A panel of scientists from around the world said in a review that COVID-19 vaccines worked so well that most people don¢¥t need a booster.

Scientists based their information on a wide range of real-world observational studies as well as data from clinical trials. All of this is likely to add to a debate over whether to use booster vaccines at all. Experts said that governments should focus on immunizing the unvaccinated and wait for more data on which boosters are most effective and at what levels.

The WHO said that wealthier countries offering booster shots increases the risk of variants appearing elsewhere. This is because if the rich countries take booster shots and introduce regular booster shots for the current viruses, then they will use up all the capacity of vaccine companies. There will be no or minimal vaccines available for the rest of the world. Therefore, it¢¥s necessary to push national priorities to the side for global needs.

Difficult words: booster (a thing that increases the effectiveness of something), clinical trial (a research study performed in people to evaluate the effectiveness and safety of experimental medical treatments), immunize (to provide somebody with protection against a disease by putting a medicine into the body).