COVID-19 can indeed lead to loss of smell, a condition closely linked to the virus's impact on the olfactory system. The virus can cause significant damage to the olfactory mucosa, particularly at the peripheral nerve endings, and may even invade the olfactory bulb, which is located at the olfactory nerve junction. This invasion can result in viral inflammation of the olfactory nerves, leading to a loss of smell. 

In many patients, the loss of smell is often one of the earliest symptoms following infection, and the recovery of this function is sometimes slow, with some individuals experiencing prolonged periods of diminished smell. Whether the sense of smell can fully recover remains uncertain, and further studies are needed to confirm the long-term prognosis. Nevertheless, it is clear that COVID-19 can cause olfactory dysfunction. 

Additionally, many other viruses are also capable of causing loss of smell, either by directly damaging the olfactory system or through inflammation. Therefore, the loss of smell, as a potential symptom of COVID-19, warrants careful attention and further research.