>>John, just to clarify, are you saying that you know some medical doctors who are reluctant to take "one" of the specific vaccines? (i.e. J&J, versus Pfizer/Moderna)

Perhaps it's because Trump started Operation Warpspeed and Biden keeps urging everybody to vaccinate, so every armchair scientist has a reason to be suspicious.

;-)

Background would be strong medical support for vaccination, especially amongst pre-millennials who saw the last of the Polio sufferers in iron lungs, whooping cough, tetanus deaths, the list goes on. They've also watched various substances or treatments turn into important causes of morbidity and mortality as understanding evolves. Most medics also allocate special consideration for pregnant women/people or anybody who may be pregnant in future.

Then there's geographic location; medical or scientific imperative changes if you can keep C19 out of the community.

With that background, many docs are very pro-C19 vaccination while others are more hesitant. Where I am located in May 2021, the moat makes it easier to keep C19 out so that NZ has been donating C19 vaccines to Pacific Islands or elsewhere where need is greater. Ministry of Health says vaccine for most of the population is not yet a priority. Given the choice in May 2021, I'd start by excluding antibody evidence of recent C19 infection and I'd review latest outcomes from vaccinated groups.