Rapid onset optic neuritis following measles vaccine in India: Case report

Ocular adverse events following vaccination: overview and update

The Food and Drug Administration has licensed, approved, and expanded guidelines for dozens of vaccines since 2010. Although advancements in biotechnology have made vaccines more effective and safer, none are completely free from adverse effects. Many vaccines have been implicated in causing ocular adverse events based on the temporal association of exposure and putative complication. Determination of causality is difficult. We provide an overview of vaccine side effects and also examine the English literature and the Vaccine Adverse Events Reporting System (VAERS) from 2010 through 2020 for vaccine-implicated ocular adverse events. While reactions of eyelids and conjunctiva are commonly reported, the most frequently implicated serious adverse events are optic neuritis and various patterns of intraocular inflammation. Live attenuated vaccines have the potential to cause ocular infection from vaccine-strain organisms, particularly in those immunosuppressed. While postmarketing registries for suspect vaccination adverse events, such as VAERS, are unable to determine causal associations, they are a mainstay in signaling suspected trends that require investigation. The majority of probable and possible serious ocular adverse effects are distinctly uncommon.

Application of the revised WHO causality assessment protocol for adverse events following immunization in India

BACKGROUND

In 2013, the World Health Organization (WHO) and CIOMS introduced a revised Causality Assessment Protocol (CAP) for Adverse Events following Immunization (AEFI). India is one of the first countries to adopt the revised CAP. This study describes the application of the revised CAP in India.

METHODS

We describe use of CAP by India's AEFI surveillance program to assess reported AEFIs. Using publicly available results of causality assessment for reported AEFIs, we describe the results by demographic characteristics and review the trends for the results of the causality assessment.

RESULTS

A total of 771 reports of AEFI between January 2012 and January 2015, completed causality review by August 2016. The cases were reported as belonging to a cluster (54%; n=302), hospitalized or requiring hospitalization (41%; n=270), death (25%; n=195), or resulting in disability (0.4%; n=3). The most common combinations of vaccines leading to report of an AEFI were DTwP, Hepatitis B, and OPV (14%; n=106), followed by Pentavalent and OPV (13%; n=103), and JE vaccine (13%; n=101). Using the WHO Algorithm, most AEFI reports (89%, n=683) were classifiable. Classifiable AEFI reports included those with a consistent causal association (53%; n=407), an inconsistent causal association (29%; n=226) or were indeterminate causal association with implicated vaccine(s) or vaccination process (6.5%; n=50) (Fig. 1); 88 reports remained unclassifiable.

CONCLUSIONS

The revised CAP was informative and useful in classifying most of the reviewed AEFIs in India. Unclassifiable reports could be minimized with more complete information from health records. Improvements in causality assessment, and standardization in reporting between countries, can improve public confidence in vaccine system performance and identify important vaccine safety signals.