No approved vaccine is injected directly into the bloodstream; they are administered via other routes (such as into the muscle, under the skin, by mouth, or through the nose) to optimally stimulate our natural defenses.

noli's read

The creator's assessment is scientifically accurate: no vaccine on the market is administered intravenously. Official recommendations from reference organizations like the US CDC (expert opinion) confirm that injections are primarily given into the muscle or under the skin to ensure a protective immune response. In the event of accidental administration into a vein, health protocols actually recommend repeating the dose because efficacy is not guaranteed in the blood. Regarding research, Phase I clinical trials (notably for malaria) and experimental studies on animal models (for tuberculosis) have explored the intravenous route to strengthen protection, but these approaches remain experimental and unapproved. The explanations provided are therefore entirely consistent with current scientific knowledge.

the sources

No named source held this one up — that absence is part of the verdict.