Which Vaccines offer the best protection?
According to the data obtained from various literature, we can say that overall, the Pfizer vaccines, Oxford AstraZeneca and Moderna vaccines all provide the highest percentage of protection when tested amongst individuals present in their clinical trials.
What must be considered, therefore is what has been previously mentioned about why certain countries may have access vaccines compared to others. Therefore, we don’t want to dissuade anyone from taking a particular vaccine because they all provide a very good level of protection when observing the data trends objectively.

What are the main side effects observed across vaccines?
According to the NHS.UK the most common symptoms reported throughout your body are tiredness, headaches, muscle pain, chills, fever, nausea while at the site of injection, you might experience pain, redness and swelling.
https://www.nhs.uk/conditions/coronavirus-covid-19/coronavirus-vaccination/coronavirus-vaccine/

How did we make the vaccines available so fast?
It was found that the previous epidemics of SARS and MERS had very similar genomic and protein structures. This information proved to be of importance when used to create the “prototype” vaccine in previous epidemics,
This pre-existing understanding about SARS, MERS and their genomic similarities, allowed scientists to shorten the usual time frames expected in conventional vaccine development.