double_barrel
Preventative treatment can affect spread. For example inexpensive Ivermectin has been used widely as a prophylacticand for treatment outside of Western nations to good effect:
https://swprs.org/who-preliminary-re...effectiveness/
Immunity can be increased by vaccines but also naturally as we are seeing in Swedish population (particularly Stockholm). In Spring 2020 they had 500 "cases" (RT PCR positives) per day, now around 7000. However mortality rate is not worse - if anything less than the previous disaster in the care homes (a la NYC, UK, Italy). Anti body testing has revealed increase from 15% in Spring to 40% Jan2021.
https://www.folkhalsomyndigheten.se/...-for-covid-19/
https://news.ki.se/immunity-to-covid...sts-have-shown
This is in part due to following 2019 WHO pandemic guidelines instead of complete national lockdowns and masking up healthy. There is evidence that Lockdowns reduce immunity (lowering Vitamin D and exercise for example) and increase spread in confined spaces - compare Peru with Brazil or South Dakota with N Dakota and EuroMOMO data for EU and UK.
https://onlinelibrary.wiley.com/doi/10.1111/eci.13484
On vaccine safety, main players Phase 3 trials have been published:
https://www.nejm.org/doi/full/10.105...KweLxY.twitter
Whilst that should reassure many, they have been released under emergency regulation not the normal FDA like process. Some will not report on their trials until 2023.
https://blogs.bmj.com/bmj/2021/01/04...-the-raw-data/
We would do well to remember most folk who have concerns about novel vaccines are NOT Anti-vax, Flat_Earthers, or climate change deniers. Neither do they hold extreme views. They are just concerned human beings who took a Yellow Fever shot every 10 years (now once for life
https://www.who.int/ith/updates/20160727/en/) , Flu jabs every year. They seek transparency in a world that is more confusing that the "goode olde days" of the Cold War but see the dumbing down in the media and polarisation of society, the destruction of jobs and economy, the massive debts from response to this crisis as bad for everybody, especially the future for the least physically affected by SARS-CoV2, their kids.
Meanwhile, the WHO has recommended against forced Vaccine Passports:
https://www.who.int/bulletin/volumes...-280701-ab/en/