I'm a medical practitioner from India. It would be unwise to have a general guideline (on medical grounds) for everyone because vaccination is dependent on the risk an individual has and the risk they're willing to take.
As for risks, the following come into consideration: - general health of the individual - previous history of exposure to a disease or its vaccine - any specific conditions that makes them especially vulnerable - chance of exposure in the place being visited - rare adverse effects of medical procedures Most of these are best assessed by the individual's primary care provider or family doctor. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4635693/ might be a useful reference for those who like to know the nuances to be considered. Akshay
