Adverse Events Following Immunization Cases Research Articles

Surveillance for adverse events following immunization in Hebei Province, China, 2018-2020

ABSTRACT The aim of this study was to analyze the incidence and characteristics of adverse events following immunization (AEFI) with post-licensure vaccines used in Hebei province from 2018 to 2020 and to evaluate the safety of vaccines. All information of AEFI was gained from national adverse event following immunization surveillance system (NAEFISS) in Hebei Province from 2018 to 2020. Descriptive epidemiology method was used to analyze the data about AEFI in Hebei province. Reporting rates of AEFI were calculated by sex, age, city, categories of AEFI, severity of AEFI, reaction categories, etc. A total of 35,999 AEFI were reported through NAEFISS, and the average annual rate was 47.64/100,000 doses. The reporting rates of common adverse reactions and rare adverse reactions were 46.37/100,000 doses and 1.05/100,000 doses. The male-to-female ratio was 1.26:1. Most of the AEFI were concentrated in the ≤1 year age group and were reported in the second quarter and third quarter. The majority of AEFI were reported to be recovered or improved, and about 62% of the AEFI occurred within 24 hours after vaccination. Vaccines associated with the highest reporting rate of AEFI were diphtheria, tetanus and acellular pertussis combined vaccine (DTaP, 170.45/100,000 doses). The reporting rate of allergic rash was found to be the highest in the adverse reactions (0.29/100,000 doses). The majority of AEFI cases were common adverse reactions, while serious rare adverse reactions caused by vaccines were extremely uncommon, and all vaccines used in Hebei Province were safe.

Adverse events following immunization of co- and separate administration of DTaP-IPV/Hib vaccines: A real-world comparative study

ABSTRACT To fully understand the safety of DTaP-IPV/Hib vaccination, we evaluated the differences between DTaP-IPV/Hib co-administration and separate administration of the DTaP, IPV and Hib vaccines (DTaP+IPV+Hib) based on adverse events following immunization (AEFI). All AEFI reported in Hebei Province, China, between 2020 and 2022 were included in this study. The risk difference (RD%), relative risk (RR), and Chi-square value were used to compare the differences in reported rates of AEFI between the DTaP-IPV/Hib and DTaP+IPV+Hib groups. From 2020 to 2022, 130 AEFI cases were reported in Hebei Province after DTaP-IPV/Hib vaccination, corresponding to an AEFI reported rate of 66.9/million doses, which was significantly lower than that for DTaP+IPV+Hib (9836 AEFI with a reported rate of 637.8/million doses). The overall reported rate of non-severe AEFI for DTaP+IPV+Hib vaccines was 9.5 times that of DTaP-IPV/Hib vaccination [95% confidence interval (CI): 8.0, 11.3]. Meanwhile, the reported rate of AEFI among infants aged 0–1 y was 9.8 times higher for DTaP+IPV+Hib than for DTaP-IPV/Hib (95% CI: 8.2, 11.7). DTaP+IPV+Hib vaccination also resulted in higher risks of high fever, localized redness and swelling, localized induration, and allergic rash compared with DTaP-IPV/Hib vaccination. The risk of AEFI, which were mostly mild reaction, was higher after vaccination with DTaP+IPV+Hib than after DTaP-IPV/Hib vaccination.

Analysis of Adverse Events Post-13-Valent Pneumococcal Vaccination among Children in Hangzhou, China.

With the widespread use of the 13-valent pneumonia vaccine (PCV13) in China, monitoring adverse events following immunization (AEFIs) is critical. We conducted a descriptive analysis of the AEFI occurrences reported within Hangzhou between the years 2020 and 2023, including the temporal trend of case reports and variables such as sex, age, type of PCV13, dose number, type of reporter, cause-specific classification, severity, and onset from vaccination. Vaccine safety signals were analyzed using reporting odds ratios (RORs). Over the 4 years analyzed in the study, 2564 AEFI cases were reported, including seven severe cases. Most AEFIs occurred within 0-1 days after vaccination (2398, 93.53%), with over half affecting infants aged 1.5-6 months of age. No statistically significant difference was observed between PCV13-TT and PCV-CRM197. Seasonal differences in AEFI reports were noted. Positive signals were detected for fever (ROR-1.96SE: 1.64) and persistent crying (ROR-1.96SE: 1.61). Four serious AEFI cases were coincidental events, while three others were considered vaccine-related cases (including one case each of allergic reaction, febrile seizure, and thrombocytopenia). The safety and tolerability of PCV13 are good, and attention should be paid to severe AEFIs, as well as long-term safety disparities between different types of PCV13.

Adverse events following immunization reported with COVID-19 vaccines in Burkina Faso: Analysis of spontaneous reports

The rapid deployment of COVID-19 vaccines to a large proportion of the population requires a focus on safety. However, few studies have assessed the safety of COVID-19 vaccines in Africa. In Burkina Faso, this issue has not yet been addressed. The objective of this study was to contribute to the description of the characteristics of adverse events following immunization (AEFIs) related to COVID-19 vaccines in Burkina Faso. This was a cross-sectional descriptive retrospective study of spontaneous reports of COVID-19 vaccine-related AEFIs recorded in VigiBase® between June 2021 and November 2022 in Burkina Faso. Individual case safety reports (ICSRs) were extracted from VigiBase® using the Anatomical Therapeutic Chemical level 2 (ATC2) code. The proportion of ICSRs according to the reporter’s qualification, the reporting rate, the time taken to submit and record ICSRs, and the completeness score were calculated. A total of 973 ICSRs concerned COVID-19 vaccines and represented 32.6% of all 2,988 reports in VigiBase®. Overall, 82.0% of the reporters were nurses/midwives, 7.8% were physicians, 6.7% were pharmacists, and 3.4% were patients. The median time between the onset of AEFIs and the submission of the report to the Pharmacovigilance Center was 180 days (IQR: 136; 281). The median registration time was 188 days (IQR: 149; 286). The mean ICSR completeness score was 0.8 (standard deviation = 0.1). The overall AEFI reporting rate was 27.8 per 100,000 vaccine doses. The AEFI reporting rates for the ChAdOx1-nCoV-19, JNJ 78436735, Elasomeran, Tozinameran, and HB02 vaccines were 454.2, 17.4, 11.0, 10.2, and 0.4 per 100,000 vaccine doses, respectively. The majority of AEFIs were systemic in nature (90.1%). Headache (21.2%), fever (19.4%), and myalgia (11.0%) were the most frequently reported AEFIs. Eighteen cases (1.8%) of serious AEFIs (9 hospitalizations, 4 life threatening, 3 temporary disabilities, and 2 others unspecified) were reported. The majority of AEFIs reported were systemic in nature and mild. However, there have been reports of serious AEFIs. The overall AEFI reporting rate was low. There is a need to strengthen the monitoring of these vaccines to better organize strategies to optimize the adherence of the population of Burkina Faso.

Adverse events following immunization (AEFIs) with anti-meningococcus type B vaccine (4CMenB): Data of post-marketing active surveillance program. Apulia Region (Italy), 2019–2023

The four-component recombinant-DNA anti-meningococcus B vaccine (4CMenB) has been approved by the European Medicines Agency in 2013. In Italy, 4CMenB is recommended since 2017 for use in infants under one year of age. Due to the strong evidence of increased risk of fever after administration, surveillance of adverse events following immunization (AEFIs) is a priority for 4CMenB.This cross-sectional prospective study aims at investigating 4CMenB’s safety profile. The study population is represented by infants under twelve months of age vaccinated with 4CMenB in selected ambulatories in Apulia, a region in South-Eastern Italy, from October 1st, 2020, to March 31st, 2023. Parents were provided with a post-vaccination diary covering up to seven days after immunization and were contacted one week after the vaccination day. Information about AEFIs was collected, and reactions were classified following World Health Organization guidelines. For serious AEFIs, causality assessment was carried out. AEFI risk determinants were investigated via logistic regression.A total of 4,773 diaries were completed, with 78.13 % of them (3,729/4,773) containing one or more AEFI reports. Systemic reactions such as malaise, drowsiness/insomnia and fatigue were the most common ones, followed by fever and local pain, tenderness, redness and swelling.Twenty-three cases of serious AEFIs were reported. Following causality assessment, 78.26 % of serious adverse events (18/23) were deemed to have a consistent causal association with the administration of 4CMenB (reporting rate: 0.38 %). Three infants were hospitalized following vaccination, but no cases of death or permanent/severe impairment were reported. Prophylactic paracetamol administration showed a significant protective effect against the risk of manifesting fever within the first 24 h after administration (OR: 0.75; p < 0.005).Our data confirms existing evidence regarding the safety of 4CMenB vaccination in babies under 2 years of age, but also highlight a significant risk of fever after vaccination. Prophylactic paracetamol administration could represent a protective factor against fever, especially during the first 24 h after vaccination.

Evaluation of vaccination status of children with special health care needs in Suzhou, China, 2020-2022: A retrospective survey study

ABSTRACT Children with special health care needs (CSHCNs) are at an increased risk of vaccine-preventable infections (VPDs), but they also face the dilemma of vaccine hesitancy. We obtained information on pediatric visits from the Referral and Assessment Information System for Vaccination (RAISV) and information on vaccination from the Jiangsu Province Immunization Information System (JSIIS). We followed the occurrence of Adverse Events Following Immunization (AEFIs) and VPDs by actively calling and querying the China Information System for Disease Control and Prevention (CISDCP). The Poisson test was used to compare the incidence of AEFIs between groups. A total of 5,037 children who visited a vaccination assessment clinic were followed-up in this study. The majority were children with developmental anomalies (28.5%), certain conditions originating in the perinatal period (12.1%), and nervous system disorders (9.0%). Most CSHCNs (66.9%) were advised to have all vaccines according to routine practice, 29.0% were advised to have partial vaccination, and 4.1% were advised to delay all vaccines and wait for future assessment. A total of 201 (4.0%) CSHCNs were not vaccinated, although they were assessed to be eligible for vaccination. By querying the immunization planning module in CISDCP, we observed 55 AEFI cases, which amounted to an incidence rate of 1.2 per 1,000, and the occurrence of abnormal reactions was not significantly different compared with the general population. The vaccination program following the designed workflow for CSHCNs was safe and could be recommended in other areas.

Cholera and COVID-19 pandemic prevention in multiple hotspot districts of Uganda: vaccine coverage, adverse events following immunization and WASH conditions survey

BackgroundBetween March, 2020 and December, 2021 due to cholera and coronavirus disease 2019 (COVID-19) pandemics, there were 1,534 cholera cases with 14 deaths and 136,065 COVID-19 cases with 3,285 deaths reported respectively in Uganda. This study investigated mass vaccination campaigns for the prevention of the two pandemics namely: oral cholera vaccine (OCV) and COVID-19 vaccine coverage; adverse events following immunization (AEFI); barriers and enablers for the vaccine uptake and assessed water, sanitation and hygiene (WASH) conditions in the six cholera and COVID-19 hotspot districts of Uganda.MethodsA household survey was conducted between January and February, 2022 in the six cholera hotspot districts of Uganda which had recently conducted OCV mass vaccination campaigns and had ongoing COVID-19 mass vaccination campaigns. The survey randomly enrolled 900 households with 4,315 persons of whom 2,085 were above 18 years. Data were collected using a data entry application designed in KoBoToolbox and analysed using STATA version 14. Frequencies, percentages, odds ratios, means, confidence intervals and maps were generated and interpreted.ResultsThe OCV coverage for dose one and two were 85% (95% CI: 84.2—86.4) and 67% (95% CI: 65.6—68.4) respectively. Among the 4,315 OCV recipients, 2% reported mild AEFI, 0.16% reported moderate AEFI and none reported severe AEFI. The COVID-19 vaccination coverage for dose one and two were 69.8% (95% CI: 67.8–71.8) and 18.8% (95% CI: 17.1–20.5) respectively. Approximately, 23% (478/2,085) of COVID-19 vaccine recipient reported AEFI; most 94% were mild, 0.6% were moderate and 2 cases were severe. The commonest reason for missing COVID-19 vaccine was fear of the side effects. For most districts (5/6), sanitation (latrine/toilet) coverage were low at 7.4%—37.4%.ConclusionThere is high OCV coverage but low COVID-19 vaccine and sanitation coverage with high number of moderate cases of AEFI recorded due to COVID-19 vaccines. The low COVID-19 vaccine coverage could indicate vaccine hesitancy for COVID-19 vaccines. Furthermore, incorporation of WASH conditions assessment in the OCV coverage surveys is recommended for similar settings to generate data for better planning. However, more studies are required on COVID-19 vaccine hesitancy.

Safety of delayed vaccination with the national immunization program vaccines in children aged 0-6 years from 2019 to 2021 in Xuhui District, Shanghai City in China

Objective: To understand the incidence of delayed vaccination with the national immunization program vaccines among children aged 0-6 years in Xuhui District, Shanghai, and to evaluate the safety of delayed vaccination. Methods: A stratified random sampling was used to obtain six vaccination clinics in Xuhui District, Shanghai. The vaccination records of children 0-6 years from these six vaccination clinics were collected from the Shanghai Immunization Program Information Management System. Adverse events following immunization (AEFI) data were collected from the China Information System for Disease Control and Prevention. Descriptive epidemiology was used to analyze the data. Children were divided into the timely vaccination group and delayed vaccination group according whether they were delayed in vaccination (received one month or more after the recommended age among children aged ≤1 year; received three months or more after the recommended age among children aged >1 year). The safety of four vaccination methods-individual vaccination, simultaneous vaccination, routine vaccination and combined vaccination-were further compared. Differences between groups were compared using chi-square test. Results: From 2019 to 2021, six vaccination clinics in Xuhui District administered 124 031 doses of the national immunization program vaccines among children aged 0-6 years, and delayed vaccinations accounted for 25.99% (32 234/124 031) of these doses. In 2020, the delayed vaccination rate during the first-level COVID-19 public health emergency response period in Shanghai was significantly higher than that in the same period in 2019 (34.70% vs. 24.19%, χ2=136.23, P<0.05). The delayed vaccination rate during the COVID-19 vaccination campaign in 2021 was significantly higher than that in the same period in 2019 (25.27% vs. 22.55%, χ2=82.80, P<0.05). From 2019 to 2021, a total of 475 cases of AEFI were reported in six vaccination clinics, with a reported incidence of 382.97 per 100 000 doses, including 421 cases of common adverse reaction (88.63%, 339.43 per 100 000 doses), 51 cases of rare adverse reaction (10.74%, 41.12 per 100 000 doses) and 3 cases of coincidences (0.63%, 2.42 per 100 000 doses). The reported incidence of AEFI among delayed vaccinations was significantly lower than that among timely vaccinations (291.62 per 100 000 doses vs. 415.05 per 100 000 doses). The incidence of AEFI for the four delayed vaccination methods (individual vaccination, simultaneous vaccination, routine vaccination and combined vaccination) was lower than that for timely vaccination. There were significant differences between the groups except for the routine vaccination group (χ2=9.82, P<0.05; χ2=5.46, P<0.05; χ2=2.97, P>0.05; χ2=11.89, P<0.05). Conclusions: In Xuhui District of Shanghai, 25.99% of doses of the national immunization program vaccines administered to children 0-6 years were delayed. Delayed vaccination does not increase the risk of AEFI compared with timely vaccination.

Imprecision in vaccine adverse event reporting and a methodological analysis of reporting systems to improve pharmacovigilance and public health.

This study documents imprecision in Japanese reports of adverse events following immunization (AEFI). In doing so, it presents methods to analyze this imprecision. These methods include use of unique Japanese data on the validity of certain AEFIs. They also include ways to estimate AEFI rates, which allow comparison of AEFI data between countries. Using US AEFI data for comparison, we show how differences in AEFI reporting systems likely influence AEFI statistics. Although our comparisons of AEFI rates are not precise, many of the difference we detected between Japanese and US statistics make sense and reflect differences in the societal and medical perspectives on various vaccines or can be explained by differences in the reporting systems including reporting sources. For example, differences in societal and medical perspective probably underly the extraordinarily high Japanese rates of anaphylaxis and other AEs following HPV immunizations from 2010 to 2016 compared to US rates and to Japanese rates for other vaccines. High US rates of reported Guillain-Barré syndrome following influenza vaccination relative to Japanese rates and to rates for other US vaccines are consistent with data suggesting that the index of suspicion for such reactions could affect AEFI rates. The findings that over half of Japanese anaphylaxis reports for every vaccine are erroneous, and that close to half of "serious" Japanese AEFI cases probably are not serious may be due in part not only to explanations unique to Japan, but also to factors that apply to the USA and other countries. Differences in reporting systems account for a much higher rate of non-serious AEFI reports in the USA compared to Japan. Japanese marketing authorization holders are probably at least as assiduous and timely in their reporting of AEFIs as health care providers, though granular level differences are apparent in reporting by various sources. The methods we used to analyze the validity of Japanese statistics can be used to analyze the validity of AEFI reports from other countries and aid the harmonization of adverse event reporting systems. Eventually, similar reporting systems might be adapted for drugs and medical devices.

Safety of concomitant administration of inactivated hepatitis A vaccine with other vaccines in children under 16years old in post-marketing surveillance.

Concomitant administration refers to the receipt of two or more vaccines during a single healthcare encounter, which is an efficient way to increase vaccination coverage in children. However, the post-marketing safety studies of concomitant administration are scarce. Inactivated hepatitis A vaccine (Healive®) has been used widely in China and other countries for more than a decade. We aimed to explore the safety of Healive® co-administered with other vaccines compared to Healive® alone in children under 16years old. We retrieved Adverse Events Following Immunization (AEFI) cases and vaccination doses of Healive® during 2020-2021 in Shanghai, China. The AEFI cases were divided into concomitant administration group and Healive® alone group. We used administrative data on vaccine doses as denominators to calculate and compare crude reporting rates between groups. We also compared baseline gender and age distribution, clinical diagnoses, and time interval from vaccination to onset of symptoms between groups. A total 319,247 doses of inactivated hepatitis A vaccine (Healive®) were used and 1,020 AEFI cases (319.50 per million doses) associated with Healive® were reported during 2020-2021 in Shanghai. There were 259,346 doses concomitantly administered with other vaccines and 830 AEFI cases (320.04 per million doses) were reported. There were 59,901 doses of Healive® that vaccinated alone, with 190 AEFI cases (317.19 per million doses). There was only one case with serious AEFI in concomitant administration group, with a rate of 0.39 per million doses. Reported rates of AEFI cases were similar between groups in general (p>0.05). Concomitant administration of inactivated hepatitis A vaccine (Healive®) with other vaccines has a similar safe profile as Healive® alone.

Vaccination against COVID-19: Surveillance of Adverse Events in Brazzaville

Introduction: All countries have embarked on vaccinating populations against COVID-19 to reduce the incidence and severe forms of this disease. Several vaccines are used and the risk of occurrence of Adverse Events Following Immunization (AEFI) is not to be neglected. The objective of this study is to describe the AEFI of COVID-19 vaccination in Brazzaville. Population and Method: This was a descriptive cross-sectional study conducted in Brazzaville at all AEFI reporting points of the Expanded Programme on Immunization in the period from March 25th to October 15th 2021. A standardized notification sheet of AEFI cases occurring after vaccination against COVID-19, validated by the WHO, collected the data. These have been analyzed with R Studio software version 4.0.3. Qualitative variables were expressed in numbers and percentages. Quantitative variables were expressed as average, standard deviation, maximum and minimum. Pearson's Chi-2 test and ANOVA's were used to compare variables. Results: The average age of people with AEFI was 46 years ± 12.6 years; men were more affected than women non-significantly (p-value=0.063). AEFI frequencies were 56 per 10,000 people vaccinated. Mild AEFI such as joint and muscle pain (63.07%), headache (59.70%) fever (55.84%) were the most recorded while severe forms were rare. These AEFI appeared most often in the first week of administration of the COVID-19 vaccine and had a favorable evolution in 90.69% of cases. Conclusion: This study revealed that vaccination against COVID-19, can cause AEFI. These are infrequent and in most cases they are mild forms. High vaccination coverage must be a priority objective to better counter the COVID-19 pandemic.

Adverse events following vaccination against coronavirus disease 2019

To overcome the coronavirus disease 2019 (COVID-19) pandemic, large-scale vaccination is proceeding worldwide. As of December 23, 2021, 10 novel vaccines against COVID-19 had been validated for use by the World Health Organization (WHO), including BNT162b2 (Pfizer/BioNTech), mRNA-1273 (Moderna), AZD1222 (AstraZeneca), and Ad26.COV2.S (Janssen). These novel vaccines against COVID-19 showed acceptable safety profiles in randomized clinical trials. Most adverse events following immunization (AEFIs) associated with these novel vaccines ranged from mild to moderate and improved within a few days after administration. However, serious adverse events associated with vaccines that were not observed in the clinical trials were reported in real-world data. Adverse events of special interest include not only anaphylaxis or neurologic disorders (such as Guillain-Barré syndrome, transverse myelitis, or seizure) but also myocarditis or pericarditis associated with the messenger RNA (mRNA) vaccines and thrombosis with thrombocytopenia syndrome associated with the adenovirus-vector vaccines. Although several fatal cases of serious AEFIs that may have been related to vaccination have been reported, it is recommended to continue vaccination because the benefits of vaccines’ preventive effects against COVID-19 outweigh the risks of rare serious adverse events. Long-term monitoring of various AEFIs and sharing of clinical experiences are necessary for safe and efficient large-scale vaccination.

Safety evaluation on concomitant immunization with inactivated poliomyelitis vaccine produced from Sabin strains and other vaccines (from 2015 to 2020)

ABSTRACT Objective To evaluate the safety of concomitantly administering inactivated poliomyelitis vaccine produced from Sabin strains (sIPVs) with other vaccines. Methods A descriptive analysis was carried out on adverse events following immunization (AEFI) based on the administration of sIPV alone or concomitant with other vaccines (from 2015 to 2020) using data from the national AEFI surveillance system of China (CNAEFIS). All adverse reactions (ADRs) of the concomitant immunization were coded using a medical dictionary for regulatory activities (MedDRA) before comparison. Results The CNAEFIS reported a total of 9130 sIPV-related AEFI cases, including 6842 AEFI cases collected after immunization with sIPV alone and 2288 AEFI cases collected after immunization of sIPV concomitant with other vaccines. The combination of sIPV with diphtheria, tetanus and pertussis vaccine (DTaP) was correlated with the highest frequency of AEFI, which accounted for 53.50% of all 2288 AEFI cases. After MedDRA-based coding, the most frequent ADR was fever (70.18%), followed by erythema and swelling at the injection site (6.95%), induration at the injection site (3.85%), dermatitis allergy (3.56%) and urticaria (1.55%). A statistically significant difference (P < .001) was found between sIPV immunization and sIPV immunization concomitant with other vaccines for general reactions (95.36% and 93.22%, respectively) and abnormal reactions (4.64% and 6.78%, respectively). Conclusion No new safety signal is found for sIPV administered concomitantly, although its administration with other vaccines may increase the occurrence of abnormal reactions. Vaccine manufacturers should focus on the safety of administering sIPV with DTaP and carry out relevant clinical studies when necessary.

Adverse event following vaccine surveillance in Kaduna State, Northwestern Nigeria (January 2018 -June 2019): analysis of health facility´s records.

IntroductionAdverse Events Following Immunization (AEFI) are one of the main reasons for inadequate immunization coverage in Kaduna State, and AEFI underreporting serves as a barrier to achieving goals of global pharmaco-vigilance for vaccine. The purpose of this study is to estimate the completeness of variables in the AEFI line-listing forms, calculate AEFI reporting rates by Local Government Areas & vaccine type and profile the reported cases according to their reactions.Methodswe conducted a descriptive, cross-sectional, retrospective study of primary surveillance records. We calculated AEFI reporting rates in the State and Local Government areas and AEFI Vaccine reaction rates to the various antigens. We used Binary logistic regression to determine the association between gender and vaccine reactions.Resultsseven thousand eight hundred and twenty-four (7,824) AEFI cases were reported. The completeness of variables on the filled AEFI line-list varied from 21% to 100%. The State had a high AEFI reporting rate of 9.09 per 10,000 administered doses. Fever (<38oC) was the main AEFI reaction. Severe AEFI cases accounted for only 0.89% of the total reported cases. Pentavalent vaccine was the suspect antigen responsible for the highest number of AEFI cases, with a vaccine reaction rate of 44.77 per 10,000 doses. The Zaria Local Government area had the highest AEFI reporting rate, while the Sanga Local Government area had the lowest AEFI reporting rate in the State. The difference between genders in the number of reported AEFI cases was not statistically significant (p>0.05). There were 35% higher odds of occurrence of bleeding among males than among females (aOR: 1.354; P-value: p=.012; 95% CI: 1.070-1.715; Nagelkerke-R2-: 0.003). The other reactions were not significantly related to gender.Conclusionour study shows a higher occurrence of severe AEFI in subjects undergoing pentavalent vaccine. Thiscaused the highest incidence of AEFI. There was no significant association between gender and AEFI reactions.

The characteristics and trend of adverse events following immunization reported by information system in Jiangsu province, China, 2015\u20132018

ObjectiveAdverse events following immunization is an important factor influencing public trust in vaccination. Publicizing its incidence timely can increase public trust. The aim of this study is to describe the incidence and characteristics of adverse events following immunization in Jiangsu province of China from 2015 to 2018.MethodsAll information of adverse events following immunization (AEFIs) was gained from Jiangsu Province Vaccination Integrated Service Management Information System. The reported AEFI trend was analyzed using Chi-square test.ResultsA total of 77,980 AEFI cases were reported through the AEFI system; Among which, 77,731 were classified as non-serious AEFI cases and 249 were serious AEFI cases. The male to female ratio was 1.31:1, cases less than 7 years old accounted for 97.7%. The total estimated AEFI rate was 62.70/100,000 doses. By severity, 60.75/100,000, 4.46/100,000 and 0.11/100,000 AEFI cases were common vaccine reaction, rare vaccine reaction, and serious rare vaccine reaction, respectively. The top two serious AEFI were thrombocytopenic purpura and febrile. The incidence rates showed the increasing trend and the linear trend of the increasing incidence rates passed the significant test at 0.05 levels.ConclusionThe sensitivity of AEFI monitoring in Jiangsu Province is increasing and higher than the national average and most countries. The majority of AEFI cases were common adverse reactions, while the serious vaccine reactions caused by vaccines were extremely low. To elevate the sensitivity of AEFI surveillance may reduce the incidence of developing serious AEFI cases.

Adverse events following immunization in pregnant women from Minas Gerais.

ABSTRACTOBJECTIVE:To analyze the distribution of adverse events following immunization (AEFI) in pregnant women in the state of Minas Gerais, between 2015 and 2019.METHODS:This is an epidemiological, descriptive study conducted with AEFI data from 2015 to 2019, recorded in the Adverse Events Surveillance Information System, in the state of Minas Gerais (MG), Brazil. A total of 670 AEFI were analyzed in pregnant women. The estimates were presented in proportions, according to the year of occurrence, health macro-region of Minas Gerais and immunobiological administered.RESULTS:The year in which there were the most records was 2017 (36.8%). Among the 14 macro-regions, the ones with the lowest and highest number of records were the Vale do Jequitinhonha (0.5%) and Center (31.8%), respectively. The vaccines contraindicated during pregnancy represented 27.6% of the total notifications. The total of 69.5% of the cases were considered immunization errors. In 75.9% of the records, the variable of medical care was ignored, and in 73.7% of the cases no information on the evolution was presented.CONCLUSION:This study shows the need for continuing education for the multidisciplinary team, in order to reduce cases of AEFI and ensure the adequate completion of notifications by health professionals.

Post-marketing safety surveillance for inactivated Enterovirus 71 vaccines in Jiangsu, China from 2017 to 2019

IntroductionTwo types of enterovirus 71 (EV71) vaccines, manufactured using human diploid (H2) and Vero cells, have been administered in Jiangsu Province, China since 2017. In this study, we evaluated their safety profiles using records collected from the Chinese National Adverse Events Following Immunization (AEFIs) Information System (CNAEFIS) and Electronic Immunization Registries System (EIRS) between 2017 and 2019. MethodsDemographic characteristics of the patients, AEFI incidence rates(IRs), symptoms, and time intervals were summarized from the reported AEFI data in the CNAEFIS. Also, the administered doses of the two vaccines were exported from the EIRS to calculate the IRs of AEFIs and thus compare the AEFIs between the two types of EV71 vaccines. ResultsIn total, 209, 407, and 344 AEFIs cases following EV71 vaccine administration were reported during 2017, 2018, and 2019, respectively, yielding IRs of 59.2, 48.2, and 54.2 per 100,000 doses, respectively. Fever, irritability, allergic eruptions, fatigue, loss of appetite, redness and induration at the injection site were the most commonly reported AEFIs. No significant differences in rare reactions were found between the two types of EV71 vaccinations. The majority of AEFIs were developed within 30 min to 3 days after administration. ConclusionEV71 vaccines showed satisfactory safety profiles since their first use 3 years ago in the Jiangsu Province. The AEFI profiles were identical to those in pre-marketing studies; most AEFIs after vaccination were mild and common. More active surveillance studies should be performed to provide more comprehensive post-marketing safety data.

Epidemiological study of adverse events following immunization in under 5 year children

Background:The present study was conducted to study the socioeconomic and the demographic profile of children reporting with adverse events following immunization (AEFI) along with the determinants associated with AEFIs, based on investigation of each case and to assess the proportion of programmatic errors linked with AEFI cases.Materials and Methods:Record-based cross–sectional study conducted among sample of 118 cases of AEFI were reported. The case reports of all AEFI cases were procured and analyzed to identify factors associated with reported AEFI. The questionnaires related with preliminary investigation reports (PIRs) including forensic evidence of death cases were analyzed. Percentage analysis of data was done by proportions, measures of central tendencies, and Chi-square test.Results:Most of the cases reported were between 0 and 3 months of age constituting 39%. AEFI was seen more in male child than female. more than half of cases of AEFI were recorded following immunization with OPV/DPT/HBV together (66.94%). Most common AEFI reported were convulsion (68.64 %) and fever (58.47%) followed by local swelling at site of injection (11.86%). More than half of the cases of AEFI occurred within 12 hours of immunization (61.88%). Birth weight of most cases of AEFI were in the range between 2 and 2.4 kg (44.06%), followed by range between 2.5 and 2.9 kg (32.20%), the mean of birth weight was 2.51 kg.Conclusion:Convulsion was the most commonly reported AEFI, majority of AEFI occur within 12 h of immunization. Most of the AEFI were recorded following immunization with OPV/DPT/HBV together.

Surveillance for Adverse Events Following Immunization With COVID-19 Vaccines in Dalian, China

Background: Coronavirus disease 2019 (COVID-19) vaccines have been administered in priority populations in China since December 15, 2020. This study aims to assess the safety of the COVID-19 vaccination programme in Dalian, China.Methods: Passive surveillance for adverse events following immunization (AEFIs) with COVID-19 vaccines was performed by the Dalian Center for Disease Control and Prevention (CDC). Data were collected through June 8, 2021, from the Chinese National Adverse Events Following Immunization System (CNAEFIS) and were verified by local and upper-level CDCs.Findings: A total of 7.12 million doses of vaccine were administered from November 27, 2020, through June 8, 2021, and 623 vaccinees reported adverse events, resulting in a rate of 87.5 events per one million doses. The age-specific rates of AEFIs ranged from 74.0 per one million doses among persons aged 45 to 59 years to 102.0 per one million doses among persons aged 18 to 44 years; the manufacturer-specific rates ranged from 81.1 to 125.2 per one million doses. Among the 623 AEFIs, 544 (87.3%; rate, 76.4 per one million doses) were confirmed as common minor vaccine reactions. Very rare cases of anaphylaxis after vaccination were reported (5 cases; 0.7 per one million doses). Seven cases of AEFIs were classified as serious; however, available information indicated that there was no causal relationship with COVID-19 vaccination.Interpretation: No major safety concerns were identified during the COVID-19 vaccination campaign. There was no evidence of an increased risk of serious adverse events (SAEs).Funding Information: The study was supported by grants from the National Science Fund for Distinguished Young Scholars (No. 81525023), Key Emergency Project of Shanghai Science and Technology Committee (No. 20411950100).Declaration of Interests: H.Y. has received research funding from Sanofi Pasteur GlaxoSmithKline, Yichang HEC Changjiang Pharmaceutical Company, and Shanghai Roche Pharmaceutical Company. None of those research funding is related to development of COVID-19 vaccines. All other authors report no competing interests.

Safety evaluation of mass inoculation of 23 valent pneumococcal polysaccharide vaccine among elderly people aged 60 and above in Shanghai from 2013 to 2017

Objective: To evaluate the safety of 23 Valent Pneumococcal Polysaccharide Vaccine (PPV23) among eldly people aged 60 and above in Shanghai. Methods: A total of 1 310 660 monitoring data of adverse events following immunization (AEFI) of PPV23 among people aged 60 and above were collected through the National AEFI Surveillance System from September 14, 2013 to December 31, 2017 in Shanghai. And the descriptive epidemiological methods were used for analysis. Results: 433 cases of AEFI were reported from September 14, 2013 to December 31, 2017, with the incidence rate of AEFI was 33.04/100 000 doses. The general reactions were reported as 392 cases (90.53%), with 17 cases of abnormal reactions (3.93%), 23 cases of coincidences (5.31%) and 1 case of psychogenic reactions (0.23%). The reported incidence rates of general reactions and abnormal reactions of free PPV23 inoculation among elderly people in urban areas were 41.31 per 100 000 doses and 1.91/100 000 doses, respectively, which were higher than those in suburban areas (24.18/100 000 doses, 1.32/100 000 doses) and exurban areas (27.84/100 000 doses, 0.59/100 000 doses). The reported incidence rate of general reaction in females (35.38/100 000 doses) was higher than that in males (24.06/100 000 doses), and the reported incidence rate of abnormal reaction in males (1.58/100 000 doses) was higher than that in females (1.03/100 000 doses). The reported incidence rates of general and abnormal reactions were the highest in 60-64 years old group (62.65/100 000 doses and 4.87/100 000 doses, respectively). In addition, all patients with general reactions or abnormal reactions were better or cured. Conclusion: PPV23 vaccination is safe among people aged 60 and above in Shanghai.