What exactly is an 'unexplained illness' during a vaccine trial
The clinical trials of Johnson & Johnson coronavirus vaccine have been temporarily halted after a volunteer developed ‘unexplained illness. While the details of the adverse side-effects or the study participant have not been revealed by the American multinational corporation citing privacy, it said that such pauses are ‘normal’ and often happen during large-scale clinical trials which involve tens of thousands of people.
Why have been the trials put on hold? Here’s what the company has to say
“We have temporarily paused further dosing in all our Covid-19 vaccine candidate clinical trials, including the Phase 3 ENSEMBLE trial, due to an unexplained illness in a study participant," said the J&J company in a statement. The online enrolment for the clinical trials of its COVID-19 vaccine candidate has also been put on a hold, till the time the volunteer’s illness is being monitored and reviewed by an independent safety monitoring committee.
What exactly are serious adverse events (SAEs) during clinical trails
The company notes that such serious adverse events (SAEs) are part of all large-scale clinical trials and are an expected part of large studies. However, it is crucial to understand what exactly constitutes as serious adverse events and adverse events and why they are not uncommon during late-stage trials which usually involve thousands of volunteers.
According to the World Health Organization, a serious adverse event or reaction stands for any untoward medical occurrence that at any dose; which:
1.Results in death
2.Life-threatening
3.Requires inpatient hospitalization or prolongation of existing hospitalization
4.Results in persistent or significant disability or incapacity
What is an adverse event?
As per the global health agency, an adverse event during clinical trials is defined as a medical occurrence temporally associated with the use of a medicinal product, but not necessarily causally related. This medical occurrence does not have to be directly related to the drug.
Trials of Oxford vaccine candidate were also put on hold
It should be noted that it is not the first time that clinical trials of a major COVID-19 vaccine candidate have been put on hold. In September, late-stage trials of the Oxford-AstraZeneca vaccine candidate, which has been touted as the front runner in the race to develop a vaccine for COVID-19, had also been paused after a UK volunteer experienced adverse side-effects. The crucial last stage trials were resumed after a few days, after being given the go-ahead by the independent safety review committee.
Several media reports doing rounds said that the study participant had developed transverse myelitis, which is an inflammation of the spinal cord. Later on, after the safety reviews were conducted, Oxford University said there is insufficient evidence to be certain that neurological symptoms developed by the participant were or were not related to the COVID-19 vaccine.