A study, which enrolled more than 44,000 volunteers, found that the Covid vaccine's efficacy declined by an average of 6 percent every two months after administration, and efficacy peaked at more than 96 percent within two months of vaccination and then slipped to 84 percent after six months. Israel's Ministry of Health recently found that the Pfizer vaccine is only 39 percent effective at combating the Delta variant. This ensures that there will need to be multiple shots to presumably offer “protection,” whatever that now means.
https://www.zerohedge.com/markets/latest-data-show-efficacy-pfizer-vaccine-falls-84-after-6-months