The difference is that these vaccines use an attenuated, or weakened, virus or bacterium as a ride, or vector, for the DNA. In essence, scientists are able to take a harmless pathogen, dress it in the DNA of a more dangerous disease, and train the body to recognize and fight both effectively. The Herd Immunity Imperative Vaccines don't just work on an individual level, they protect entire populations. Featured Online Programs This is critical because there will always be a percentage of the population that cannot be vaccinated, including infants, young children, the elderly, people with severe allergies, pregnant women, or people with compromised immune systems.
Types of Vaccines The key to vaccines is injecting the antigens into the body without causing the person to get sick at the same time. Advantages: Because these vaccines introduce actual live pathogens into the body, it is an excellent simulation for the immune system.
So live attenuated vaccines can result in lifelong immunity with just one or two doses. Disadvantages: Because they contain living pathogens, live attenuated vaccines are not given to people with weakened immune systems, such as people undergoing chemotherapy or HIV treatment, as there is a risk the pathogen could get stronger and cause sickness. Additionally, these vaccines must be refrigerated at all times so the weakened pathogen doesn't die. Specific Vaccines: Measles Mumps Rubella MMR combined vaccine Varicella chickenpox Influenza nasal spray Rotavirus Inactivated Vaccines: For these vaccines, the specific virus or bacteria is killed with heat or chemicals, and its dead cells are introduced into the body.
Advantages: These vaccines can be freeze dried and easily stored because there is no risk of killing the pathogen as there is with live attenuated vaccines. They are also safer, without the risk of the virus or bacteria mutating back into its disease-causing form. Disadvantages: Because the virus or bacteria is dead, it's not as accurate a simulation of the real thing as a live attenuated virus.
Therefore, it often takes several doses and "booster shots" to train the body to defend itself. Immunity usually lasts for years, and sometimes for a lifetime. The length of time varies by disease and by vaccine. Immunity through vaccination protects not only the immunised individual but also protects unvaccinated people in the community, such as infants who are too young to be vaccinated. In contrast, a person who becomes immune by getting the disease can expose other unvaccinated people to the disease.
The person is also at risk of complications. Some newer vaccines do not contain an antigen. It is the latter discovery that led to the development of the subunit vaccine. There are 85 single and combination vaccines approved for use by the U.
Among these are the many inactivated vaccines, also known as whole-killed vaccines, that protect against the following diseases:. Some inactivated vaccines are no longer available in the United States, including those for cholera and plague.
There are pros and cons to every vaccine. In many cases, there is only one version of a vaccine to choose from. Even so, understanding how inactivated vaccines work can help you understand why vaccine doses differ and why some cost more than others. Vaccine durability refers to the timeframe that a vaccine is effective.
Comparatively speaking, the durability of inactivated vaccines tends to fall short when compared to live vaccines. This is because the immune system can better recognize a bacteria or virus that actively replicates, even if it doesn't cause disease.
While inactivated vaccines may require up to four doses to achieve the optimal level of protection, live ones generally require one or two.
Subunit Vaccine Durability : While subunit vaccines are technically inactivated, they do not involve the whole pathogen but rather a fragment of a pathogen and are considered a distinct category of vaccines. The fragment that's used is chosen for its strong antigenic immune-stimulating effect.
Subunit vaccines often need booster shots to maintain immune protection. Because the pathogen in the vaccine is dead, inactivated vaccines have the advantage of being easily stored and shipped, which makes transport easier, especially in parts of the world where resources are limited. Live vaccines, on the other hand, typically require special shipping and storage requirements. This limitation creates problems in resource-poor areas. These needs can also increase costs and lead to waste due to shorter shelf life.
Storage and shipping have become major topics of concern with the approval of the Moderna and Pfizer COVID vaccines in , both of which require subzero storage temperatures. This limits their distribution to sites that have the facilities to properly store them, slowing the rate of vaccination. Inactivated vaccines can be given to most people because there is no chance of the dead virus causing disease. With live vaccines, however, there is a small chance that a virus can replicate and cause illness in some people.
With that said, the only vaccine that is known to have reverted to its pathogenic disease-causing form is the live oral polio vaccine, which is no longer used in the United States. There is a live vaccine for influenza that is licensed in the United States called FluMist , and the live oral vaccine for polio is not licensed in the US. Organ transplant recipients or anyone taking immunosuppressive drugs , people with HIV , and those undergoing cancer chemotherapy can be at risk of getting an infection from a live vaccine.
Even though their genetic material has been destroyed, inactivated viruses usually contain many proteins which the immune system can react to. But because they cannot infect cells, inactivated vaccines only stimulate antibody-mediated responses, and this response may be weaker and less long-lived.
To overcome this problem, inactivated vaccines are often given alongside adjuvants agents that stimulate the immune system and booster doses may be required. Subscribe and be the first to know about new additions to this platform. Thank you! Something went wrong while submitting the form.
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