Final answer:
The recommendation in public health is for everyone who can safely be vaccinated to do so, to protect themselves and contribute to herd immunity.
Step-by-step explanation:
The discussion about who should get vaccinated stems from the field of public health and pertains to immunization strategies. When someone like Karen, who is generally healthy, is considering vaccination, it's important to understand that vaccines are critical not only for creating herd immunity, which protects those who cannot get vaccinated due to medical conditions.
Therefore, in a public health context, it is usually recommended that everyone who can safely be vaccinated should be, to protect themselves and others.