Why the restriction of smallpox vaccination to persons less than 65 years of age (and greater than 18 years)?
At this time the vaccine is not recommended for the general public. The original restriction was based on absence of studies about smallpox vaccination in the “geriatric” age group, which CDC defined as 65 years and greater. This cutoff was chosen for simplicity. However, if an individual older than 65 is asked to participate in a smallpox response team (and does not have a contraindication to receiving the vaccine, http://emergency.cdc.gov/agent/smallpox/vaccination/contraindications-clinic.asp), they can volunteer and be vaccinated. At this time, vaccination against smallpox is only recommended for laboratorians who work with orthopox viruses, and public health and health care response team members. It is unlikely that smallpox response team members are under the age of 18, but can be older than 65.
