NEW JERSEY • Johnson & Johnson halted clinical trials of its Covid-19 vaccine after a participant fell ill, the second time that a front runner developer has paused testing in the race to create a viable immunisation against the virus.
The participant's illness is being evaluated, the New Jersey-based company said late on Monday, adding that it would share information after further investigation.
J&J shares fell 2.4 per cent in trading before US exchanges opened yesterday. The vaccine is undergoing tests in as several as 60,000 volunteers from Peru to South Africa.
J&J is racing alongside rivals like Moderna, Pfizer and AstraZeneca to deliver a shot to help blunt the pandemic. Drugmakers must balance time pressuresespecially as Covid-19 cases set new recordswith safety considerations in the crucial last stage of testing.
"We're going to have to get used to hearing these sorts of reports of pauses," Prof Hassan Vally, an associate professor in epidemiology at La Trobe University in Melbourne, said.
"As you vaccinate more people in these trials, the chances are that there will be some illnesses in participants. The only difference here is that in the world that we live in right now, the progress of these trials are in the public eye, and so we're riding every bump."
AstraZeneca the previous month temporarily stopped tests of its own vaccine candidate after a trial participant fell ill. That study has resumed in some countries, but remains halted in the United States.
While such pauses are routine in the pharmaceutical industry, J&J's interruption may contribute to concerns over safety with vaccine research progressing at an unprecedented pace. Developmental processes that usually take years have been compressed into months, egged on by politicians wanting a solution to a pandemic that has killed over one million people and scuppered economic growth.
"We're devoted to providing transparent updates," J&J said. "Adverse eventsillnesses, accidents, et ceteraeven those that are serious, are an expected part of any clinical study, especially large studies."
In recent days, officials have sought to dampen expectations for a quick fix. European Medicines Agency executive director Guido Rasi said the previous week that a vaccine was looking unlikely by year end.
The US Food and Drug Administration plans to demand two months of safety data before reviewing any application and said any shot submitted will need to be evaluated by an independent panel.
The pause "is good news in that it demonstrates that the regulatory safeguards to protect the public are still in place", said Professor Michael Kinch, a vaccine specialist at Washington University in St Louis. He said more information was needed to determine if the issues with J&J's vaccine are related to the illness experienced by AstraZeneca's trial participant.
IN THE PUBLIC EYE
As you vaccinate more people in these trials, the chances are that there will be some illnesses in participants. The only difference here is that in the world that we live in right now, the progress of these trials are in the public eye, and so we're riding every bump.
PROF HASSAN VALLY, an associate professor in epidemiology.
J&J chief executive Alex Gorsky joked in an interview earlier this month that he was asked "nearly every 15 minutes" when a vaccine will be available. At the time, he reaffirmed J&J's expectation that by "late this year, early next year", the firm could begin reviews with regulators for possible emergency use authorisation. That timeline may now be in question.
BLOOMBERG