is a b12 injection im vitamin Store Intramuscular vs Subcutaneous Injections for vitamin B12 supplements Oral vs. Intramuscular Vitamin B12

If folate deficiency is suspected, it is reasonable to give oral folic acid (0.4 1 mg/day) without doing laboratory investigation for deficiency at least until the hemoglobin and mean corpuscular volume normalizes (or longer if the underlying cause cannot be eliminated)

So if you have had an organ transplant and are taking immunosuppressant drugs or taking those drugs to treat an autoimmune disease, or if you're taking certain cancer chemotherapies, the immunosuppressive drug could decrease the efficacy of the vaccine, says William Moss, M.D., executive director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health

it actively inhibits microbial growth within the vial following access

Follow standard handling and hygiene practices.