HYBRID IMMUNITY
WHAT IS HYBRID IMMUNITY ?
- Also known as ‘superhuman immunity’, hybrid immunity refers to a combination of immunity gained from a natural infection as well as from vaccines.
- According to studies, a hybrid immunity offers a “higher magnitude and durability” of protection as compared to infection alone, emphasising the need for vaccination.
- The immunological advantage from hybrid immunity arises mostly from memory B cells.
What are memory B cells?
- Memory B cell (MBC) is a type of B lymphocyte that forms part of the adaptive immune system.
- B-lymphocytes are the cells of the immune system that develop antibodies to invade pathogens like viruses.
- They form memory cells that remember the same pathogen for faster antibody production in future infections.
Covid-19 & Hybrid Immunity
- It is believed that both vaccine-induced immunity and natural infection trigger memory B cells to generate antibodies against COVID-19.
- Studies have suggested that memory B cell levels are much higher in people who have a hybrid immunity, leading to more antibodies.
- The memory B cells triggered by infection and those triggered by vaccination have different responses to viruses.
- Hybrid immunity with just the primary vaccine doses was found to be 96% at three months and 97.4% at 12 months.
- The same can offer 69% protection against reinfection at three months, dropping to 41.8% at 12 months.
- All estimates of protection waned within months against reinfection but remained high and sustained for hospital admission or severe disease.
- Individuals with hybrid immunity had the highest magnitude and durability of protection, and as a result might be able to extend the period before booster vaccinations are needed compared to individuals who have never been infected.
Syllabus: Prelims – Basic Economic Concepts and MAINS
