[BostonCard]

Some quick drug-safety terms:

"Serious" in this context has specific meaning.  The patient had to meet one of the following:

• They were hospitalized
  
• If already hospitalized, their hospitalization was prolonged
  
• The event was considered life-threatening
  
• The event was fatal (not in this case, since the patient is expected to recover)
  
• The event caused long term disability
  
• There was a fetal malformation or led to the loss of the fetus
  
• Urgent medical action was required to prevent one of the above
  

An "adverse drug reaction" in the above context means that the investigator (or whoever assessed the AE) tied it to the vaccine.  This is challenging, of course, because it is hard to know if someone who developed a migraine a day after the vaccine would have had it anyways.  It is in the judgment of the investigator who (hopefully) knows the details about the nature of the event (like whether it is a typical vaccine reaction, how often it happens in the underlying population), the timing of the event (whether it occurred in the first couple days after the vaccine was given versus weeks later), etc.  There is a nice study (in oncology populations) that something like 15% of more severe reactions attributed to the study drug, actually occurred in people in the placebo arm, so it is by no means certain.

The temporary hold by AZ makes sense for the reasons they say "out of an abundance of caution" to figure out the details and because it is very  difficult to come to definitive conclusions from n = 1 events.  There is a pretty good chance that they will resume dosing again, and it is certainly possible that they won't see an event like this again in the trial, but I agree with dabigv... with a half dozen vaccines in advanced trials, it was probably inevitable that an event like this would happen in one or more of the vaccines.

Regardless, this is why multiple shots on goal is important.  If this winds up being fatal for the development program (I hope not and I think it won't be), at least we have a bunch of other vaccines in the pipeline.

BC

[BostonCard]

Some quick drug-safety terms:

"Serious" in this context has specific meaning.  The patient had to meet one of the following:

• They were hospitalized
  
• If already hospitalized, their hospitalization was prolonged
  
• The event was considered life-threatening
  
• The event was fatal (not in this case, since the patient is expected to recover)
  
• The event caused long term disability
  
• There was a fetal malformation or led to the loss of the fetus
  
• Urgent medical action was required to prevent one of the above
  

An "adverse drug reaction" in the above context means that the investigator (or whoever assessed the AE) tied it to the vaccine.  This is challenging, of course, because it is hard to know if someone who developed a migraine a day after the vaccine would have had it anyways.  It is in the judgment of the investigator who (hopefully) knows the details about the nature of the event (like whether it is a typical vaccine reaction, how often it happens in the underlying population), the timing of the event (whether it occurred in the first couple days after the vaccine was given versus weeks later), etc.  There is a nice study (in oncology populations) that something like 15% of more severe reactions attributed to the study drug, actually occurred in people in the placebo arm, so it is by no means certain.

The temporary hold by AZ makes sense for the reasons they say "out of an abundance of caution" to figure out the details and because it is very  difficult to come to definitive conclusions from n = 1 events.  There is a pretty good chance that they will resume dosing again, and it is certainly possible that they won't see an event like this again in the trial, but I agree with dabigv... with a half dozen vaccines in advanced trials, it was probably inevitable that an event like this would happen in one or more of the vaccines.

Regardless, this is why multiple shots on goal is important.  If this winds up being fatal for the development program (I hope not and I think it won't be), at least we have a bunch of other vaccines in the pipeline.

BC