Many that got the real jab and not the control placebo are not so eager to roll up their sleeves for a booster - especially if they were really ill following the shot. They are not willing to be jabbed every few months and become sick for several weeks. Some are still suffering the effects and do not want another shot. My brother is one. He got the shot because his job requires him to travel. About a week after the second jab he developed a severe case of shingles. Only recently has he returned to work after about three months off. The pain was so bad he could not wear a shirt. He is considering retiring if required to get another jab. There is a resistance developing among the previously jabbed.