Infectious Disease Specialist Questions Infectious Disease Specialist

S1 protein and the Blood Brain Barrier?

I recently got the 1st shot of Moderna covid-19 vaccine but I found one recent study that I need clarification on. Does the S1 Protein from the covid-19 mRNA vaccine have the ability to pass through the blood-brain barrier? If so, how bad of a side effect could occur.

Male | 26 years old

1 Answer

Thanks for the question. In fact, it does cross the blood brain barrier, but to date causes no ill effects. Lots of proteins cross the barrier, including whole viruses. But the central nervous system symptoms of the whole virus, other than transient fatigue of 2 days, do not occur with the S1 alone.