Acam2000
Smallpox vaccine is a vaccine that helps prevent smallpox caused by the variola virus. It isn't a routine vaccination for everyone, but only for certain people who are at high risk for smallpox infection. Some side effects can include redness or soreness at the injection site, fever, and swollen lymph nodes in the armpits.
What is Smallpox vaccine?
What is Smallpox vaccine used for?
Prevention of smallpox infection
How Smallpox vaccine works
Smallpox vaccine is a live vaccine that protects you from the variola virus, which is a virus that causes a condition known as smallpox. Smallpox vaccine doesn't contain the variola virus. But rather, it contains a different virus that can help you build up protection against smallpox.
Drug Facts
What are the side effects of Smallpox vaccine?
Common Side Effects
- Itching, swelling, redness, pain at injection site (up to 92%)
- Lymph node pain (up to 57%)
- Headache (up to 50%)
- Feeling tired (up to 48%)
- Muscle pain (up to 46%)
- Feeling unwell (up to 37%)
- Feeling hot (up to 32%)
Other Side Effects
- Shivering
- Nausea
- Diarrhea
- Enlarged lymph nodes under armpits
- Constipation
- Rash
- Fever
Serious Side Effects
Source: DailyMed
The following side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Dizziness, loss of balance or coordination, confusion or trouble speaking
- Eye pain, redness, irritation, or discharge with blurry or decreased vision
- Heart muscle inflammation—unusual weakness or fatigue, shortness of breath, chest pain, fast or irregular heartbeat, dizziness, swelling of the ankles, feet, or hands
- Redness, blistering, peeling, or loosening of the skin, including inside the mouth
- Skin infection—skin redness, swelling, warmth, or pain
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
- Fever
- General discomfort and fatigue
- Headache
- Muscle pain
- Nausea
- Pain, redness, or irritation at injection site
- Swollen lymph nodes in the neck, groin, chest, or underarm area
Pros and cons of Smallpox vaccine
Pros
Works well to prevent smallpox
Not a routine vaccine that everyone needs to get
Only one dose is needed to complete vaccination
Cons
Given as multiple pricks into the skin
Risk of serious side effects, including heart and skin problems
Hasn't been well-studied in children or people age 65 years and older
Pharmacist tips for Smallpox vaccine
Make sure to keep a record of all your immunizations and show it to your provider or pharmacist before receiving any vaccine, including smallpox vaccine, to make sure you're receiving all your vaccines on schedule.
It isn't known if receiving other vaccines with smallpox vaccine affects how well each one works. Additionally, smallpox vaccine can interfere with other tests (e.g., syphilis, TB skin test) providers use to diagnose different infections. Make sure to tell your providers you received smallpox vaccine. TB skin tests need to be delayed until at least 1 month after receiving smallpox vaccine.
After receiving the vaccine, there are several things you need to do to care for the vaccination site. This will make sure the vaccination site isn't damaged so the vaccine works as well as possible for you. This will also make sure you don't spread the virus in the smallpox vaccine vaccine to others around you.
Loosely cover the area where you got smallpox vaccine to keep it clean and dry. If the gauze bandage around the injection site gets wet, change it right away. Also, make sure to cover the vaccination site while bathing with waterproof bandages and don't share towels with others.
The virus from smallpox vaccine can be spread to others who are in close contact with you. Make sure to always wear shirts with sleeves to cover the smallpox vaccine vaccination site. Try as much as possible to not touch the vaccination site with your bare hands, and use gloves when changing bandages. If you do touch the vaccination site by accident, make sure to wash your hands well as soon as possible.
Make sure to do your own laundry and separate your clothes from other people's clothes in hampers and in the washer and dryer machines.
Change the bandage at least every 3 days, but change it sooner if it gets dirty or wet. Place used bandages into a plastic zip-loc bag and throw it away in the regular trash.
Eventually, the scab on the smallpox vaccine injection site will fall off. Take the scab that falls out and put it in a plastic zip-loc bag and throw it away. Wash your hands afterwards to prevent spreading infection.
If you experience a severe reaction to smallpox vaccine, you or your provider can report it to the vaccine adverse event reporting system (VAERS) website or by calling 1-800-822-7967.
Frequently asked questions about Smallpox vaccine
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What are the risks and warnings for Smallpox vaccine?
Smallpox vaccine can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Severe side effects throughout your body
Risk factors: Heart problems| Skin problems treated by topical steroids | Weakened immune system from medical conditions or medications | Pregnant females | Children ages 1 year or younger
Although rare, smallpox vaccine can cause severe and life-threatening complications in several parts of your body. Your provider will monitor you for signs and symptoms and might order certain lab tests regularly. If you have symptoms of these side effects, seek medical help right away or contact your provider so they can manage your treatment. Conditions include, but aren't limited to, the following.
Heart problems (e.g., heart attack, cardiomyopathy, heart inflammation): heart attack, chest pain, trouble breathing, irregular heartbeat, stomach pain, cough, leg swelling, tiredness, pounding heart.
Brain and spinal cord inflammation: confusion, headache, nausea, vomiting, weakness, unstable balance and coordination, numbness or tingling, changes in personality or behavior, loss of consciousness, seizures.
Skin problems (e.g., progressive vaccinia, eczema vaccinatum, Stevens-Johnson syndrome: necrosis (skin death), infection, eczema, inflammation, rash, redness.
Eye problems: vision loss, changes in vision, inflammation, redness.
Severe allergic reactions
Risk factors: Allergy to neomycin or polymyxin B
As with any vaccine, there's a small chance that you might have a severe allergic reaction to smallpox vaccine. Your provider might ask you to stay at the clinic for a short period of time after you've received your vaccine to make sure you can get proper care in case of a serious allergic reaction. Sometimes, these reactions can happen after you've already left the clinic. Get medical help right away if you notice symptoms of a severe allergic reaction, such as feeling faint, swelling of the face, closing of the throat, difficulty breathing, hives or rash, dizziness, shaking, nausea, or chest pain.
Accidental transmission of live virus
Try your best to avoid coming in contact with people with poor immune systems after you've received smallpox vaccine. Because this vaccine contains a live virus, there's a possibility that people who've poor immune systems can become infected with the vaccinia virus if they accidentally come in contact with it. Make sure to thoroughly wash your hands after changing the bandage to your vaccine.
Delay blood and organ donation
People receiving smallpox vaccine shouldn't undergo blood or organ donation for at least 30 days after the dose.
Smallpox vaccine dosage forms
Typical dosing for Smallpox vaccine
Primary vaccination: The typical dose is a drop of smallpox vaccine onto clean, dry skin in the shoulder area. The vaccine is given as pricks into your skin.
Booster: The dose is repeated every 3 years for people who continue to be at high risk for smallpox.
Smallpox vaccine contraindications
People with weakened immune systems from medical conditions or medications
What are alternatives to Smallpox vaccine?
Prevention of smallpox and monkeypox in adults
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References
Best studies we foundAmerican Heart Association. (2022). What is cardiomyopathy in adults?
Badell, M. L., et al. (2015). Risks associated with smallpox vaccination in pregnancy: A systematic review and meta-analysis. Obstetrics and Gynecology.
Centers for Disease Control and Prevention. (2016). Signs and symptoms.
Centers for Disease Control and Prevention. (2016). Transmission.
Centers for Disease Control and Prevention. (2016). What is smallpox?
Centers for Disease Control and Prevention. (2017). Side effects of smallpox vaccination.
Centers for Disease Control and Prevention. (2017). Smallpox.
Centers for Disease Control and Prevention. (2017). Who should get vaccination.
Centers for Disease Control and Prevention. (2022). Prevention and treatment.
Centers for Disease Control and Prevention. (2022). Vaccine basics.
Centers for Disease Control and Prevention. (2022). Vaccines.
Emergent Product Development Gaithersburg Inc. (2018). ACAM2000 (smallpox- vaccinia vaccine, live injection, powder, lyophilized, for solution [package insert]. DailyMed.
National Heart, Lung, and Blood Institute. (2023). What is heart inflammation?
National Institute of Neurological Disorders and Stroke. (2023). Encephalitis.
Reed, J.L., et al. (2012). Eczema vaccinatum. Clinical Infectious Diseases.
ScienceDirect. (n.d.). Progressive vaccinia.
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