When the viral load is undetectable what are chances of transmission?

When a person's viral load is undetectable, the risk of transmission of the virus is significantly reduced, but it is not zero. The specific chances of transmission depend on a number of factors, including:

- The type of virus. Some viruses, such as HIV, are more transmissible than others, even when the viral load is undetectable.

- The route of transmission. Some routes of transmission, such as sexual contact, are more efficient than others, such as casual contact.

- The immune status of the exposed person. People with compromised immune systems are more likely to become infected, even if the viral load of the source person is undetectable.

In general, the risk of transmission when the viral load is undetectable is estimated to be less than 1% for most viruses. However, it is important to note that this is not a zero risk, and precautions should still be taken to prevent transmission.