A vaccination exemption letter details why a child is exempt from a vaccine on religious or medical grounds, according to the New York City Department of Education. Travelers may require such a letter when they're unable to receive the yellow fever vaccine, states the Centers for Disease Control and Prevention.
The detail level of a vaccination exemption letter varies by state, and some may require a certificate instead. For example, the New York City Department of Education allows parents to opt out of vaccines on religious grounds. However, the letter must provide an explanation rather than a simple statement that their religion prevents vaccinating. The department may request evidence of the parents' claims, and all medical exemption letters require evidence from a licensed physician.
In contrast, the Washington State Department of Health requires a certificate with details of health care professionals and religious persons who can support their claim. The Texas Department of State Health Services requires parents to request an affidavit that verifies their claims.
Some travelers are unable to receive the yellow fever vaccine and require an exemption letter, according to the CDC. This allows travelers with medical contraindications to the vaccine to move through areas where the disease is present. While the CDC does provide such exemptions, it also advises that patients protect themselves by not traveling through endemic areas.