Hybrid Immunity
- October 24, 2021
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Hybrid Immunity
Subject – Science and Tech
Context – More studies show the superiority of hybrid immunity
Concept –
- A study has shown that a combination of natural infection with a single dose of vaccine provides greater immunity than either natural infection without vaccination or full vaccination in infection-naïve individuals.
- Hybrid immunity — natural immunity from an infection combined with the immunity provided by the vaccine — had a higher and more durable neutralising antibody response. The hybrid immunity offers stronger protection than just infection or full vaccination alone.
- The immunological advantage from hybrid immunity arises mostly from memory B cells. While the bulk of antibodies after infection or vaccination decline after a short while, the memory B cells, which evolve in the lymph nodes, get triggered on subsequent infection or vaccination.
- Differences between the memory B cells triggered by infection and those triggered by vaccination — as well as the antibodies they make — might also underlie the heightened responses of hybrid immunity. Infection and vaccination expose the spike protein to the immune system in vastly different ways.
- After full vaccination, antibodies produced by natural infection continued to grow in potency and their breadth against variants for a year after infection. Unlike after vaccination, the memory B cells formed after natural infection are more likely to make antibodies that block immune-evading variants.
- Memory B cells in the fully vaccinated people without prior infection are growing in number and gaining mutations up to 12 weeks after the second dose, which allows the B cells to recognise and neutralise variants.