evidence: Fact check: No, the COVID-19 nasal test doesn't swab the blood-brain barrier [...] Nasseri, who has performed COVID-19 nasal swabbing countless of times in his own clinic, emphasized that piercing the dura mater to get to the blood-brain barrier with the typical soft swab used, even with poor sampling technique, was "very incredibly unlikely." [...] We rate the claim that the COVID-19 nasal test samples the blood-brain barrier as FALSE because it is not supported by our research. The blood-brain barrier, a system of vessels surrounding the central nervous system, is not readily in reach without piercing through several protective layers – an unlikely feat with a soft nasal swab. The additional claim that swabbing leads to damage in the olfactory epithelium is also unlikely.