Surveillance of Adverse Events Following Immunization (AEFI) - Post COVID 19 vaccination

Vaccination is a safe and effective way to prevent disease and save lives, but they may also produce some undesirable side effects which may affect the healthy individuals. Therefore, the monitoring of adverse events following immunization is necessary. Any untoward medical occurrence which follows immunization, and which does not necessarily have a causal relationship with the use of the vaccine. The adverse event may be any unfavorable or unintended sign, an abnormal laboratory finding a symptom or a disease. AEFI surveillance studies helps to detect to identify a specific risk among the local population. In this study, we included 20 healthcare workers who were admitted in Gandhi medical college and hospital following immunization by Covid vaccination drive. No major AEFI was reported following vaccination. Our study concludes that proper counselling about the need for covid vaccination and the possible adverse events following vaccination would create an awareness among the public would prevent them from apprehension of second dose after developing AEFI following first dose.

Incidence of adverse events following immunization (AEFI) among infants after immunization with primary doses of scheduled vaccines in district Srinagar (J&K)

Immunization is the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine. However, like other medicinal products, vaccines are not free from adverse reactions. AEFI is any untoward medical occurrence which follows immunization and which does not necessarily have a causal relationship with the usage of the vaccine. The reporting of AEFI’s from the routine system is inadequate due to many reasons. Hence this study was conducted to throw some light and provide the baseline data. To find out the incidence of adverse events following immunization among infants in District Srinagar. It was a prospective study in which parents of infants receiving vaccines were contacted telephonically after specified time intervals to verify the occurrence of adverse events. The children were followed till 30 days of the administration of vaccines up to measles rubella vaccine. The incidence of AEFI reported in this study was 23.03% with 95% CI (22.24% to 23.85%). The most frequently reported AEFI was Fever (54.90%, n=1322), followed by Diarrhea (8.30%, n=200) and Vomiting (8.14%, n=196). AEFI were more in frequency during first week of receiving vaccine and most of the parents of children did not report AEFI after 7 days after vaccination. This study reveals that most of the vaccines associated adverse reactions were of mild and non-serious type and rarely of serious nature, yet proper monitoring of vaccine associated adverse reactions; is too essential. Proper and complete reporting of AEFI’s by field workers needs to be encouraged.

Utilization of the evidence from studies with no events in meta-analyses of adverse events: an empirical investigation

Backgrounds Zero-events studies frequently occur in systematic reviews of adverse events, which consist of an important source of evidence. We aimed to examine how evidence of zero-events studies was utilized in the meta-analyses of systematic reviews of adverse events. Methods We conducted a survey of systematic reviews published in two periods: January 1, 2015, to January 1, 2020, and January 1, 2008, to April 25, 2011. Databases were searched for systematic reviews that conducted at least one meta-analysis of any healthcare intervention and used adverse events as the exclusive outcome. An adverse event was defined as any untoward medical occurrence in a patient or subject in healthcare practice. We summarized the frequency of occurrence of zero-events studies in eligible systematic reviews and how these studies were dealt with in the meta-analyses of these systematic reviews. Results We included 640 eligible systematic reviews. There were 406 (63.45%) systematic reviews involving zero-events studies in their meta-analyses, among which 389 (95.11%) involved single-arm-zero-events studies and 223 (54.93%) involved double-arm-zero-events studies. The majority (98.71%) of these systematic reviews incorporated single-arm-zero-events studies into the meta-analyses. On the other hand, the majority (76.23%) of them excluded double-arm-zero-events studies from the meta-analyses, of which the majority (87.06%) did not discuss the potential impact of excluding such studies. Systematic reviews published at present (2015-2020) tended to incorporate zero-events studies in meta-analyses than those published in the past (2008-2011), but the difference was not significant (proportion difference=−0.09, 95% CI −0.21 to 0.03, p = 0.12). Conclusion Systematic review authors routinely treated studies with zero-events in both arms as “non-informative” carriers and excluded them from their reviews. Whether studies with no events are “informative” or not largely depends on the methods and assumptions applied, thus sensitivity analyses using different methods should be considered in future meta-analyses.

Safety of the APOLLO Onyx delivery microcatheter for embolization of brain arteriovenous malformations: results from a prospective post-market study

BackgroundCatheter retention and difficulty in retrieval have been observed during embolization of brain arteriovenous malformations (bAVMs) with the Onyx liquid embolic system (Onyx). The Apollo Onyx delivery microcatheter (Apollo) is a single lumen catheter designed for controlled delivery of Onyx into the neurovasculature, with a detachable distal tip to aid catheter retrieval. This study evaluates the safety of the Apollo for delivery of Onyx during embolization of bAVMs.MethodsThis was a prospective, non-randomized, single-arm, multicenter, post-market study of patients with a bAVM who underwent Onyx embolization with the Apollo between May 2015 and February 2018. The primary endpoint was any catheter-related adverse event (AE) at 30 days, such as unintentional tip detachment or malfunction with clinical sequelae, or retained catheter. Procedure-related AEs (untoward medical occurrence, disease, injury, or clinical signs) and serious AEs (life threatening illness or injury, permanent physiological impairment, hospitalization, or requiring intervention) were also recorded.ResultsA total of 112 patients were enrolled (mean age 44.1±17.6 years, 56.3% men), and 201 Apollo devices were used in 142 embolization procedures. The mean Spetzler–Martin grade was 2.38. The primary endpoint was not observed (0/112, 0%). The catheter tip detached during 83 (58.5%) procedures, of which 2 (2.4%) were unintentional and did not result in clinical sequelae. At 30 days, procedure related AEs occurred in 26 (23.2%) patients, and procedure-related serious AEs in 12 (10.7%). At 12 months, there were 3 (2.7%) mortalities, including 2 (1.8%) neurological deaths, none of which were device-related.ConclusionThis study demonstrates the safety of Apollo for Onyx embolization of bAVMs.Clinical trial registrationCNCT02378883.

Some adverse events following immunization in veterinary medicine

Vaccines are a very effective tool for the prevention and eradication of infective diseases in both veterinary and human medicine. Although for safety reasons, vaccines undergo very strict controls before being placed on the market, the risk of adverse reactions is not eliminated. According to the World Health Organization (WHO), adverse event following immunization (AEFI) is any untoward medical occurrence that follows immunization and which does not necessarily have a causal relationship with the usage of the vaccine. Adverse reactions may arise as a direct consequence of immunization due to the specificity of the vaccine itself, the quality of the vaccine or the immunization errors. In addition, adverse reactions may also be the result of a coincidental relationship between the effect and immunization. However, biological mechanisms of AEFI are very complex. During the mass vaccination campaigns, when a large number of animals are vaccinated in a short period of time, adverse reactions are expected to be the most frequently reported. In Serbia, livestock is currently being vaccinated against Lumpy Skin Disease, Bluetongue, and Classical swine fever.