@misc{indiciaef6b5d0fbff30,
  title = {Smallpox vaccines: from first to second to third generation.},
  author = {Gregory A Poland},
  doi = {10.1016/s0140-6736(05)17840-4},
  url = {https://pubmed.ncbi.nlm.nih.gov/15680437/},
  note = {Source identifier: 15680437}
}