Vaccinia Immunization Policy
The objective of this policy is to clarify the requirements for all personnel who work in an area where vaccinia, orthopoxviruses, or animals vaccinated with those agents are used, handled or housed.
All personnel who work in an area where vaccinia, orthopoxviruses, or animals vaccinated with those agents are used, handled or housed must have received a vaccinia vaccination within the last ten years. Individuals must declare their vaccination status prior to engaging in such work. This may be accomplished by using the UF Smallpox Vaccine Consent form.
By authority delegated from the University President, the Vice-President for Business Affairs is responsible for the safety of all University facilities. Under this authority, policies are developed to provide a safe teaching, research, service, housing and recreational environment.
1. Request a Vaccinia Vaccination Information Packet from Environmental Health &Safety (EH&S) at 392-1591.
2. Following review of the material, questions should be directed as follows:
- Medical questions – Student Health Care Center’s Occupational Medicine Program (391-1161 X4259)
- Virology questions – EH&S and/or principal investigator
3. All projects involving “pox” viruses require vaccination.
4. Any medical condition precluding vaccination will also preclude participation in a project involving infectious
orthopoxvirus. It shall be the responsibility of each principal investigator to insure that: Each project is evaluated
to determine whether vaccination is required. These evaluations are conducted by EH&S and its various committees.
- Each participant complies with the vaccine policy requirements prior to participation in any covered research project.
- EH&S is notified of vaccination dates for all researchers working with Vaccinia.
Issued October, 2011
Important Information About Vaccinia (Smallpox) Vaccine
Please Read This Carefully
Introduction Vaccinia vaccine, previously known as smallpox vaccine, is highly effective in producing immunity to smallpox (variola), and other closely related viruses of the Orthopox genus, such as monkeypox and cowpox. The use of vaccinia vaccine led to the global eradication of smallpox in 1977. Because of the low risk of smallpox, the routine use of vaccinia vaccine in the United States was discontinued in 1971. In 1976, the recommendation for routine vaccination of health-care workers was also discontinued. In 1983, the only active producer of vaccinia vaccine in the United States discontinued distribution of vaccinia vaccine for civilians.
Currently, there is essentially no risk of infection with an orthopoxvirus in the United States except in research laboratories. Only the WHO Collaborating Center for Smallpox and Other Poxvirus Infections at the Centers for Disease Control in Atlanta is working with smallpox virus, and a few laboratories are working with monkeypox, cowpox, or other non-vaccinia orthopoxviruses. Many laboratories, however are working with vaccinia virus. Some of these viruses have been genetically modified to express foreign proteins, and are known as recombinants. Much of the work with recombinant vaccinia viruses is part of an effort to produce new vaccines, or to promote the production of other proteins in cell culture. A recombinant vaccinia virus which expresses portions of human immunodeficiency virus (HIV) is now being used in trials in humans at several research centers.
The risk of a laboratory-acquired infection with vaccinia virus is not known with certainty. However, several laboratory-acquired infections have been reported, including infections with recombinant vaccinia viruses. Because human trials are being conducted with experimental vaccinia-HIV recombinant vaccines, it is also possible that other health care workers, such as nurses and physicians, could be exposed to both vaccinia and recombinant vaccinia viruses.
Since 1980, the United States Public Health Service has recommended the use of vaccinia vaccine to protect laboratory workers from infection with orthopoxviruses, including persons working with animals infected with orthopoxviruses.
Vaccinia (smallpox) Vaccine
The vaccinia vaccine licensed in the United States contains live vaccinia virus, derived from the New York City Board of Health strain of vaccinia. Vaccine is administered using the multiple puncture technique with a bifurcated needle.
More then 95% of primary vaccinees (i.e., persons receiving their first dose of vaccine) will develop neutralizing and/or hemagglutination inhibition antibody at a titer of >1:10. Neutralizing antibody appears to persist for many years, with antibody titers of >1:10 found in 75% of persons 10 years following a second dose, and up to 30 years following three doses of vaccine. The level of antibody required for protection against vaccinia infection is not known. However, fewer than 10% of persons with neutralizing titers of >1:10 will have a primary-type response to revaccination, suggestion that these persons are protected from viral replication, and presumably infection.
Who should receive vaccinia vaccine?
The United States Public Health Service recommends vaccinia vaccine for the following persons:
- Laboratory workers who directly handle cultures contaminated or infected with vaccinia, recombinant vaccinia, or other orthopoxviruses (such as monkeypox, cowpox, and others);
- Laboratory workers who directly handle animals contaminated or infected with vaccinia, recombinant vaccinia, or other orthopoxviruses.
Other health-care workers (such as physicians and nurses) whose contact with these viruses is limited to contaminated material (for example, dressings), but who adhere to appropriate infection control measures, are probably at lower risk for inadvertent infection than laboratory workers. However, because a theoretical risk of infection exists, vaccination may be considered for this group.
Because of the low risk of infection, vaccination is not recommended for persons who do not directly handle virus cultures, or who do not work with material or animals contaminated or infected with these viruses (for example, security guards, janitorial and engineering personnel).
How often should I be revaccinated?
Antibody to vaccinia following vaccination appears to persist for many years. The Public Health Service recommends that persons working with vaccinia, recombinant vaccinia viruses, or other non-variola orthopoxviruses be revaccinated every 10 years.
What are the benefits of vaccinia vaccination?
The immunity to vaccinia should help protect recipients against infection resulting from uncontrolled, inadvertent exposure to vaccinia, recombinant vaccinia, or other orthopoxviruses. These unintentional exposures could occur by unusual routes (for example, splashes into the eye, or inhalation of an aerosol). These exposures could also involve a large dose of virus which is more likely to cause illness. In addition, persons with preexisting immunity to vaccinia may be protected against seroconversion to the foreign antigen expressed by a recombinant virus.
What are the risks of vaccination?
Successful vaccination, particularly in persons receiving their first dose of vaccine, is associated with tenderness, redness, swelling, and a lesion at the vaccination site, and may cause fever for a few days. The lymph nodes in the axilla of the vaccinated arm may become enlarged or tender. These symptoms are more common in persons receiving their first dose of vaccine (15%-20%) than in persons being revaccinated (5%-10%).
The overall risks of serious complications of vaccinia vaccination are low, and occur more frequently in persons receiving their first dose of vaccine, and among young children. The most frequent serious complication of vaccination are encephalitis (brain inflammation), vaccinia necrosum (progressive destruction of skin and other tissues at the vaccination site), and eczema vaccinatum (severe and destructive infection of skin affected by eczema or other chronic skin disorder caused by spread of vaccinia virus).
Among adults receiving their fist dose of vaccine, the following serious complications have been observed:
- encephalitis – about one in 300,000 doses. ٠vaccinia necrosum – this complication has been limited to recipients
- who have abnormalities of their immune system, for whom the vaccine is contraindicated. ٠eczema vaccinatum
- this complication has been limited to recipients who have eczema or other chronic skin conditions, for whom the vaccine is contraindicated
Vaccinia (Smallpox) Vaccine
Recommendations of the Immunization Practices Committee (ACIP)
Centers for Disease Control and Prevention. Vaccinia (smallpox) vaccine recommendations of the Advisory Committee on Immunzation Practices (ACIP). Morbidity and Mortality Weekly Report, Recommendations and Reports 2001, 50 (No.RR-10).