What can cause immunity to rubella?

Immunity to rubella can be achieved primarily through vaccination and having had a previous infection. The rubella vaccine is a live attenuated vaccine, which means it contains a weakened form of the virus. When a person receives the vaccine, their immune system responds by producing antibodies against the rubella virus, which provides protection from future infections.

Additionally, if an individual has previously contracted rubella, their immune system has already mounted a response to the virus, creating memory cells that will recognize and fight off the virus if re-exposed. Thus, both vaccination and natural infection result in the development of immunity, making this the correct option.

The other choices—exposure to other viruses, long-term health insurance, and consuming certain foods—do not have a direct relationship to the immunity to rubella. While overall health and immune function can be influenced by various factors, they do not specifically confer immunity to rubella in the way that vaccination and prior infection do.