The most important method for preventing transmission of smallpox is vaccination. All staff who provide care for smallpox patients must be vaccinated against smallpox. In a smallpox emergency, only staff with confirmed vaccination status should provide direct care to patients with suspected or confirmed smallpox.
Of the three smallpox vaccines available for use in a smallpox emergency, two provide immunity after the confirmation of a “take” 6 to 8 days after vaccination: ACAM2000® and APSV. The third, Imvamune, may not provide full immunity until 2 weeks after the second dose (for primary vaccinees – those who have not previously been vaccinated for smallpox), which may leave primary vaccinees unprotected for 6 weeks after the initial dose.
Consider ways to use only staff who are able and willing to be vaccinated with ACAM2000® or APSV for work that exposes them to the smallpox virus. Staff who should be vaccinated with Imvamune should not be exposed to patients with smallpox or the vaccination sites of those who have received ACAM2000® or APSV until they achieve full immunity.
The considerations in this section apply to staff vaccinated with ACAM2000® or APSV.
Staff with confirmed vaccination status includes those vaccinated prior to, or who could be vaccinated within 72 hours after (preferably within 24 hours), contact with a smallpox patient.
Staff may continue to work, as they feel able, including providing patient care during the time between vaccination and take-evaluation.
This includes staff who:
- Provide direct patient care (including nurses, doctors, mid-level providers, assistants, and technicians)
- Collect specimens or perform laboratory testing for smallpox patients (such as phlebotomists and laboratorians)
- Perform supportive, housekeeping, and administrative assistance (such as maintenance, housekeeping, laundry, food service, and administrative staff)
- Transport patients to the healthcare facility (including EMTs and other ambulance service staff)
Contraindication to Vaccination
During a smallpox emergency, there are no clear, absolute contraindications to vaccination. Each staff member will need to make an informed decision about receiving the smallpox vaccination based upon his or her personal medical history and current health status.
Any staff person who cannot be vaccinated or refuses vaccination should not work in a healthcare facility that is caring for smallpox patients. They should also follow the same precautions as unvaccinated members of the general public.
Obtain and Administer the Vaccine
In the event of a declared smallpox emergency, CDC will coordinate with state and local public health departments to provide smallpox vaccine from the Strategic National Stockpile to affected areas.
Work with your state or local public health department to coordinate vaccination of all staff in your facility. More information about the vaccines and how to administer them are available in the Vaccination section for Clinicians.
ACAM2000® and APSV are live virus vaccines containing vaccinia virus. Those vaccinated with either of these vaccines who do not properly care for their vaccination site may spread the vaccinia virus to other parts of their body or to other people, including patients. All vaccinees who receive either of these vaccines should follow vaccination site care instructions fully until the vaccination scab falls off.
Clinical staff may continue to treat patients after receiving the vaccination. The facility’s Infection Control Practitioner(s) should consider ways to ensure each worker’s vaccination site is properly protected, following additional precautions, before the worker begins patient interaction each shift.
When clinical staff are caring for patients, they should take additional precautions to prevent the spread of vaccinia virus. They should:
- Cover the vaccination site with gauze or other similar absorbent material, changing the material every 3 days or sooner, if it becomes soiled.
- Cover the gauze dressing with a semipermeable bandage to provide a barrier over the vaccination site. Do not use a semipermeable bandage without gauze. This may cause the skin at the vaccination site to soften and wear away (maceration), which may lead to irritation and itching, and possible transfer of vaccinia to other parts of the body or to other people.
- Wear long sleeves to cover the bandage.
- Follow these instructions until the scab falls off the vaccination site.
- Practice thorough hand hygiene, by either washing hands with soap and water or using an alcohol-based hand sanitizer.
Monitor Symptoms after Vaccination
Even though the smallpox vaccines are believed to be highly effective when given prior to exposure to the smallpox virus, there is a chance that a vaccinated staff member will not develop immunity. This chance may increase if the staff member is not vaccinated within 72 hours of initial exposure to the smallpox virus.
To protect both staff and patients, monitor all vaccinated staff members for signs of illness. Assign a staff person to monitor and record any symptoms staff members have after vaccination, in case they begin to develop signs or symptoms of smallpox. Staff members should take their temperature every 12 hours and report the results to the designated monitor. If a staff member has 2 successive fevers greater than or equal to 101°F (38.3°C), medical personnel should evaluate the staff member for possible smallpox infection.
Evaluate Vaccination Site for “Take”
Evaluate the staff member’s vaccination site 6 to 8 days after vaccination with ACAM2000® or APSV to determine the success of the vaccination. If a staff member does not have a successful take, repeat the vaccination. If the staff member does not have a successful take after the second vaccination attempt, contact local public health authorities for consultation.
Plan for Effects on Staffing: Normal Responses, Adverse Events, and Vaccine Refusals
Up to one-third of all smallpox vaccinees may feel sufficiently ill after vaccination to stay home from work. This is considered a normal reaction to vaccination. Some staff, such as those who were not screened for contraindications properly, may experience an adverse event, which will require follow-up care. These staff members will not be available to work. Other staff members may choose not to be vaccinated, which may also reduce staff available to provide direct patient care and other support during the emergency. Include contingencies for reduced staff availability in your facility’s emergency plan.
MMWR: Smallpox Vaccination and Adverse Reactions: Guidance for Clinicians Cdc-pdf[PDF – 32 pages] Source: MMWR. 2003, Vol.52/No.RR-4.