If you dream or have a vision that you are being vaccinated, it tells you that you need to overcome your vulnerabilities and try to see this. Another explanation is the awareness of inner healing, spiritual victory over obstacles and problems that you have not overcome.
Dreams about medicines are about inner healing, as it were you are healing yourself and/or something is being enriched from the outside so that you experience a kind of healing. An alternative is that there may be a negative experience around medicines and/or vaccinations.
Another explanation is that the obstacles and problems that seem to hurt your attachment in life turn out to be good for you in the long run and you will start to reap the benefits. Spiritually, dreams about vaccination have multiple explanations, it is mainly connected with your own feeling, intuition, experience and soul connections.