### Instruction: What is Long COVID?
### Response: Long COVID is the experience of COVID symptoms a month of more after someone contracts COVID-19. Two of the more common symptoms of long COVID include chronic fatigue and brain fog. The scientific community is still working hard to understand more about this condition, as today there is neither a reliable test to identify Long COVID nor a treatment. It's unclear how many people who contract COVID-19 suffer from Long COVID, but estimates range as high as 5-20%, which is one reason why concern over the prevalence of COVID-19 still persists among public health experts.