Government officials have already warned that people with compromised immune systems, including patients with HIV disease, and those who reside with them should not receive smallpox vaccinations because of the threat of infection and other complications. Now Food and Drug Administration officials are warning that anyone who has been vaccinated should not donate blood for at least three weeks after getting the inoculation because the live virus from the vaccine could end up in the donated blood and could pose a threat to those whose immune systems may not be able to fight off the effects of the virus.
The new guidelines, developed jointly by the FDA, the Centers for Disease Control and Prevention, and the Department of Defense, say that recipients of the smallpox vaccine should not be allowed to give blood for at least 21 days after vaccination or until the scab at the injection site falls off on its own--whichever is later. Anyone who has scratched off the scab should not give blood for three months, and vaccine recipients who suffered side effects from a vaccination should wait until two weeks after all symptoms of the side effects subside before donating blood.
Blood banks are being instructed to ask donors if they have received the smallpox vaccine within the prior eight weeks and to defer those who received the vaccine within the past 21 days, who still have a scab at the vaccination site, who scratched the scab off the injection site, or who experienced complications from the vaccine. All others can be approved for donation. Blood banks also are being instructed to ask all potential donors who have not been vaccinated if they suffered any skin lesions or other complications from close contact with a smallpox vaccine recipient and to defer any patient who experienced these complications.
Donated blood later found to have been given wrongly by a vaccine recipient or contact must be destroyed or used for nonhuman research. If it already has been transfused, blood banks may need to alert the patient and his or her doctor. Although donated blood is not specifically screened for the vaccinia virus that is used in the smallpox vaccine, virus inactivation procedures used on pooled blood products is believed to be adequate in rendering the virus harmless for most blood product recipients.
The complications of transfusion-transmitted vaccinia virus could be severe and life-threatening--particularly for transfusion recipients who are immunocompromised or who have burns or other serious skin conditions. Vaccinia infection can result in a host of complications, ranging from painful skin rashes and persistent infections to potentially fatal cases of encephalitis.
Patients with HIV disease and other conditions resulting in immune system deficiencies, including cancer patients receiving chemotherapy and organ transplant recipients, should talk to their doctors about any health risks associated with donated blood products.
The full guidelines can be seen online at http://www.fda.gov/cber/gdlns/smpoxdefquar.htm.