Harmonizing the collection of solicited adverse events in prophylactic vaccine clinical trials

INTRODUCTION

During the clinical development of a vaccine, study participants are monitored for the occurrence of adverse events (AEs) over a defined period post-vaccination to assess the safety of prophylactic vaccines. Among the safety data collected, a standard practice in prophylactic vaccine clinical trials involves collecting reactogenicity data through daily AE solicitation of pre-defined sets of symptoms (i.e. solicited AEs).

AREAS COVERED

This paper aims to propose recommendations to improve and harmonize the collection of active AE solicitation in prophylactic vaccine clinical trials.

EXPERT OPINION

We recommend using limited lists of solicited AEs adapted to the vaccine technology and target population. While the US Food and Drug Administration toxicity grading scale is commonly used in adolescents/adults, harmonizing grading criteria in infants/children would facilitate the comparison of vaccines' safety profiles. Solicited systemic AEs should not systematically be considered causally related to vaccination. Collection of solicited AEs should occur in cohorts of a maximum of 1,000 vaccinated participants, as larger cohort sizes do not improve substantially the precision of AE incidence. The incidence of daily solicited AEs should be compared with a control group for improved interpretations of their clinical relevance. These suggestions would improve the characterization of safety profiles of vaccines.

A Clinical Practice Guideline for the Emergency Management of Anaphylaxis (2020)

Background: For anaphylaxis, a life-threatening allergic reaction, the incidence rate was presented to have increased from the beginning of the 21st century. Underdiagnosis and undertreatment of anaphylaxis are public health concerns. Objective: This guideline aimed to provide high-quality and evidence-based recommendations for the emergency management of anaphylaxis. Method: The panel of health professionals from fifteen medical areas selected twenty-five clinical questions and formulated the recommendations with the supervision of four methodologists. We collected evidence by conducting systematic literature retrieval and using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Results: This guideline made twenty-five recommendations that covered the diagnosis, preparation, emergency treatment, and post-emergency management of anaphylaxis. We recommended the use of a set of adapted diagnostic criteria from the American National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network (NIAID/FAAN), and developed a severity grading system that classified anaphylaxis into four grades. We recommended epinephrine as the first-line treatment, with specific doses and routes of administration for different severity of anaphylaxis or different conditions. Proper dosage is critical in the administration of epinephrine, and the monitor is important in the IV administration. Though there was only very low or low-quality evidence supported the use of glucocorticoids and H1 antagonists, we still weakly recommended them as second-line medications. We could not make a well-directed recommendation regarding premedication for preventing anaphylaxis since it is difficult to weigh the concerns and potential effects. Conclusion: For the emergency management of anaphylaxis we conclude that: • NIAID/FAAN diagnostic criteria and the four-tier grading system should be used for the diagnosis • Prompt and proper administration of epinephrine is critical.

Evaluation of chronic ocular sequelae in patients with symblepharon caused by ocular burns

AIM

To evaluate chronic ocular sequelae in patients with symblepharon caused by ocular burns and propose an objective grading system.

METHODS

This was a retrospective, single-center clinical study. Patients with symblepharon caused by ocular burns at least six months later were assessed. Chronic ocular sequelae were classified into 3 categories (eyelid, conjunctiva, and cornea) and 9 chronic ocular sequelae [friction factors, exposure factors, conjunctival hyperemia, length of symblepharon, scope of adhesion, lacrimal area adhesion, loss of the palisades of Vogt (POV), corneal neovascularization, and corneal opacification]. Each ocular sequela was graded from 0 to 3, depending on the increasing severity. The 9 ocular sequelae were evaluated to obtain the total severity score for each eye. The total severity score was defined as Grade I (1-9), Grade II (10-18), and Grade III (19-27). Moreover, the correlation between the severity of chronic ocular sequelae and visual acuity, surgical strategy, and the prognosis was analyzed, respectively.

RESULTS

Cases of 79 eyes with symblepharon caused by ocular burns were included in this study. Of these, 20 (25.32%) were defined as Grade I, 43 (54.43%) as Grade II, and 16 (20.25%) as Grade III. Eyes with a high total severity score had reduced visual acuity, required complicated surgery strategies, and poor prognosis (P<0.001). Multivariate regression analysis showed that the scope of adhesion, corneal opacification, and corneal neovascularization significantly affected visual acuity, surgical strategy, and prognosis (all P<0.001).

CONCLUSION

The evaluation of chronic ocular sequelae enabled the development of an objective grading system for patients with symblepharon caused by ocular burns. This grading system can be applied to guide the treatment and predict the prognosis.