How Polio Vaccine is Made: A Fascinating Process

The polio vaccine is one of the most important medical breakthroughs of our time. The vaccine has saved countless lives and has almost eradicated polio from the world. This article will explore the fascinating process of how the polio vaccine is made.

The First Polio Vaccine

The first polio vaccine was developed by Dr. Jonas Salk in 1955. Dr. Salk developed the vaccine using inactivated poliovirus. This means that the virus is killed and cannot cause the disease. The vaccine was so successful that it was widely adopted as the primary method of preventing polio.

Dr. Salk’s vaccine was made by growing poliovirus in large vats, then treating it with formaldehyde to kill the virus. The inactivated virus was then purified and combined with other ingredients to create the vaccine.

Live Attenuated Polio Vaccine

Another type of polio vaccine is the live attenuated polio vaccine. This vaccine is made by weakening the virus so that it cannot cause disease, but is still able to trigger an immune response. This vaccine is typically used in areas where polio is still endemic.

The live attenuated polio vaccine is made by growing poliovirus in a culture of monkey kidney cells. The virus is then harvested and treated with a chemical that weakens it. This weakened virus is then purified and combined with other ingredients to create the vaccine.

Types of Polio Vaccines

There are two types of polio vaccines: the inactivated polio vaccine and the live attenuated polio vaccine. The inactivated polio vaccine is the primary method of preventing polio in most parts of the world. The live attenuated polio vaccine is used in areas where polio is still endemic.

Inactivated Polio Vaccine

The inactivated polio vaccine is made by killing the virus using a chemical called formaldehyde. The inactivated virus is then purified and combined with other ingredients to create the vaccine. The vaccine is given in three doses, usually starting at two months of age.

The inactivated polio vaccine is very safe and has few side effects. The main side effect is pain at the injection site.

Live Attenuated Polio Vaccine

The live attenuated polio vaccine is made by weakening the virus so that it cannot cause disease, but is still able to trigger an immune response. The vaccine is given orally, usually in the form of drops. The vaccine is given in multiple doses, usually starting at six weeks of age.

The live attenuated polio vaccine is very effective at preventing polio. However, because it is a live virus, it can be dangerous for people with weakened immune systems. It is also not recommended for pregnant women or people with certain medical conditions.

Ingredients in Polio Vaccines

Polio vaccines contain a number of ingredients, including the inactivated or weakened poliovirus, purified water, formaldehyde, neomycin, streptomycin, and polymyxin B. The vaccines may also contain trace amounts of other substances, such as bovine serum.

Formaldehyde

Formaldehyde is used to kill the virus in the inactivated polio vaccine. Formaldehyde can be toxic in large doses, but the amount used in vaccines is very small, typically less than 0.1%. The amount of formaldehyde in vaccines is tightly regulated by the FDA and other regulatory agencies to ensure safety.

Neomycin, Streptomycin, and Polymyxin B

Neomycin, streptomycin, and polymyxin B are antibiotics that are used to prevent bacterial contamination during vaccine production. These antibiotics are used in very small amounts, and their use is tightly regulated.

Trace Amounts of Other Substances

Polio vaccines may contain trace amounts of other substances, such as bovine serum. These substances are used in the production of the vaccine, but are present in very small amounts and are not harmful.

Conclusion

The process of making the polio vaccine is a fascinating one that involves growing and purifying the virus, and combining it with other ingredients to create a safe and effective vaccine. The inactivated polio vaccine and the live attenuated polio vaccine have both been highly effective in preventing polio, and have almost eradicated the disease from the world. Polio vaccines are a testament to the power of science and medicine.

Common Questions and Answers

  • Q: How effective is the polio vaccine?

    A: The polio vaccine is highly effective at preventing polio. The inactivated polio vaccine is about 90% effective after two doses, and 99% effective after three doses. The live attenuated polio vaccine is even more effective, with a success rate of over 95% after three doses.
  • Q: What are the side effects of the polio vaccine?

    A: The polio vaccine is generally very safe, but can sometimes cause mild side effects, such as soreness at the injection site, fever, and fussiness. Rarely, the vaccine can cause more serious side effects, such as an allergic reaction. Serious side effects are very rare, and the benefits of vaccination far outweigh the risks.
  • Q: Can the polio vaccine cause polio?

    A: No, the polio vaccine cannot cause polio. The inactivated polio vaccine contains killed virus, while the live attenuated polio vaccine contains weakened virus. Neither vaccine can cause polio.
  • Q: Can the polio vaccine be given to people with weakened immune systems?

    A: The inactivated polio vaccine can be given to people with weakened immune systems, but the live attenuated polio vaccine cannot. People with weakened immune systems should talk to their doctor before receiving any vaccine.

References

  • World Health Organization. Polio vaccines: WHO position paper – March, 2016. Weekly Epidemiological Record. 2016;13(91):145-168.
  • Centers for Disease Control and Prevention. Polio vaccine: what you need to know. Available at: https://www.cdc.gov/vaccines/vpd/polio/public/index.html.
  • National Institutes of Health. Polio vaccines. Available at: https://www.niaid.nih.gov/diseases-conditions/polio-vaccines.

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