Name	Info	Provider	Link
	free resource	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/S0264-410X(12)00682-2
Vaccines	free resource	MedlinePlus Health Information	https://medlineplus.gov/vaccines.html
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22609011/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/22609011