Immunization Campaign Research Articles

Prevention of Meningococcal Disease: Knowledge, Attitudes, and Practices of General Practitioners and Primary Care Pediatricians in South Italy.

The purpose of this study was to evaluate the knowledge, attitude, and current practices about prevention of meningococcal disease among general practitioners (GPs) and primary care pediatricians (PCPs) in Italy. A cross-sectional survey was carried out between February 2022 and July 2023 among a random sample of GPs and PCPs in Southern Italy. The data were collected using a questionnaire accessible via an internet link with the free software Google Forms®. Regarding the participants' knowledge toward meningococcal vaccinations, 84.2% of the PCPs and more than half of the GPs (55.2%) knew that the meningococcal B (MenB) vaccination is recommended for infants from the second month of life and 84.2% and 82.7% of the PCPs were aware that quadrivalent meningococcal ACWY (MenACWY) vaccine is recommended for children in the second year of life and adolescents, respectively. The GPs and PCPs considered vaccination against meningococcal disease to be very effective and safe with average values of 8.8 and 8.7, respectively, on a scale ranging from 1 to 10. Those with an older age, those who knew the medical conditions that expose patients to a higher risk of contracting meningococcal disease, and those who self-rated their knowledge on meningococcal disease as excellent/very good were more likely to consider the vaccination to be very effective and safe. Only 15.5% of the GPs and more than half of the PCPs (54.3%) administered anti-meningococcal vaccines to their patients. GPs and females were less likely to administer anti-meningococcal vaccines to their patients, whereas those who acquired information on meningococcal vaccinations by scientific journals were more likely to administer meningococcal vaccines. The findings of the survey highlighted the need of a greater engagement of GPs and PCPs in the immunization campaigns in order to increase meningococcal vaccination coverage.

Between Political Strife and National Science: COVID-19 Vaccines on the Main Brazilian TV newscast

ABSTRACT Brazil ranks second worldwide in COVID-19 deaths. In this country, television is the most popular means of mass communication, and 95.5% of Brazilian homes have a TV set. During the coronavirus pandemic, Brazilians considered TV news the most reliable source of information about COVID-19. In this context, we examined the coverage of vaccines, between 2020 and 2021, on the main Brazilian TV newscast – Jornal Nacional. We identified 1,173 reports on vaccination in the digital collection of this news show, which we analyzed based on six dimensions that systematize the following: general characteristics of the news, approach to vaccination, framing the news, general handling of the topic, actors and geographic location of the study and/or the immunization campaign on the agenda. The reports evinced a mostly positive attitude towards vaccines, emphasizing the political strategies and public policies adopted in COVID-19 vaccine development. National science gained prominence in the coverage. The most common news sources were institutions and/or representatives of the executive branch, and scientists were the voices most present in the reports. Just over half of the reports discussed the topic using visual aids, but only a few explained scientific concepts pertaining to the vaccine.

Integrating Digital Health Solutions with Immunization Strategies: Improving Immunization Coverage and Monitoring in the Post-COVID-19 Era.

The COVID-19 pandemic underscored the critical importance of vaccination to global health security and highlighted the potential of digital health solutions to improve immunization strategies. This article explores integrating digital health technologies with immunization programs to improve coverage, monitoring, and public health outcomes. It examines the current landscape of digital tools used in immunization initiatives, such as mobile health apps, electronic health records, and data analytics platforms. Case studies from different regions demonstrate the effectiveness of these technologies in addressing challenges such as vaccine hesitancy, logistics, and real-time monitoring of vaccine distribution and adverse events. The paper also examines ethical considerations, data privacy issues, and the need for a robust digital infrastructure to support these innovations. By analyzing the successes and limitations of digital health interventions in immunization campaigns during and after the COVID-19 pandemic, we provide recommendations for future integration strategies to ensure resilient and responsive immunization systems. This research aims to guide policymakers, health professionals, and technologists in leveraging digital health to strengthen immunization efforts and prepare for future public health emergencies.

Optimal Timing Regularly Outperforms Higher Coverage in Preventative Measles Supplementary Immunization Campaigns.

Measles threatens the lives and livelihoods of tens of millions of children and there are countries where routine immunization systems miss enough individuals to create the risk of large outbreaks. To help address this threat, measles supplementary immunization activities are time-limited, coordinated campaigns to immunize en masse a target population. Timing campaigns to be concurrent with building outbreak risk is an important consideration, but current programmatic standards focus on campaigns achieving a high coverage of at least 95%. We show that there is a dramatic trade-off between campaign timeliness and coverage. Optimal timing at coverages as low as 50% for areas with weak routine immunization systems is shown to outperform the current standard, which is delayed by as little as 6 months. Measured coverage alone is revealed as a potentially misleading performance metric.

Implementation of the first respiratory syncytial (RSV) immunization campaign with nirsevimab in an autonomous community in Spain

ABSTRACT Respiratory syncytial virus (RSV) is the main cause of low respiratory tract infections in infants under one year of age. In the 2023/2024 season, the monoclonal antibody nirsevimab was available to protect children from RSV, and Spain has become one of the first countries worldwide to implement this strategy. It is essential to evaluate the results of this first campaign and different characteristics of the immunized population in order to plan next campaigns, especially for countries that are going to include this immunization. Our coverage was high (91.5% for those born during the season and 88.3% globally). For those born during the season, only 4.9% preferred not to immunize at the maternity hospital, which meant an average delay of 27.45 days. We observed a lower coverage in the population of immigrant origin. There was a rapid pace of immunization, since for those born before the beginning of the campaign the mean to be immunized was 15.63 days, without differences between healthy and at-risk children. This allows immunization before the RSV season (90% of the catch-up children had been immunized on November 3). The average age at which all the immunized children have received nirsevimab was lower in healthy children compared to those with risk conditions (49.65 versus 232.85 days). For those born during the campaign, the average age was also lower in healthy children (3.14 versus 14.58 days). In conclusion, we consider that the implementation of the immunization strategy with nirsevimab in the Region of Murcia, Spain, has been a success.

Effectiveness of nirsevimab immunoprophylaxis against respiratory syncytial virus-related outcomes in hospital and primary care settings: a retrospective cohort study in infants in Catalonia (Spain)

BackgroundIn Catalonia, infants under 6 months old were eligible to receive nirsevimab, a novel monoclonal antibody against respiratory syncytial virus (RSV). We aimed to analyse nirsevimab’s effectiveness across primary and...

Adverse Events Following Immunization with Novel Oral Polio Vaccine Type 2, and the Experience and Challenges of Reporting in Sierra Leone.

The manifestation and spread of neuroinvasive circulating vaccine-derived polioviruses (cVDPVs) across several countries, which led to the emergency use of the novel oral polio vaccine type 2 (nOPV2), raised concerns about adverse events following immunization (AEFI) surveillance. We assessed the attributes of AEFI with nOPV2 and examined stakeholder experiences and challenges in AEFI surveillance in Sierra Leone. Using a mixed method approach, we retrospectively reviewed passive data collected during a 2021 immunization campaign, and conducted semi-structured, interviews with vaccinators, district AEFI focal persons, and key stakeholders at the national Expanded Program on Immunization and the National Medicines Regulatory Authority. AEFI were categorized using the Medical Dictionary for Regulatory Activities (MedDRA) Preferred Terms (PTs) and System Organ Class (SOC). Outcomes were stratified as recovered or not, with preventability and causality assessed using the Schumock and Thornton and World Health Organization (WHO) algorithms, respectively. A total of 528 suspected AEFI were documented, predominantly affecting children aged 28 days to 23 months (63.3%). Most reported AEFI were administration site conditions and general disorders, with pyrexia being the predominant PT. Of 80 serious cases, 78 recovered, with 74 having an inconsistent causal relationship with the vaccine. Most serious cases (78) were deemed non-preventable, with only two being probably preventable. AEFI reporting was not routinely carried out across the group of people interviewed. AEFI reporting was not consistently performed, with discrepancies in defining reportable events and confusion over responsibility. Challenges with the open data kit (ODK) platform were noted, along with perceived inadequacies in training. While the nOPV2 is relatively new, the majority of AEFI were not serious, and most serious cases were not causally linked to the vaccine. Participants exhibited variations in experience and awareness of AEFI reporting.

Nirsevimab Effectiveness Against Cases of Respiratory Syncytial Virus Bronchiolitis Hospitalised in Paediatric Intensive Care Units in France, September 2023-January 2024.

In September 2023, France was one of the first countries that started a national immunisation campaign with nirsevimab, a new monoclonal antibody against respiratory syncytial virus (RSV). Using data from a network of paediatric intensive care units (PICUs), we aimed to estimate nirsevimab effectiveness against severe cases of RSV bronchiolitis in France. We conducted a case-control study based on the test-negative design and included 288 infants reported by 20 PICUs. We estimated nirsevimab effectiveness at 75.9% (48.5-88.7) in the main analysis and 80.6% (61.6-90.3) and 80.4% (61.7-89.9) in two sensitivity analyses. These real-world estimates confirmed the efficacy observed in clinical studies.

Non-governmental organizations’ development interventions and community empowerment in Kitui County, Kenya

Non-governmental organizations (NGOs) are crucial actors in international development, addressing global challenges and fostering sustainable development in communities worldwide. Despite concerted NGO efforts, Kitui County in Eastern Kenya remains underdeveloped, grappling with significant challenges in education, healthcare, women empowerment, and food security. With 48% of its population living in poverty, surpassing the national average, and 39.4% facing food insecurity, Kitui County is in urgent need of intervention. This study investigates the impact of NGO interventions on community empowerment in Kitui County, focusing on education, health, and women empowerment sectors. Drawing on the Empowerment Theory and Sustainable Development Theory, a pragmatic research approach was adopted, employing a descriptive survey design. Data were collected from 384 residents aged 18 and above, utilizing structured questionnaires and interviews. Quantitative data were analyzed using the Statistical Package for the Social Sciences (SPSS), while qualitative data underwent thematic analysis. Findings reveal that NGO interventions have positively influenced education, with 66% acknowledging improved access to quality education through provided materials and teacher training programs. In healthcare, immunization campaigns (65%) and maternal and child health clinics (65%) have significantly reduced mortality rates and increased health awareness. Women empowerment initiatives, including microfinance and leadership training, have empowered women economically (64%) and facilitated their advocacy for rights (69%). This study underscores the vital role of NGOs in enhancing community empowerment in Kitui County. It emphasizes the need for sustained NGO interventions tailored to local contexts to address multifaceted development challenges effectively.

Strategi Komunikasi Kesehatan Untuk Mendukung Program Imunisasi Bayi dan Balita di Kabupaten Aceh Barat

Immunization is an important factor that is useful in increasing the immunity of children from the age of 0 months. However, immunization campaigns are often rejected by the public due to misinformation and misconceptions about immunization. Therefore, an effective communication strategy is an important factor in planning communication programs to succeed immunization achievements and encourage behavior change in the community. This study aims to analyze the health communication strategy conducted in Peunaga Baro Preparatory Village, West Aceh District. We used a qualitative method by collecting data through interviews with 8 parents who participated in the immunization program as well as health workers as the person in charge of the immunization program. The analysis was developed using the KAP - based communication planning model. The results found that there are still misperceptions of immunization in the community so that they do not allow their children to be immunized. By combining communication patterns, the communication patterns of health workers are linear-secondary communication patterns in the form of oral communication with direct counseling, linear-secondary communication patterns in the form of posters, circular-secondary communication patterns in the form of oral communication with direct counseling and the last is circular-secondary communication patterns in the form of WhatsApp Groups. The health communication strategy has not been implemented optimally, where health workers do not make structured message planning and do not consider the selection of media for delivering immunization messages.

Exploring barriers to influenza vaccine uptake and recommendation among healthcare providers in the community in China: A qualitative study

ABSTRACT Healthcare providers (HCPs) are recommended for priority influenza vaccination due to their high risk of contracting influenza. HCPs greatly aid in targeted population immunization campaigns. Therefore, understanding the factors that influence HCPs’ decisions to get vaccinated and to recommend influenza vaccination is essential. However, there currently needs to be more evidence on this topic in China. Qualitative interviews using a semi-structured interview method were conducted with 180 HCPs from urban community hospitals and town hospitals in four cities in Shandong Province during August 2023. The interview content was analyzed using thematic analysis to identify the variables impacting the vaccination and recommendation practices of HCPs, as well as their suggestions for improving vaccination services. The results will help support the future development of precise intervention measures as well as focused education and training.

Assessment of effectiveness and impact of universal prophylaxis with nirsevimab for prevention of hospitalizations due to respiratory syncytial virus in infants. The NIRSE-GAL study protocol

ABSTRACT Nirsevimab has been recently licensed for universal RSV prophylaxis in infants. NIRSE-GAL is a three-year population-based study initiated in Galicia in September 2023. It aims to evaluate nirsevimab effectiveness against RSV-related hospitalizations lower respiratory tract infections (LRTI), severe RSV, all-cause LRTI, and all-cause hospitalization. NIRSE-GAL also aims to estimate nirsevimab impact on primary healthcare use in the short and mid-term, children’s wheezing and asthma, and medical prescriptions for RSV. The immunization campaigns will be scheduled based on the expected start week for the RSV season and will last the whole season. Immunization will be offered to: i) infants born during the campaign (seasonal), ii) infants < 6 months at the start of the campaign (catch-up), and iii) infants with high-risk factors, aged 6–24 months at the start of the campaign (high-risk). The follow-up period will start: i) the immunization date for all immunized infants, ii) the start of the campaign, for the non-immunized catch-up or high-risk groups, or iii) the birthdate for the non-immunized seasonal group. Infants will be followed up until outcome occurrence, death, or end of study. Nirsevimab effectiveness will be estimated using Poisson and Cox regression models. Sensitivity and stratified analyses will be undertaken. The number of averted cases and the number needed to immunize will be estimated. Immunization failure and nirsevimab safety will be monitored. NIRSE-GAL was approved by the ethics committee of Galicia (CEIC 2023–377) and registered in ClinicalTrials.gov (ID: NCT06180993). Findings will be mainly shared via peer-reviewed publications and scientific conferences.

Perceptions of yellow fever emergency mass vaccinations among vulnerable groups in Uganda: A qualitative study.

Yellow fever (YF), a mosquito-borne viral hemorrhagic fever, is endemic in Uganda and causes frequent outbreaks. A total of 1.6 million people were vaccinated during emergency mass immunization campaigns in 2011 and 2016. This study explored local perceptions of YF emergency mass immunization among vulnerable groups to inform future vaccination campaigns. In this qualitative study, we conducted 43 semi-structured interviews, 4 focus group discussions, and 10 expert interviews with 76 participants. Data were collected in six affected districts with emergency mass vaccination. We included vulnerable groups (people ≥ 65 years and pregnant women) who are typically excluded from YF vaccination except during mass immunization. Data analysis was conducted using grounded theory. Inductive coding was utilized, progressing through open, axial, and selective coding. Participants relied on community sources for information about the YF mass vaccination. Information was disseminated door-to-door, in community spaces, during religious gatherings, and on the radio. However, most respondents had no knowledge of the vaccine, and it was unclear to them whether a booster dose was required. In addition, the simultaneous presidential election during the mass vaccination campaign led to suspicion and resistance to vaccination. The lack of reliable and trustworthy information and the politicization of vaccination campaigns reinforced mistrust of YF vaccines. People in remote areas affected by YF outbreaks rely on community sources of information. We therefore recommend improving health education, communication, and engagement through respected and trusted community members. Vaccination campaigns can never be seen as detached from political systems and power relations.

Immunity against measles, mumps, rubella, and varicella among homeless individuals in Germany - A nationwide multi-center cross-sectional study.

Homeless individuals suffer a high burden of vaccine-preventable infectious diseases. Moreover, they are particularly susceptible to adverse infection outcomes with limited access to the health care system. Data on the seroprevalence of measles, mumps, rubella, and varicella within this cohort are missing. The seroprevalence of measles, mumps, rubella, and varicella was determined within the homeless population in Germany. Predictors of lacking immune protection were determined using multivariable logistic regression analysis. Homeless individuals in Germany (n = 611) showed a seroprevalence of 88.5% (95% CI: 85.8-91.0) for measles, 83.8% (95% CI: 80.6-86.6) for mumps, 86.1% (95% CI: 83.1-88.7) for rubella, and 95.7% (95% CI 93.8-97.2) for varicella. Measles seroprevalences declined from individuals born in 1965 to individuals born in 1993, with seroprevalences not compatible with a 95% threshold in individuals born after 1980. For mumps, seroprevalences declined from individuals born in 1950 to individuals born in 1984. Here, seroprevalences were not compatible with a 92% threshold for individuals born after 1975. Seronegativity for measles, mumps and rubella was associated with age but not with gender or country of origin. Herd immunity for measles and mumps is not achieved in this homeless cohort, while there was sufficient immune protection for rubella and varicella. Declining immune protection rates in younger individuals warrant immunization campaigns also targeting marginalized groups such as homeless individuals. Given that herd immunity thresholds are not reached for individuals born after 1980 for measles, and after 1975 for mumps, vaccination campaigns should prioritize individuals within these age groups.

Effectiveness and impact of universal prophylaxis with nirsevimab in infants against hospitalisation for respiratory syncytial virus in Galicia, Spain: initial results of a population-based longitudinal study

Galicia (Spain) was one of the first regions worldwide to incorporate nirsevimab for universal respiratory syncytial virus (RSV) prophylaxis in infants into its immunisation programme. The NIRSE-GAL longitudinal population-based study aimed to assess nirsevimab effectiveness in preventing hospitalisations (ie, admittance to hospital). The 2023-24 immunisation campaign with nirsevimab in Galicia began on Sept 25, 2023, and concluded on March 31, 2024. The campaign targeted three groups: infants born during the campaign (seasonal group), infants younger than 6 months at the start of the campaign (catch-up group), and infants aged 6-24 months with high-risk factors at the start of the campaign (high-risk group). Infants in the seasonal group were offered immunisation on the first day of life before discharge from hospital. Infants in the catch-up and high-risk groups received electronic appointments to attend a public hospital or health-care centre for nirsevimab administration. For this interim analysis, we used data collected from Sept 25 to Dec 31, 2023, from children born up to Dec 15, 2023. Data were retrieved from public health registries. Nirsevimab effectiveness in preventing RSV-associated lower respiratory tract infection (LRTI) hospitalisations; severe RSV-related LRTI requiring intensive care unit admission, mechanical ventilation, or oxygen support; all-cause LRTI hospitalisations; and all-cause hospitalisations was estimated using adjusted Poisson regression models. Data from five past RSV seasons (2016-17, 2017-18, 2018-19, 2019-20, and 2022-23), excluding the COVID-19 pandemic period, were used to estimate the number of RSV-related LRTI hospitalisations averted along with its IQR. The number needed to immunise to avoid one case in the 2023-24 season was then estimated from the averted cases. Nirsevimab safety was routinely monitored. The NIRSE-GAL study protocol was registered on ClinicalTrials.gov (NCT06180993), and follow-up of participants is ongoing. 9408 (91·7%) of 10 259 eligible infants in the seasonal and catch-up groups received nirsevimab, including 6220 (89·9%) of 6919 in the catch-up group and 3188 (95·4%) of 3340 in the seasonal group. 360 in the high-risk group were offered nirsevimab, 348 (97%) of whom received it. Only infants in the seasonal and catch-up groups were included in analyses to estimate nirsevimab effectiveness and impact because there were too few events in the high-risk group. In the catch-up and seasonal groups combined, 30 (0·3%) of 9408 infants who received nirsevimab and 16 (1·9%) of 851 who did not receive nirsevimab were hospitalised for RSV-related LRTI, corresponding to an effectiveness of 82·0% (95% CI 65·6-90·2). Effectiveness was 86·9% (69·1-94·2) against severe RSV-related LRTI requiring oxygen support, 69·2% (55·9-78·0) against all-cause LRTI hospitalisations, and 66·2% (56·0-73·7) against all-cause hospitalisations. Nirsevimab effectiveness against other endpoints of severe RSV-related LRTI could not be estimated because of too few events. RSV-related LRTI hospitalisations were reduced by 89·8% (IQR 87·5-90·3), and the number needed to immunise to avoid one RSV-related LRTI hospitalisation was 25 (IQR 24-32). No severe adverse events related to nirsevimab were registered. Nirsevimab substantially reduced infant hospitalisations for RSV-associated LRTI, severe RSV-associated LRTI requiring oxygen, and all-cause LRTI when given in real-world conditions. These findings offer policy makers and health authorities robust, real-world, population-based evidence to guide the development of strategies for RSV prevention. Sanofi and AstraZeneca. For the Spanish translation of the abstract see Supplementary Materials section.

Sri Lanka's strategic response to the recent measles outbreak through Measles Special Immunization Campaign

No abstract available

I want to be safe: understanding the main drivers behind vaccination choice throughout the pandemic

BackgroundDespite being a major advancement in modern medicine, vaccines face widespread hesitancy and refusal, posing challenges to immunization campaigns. The COVID-19 pandemic accentuated vaccine hesitancy, emphasizing the pivotal role of beliefs in efficacy and safety on vaccine acceptance rates. This study explores the influence of efficacy and safety perceptions on vaccine uptake in Italy during the pandemic.MethodsWe administered a 70-item questionnaire to a representative sample of 600 Italian speakers. Participants were tasked with assessing the perceived effectiveness and safety of each vaccine dose, along with providing reasons influencing their vaccination choices. Additionally, we conducted an experimental manipulation, exploring the effects of four framing messages that emphasized safety and/or efficacy on participants’ willingness to receive a hypothetical fourth vaccine dose. Furthermore, participants were asked about their level of trust in the scientific community and public authorities, as well as their use of different information channels for obtaining COVID-19-related information.ResultsOur study reveals a dynamic shift in vaccine efficacy and safety perceptions throughout the COVID-19 pandemic, potentially influencing vaccination compliance. Initially perceived as more effective than safe, this assessment reversed by the time of the third dose. Beliefs regarding safety, rather than efficacy, played a significant role in anticipating future vaccinations (e.g., the booster dose). Safety-focused messages positively affected vaccination intent, while efficacy-focused messages showed limited impact. We also observed a changing trend in reasons for vaccination, with a decline in infection-related reasons and an increase in social related ones. Furthermore, trust dynamics evolved differently for public authorities and the scientific community.ConclusionsVaccine perception is a dynamic process shaped by evolving factors like efficacy and safety perceptions, trust levels, and individual motivations. Our study sheds light on the complex dynamics that underlie the perception of vaccine safety and efficacy, and their impact on willingness to vaccinate. We discuss these results in light of bounded rationality, loss aversion and classic utility theory.

Improving Influenza Vaccination Coverage in Patients with Cancer: A Position Paper from a Multidisciplinary Expert Group.

Patients with cancer can be immunocompromised because of their disease and/or due to anticancer therapy. In this population, severe influenza virus infections are associated with an elevated risk of morbidity and mortality. Influenza vaccination is therefore highly recommended in cancer patients, including those receiving anticancer therapy. However, vaccination coverage remains far below the recommended target for vulnerable subjects. Six specialists in oncology, hematology, immunology, and public health/vaccinology convened with the objective of developing strategies, based on evidence and clinical experience, for improving influenza vaccination coverage in cancer patients. This viewpoint provides an overview of current influenza vaccination recommendations in cancer patients, discusses barriers to vaccination coverage, and presents strategies for overcoming said barriers. New immunization issues raised by the COVID-19 pandemic are also addressed. Future directions include improving public education on influenza vaccination, providing the media with accurate information, improving knowledge among healthcare professionals, improving access to vaccines for cancer patients, co-administration of the influenza and COVID-19 vaccines, increased collaboration between oncologists and other health professionals, increased accessibility of digital vaccination registries to specialists, shared information platforms, and promoting immunization campaigns by healthcare systems with the support of scientific societies.

Global Measles Surveillance: Trends, Challenges, and Implications for Public Health Interventions.

Measles, a highly contagious disease primarily affecting children, carries serious health risks, including complications and mortality. Vaccination remains the most effective preventive measure against measles transmission. The COVID-19 pandemic has exacerbated challenges in surveillance and immunization efforts, leaving millions of people exposed to preventable diseases such as measles. Globally accelerated immunization campaigns are critical for achieving regional elimination goals and mitigating the risk of outbreaks. Our team has developed an open-access database for global measles monitoring, facilitating standardized data collection and analysis. The analysis of measles cases from 2011 to 2023 reveals fluctuating trends, with notable increases in Africa in 2019 and 2023, indicating potential gaps in control strategies. Using an automated signal detection tool developed by the European Centre for Disease Prevention and Control (ECDC) team, we identified significant variations between World Health Organization (WHO) regions, underscoring the importance of continuous monitoring to detect epidemiological changes early. These results underscore the need for robust surveillance systems and accelerated vaccination efforts to safeguard public health.

Distinct Adverse Reactions to mRNA, Inactivated Virus, and Adenovirus Vector COVID-19 Vaccines: Insights from a Cohort Study on Atopic and Non-Atopic Subjects in Brazil.

The emergence of COVID-19 caused by SARS-CoV-2 prompted an unprecedented global response to develop vaccines at an accelerated pace. Messenger RNA (mRNA) and adenovirus vector vaccines emerged as the frontrunners in global immunization efforts, significantly reducing hospitalization, severity, and mortality, supplemented by inactivated virus-based vaccines in developing countries. However, concerns regarding adverse effects, including allergic reactions, have been raised. This study aimed to investigate the adverse effects following COVID-19 vaccination, particularly in atopic and non-atopic individuals. A cohort of 305 volunteers receiving BNT162, ChAdOx1, or CoronaVac vaccines were assessed based on a Skin Prick Test (SPT), specific IgE levels, and clinical history of asthma and rhinitis. Adverse effects were self-reported and scored across the different vaccination shots. The results indicated a notable presence of mild adverse effects following the first and third doses, regardless of vaccine type. ChAdOx1 recipients experienced more adverse effects compared to those receiving BNT162 and CoronaVac, including headaches, muscle pain, fever, chills, nausea, and flu-like symptoms. Atopic individuals receiving ChAdOx1 reported more adverse effects, such as muscle pain, fever, and chills, compared to non-atopic individuals. Conversely, headaches were more frequently reported in non-atopic individuals receiving BNT162 compared to atopic individuals. No anaphylaxis or allergic reactions were reported, indicating valuable evidence supporting the safety of COVID-19 vaccination in individuals with respiratory allergies. This study highlights the importance of understanding vaccine-related adverse effects, particularly in vulnerable populations, to inform vaccination strategies and address safety concerns in global immunization campaigns.