and vaccination in Family Medicine Practice: A retrospective study.

To examine the relationship between Hepatitis B vaccination status and demographic and hepatitis B markers of individuals receiving healthcare services. The study designed in a retrospective structure using quantitative research methods was conducted with a total of 1837 individuals including medical school students and other healthcare professionals (975 female, 862 male) aged 19-77 who were registered to the Family Health Center between March 1, 2023, and March 31, 2023. In the study, sociodemographic characteristics, infancy and adult full-dose hepatitis-B vaccines, and marker laboratory measurements of these individuals who were registered to the Family Health Center were examined. SPSS 25.00 program was used for statistical analysis and the level of significance was determined as 0.05. In general, the rate of three doses of vaccination in infancy was 55.1%. Vaccine doses administered to individuals were one with 15.1%, two with 22.9%, and three with 62.1%. In the study, it was determined that anti-HBs levels before and after vaccination differed significantly according to vaccine doses (p=0.01). It was determined that the anti-HBs levels of the three doses vaccine group were 100 and above (p=0.01). Although the Universal Hepatitis-B Vaccination Program was followed in our study, it was determined that antibody levels in healthcare workers decreased or ended over time, and hepatitis-B antibody levels increased significantly with each dose of vaccine administered. For this reason, it is of great importance to determine regular antibody levels and develop standard vaccination programs, especially in healthcare workers.

Immunization, new viruses, and new vaccines

A global outbreak of Coronavirus Disease 2019 (COVID-19) which is caused by a new virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has just occurred. An instance of an infectious virus that has been transmitted to humans and had a substantial effect on worldwide health and the economy is SARS-CoV-2. In the human population, besides SARS-CoV-2, numerous additional viruses have lately emerged or re-emerged. To accurately predict the hazards of emerging and re-emerging viral infections, close cooperation between the public health system and the scientific community is essential. Some of the reasons that may be related to the emergence and re-emergence of novel viruses include urbanization, alterations in the natural environment, globalization, and insufficient public health infrastructure.Vaccines will aid in efficiently controlling the intense outbreaks caused by these emerging viruses. Nevertheless, the creation of novel vaccines encounters various obstacles, including tight deadlines for development and the ongoing evolution of viral variants. Notwithstanding, the difficulties encountered in vaccine development, recent progress in the vaccine development process has yielded a significant breakthrough in combating disease outbreaks. Recent advancements in immunology, genetics, and biotechnology have enabled the creation of several vaccines, including those for dengue, RSV, chikungunya, malaria, and most notably, COVID-19. These novel vaccinations protect a broad spectrum of viruses and other pathogenic microorganisms, including those that are challenging to control or have just emerged.

Risk Factors Associated with Cutaneous Reactions Following COVID-19 Vaccine Immunisation: A Registry-Based Case-Control Study.

In Malaysia, following extensive COVID-19 vaccination, Hospital Kuala Lumpur reported an increase in cutaneous reactions post-immunisation. To understand this, a case-control study was initiated to identify potential risk factors. This registry-based, unmatched case-control study encompasses all adverse event following immunisation (AEFI) reports associated with COVID-19 vaccines, received by the Department of Pharmacy at Hospital Kuala Lumpur through the Malaysian Adverse Drug Reactions Advisory Committee (MADRAC) AEFI reporting forms. Twenty-four potential risk factors were evaluated, including demographic information, medical history, food allergies, COVID-19 vaccination history and prior SARS-CoV-2 infection, were evaluated using MADRAC AEFI reporting forms. Odds ratio (OR) with 95% confidence interval (CI) were estimated using univariable and multivariable logistic regression. Cutaneous reactions were more frequent in middle-aged females, especially after the first COVID-19 vaccine dose. These reactions, primarily mild and generalised, included pruritus and urticaria. Notably, 52% were delayed reactions (more than 4 h post-vaccination). Factors associated with increased risk of cutaneous reaction following COVID-19 immunisation included history of seafood and shellfish allergy (adjusted odds ratio [adjOR]: 2.11; 95% CI: 1.12, 3.96; P = 0.020), history of vaccine allergy (adjOR: 4.07; 95% CI: 1.44, 11.54; P = 0.008), past dermatological diseases (adjOR: 5.48; 95% CI: 2.03, 14.78; P = 0.001), and past medication allergy (adjOR: 2.12; 95% CI: 1.36, 3.31; P = 0.001). Self-reported histories of allergies to vaccines, foods or medications were found to increase the likelihood of cutaneous reactions following COVID-19 vaccination. These reactions, which were predominantly mild, did not hinder the administration of the second vaccine dose. The majority of reactions occurred after the first dose, manifesting as generalised pruritus and urticaria. They were effectively managed with oral antihistamines and low-dose corticosteroids, thereby avoiding the need for hospitalisation.