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Infectious Diseases

Updated 13 October 2020

Second Covid vaccine trial paused for unexplained illness

A second coronavirus vaccine trial has been paused after an unexplained illness surfaced in one of the trial's volunteers.

  • Company says adverse events are an expected part of trials
  • For now still learning about the illness, and wants all facts before sharing more info
  • Infectious diseases expert says pausing trials is good, and thorough investigation must take place


A second coronavirus vaccine trial was paused on Monday after an unexplained illness surfaced in one of the trial's volunteers.

READ | Covid vaccines 101

Johnson & Johnson, which only began a phase 3 trial of its vaccine last month, did not offer any more details on the illness and did not say whether the sick participant had received the vaccine or a placebo. The trial pause was first reported by the health news website STAT.

While Johnson & Johnson was behind several of its competitors in the vaccine race, its candidate has an advantage in that it doesn't need to be frozen and it could be given in one dose instead of two, The New York Times reported.

The J&J vaccine is also the focus of the largest Covid-19 vaccine trial, with a goal of enrolling 60 000 volunteers.

"Adverse events - illnesses, accidents, etc - even those that are serious, are an expected part of any clinical study, especially large studies," the company said in a statement.

"We're also learning more about this participant's illness, and it's important to have all the facts before we share additional information."

"It's actually a good thing that these companies are pausing these trials when these things come up," Dr Phyllis Tien, an infectious disease physician at the University of California, San Francisco, a vaccine trial site for both Johnson & Johnson and AstraZeneca, told the Times. "We just need to let the sponsor and the safety board do their review and let us know their findings."

Another expert agreed. "It doesn't mean that the adverse event is related to the vaccine, but it needs to be investigated thoroughly," said Dr Luciana Borio, who oversaw public health preparedness for the National Security Council under President Donald Trump and was acting chief scientist at the US Food and Drug Administration under former President Barack Obama.

Depending on the findings, more data may be collected, trial rules may be changed, or other safety steps may be taken, she told the Times.

Johnson & Johnson is not the first company to pause a coronavirus vaccine trial. Two participants in AstraZeneca's trial became seriously ill after getting its vaccine. That trial has been halted and has not yet resumed in the United States.

Experts said safety issues must be investigated and are one reason late-stage trials cannot be rushed, even if Trump has repeatedly claimed that a vaccine will be ready before Election Day on Nov. 3.

"This kind of event epitomizes why vaccine development can't be influenced by artificial timelines such as an election," John Moore, a virologist at Weill Cornell Medicine in New York City, told the Times.

Two companies seek emergency approval for antibody cocktails

Regeneron Pharmaceuticals Inc. said last week that it is seeking emergency approval from the US Food and Drug Administration for an experimental antibody cocktail given to Trump shortly after he was diagnosed with Covid-19.

Hours before the company made the announcement, Trump proclaimed in a video released by the White House that the drug had an "unbelievable" effect on his recovery from coronavirus infection, the Washington Post reported.

"I think this was the key," Trump said, after acknowledging that the antibody cocktail was just one of several drugs he was prescribed by his medical team. While there is no hard evidence yet proving the drug's effectiveness in humans, it has shown promise in treating mild cases of the new coronavirus, the Post reported.

In his video, Trump said, "I have emergency-use authorization all set, and we've got to get it signed now." However, an FDA spokeswoman told the Times that the agency does not confirm or deny product applications.

Regeneron said in its statement that it could initially produce doses of the antibody cocktail for 50 000 patients, and then ramp production up to doses for 300 000 patients in the next few months if granted emergency authorisation.

The antibody cocktail is now in late-stage testing. The company has granted fewer than 10 "compassionate use" requests allowing people not enrolled in its trials to use the drug, the Associated Press reported.

The US government first inked a contract with Regeneron back in July, and has promised to distribute initial doses of the treatment at no cost if it is approved, the Post reported.

Regeneron isn't the only company developing an antibody cocktail to battle Covid-19 infection: Eli Lilly and Co has also announced that it is seeking emergency-use authorisation from the FDA for a similar cocktail.

Both treatments use lab-made antibodies to give patients' immune systems a boost. In both cases, scaling up production to meet demand is expected to be a major challenge, the Post reported.

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