Over a year into the pandemic, questions around immune responses after COVID continue to confound.
One question many people are asking is whether the immunity you get from contracting COVID and recovering is enough to protect you in the future.
The answer is no, it’s not.
Here’s why.
Immune responses are innate or acquired. Innate, or short-term immunity, occurs when immune cells that are the body’s first line of defence are activated against a pathogen like a virus or bacteria.
If the pathogen is able to cross the first line of defence, T-cells and B-cells are triggered into action. B-cells fight through secreted proteins called antibodies, specific to each pathogen. T-cells can be categorised into helper T-cells and killer T-cells. Helper T-cells “help” B-cells in making antibodies. Killer T-cells directly kill infected cells.
Once the battle is over, B-cells and T-cells develop “memory” and can recognise the invading pathogen next time. This is known as acquired or adaptive immunity, which triggers long-term protection.
What happens when you get reinfected? Memory B-cells don’t just produce identical antibodies, they also produce antibody variants. These diverse set of antibodies form an elaborate security ring to fight SARS-CoV-2 variants.