Johnson & Johnson pauses vaccine trial to probe unexplained illness

Johnson shows a single-dose Covid-19 vaccine being developed by the company. — AP

"Right now, we're waiting for the independent drug safety monitoring to do their analysis", Wolk said, adding that it's not yet known if the person who became ill had received a placebo or the company's vaccine itself.

The company said in a statement on Monday that illnesses, accidents and other so-called adverse events "are an expected part of any clinical study, especially large studies", but that its physicians and a safety monitoring panel would try to determine what might have caused the illness. Pivotal Phase 3 trials for Covid-19 vaccines in the US have been created to include roughly 30,000 participants, in some cases more, with some receiving the experimental shots and others placebos.

While J&J launched Phase 3 clinical trial for its COVID-19 vaccine candidate last month, with plans to enrol up to 60,000 volunteers across three continents for the study, it is unclear how long the pause will last.

Pauses in late-stage clinical trials are not uncommon, nor is Johnson & Johnson the first company to temporarily suspend progress.

They are both also part of the US government's Operation Warp Speed programme to support vaccine development.

In September, AstraZeneca paused all of its clinical trials for COVID-19 vaccines following a case of transverse myelitis in a United Kingdom patient.

In implementing the programme, the World Bank will support multilateral efforts now led by the World Health Organisation (WHO) and COVAX, a ground-breaking global collaboration to accelerate the development, production and equitable access to Covid-19 tests, treatments and vaccines.

Others have said not to expect one until sometime between March and May. Elsewhere, Russia's government in August approved a vaccine called Sputnik V-named after the Soviet space satellite-after researchers completed only small-scale tests on 76 volunteers. In fact, the pause is the second such hold to occur among several vaccine candidates that have reached large-scale final tests in the U.S.

Hopes have been high that the Oxford University/AstraZeneca vaccine might be one of the first on the market after its successful Phase 1 and 2 trials.

Mr. Wolk said the J&J trial is on a "pause", which is different than the regulatory "hold" that USA regulators placed on AstraZeneca. "We just need to let the sponsor and the safety board do their review and let us know their findings".