Vaccines. what exactly is the significance of using killed microbes

In summary, vaccines may contain attenuated microorganisms, killed microorganisms or toxoids. Certain vaccines, such as cholera, rabies, hepatitis B, and Japanese encephalitis, use killed forms of microorganisms. This may be due to the deadly nature of these diseases and the potential risk of using attenuated forms. Attenuated forms can also potentially revert to their virulent state or be contaminated during production. Inactive vaccines, while less effective, are safer and more practical for use in certain situations, such as for people with immunodeficiency or in transportation to poorer countries. Attenuated vaccines are still preferred for their larger immune response and longer-lasting immunity, but inactive vaccines may be a safer alternative in some cases.
  • #1
sinjan.j
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vaccine may contain attenuated microorganisms, killed microorganisms or toxoids.
Certain vaccines contain attenuated forms or killed forms or toxoids.

For example, in case of cholera, rabies, hepatitis B, Japanese encephalitis, we use killed form. Why can't we form attenuated forms here? Is it because the diseases are so deadly that usage of attenuated forms can cause the death of the recipient of the vaccine. But, if it is attenuated isn't it true that the life form has lost it's toxic properties and is still being able to produce antibodies?

So what exactly is the significance of using killed microbes for these particular diseases?
 
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  • #2


One of the reason could be that there is too much danger in using attenuated forms. Back in my undergrad immunology modules I remember being taught that there is always a small chance that a batch will contain a fully capable organism. Reasons for this were almost always industrial error.

It could also be that the attenuated form is not needed, part of the reason to use an attenuated form is that the pathogen will in possession of all it's http://en.wikipedia.org/wiki/Pathogen-associated_molecular_pattern" [Broken] because that may be all that is needed to grant a good immunity. Think of it this way, if you were showing me an enemy Knight I could learn a lot more from examining all the weaknesses in his armour as opposed to just examining his chest plate. Otherwise there's a chance that one day I face a group of knights who have bought (evolved) new chest plates without the weakness I'm familiar with.

As for antibodies these are Y-shaped proteins also known as http://en.wikipedia.org/wiki/Antibody" [Broken] that are produced by the body's immune cells in response to a pathogen.
 
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  • #3
sinjan.j said:
But, if it is attenuated isn't it true that the life form has lost it's toxic properties and is still being able to produce antibodies?

I think you meant antigens instead of antibodies.


sinjan.j said:
Is it because the diseases are so deadly that usage of attenuated forms can cause the death of the recipient of the vaccine.So what exactly is the significance of using killed microbes for these particular diseases?

Attenuated vaccines are largely produced by repeatedly growing original strains of pathogens in a foreign host cell culture which are allowed to accumulate mutations. Therefore they lose their effectiveness in human tissue and are then administered as vaccines. However there is always a possibility of the strain's reversion to virulence i.e. after entering our bodies they may regain their virulence due to new mutations. This and the possibility of contamination of orignal culture like Ryan said, are some of the primary concerns associated with attenuated vaccines.
 
  • #4
mishrashubham said:
Attenuated vaccines are largely produced by repeatedly growing original strains of pathogens in a foreign host cell culture which are allowed to accumulate mutations. Therefore they lose their effectiveness in human tissue and are then administered as vaccines. However there is always a possibility of the strain's reversion to virulence i.e. after entering our bodies they may regain their virulence due to new mutations. This and the possibility of contamination of orignal culture like Ryan said, are some of the primary concerns associated with attenuated vaccines.

Exactly, and it's always a risk vs benefit scenario. So when we look at what's required from the vaccine we can accomplish what's needed with least amount of risk.

For instance with cholera it's mostly used for people traveling and in poorer countries. (AFAIK) Why put people at risk with the attenuated version if the inactive version provides moderate protection which will last more than long enough for the average 'trip'. This type of vaccination also works out well because it needs to be transported (most likely) to poorer nations. Attenuated vaccines require more advanced technology to regulate its environment, this isn't needed in inactive vaccines.

Another major concern is for people with immunodeficiency. Whether this is due to disease or other medicines taken at the time of vaccination it is important that they do not take the attenuated virus. The attenuated virus is still living and able to reproduce. The only thing is though, that it reproduces slowly and it's viral efficiency is low enough that the average immune response can easily deal with it. But if we now have a person with very low immune response they may not be able to handle the vaccine and the probability of them getting sick as result is significantly higher.

So as has already been stated, why put a patient at risk with a live virus/bacteria when they could easily just be treated with inactive virus/bacteria or even a fragment of that it. (as ryan mentioned).

Attenuated vaccines are still preferred though due to the larger immune response, the patient needs to take only once and boosters are less frequent and the immunity is much more efficient due to the larger immune response. Sometimes though it's not necessary, or safe so instead the inactive vaccine is used.
 
  • #5


The use of vaccines, whether they contain attenuated or killed microbes, is a crucial tool in preventing the spread of infectious diseases. The significance of using killed microbes in certain vaccines is to provide protection against the disease without risking the recipient's health.

In some cases, it may not be possible to use attenuated forms of the microbe in a vaccine due to safety concerns. Attenuated forms are weakened versions of the microbe that can still stimulate the immune system to produce antibodies, but may also carry a small risk of causing the disease in individuals with weakened immune systems.

For diseases like cholera, rabies, and hepatitis B, which can be life-threatening, the use of killed microbes in the vaccine is a safer option. This is because the microbes are completely inactivated and unable to cause the disease, but still capable of stimulating the immune system to produce antibodies.

In the case of toxoids, these are toxins produced by the microbe that have been inactivated and can no longer cause harm. By using toxoids in vaccines, the immune system can produce antibodies against the toxin without being exposed to the harmful effects of the actual toxin.

Overall, the significance of using killed microbes in vaccines is to provide effective protection against diseases while minimizing the risk of adverse reactions. The choice of whether to use attenuated or killed forms in a vaccine is based on the specific characteristics of the microbe and the potential risks to the recipient.
 

1. What are vaccines and how do they work?

Vaccines are a type of medicine that help protect us from infectious diseases. They work by stimulating our immune system to produce antibodies, which are proteins that fight against specific microbes. This way, if we come into contact with the actual disease-causing microbe, our immune system is already prepared to fight it off.

2. What are killed microbes in vaccines and why are they used?

Killed microbes, also known as inactivated vaccines, contain dead versions of the disease-causing microbe. These are used in vaccines because they are not able to cause illness, but can still trigger our immune system to produce antibodies. This makes them a safe and effective way to protect against certain diseases.

3. Are there any risks associated with using killed microbes in vaccines?

There is a very small risk of adverse reactions to vaccines, including those containing killed microbes. However, the benefits of vaccination far outweigh the potential risks. These reactions are usually mild and temporary, such as fever or soreness at the injection site. Severe reactions are extremely rare.

4. How long does the protection from a vaccine last?

The duration of protection from a vaccine varies depending on the disease and the individual's immune response. Some vaccines may provide lifelong immunity, while others may require booster shots to maintain protection. It is important to follow the recommended vaccination schedule to ensure continuous protection.

5. Are vaccines necessary if the disease is no longer prevalent?

Yes, vaccines are still necessary even if a disease is no longer prevalent. This is because the disease can resurface if vaccination rates drop. Additionally, some diseases may still be present in other parts of the world and can easily spread to unvaccinated individuals. Vaccines are the most effective way to prevent the spread of infectious diseases and protect both individuals and communities.

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