Viruses crossing multiple critical barriers, how common is it? Zika virus is often associated with microcephaly when pregnant women get infected. Still, we and others have shown that several anatomical abnormalities can be observed without directly impacting the baby's brain size. For this, Zika has to cross two crucial barriers: the blood-placental barrier (BPB) and the blood-brain barrier (BBB). Several viruses are known to cross these barriers, such as HSV, CMV, H1N1, HPV, HIV, and others. The type of damage and tropism for the brain is highly variable among these viruses, but some, like HIV and ZIKV, are known to preferentially hide in the relatively protected brain environment. We are just starting to understand if #SARSCoV2 can cause similar damage, but recent studies indicate that COVID-19 in pregnancy appears most likely to impact fetal brain development via maternal and placental immune activation. We might have a generation of kids being born with #LongCovid, and most of these will only be noticed years or decades later.
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