Vaccines Global Summit

Passive immunization and antibody therapies are an important approach to conferring immediate immunity to infections by directly administering pre-formed antibodies to the body. This differs from vaccines, which stimulate the body to produce its own antibodies. Passive immunization provides temporary immunity through antibodies that are not naturally produced by the individual. This technique is especially useful in cases where individuals are exposed to a pathogen and need a rapid immune response, or in situations where they cannot mount an adequate immune response on their own.

Passive immunization can be achieved through several methods. One of the oldest and most well-known is the use of immune globulins, which are antibody-rich blood products taken from individuals previously exposed to specific pathogens. For example, antibodies can be administered to individuals exposed to hepatitis A or rabies, providing temporary immunity until their immune system can mount a response or they receive further treatment.

A more tailored and targeted method is through monoclonal antibody therapies, which are lab-produced antibodies engineered to neutralize a specific pathogen. Monoclonal antibody therapies have been used against diseases like COVID-19, Ebola, and RSV (respiratory syncytial virus) to provide rapid intervention before severe disease sets in. These antibodies offer precise protection by blocking key viral proteins from infecting cells, thereby preventing the infection process.

While active immunization induces long-term immunity, the effects of passive immunization do not last indefinitely. Administered antibodies decay within weeks or months, making continued protection dependent on repeated doses or subsequent vaccination to achieve long-term immunity.

In addition to providing protection, antibody therapies can also be therapeutic. They may help patients recover more quickly from infections, reduce the severity and duration of symptoms, and prevent complications. This approach is especially valuable for those at high risk, such as newborns, immunocompromised individuals, and people in outbreak settings. A natural example of passive immunity is the transfer of antibodies from mother to newborn during pregnancy.

Antibody therapies continue to undergo refinement as new research progresses. Advances in delivery methods and formulations aim to make these therapies more accessible and affordable for larger populations. Alongside vaccines, passive immunization remains a valuable tool in the prevention and management of infectious diseases worldwide.