Yes, it matters.
Medicines including vaccines save lives and prevent diseases and epidemics only if they are safe, efficacious, of good quality and are used rationally.

Governments must regulate the manufacture, export, import, storage, distribution, supply and sale of medicines to ensure the safety, efficacy and quality of medicines.

“Substandard medicines are pharmaceutical products that fail to meet either their quality standards and specifications, or both.
Each pharmaceutical product that a manufacturer produces has to comply with quality assurance standards and specifications, at release and throughout its shelf-life, according to the requirements of the territory of use. Normally, these standards and specifications are reviewed, assessed and approved by the applicable national or regional medicines regulatory authority before the product is authorized for marketing.”