booster after the immunity from the initial dose(s) naturally starts to wane. The booster is designed to help people maintain their level of immunity for longer.
Few months your jab wanes if not topped up. Top ups every few months for life on a 99% survival rate,without knowing the long term effects...only a fool would follow these rules.
The article explains it rather well itself. Also you can't have more than 100% of people vaccinated. They didn't cancel Xmas. It says right they cancelled government employee parties.
Yes, it has decreased over one. No one is saying you have no immunity after 5 months. It may wane a bit, but you still have immunity. Delta is rather virulent though.
Nothing beats natural immunity, those that have had covid and recovered , their immunity lasts way longer than any jab or booster. Those that have had 3 jabs will suffer side effects.