大象传媒

It's be come clear that immunity starts to fall over time after a vaccine. After a vaccube, there is an initial surge in immune cells and antibodies that act as the frontline defence against the virus. Over time, this immunity naturally wanes, which is why some countries are rolling out booster vaccines.

Simon Clarke, Associate Professor in cellular microbiology at the University of Reading, says a booster vaccine should be given around six to eight months after a vaccine, and 大象传媒 Science and Health correspondent James Gallagher explains to Health Check's Claudia Hammond the factors that come into play when the body is fighting infection.

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