The Latest: Why AstraZeneca pressed pause on its vaccine

Alexandra Sifferlin
Medium Coronavirus Blog
3 min readSep 9, 2020


Dear Reader,

This newsletter is a little late because I thought today was Tuesday (it’s Wednesday). The long weekend and the fact that every day during the pandemic can feel the same has me confused.

But there’s a lot to talk about! Especially regarding vaccines.

Here’s the latest: Nine executives of pharmaceutical companies developing Covid-19 vaccines pledged this week that they will not seek FDA approval before the safety and efficacy of their Covid-19 vaccines is established in phase 3 clinical trials. This is good news for all the reasons I outlined last week, mainly ensuring that a vaccine will be safe and effective when it is approved for use.

READ: Why is the AstraZeneca Vaccine Trial on Pause?

Yesterday it was announced that a trial testing a Covid-19 vaccine developed by AstraZeneca and the University of Oxford is on hold due to a suspected serious adverse reaction in a participant in the United Kingdom. This is also good news (seriously). Whenever there’s a bad reaction in a clinical trial, drug makers must investigate. It’s a normal part of the development process, and it means the vaccine’s safety board is doing its job.

Here’s what else is new:

  • Case count: There are over 6.3 million confirmed cases in the U.S. and over 27.6 million confirmed cases worldwide. So far over 189,699 Americans have died from Covid-19.
  • The Sturgis Motorcycle Rally looks like a superspreader event: A new paper estimates that over 250,000 reported cases from August 2 to September 2 are due to the Sturgis Rally, which is about 19 percent of the national cases during that month.
  • Few people are flying: CNN reports that airlines experienced about a third of the traffic they did last year over Labor Day weekend, according to numbers from the Transportation Security Administration.

Follow our Medium Coronavirus Blog for regular updates, and read some of the essential stories we’ve curated below.

Be well,

Alexandra Sifferlin
Editor, Medium Coronavirus Blog

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A Quick Q&A:

Why is the AstraZeneca vaccine trial on pause?
The trial was put on hold because there is a volunteer in the study who potentially had a serious adverse reaction to the vaccine. When that happens, the trial must be paused so the researchers can understand what happened, and whether any action is needed. As STAT reports today, the trial participant is a woman in the United Kingdom who experienced neurological symptoms “consistent with a rare but serious spinal inflammatory disorder called transverse myelitis.” The woman’s diagnosis is not yet confirmed, but she seems to be recovering and is expected to be discharged from the hospital today. As STAT reports, this appears to be the first phase 3 Covid-19 vaccine trial to be put on hold, but that “such holds are not uncommon, and it’s not clear yet how long AstraZeneca’s will last.”

New on the blog:

This Bug Is Beatable

Enough With the Herd Immunity Mansplaining

How Pharma Companies Make a Profit With Taxpayer Money

The Sturgis Motorcycle Rally Looks Like a Superspreader Event

An interesting theory

A study by researchers at Oak Ridge National Lab in Tennessee developed an early theory about how Covid-19 impacts the body called the bradykinin hypothesis. The idea and the study have been the subject of a lot of debate over the last week. What do you think? Read about it below.

A Supercomputer Analyzed Covid-19 — and an Interesting New Theory Has Emerged

A few smart reads:

All This 2020 Tumult May Be Good for Our Brains

How to Help Grieving Loved Ones in a Pandemic

Deep Breathing Could Help You Recover From Covid-19

Quarantine Has Forced Me to Confront How Little I Care About Myself

Attending College Remotely Is a Nightmare

America Is Trapped in a Pandemic Spiral (The Atlantic)

For Long-Haulers, Covid-19 Takes a Toll on Mind as Well as Body (The New York Times)



Alexandra Sifferlin
Medium Coronavirus Blog

Health and science journalist. Former editor of Medium’s Covid-19 Blog and deputy editor at Elemental. TIME Magazine writer before that