Researchers have discovered a new method to assess immunity levels after vaccination, revealing the timing of the body's protective response.

A recent study by scientists has revealed why some vaccines provide long-lasting protection while others require frequent revaccination. Vaccines for diseases such as smallpox and yellow fever trigger an antibody response that lasts a lifetime, whereas other vaccines, like those for influenza or malaria, have a more transient effect, according to Gavi.

The key to understanding the longevity of vaccine-induced immunity may lie in how the immune response is shaped by specific molecular processes in the body, and this discovery could enhance future drug development.

Vaccines primarily function by exposing the immune system to harmless components of a pathogen, thereby training it to recognize and neutralize real threats in the future. A crucial part of this defense mechanism is the production of antibodies by B cells, which bind to pathogens, blocking infections and marking them for destruction.

However, the durability of this immune memory varies significantly depending on the vaccine — a mystery that the study's author, Professor Bali Pulendran from Stanford University, describes as "one of the great mysteries of vaccinology." Pulendran and his team previously identified a molecular "signature" in immune cells known as plasmablasts that predicts the strength of the antibody response shortly after vaccination. Yet this signature did not clarify why some responses last longer.

By employing machine learning to analyze blood samples from volunteers who received influenza vaccines, researchers uncovered another molecular signature associated with a more prolonged antibody response. This RNA-related marker found in platelets and their precursor cells in the bone marrow may influence the survival of antibody-producing plasma cells.

The study, published in the journal Nature Immunology, extended its findings to vaccines for diseases such as malaria, yellow fever, and COVID-19. It demonstrated that some vaccines create a favorable cellular environment, potentially increasing the lifespan of plasma cells.

This deeper understanding could lead to the development of more durable vaccines and personalized immunization schedules based on simple blood analyses post-vaccination, the authors believe. However, experts caution that the longevity of vaccines is likely influenced by complex factors that go beyond the identified molecular signatures.

Nonetheless, the potential of a "vaccine chip" that predicts who may need revaccination opens up significant opportunities for precision medicine. Such research illustrates the growing intersection of immunology and computational analysis in addressing global health challenges and enhancing the comfort of individuals seeking medical care.

This material is for informational purposes only and does not contain advice that could affect your health. If you are experiencing issues, please consult a specialist.