Vaccinia

Important information for all workers handling genetically modified Vaccinia virus or sharing a facility where GM Vaccinia is used

Several cases of laboratory-acquired Vaccinia virus infection associated with genetic modification work are known to have occurred in the UK in recent years. Sharps use should be avoided as inoculation injuries carry a much higher risk of transmission of infection. Areas of broken skin are also vulnerable and those with skin abrasions or pre-disposing skin conditions should refrain from working with the virus if there is potential for the broken skin to be exposed to it. Vaccinia and other pox viruses have the capacity to survive for considerable periods in dried material. Survival in solutions can be for several weeks. Live virus can also be isolated from solid surfaces and fabric for as long as two weeks after contamination.

Good containment and general control measures, and laboratory procedures such as handwashing and cleaning of surfaces after use should suffice to remove the risk of transmission of virus. However, as reinforced by the Health and Safety Executive, it is important that all personnel working with Vaccinia, or sharing a facility where such work is undertaken, are aware of the risks of working with this virus and can recognise the signs and symptoms of the disease.

The viruses used in the University of Oxford are usually modified and therefore do not cause full blown Vaccinia infection but tend to cause localized infections such as a pustule or blister (with or without necrosis and scarring) particularly on the hands, mouth or around the eyes. It is possible for one infected area to contaminate and infect another (e.g. finger to eye). A wide range of photographs of Vaccinia virus infections are available at:

www.bt.cdc.gov/training/smallpoxvaccine/reactions/default.htm

and by searching for "smallpox vaccine" or Vaccinia virus at

A letter for your family doctor may be downloaded that may be kept with your general practice notes to prompt your general practitioner to consider Vaccinia if you develop such a blister or sore. Please make a copy of this and give it to your general practitioner.

     GP Vaccinia Letter (22kb)Please contact the Occupational Health Service if you have any concerns about this information or have developed a skin lesion which you are worried may be related to your work with Vaccinia.

Information for all workers directly handling Vaccinia

Workers handling Vaccinia virus should regularly inspect the skin of their hands and forearms and cover any cuts, scratches or areas of defective skin with waterproof dressings before putting gloves on. Skin and eyes should be inspected daily whilst work with Vaccinia virus is being undertaken. Any blisters, vesicles or conjunctivitis should be reported to the Occupational Health Service.

Gloves should be worn during all procedures involving Vaccinia. Individuals directly handling Vaccinia must contact the Occupational Health Service if they have any reason to think that their immunity may be reduced, for example (this list is not exhaustive) by:

1. Pregnancy

2. High dose steroid treatment or chemotherapy

3. Splenectomy

4. HIV infection

A confidential medical appointment will be offered to individuals with reduced immunity to assess their suitability for the proposed work.

Follow the containment and control procedures of your laboratory.

Pay attention to hand washing and avoid touching your mouth or eyes when in the laboratory.

Ensure that spillage/ decontamination procedures are in place and are used.

Regularly decontaminate ALL surfaces and equipment that have come in contact with the virus.

 Laboratory coats must be washed at a high temperature (at least 60 degrees centigrade) or autoclaved frequently.

Vaccination Considerations

There are different strains of vaccinia virus with different levels of risk for humans. "Standard" vaccinia virus can replicate in human cells and thus presents a risk to humans. Recombinant variants of this virus created for experimental purposes present a similar risk to laboratory personnel. Highly attentuated poxvirus strains (MVA, NYVAC, ALVAC, and TROVAC) are unable to replicate or replicate poorly in human cells and do not initiate productive infection in humans. These viruses, often in recombinant form, can also be used for experimental purposes. The recommendations for vaccinia immunization differ depending on the experimental virus that will be used in the individual laboratory and the techniques employed in the research.

Standard vaccinia virus or recombinant viruses derived from standard vaccinia virus

If the laboratory uses standard vaccinia virus or recombinant viruses derived from standard vaccinia virus all laboratory personnel who directly handle a) cultures or b) animals contaminated or infected with standard vaccinia virus, recombinant vaccinia viruses or other similar orthopoxviruses that infect humans should contact the Occupational Health Service in order to receive confidential counseling and (if it is medically appropriate) will be offered Vaccinia (Smallpox) vaccine by Occupational Medicine prior to initiating work with vaccinia virus. Whilst immunization is not a prerequisite for working with vaccinia virus at the University, counseling about vaccination is mandatory prior to working with replication competent vaccinia virus.

Because highly attenuated poxvirus strains (MVA, NYVAC, ALVAC, and TROVAC) are unable to replicate or replicate poorly in mammalian host cells they do not create productive infections. Therefore, vaccination is NOT recommended for workers who handle these highly attenuated virus cultures or materials or who work with animals contaminated or infected with these viruses.

In summary always:

Follow good laboratory practice

Protect abnormal skin if handling the virus

Consider Vaccinia if you develop a skin or eye lesion e.g. a persistent blister or sore

Give the attached letter to your general practitioner

Contact the Occupational Health Service promptly if you are concerned about any symptom described above.

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