Monoclonal antibodies are not considered immunotherapy, because they do not change the body’s own immune response to the virus. Rather, monoclonal antibodies provide passive immunity, by providing antibodies that the body has not yet had a chance to generate on its own. This can be especially important for people whose bodies have difficulty making antibodies, or where a disease progresses too quickly for the body to make antibodies fast enough to stop it.
Other types of monoclonal antibodies that have already been in use for many years include those for treating hepatitis B and rabies exposures.