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Smallpox vaccine (Injection)

Generic name: smallpox vaccine [ SMAWL-pox-VAX-een ]
Brand name: Dryvax
Drug class: Viral vaccines

Medically reviewed by Last updated on Sep 5, 2023.

Injection route(Powder for Solution)

Myocarditis, pericarditis, encephalitis, encephalomyelitis, encephalopathy, progressive vaccinia, generalized vaccinia, severe vaccinial skin infections, erythema multiforme major (including Stevens-Johnson syndrome), eczema vaccinatum resulting in permanent sequelae or death, ocular complications and blindness and fetal death, have occurred following primary vaccination or revaccination. Certain individuals are at an increased risk which may lead to severe disability, permanent neurological sequelae and/or death .

Uses for smallpox vaccine

Smallpox vaccine is an active immunizing agent used to prevent smallpox infection. It works by causing your immune system to produce its own protection (antibodies) against the virus .

This vaccine should only be administered by or under the supervision of your doctor or another health care professional .

This medicine is available only with a doctor's prescription .

Before using smallpox vaccine

In deciding to use a vaccine, the risks of taking the vaccine must be weighed against the good it will do. This is a decision you and your doctor will make. For this vaccine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies have not been performed on the relationship of age to the effects of smallpox vaccine in children less than 16 years of age. Safety and efficacy have not been established .


No information is available on the relationship of age to the effects of smallpox vaccine in geriatric patients .

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this vaccine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Receiving this vaccine with any of the following medicines is not recommended. Your doctor may decide not to use this vaccine or change some of the other medicines you take.

Receiving this vaccine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Receiving this vaccine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this vaccine. Make sure you tell your doctor if you have any other medical problems, especially:

Proper use of smallpox vaccine

A nurse or other trained health professional will give you this vaccine. This vaccine is given by using a needle to poke or jab the skin on your upper arm .

You may need a booster dose of this vaccine every three years to maintain protection against smallpox. Ask your doctor if you will need another dose of this vaccine .

This vaccine should come with a Medication Guide. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions .

Precautions while using smallpox vaccine

It is very important that your doctor check your progress at regular visits to make sure this vaccine is working properly and to check for unwanted effects .

This vaccine may cause serious heart problems in some patients. Check with your doctor right away if you are having chest pain or discomfort; dizziness; fast or irregular heartbeat; fever and chills; shortness of breath; sweating, weakness; or trouble breathing .

Tell your doctor if you smoke cigarettes or other tobacco products. The risk of heart problems is increased in people who smoke .

You should not receive this vaccine if you are using medicines that weaken your immune system, such as steroids, radiation, or cancer medicines .

You should not become pregnant for at least 3 months after receiving this vaccine without first checking with your doctor. There is a chance that this vaccine may cause problems during pregnancy. If you think you have become pregnant, tell your doctor right away .

This vaccine contains neomycin and polymyxin B. Make sure your doctor knows if you have had an allergic reaction to these medicines .

This vaccine contains a live virus. The virus can cause an infection in other parts of your body or in other people if you touch the vaccination site and then touch your body or other people. Always cover the vaccination site with a bandage. Wash your hands thoroughly after changing the bandage or after touching the vaccination site. Your doctor will tell you how to care for the vaccination site. Make sure you understand the directions and follow them carefully. Avoid contact with people who are sick or have infections until the scab falls off (usually 2 to 4 weeks after vaccination). Talk to your doctor about this if you have concerns .

You must wait at least 30 days before you can donate blood, use a hot tub or swim, handle a baby, or breastfeed .

Before you have any medical tests for syphilis or a tuberculin (TB) skin test, tell the medical doctor in charge that you have received this vaccine. The results of these tests may be affected by this vaccine .

Side Effects of smallpox vaccine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Less common

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Commonly used brand name(s)

In the U.S.

Available Dosage Forms:

Therapeutic Class: Vaccine, Live

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.