As you’ve seen in the news, there may be another safety signal to consider after the Johnson and Johnson (J&J) vaccine. Here’s the rundown.
What happened?
In the past 24 hours, the FDA published a press release and sent a fact sheet (here, here) to healthcare providers (i.e. doctors, nurses, hospitals, etc.) about a recent safety signal they detected: Guillain-Barre Syndrome (GBS).
Based on an analysis of Vaccine Adverse Event Reporting (VAERS) data, the FDA found 100 reports of GBS following 12.5 million vaccines. Out of the 100 cases, 95% were serious and required hospitalization. One person died.
What is Guillain-Barre Syndrome (GBS)?
GBS is a neurological disorder in which the body’s immune system damages nerve cells. The body tries to fight an evader, but then turns on itself and attacks the nerves. This typically causes muscle weakness or tingling sensations, especially in the legs or arms. It can worsen and spread to other parts of the body. In severe cases it causes paralysis.
GBS usually emerges following bacterial infections (like food poisoning) and a multitude of viral infections (like the flu, Zika). Each year, 3,000 to 6,000 people develop GBS in the United States. That’s about 10 per one million.
Can you get GBS from COVID19 infection?
It seems to be uncommon, but it does happen. An important study looked at 37 cases of GBS following COVID-19 infection. The majority of COVID19 GBS cases were:
Older (average age was 59 years)
Male (65%)
Time between COVID-19 symptoms to GBS symptoms took ~11 days
Symptoms and severity of COVID19 GBS were similar to non-COVID19 GBS
Case studies are incredibly valuable when describing signs and symptoms. They help physicians understand what to look for and how to treat rare diseases. But case studies are not good at describing the “true rate” of a disease. In other words, we don’t know if COVID19 GBS is higher than non-COVID19 GBS. We hypothesize that it is, but don’t have the scientific evidence to confirm.
There are ongoing studies trying to find the answer (here, here). So far, these scientists have found nerve damage among a high number of COVID19 hospitalized patients. But they have yet to publish COVID19 GBS specific rates. I’m sure it’s coming soon.
Can you get GBS from vaccines?
Yes, rare events of GBS have been linked to the new Shingles vaccine and the flu vaccine. But the rate of GBS among vaccines continues to be lower than the rate of GBS among these diseases. The CDC closely monitors the numbers each year.
If there is a safety signal with the COVID19 vaccine, why wasn’t it picked up in the clinical trial?
During the J&J COVID19 vaccine trial, there was one case of GBS among the vaccine group. A 60-year old had chills, nausea, diarrhea, and muscle pain that preceded GBS, which happened 16 days after vaccination. There was also a 75-year old participant that had a similar event 10 days after receiving the placebo jab. Because there was an equal distribution of events (one case of GBS in the vaccine and one in the placebo) FDA concluded:
“In FDA’s assessment the events of facial paralysis and GBS are unlikely related to study vaccine but a causal relationship cannot be definitively excluded.”
Clinical trials usually don’t find rare events. In order to find a very rare safety signal, we need a huge number of people in clinical trials. It took 12.5 million vaccinated to find 100 cases, which means we needed a clinical trial to have 125,000 people in the vaccine group and 125,000 in the placebo group to find one case. This is not feasible and not a good use of resources. Instead we rely on national surveillance systems to find rare safety signals. And we’ve shown time and time again that these systems work.
So, what’s next?
The ACIP (an external advisory board for the CDC) will meet next Thursday, July 22 from 11a-4p EST. Some really important questions need to be answered:
What are the 100 case details? After further investigation, were they legitimate cases? (As I’ve covered before, VAERS comes with a lot of limitations).
Is there a casual link between the vaccine and GBS?
If there is a link, do the benefits outweigh the risks?
Does the CDC recommend that the FDA add a warning to the vaccine label?
I’ll provide cliff notes. I’m sure it will be, as always, an interesting discussion.
Love, YLE
This is unrelated, but your thoughts/dissection of the news circulating about the children in the mississippi icu with delta would be really helpful. As a mom sending kids back in 4 weeks in the south with no virtual option this year, I’m panicking. Is Delta so dangerous we need to pull our kids from school? My kids can’t be re-enrolled in their school, it’s a lottery and they lose their spots if I remove them.
Thank you for adding the year to the dates on these posts. Substack does not automatically add the year (nor does it allow one to sort a search by year). Now that we are multiple years in, adding the year makes searching the archive easier. :)