| Name | Info | Provider | Link |
|---|---|---|---|
| free resource | Elsevier Science | https://linkinghub.elsevier.com/retrieve/pii/S2405-8521(20)30112-9 | |
| Vaccines | free resource | MedlinePlus Health Information | https://medlineplus.gov/vaccines.html |
| free resource | PubMed Central | https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/33161174/ | |
| free resource | Europe PubMed Central | https://europepmc.org/abstract/MED/33161174 |