Vaccines, the dilemma of duration and the effect on the Green Pass of one year

Why are we worried that vaccine efficacy is waning?

We are not sure, but various clues. We see from serological tests that antibodies naturally drop 7-10 times at 6 months after the vaccine. We then observe a slight increase in infections among the vaccinated in the first hour: health personnel and the elderly (data from law enforcement and school workers are not available).