People in many countries are concerned about the potential use of smallpox as a bioterrorism agent. The U.S. government has been preparing for some time for the remote possibility of an outbreak of smallpox as an act of terror. Those preparations quickened after September 11, 2001.
The likelihood that smallpox would be used as a bioweapon is unknown. About 30 percent of people who contract smallpox die; about 70% survive.
Vaccination prevents almost all cases of smallpox. If symptoms of smallpox do appear, they are generally milder than in unvaccinated people.
Mild reactions include swelling and tender lymph nodes that can last two to four weeks after the blister heals. Most people develop itching, headache, fatigue, muscle aches, pain, or chills after smallpox vaccination, usually about eight to 12 days later. Some individuals may have rashes that last two to four days. These side effects are usually temporary and self-limiting, meaning they go away on their own or with minimal medical treatment, for example aspirin and rest.
If the vaccination is successful, a red and itchy bump develops at the vaccine site in three or four days. Then, in the first week, the bump becomes a large blister and fills with pus. During the second week, the blister begins to dry up and a scab forms. The scab falls off in the third or fourth week, leaving a small scar. People who are being vaccinated for the first time have a stronger reaction than those who are being revaccinated.
If someone does not get the expected vaccination site response, they need to be revaccinated. If someone has a question or concern about the smallpox vaccination site they should contact their primary-care manager, medical department representative or their healthcare provider.
Smallpox vaccination is generally a safe and effective means of preventing smallpox. However, in a number of individuals, smallpox vaccination can result in untoward effects and adverse reactions. Most are totally benign, but may be alarming in appearance. Some are serious, but treatable. A few, which rarely occur, are serious, life threatening and can be fatal. Severe adverse reactions are more common in persons receiving primary vaccination compared to those being revaccinated.
In the past, between 14 and 52 people out of 1,000,000 vaccinated for the first time experienced potentially life-threatening reactions. These reactions included serious skin reactions and inflammation of the brain (encephalitis).
From past experience, one or two people per 1 million who received smallpox vaccine died as a result of vaccination side effects. Serious side effects generally are rarer after revaccination, compared to first time vaccinations. Careful screening of potential vaccine recipients is essential to ensure that those at increased risk for serious side effects do not receive the vaccine.
These side effect rates are based on data collected in the United States during the 1960s, when about 300,000 adults got their first smallpox vaccination and over 4,000,000 adults got repeat smallpox vaccinations (revaccinations).
A few heart attacks, some fatal, have been reported after smallpox vaccination. After reviewing these cases, the rate of heart attacks in smallpox vaccinated and unvaccinated people is the same and there is no evidence of a cause-and-effect link between smallpox vaccine and heart attacks. Even so, DoD medically exempts people with heart conditions.
We try to reduce the risk of side effects by exempting people who should not receive this vaccine.
For more information about side effects of the smallpox vaccine please visit http://emergency.cdc.gov/agent/smallpox/vaccination/reactions-vacc-clinic.asp
No. Pregnant women should not receive the smallpox vaccine, unless they have been exposed to smallpox. Most of the time, when pregnant women get smallpox vaccine, the pregnancy goes well. In an outbreak, personal benefit from vaccination may outweigh the risks of vaccination. Women who are pregnant or planning to become pregnant within 4 weeks after vaccination should NOT get the smallpox vaccine. In addition, anyone who has a close contact who is pregnant should not get the vaccine. Close contacts include anyone living in your household and anyone you have close, physical contact with such as a sex partner or someone you share a bed with.
Smallpox vaccine can cause a very rare but serious complication in the fetus called fetal vaccinia. Less than 50 cases of fetal vaccinia have ever occurred. Most babies born to women who got smallpox vaccine will be fine. If a woman is vaccinated, she should avoid pregnancy for a month. She should wait until the vaccination site has completely healed and the scab has fallen off before trying to become pregnant after vaccination. Until that time, effective measures should be taken to prevent pregnancy, such as abstinence, birth control pills, injections, implants, or IUDs. Other methods of birth control, such as condoms, diaphragms, spermicide, and natural family planning are less effective than abstinence.
Women uncertain about whether or not they are pregnant should get a medical evaluation. Clinics should display warning signs about asking women if they are pregnant. Urine or blood tests can help women find out if they are pregnant before immunization.
Women receiving a smallpox vaccination should wait until the scab has fallen off and the vaccination site has completely healed before trying to become pregnant after vaccination. Generally, this means vaccinated women should wait four weeks after their smallpox vaccination. Until that time, effective measures should be taken to prevent pregnancy, such as abstinence, birth control pills, injections, implants, or IUDs. Other methods of birth control, such as condoms, diaphragms, spermicide, and natural family planning are less effective than abstinence.
Vaccinated men may wish to wait a similar amount of time before fathering a child. Until the vaccination site has completely healed, they can be the source of spreading vaccinia to a close contact (such as a sex partner). Covering the vaccination site is very important for both men and women.
Women who are breastfeeding should not get the smallpox vaccine. Breastfeeding places the baby close to the vaccination site on a woman's arm. This advice is true even if women are pumping and then bottle-feeding breast milk. It is unknown whether the vaccine virus or antibodies pass on to the baby through breast milk. A woman who desires to maintain her milk supply may continue to pump breast milk, but the milk should be discarded until the vaccination site has completely healed and not be given to the baby.
Yes, if clothing is not contaminated and proper hand washing is used. Anyone who receives the smallpox vaccine should remember to wash their hands with soap and warm water after direct contact with the vaccination site, or anything that has touched the vaccination site (bandages, clothing, towels, bedding, etc.). This is will help prevent the spread of vaccinia virus to contacts, including young babies.
First, she should check with her healthcare provider to determine if the rash is related to the smallpox vaccine. If she has a vaccine-related rash, breastfeeding should not take place until all scabs from the rash have fallen off and the skin is completely healed. A woman who desires to maintain her milk supply may continue to pump breast milk, but the milk should be discarded until her scabs fully separate and the skin is completely healed.
There have been less than 50 cases of fetal vaccinia ever reported in the world. Because fetal vaccinia is so rare, smallpox vaccination during pregnancy should not be a reason to consider termination of pregnancy.
Smallpox vaccine has not been associated with an increased risk of miscarriage. There is no evidence that smallpox vaccine causes spontaneous abortion (miscarriage).
Except for the rare case of fetal vaccinia, smallpox vaccination of pregnant women has not been linked with premature birth, low birth weight, or other serious birth problems.
Most women who receive smallpox vaccine during pregnancy will deliver normal babies, and standard delivery procedures should be followed. All pregnant women who have received the smallpox vaccine during pregnancy should let their healthcare provider and their baby's healthcare provider know about their vaccination. Their providers should contact the registry by calling 619.553.9255 or e-mailing NHRCfirstname.lastname@example.org.
DoD works with the CDC in operating the National Smallpox Vaccine in Pregnancy Registry. This registry is used to monitor the outcomes of pregnant women who received the smallpox vaccine. This will help us better understand the risks of smallpox vaccine in pregnancy. The registry has already provided important information, which is generally reassuring to women in these circumstances.
Pregnant women who received the smallpox vaccine, or pregnant women whose close contacts received the smallpox vaccine, may contact their healthcare provider or their state health department for help in enrolling in the registry. Health-care providers and staff from state health departments (see www.cdc.gov/other.htm#states) are encouraged to report all exposed pregnant women to the registry by calling 619.553.9255 or e-mailing NHRCemail@example.com. To learn more, click here: www.smallpox.mil/pregnancy
You should follow the same instructions on "How should I care for the vaccination site?" and read the following:
Even patients vaccinated in the past may be at increased risk due to current immunodeficiency. If contact with unvaccinated patients is essential and unavoidable, healthcare workers can continue to have contact with patients, including those with immune deficiencies, as long as the vaccination site is well-covered and thorough hand-hygiene is maintained. In this setting, a more occlusive dressing might be appropriate. Semi-permeable polyurethane dressings (e.g., Opsite®, Tegaderm®) are effective barriers to vaccinia and recombinant vaccinia viruses.
However, exudate may accumulate beneath the dressing, and care must be taken to prevent viral contamination when the dressing is removed. In addition, accumulation of fluid beneath the dressing may increase the maceration of the vaccination site. To prevent accumulation of exudates, cover the vaccination site with dry gauze, and then apply the dressing over the gauze. The dressing should also be changed daily or every few days (according to type of bandaging and amount of exudate), such as at the start or end of a duty shift.
Three Key Points:
Vaccinia virus is present at the vaccination site for 30 days and until the vaccination site is completely healed. This means other people can get infected if they come in contact with virus from your arm.
Most vaccination sites can be left unbandaged, when not in close contact with other persons. Airing the site will speed healing. Wear sleeves covering the site and/or use an absorbent bandage to make a touch-resistant barrier when around others. Dispose of bandages in sealed or double plastic bags. You may carefully add a little bleach, if desired.
Keep the site dry. Do not use creams or ointments; they will delay healing. Long-sleeve clothing worn during the day and at night can protect the site from dirt. Launder clothing and linens that touch the site in hot water with soap or bleach.
Normal bathing can continue. Dry off carefully, so the towel does not rub or spread virus elsewhere. Don't allow others to use that towel until laundered. Don't use public towels, unless laundry workers are aware of special handling precautions. Use a waterproof adhesive bandage if you exercise enough to cause a sweat. Avoid swimming pools and spas until the site is completely healed.
Take good care of your vaccination site.
Some people should not get the smallpox vaccine unless under emergency situations:
In a smallpox outbreak, even people with exemptions to vaccination should be vaccinated if exposed to smallpox, unless extremely immunosuppressed.
You should discuss your concerns and your individual situation with your medical provider to be sure.
Certain medical conditions, such as the absence of a working spleen (asplenia) may increase a person's risk for certain infections. Some vaccines, particularly pneumococcal, meningococcal, and Haemophilus vaccines, are specifically recommended for people without a spleen. People with asplenia are generally not considered immunosuppressed for the purposes of vaccination and should receive routine vaccinations with both live and inactivated vaccines according to the usual schedules.
You should inform your Health Care Provider if you have heart disease, with or without symptoms, or if you have three or more known major cardiac risk factors (i.e., hypertension, diabetes, hypercholesterolemia, heart disease at age 50 years in a first-degree relative, and smoking).
Other contraindications include:
Also if you have had a serious reaction to polymyxin B, neomycin, latex or a previous dose of smallpox vaccine it may be a contraindication for you to receive smallpox vaccine at this time. If you have concerns, please consult with your health care provider before vaccination.
Careful prevaccination screening will help determine any risk issues you may have.
The standardized DoD smallpox screening form can be viewed at the MILVAX-VHCN website at www.smallpox.mil/screeningform
Vaccinia virus can survive in the environment for about 24 hours. It might survive longer if it stays moist and in the dark. If the bandage dries out, the virus is still present, but less able to spread.
No matter the time, it is always best to carefully dispose of used dressings or bandages in sealed or double plastic bags. Always wash your hands after handling dressings or bandages.
In a household, people have much more intimate or close contact than in work sites or other social settings (e.g., church, malls). As usual, the key here is to not move the virus from your vaccination site to another person. So be careful when around others and follow the standard precautions (band-aids, long-sleeves, hand-washing).
Regarding household members with contraindications:
You shouldn't be vaccinated if you have household members with contraindications to the smallpox vaccine, unless you can be separated from them until your scab falls off (about 14 to 28 days).
Regarding children under 1 year of age:
"Minimizing close physical contact with infants less than one year of age is prudent until the scab falls off. If unable to avoid infant contact, wash hands before handling an infant (e.g., feeding, changing diapers) and ensure that the vaccination site is covered with a porous bandage [e.g., Band-Aid, or gauze] and clothing. It is preferable to have someone else handle the infant." This quote comes from the October 2002 recommendations of the Advisory Committee on Immunization Practices.