DSRU comment on pausing of J&J COVID-19 vaccine trial

14 October 2020

Director, Professor Saad Shakir,  said: “Serious adverse events are expected in a clinical trial that includes 60,000 vaccinees. While the independent Data Safety Monitoring Board (DSMB) will know, they can’t say whether the event occurred in a person who received the active vaccine or the comparator because divulging this will compromise the blinding of the study.

“In addition, it cannot announce the clinical details of the event for confidentiality reasons.

“The description of the event as an ‘unexplained illness’ is interesting and somewhat unusual. They are likely to be investigating its nature in detail, in collaboration with the doctors who are treating the patient. Given the description ‘unexplained illness’, an educated guess is that it could be an event that affected the nervous system, though this is by no means certain.

“While the monitoring board looks for causality when assessing serious adverse events, it is acknowledged that regulators or members of the DSMB may be forced to act even in the absence of a definite causal relationship.

“We will have to wait for more details about this event to assess its impact on the development of this vaccine.”

The following are core objectives for DSMBs:

  1. Protection of the health of both current vaccinees enrolled in the study/programme and future participants.
  2. To ensure that the DSMB actions are both scientifically correct and proportionate to protect patients without compromising the study or the programme.
  3. To maintain the blinding of the study to the sponsors (not to compromise the study) and to ensure continuation of the integrity of the data.
  4. To ensure that high scientific and ethical standards are maintained throughout the conduct of the study by the sponsor, investigators and all other staff associated with the study.

At the end of every meeting the DSMB would recommend one of the following courses of action:

  • To continue the study with no modification of the study protocol
  • To continue the study with a protocol modification(s), which may include:
  • Possible exclusion of certain groups of people from the vaccination programme that may be at increased risk of developing the serious adverse event of interest
  • Additional investigations or screening criteria prior to including participants in the study
  • Request further information, either urgently or later with an agreed timeline
  • Co-opt an external expert(s) to advise on specific events
  • To suspend the study
  • To stop the study