ACAM2000

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Smallpox vaccine needle Smallpox vaccination needle.jpg
Smallpox vaccine needle

ACAM2000 is a smallpox vaccine manufactured by Sanofi Pasteur Biologics Co. It provides protection against smallpox for people determined to be at high risk for smallpox infection. [1]

Contents

Background

Smallpox is considered a biological threat due to its potential to be used as a biological agent. Biological agents are toxins or organisms that can cause illness or death in humans, animals and plants. Exposure can result from an intentional vector, like a terrorist attack, or an unintentional release of the agent. [2]

Smallpox was eradicated in 1980. However, there has been interest in the development of vaccines due to the possible use of smallpox as a biological agent. [3]

Smallpox vaccine development

Smallpox vaccine development was then in its second generation. First-generation vaccines were derived from calf-lymph, and include Dryvax, APVS, Lancy-vaxina and Lister. Second-generation vaccines are cell-cultured and include ACAM2000 and CCSV. [3]

Both Dryvax and ACAM2000 come from the New York City Board of Health strain of vaccinia. Dryvax was grown on calf skin and then freeze-dried for storage. Dryvax was first licensed by the FDA in 1931; however, it is no longer manufactured. ACAM2000 is a second generation smallpox vaccine. It comes from a clone of Dryvax which is purified and produced using modern cell culture technology. [4]

ACAM2000 history

Emergent BioSolutions developed ACAM2000 under a contract with the U.S. Centers for Disease Control and Prevention (CDC). [5]

The U.S. Food and Drug Administration (FDA) approved ACAM2000 in August 2007. By February 2008, it replaced Dryvax for all smallpox vaccinations. [6]

As of 2010, there were over 200 million doses manufactured for the U.S. Strategic National Stockpile. [6]

According to the U.S. FDA, "The approval and availability of this second-generation smallpox vaccine in the Strategic National Stockpile (SNS) enhances the emergency preparedness of the United States against the use of smallpox as a dangerous biological weapon." [4]

Administration of ACAM2000

The ACAM2000 vaccine is produced from the Vaccinia virus, which is sufficiently closely related to smallpox to provide immunity, but the ACAM2000 vaccine cannot cause smallpox because it does not contain the smallpox virus. [4] Other vaccines containing live viruses include measles, mumps, rubella, polio and chickenpox. [7]

The vaccine is administered using a bifurcated stainless steel needle. The needle is dipped into the vaccine solution and used to prick the skin several times in the upper arm. The vaccinia virus will begin to grow at the injection site. It will cause a localized infection, with a red itchy sore produced at the vaccination site within three to four days. If the infection occurs, that is an indication that the vaccine was successful. Ultimately, the sore turns into a blister and then dries up. A scab forms and then falls off in the third week, leaving a small scar behind. [4]

Risks

Administration of ACAM2000 poses risks and may cause side effects. Most people who have taken the vaccine only report mild reactions. Reactions may include a sore arm, fever, and body aches. Some people may have more serious side effects, including effects that may be life-threatening. [8]

According to the FDA-approved prescribing information leaflet, "Common adverse events include inoculation site signs and symptoms, lymphadenitis, and constitutional symptoms, such as malaise, fatigue, fever, myalgia, and headache." [9] These reactions are less frequent in people being revaccinated than those receiving the vaccine for the first time. [9]

No known contraindications exist to receiving the vaccine in case of an outbreak emergency. Furthermore, it is recommended that the vaccine should be given to pregnant women who have been exposed to smallpox. "Because the risk of maternal serious illness or death, prematurity, miscarriage, or stillbirth from a smallpox infection are greater than the risk of the vaccination, smallpox vaccine is recommended and should be offered to pregnant women in case of an outbreak emergency." [10]

Related Research Articles

<span class="mw-page-title-main">Vaccination</span> Administration of a vaccine to protect against disease

Vaccination is the administration of a vaccine to help the immune system develop immunity from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. In stimulating the body's adaptive immunity, they help prevent sickness from an infectious disease. When a sufficiently large percentage of a population has been vaccinated, herd immunity results. Herd immunity protects those who may be immunocompromised and cannot get a vaccine because even a weakened version would harm them. The effectiveness of vaccination has been widely studied and verified. Vaccination is the most effective method of preventing infectious diseases; widespread immunity due to vaccination is largely responsible for the worldwide eradication of smallpox and the elimination of diseases such as polio and tetanus from much of the world. However, some diseases, such as measles outbreaks in America, have seen rising cases due to relatively low vaccination rates in the 2010s – attributed, in part, to vaccine hesitancy. According to the World Health Organization, vaccination prevents 3.5–5 million deaths per year.

<span class="mw-page-title-main">Vaccine</span> Pathogen-derived preparation that provides acquired immunity to an infectious disease

A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's immune system to recognize the agent as a threat, destroy it, and recognize further and destroy any of the microorganisms associated with that agent that it may encounter in the future.

<span class="mw-page-title-main">Cowpox</span> Disease of humans and animals

Cowpox is an infectious disease caused by the cowpox virus (CPXV). It presents with large blisters in the skin, a fever and swollen glands, historically typically following contact with an infected cow, though in the last several decades more often from infected cats. The hands and face are most frequently affected and the spots are generally very painful.

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The smallpox vaccine is the first vaccine to have been developed against a contagious disease. In 1796, British physician Edward Jenner demonstrated that an infection with the relatively mild cowpox virus conferred immunity against the deadly smallpox virus. Cowpox served as a natural vaccine until the modern smallpox vaccine emerged in the 20th century. From 1958 to 1977, the World Health Organization (WHO) conducted a global vaccination campaign that eradicated smallpox, making it the only human disease to be eradicated. Although routine smallpox vaccination is no longer performed on the general public, the vaccine is still being produced to guard against bioterrorism, biological warfare, and mpox.

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Smallpox was an infectious disease caused by variola virus, which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) certified the global eradication of the disease in 1980, making smallpox the only human disease to have been eradicated to date.

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The monkeypox virus is a species of double-stranded DNA virus that causes mpox disease in humans and other mammals. It is a zoonotic virus belonging to the orthopoxvirus genus, making it closely related to the variola, cowpox, and vaccinia viruses. MPV is oval, with a lipoprotein outer membrane. The genome is approximately 190 kb. Smallpox and monkeypox viruses are both orthopoxviruses, and the smallpox vaccine is effective against mpox if given within 3–5 years before the disease is contracted. Symptoms of mpox in humans include a rash that forms blisters and then crusts over, fever, and swollen lymph nodes. The virus is transmissible between animals and humans by direct contact to the lesions or bodily fluids. The virus was given the name monkeypox virus after being isolated from monkeys, but most of the carriers of this virus are smaller mammals.

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References

  1. "Approved Products - ACAM2000". www.fda.gov. Retrieved 2018-09-08.
  2. "Biological Threats". Emergent BioSolutions. Retrieved 2018-08-13.
  3. 1 2 Metzger W, Mordmueller BG (2007). "Vaccines for preventing smallpox". Cochrane Database Syst Rev. 2007 (3): CD004913. doi:10.1002/14651858.CD004913.pub2. PMC   6532594 . PMID   17636779.
  4. 1 2 3 4 "Questions about Vaccines - ACAM2000 (Smallpox Vaccine) Questions and Answers". www.fda.gov. Retrieved 2018-09-08.
  5. "About ACA2000" (PDF). Emergent BioSolutions. Retrieved 2018-09-08.
  6. 1 2 Nalca, A; Zumbrun, EE (25 May 2010). "ACAM2000: the new smallpox vaccine for United States Strategic National Stockpile". Drug Design, Development and Therapy. 4: 71–9. doi: 10.2147/dddt.s3687 . PMC   2880337 . PMID   20531961.
  7. "Vaccine Basics | Smallpox | CDC". www.cdc.gov. 2017-07-13. Retrieved 2018-09-08.
  8. "Vaccine Safety | Smallpox | CDC". www.cdc.gov. 2017-07-13. Retrieved 2018-09-08.
  9. 1 2 "ACAM2000 (smallpox- vaccinia vaccine, live injection, powder, lyophilized, for solution". DailyMed. 21 March 2018. Retrieved 10 January 2023.
  10. "Smallpox vaccine Use During Pregnancy | Drugs.com". Drugs.com. Retrieved 2018-09-08.