Understanding Immunizations and Evolution: The Role of Mutations Explained

[CoolBeans]

Hello, I am new to this forum and signed up to ask this specific question.

From what i understand of evolution(which i am not trying to discredited here btw ) mutations are caused by either chance or adaption which then through natural selection favorable mutations are basically breed into the standard population, please correct me if I am wrong.

And from this immunizations cause a mutation by exposure to the disease, this mutation being favorable. But why do we keep immunizing generation after generation, if you had two parents with the mutation caused by the immunization would'nt it be passed to the child and there would be no need for the child to be immunized?

Thanks in advance.

 

[Pythagorean]

Hello, I am new to this forum and signed up to ask this specific question.

From what i understand of evolution(which i am not trying to discredited here btw ) mutations are caused by either chance or adaption which then through natural selection favorable mutations are basically breed into the standard population, please correct me if I am wrong.

I believe mutations are just caused by chance. An adaption is just what we call a mutation that was successful (in terms of the organism's survivability) after the fact.

And from this immunizations cause a mutation by exposure to the disease, this mutation being favorable. But why do we keep immunizing generation after generation, if you had two parents with the mutation caused by the immunization would'nt it be passed to the child and there would be no need for the child to be immunized?

Well, no, not really. You pass genes on to your kids and immunizations don't directly affect genes. On the other hand, a pregnant mother will "update" her child's immunizations in the womb, and her milk will provide immunities to the breastfeeding child. The child will only gain immunizations to the viruses the mother is exposed to, though.

Also, the strains of viruses mutate a lot faster than us and new strains develop, so we are always changing the immunization program to keep up with the viruses anyway.

 

[DaleSwanson]

A point that may help you understand evolution and genetics is that as soon as an organism is born its genetics are set in stone. Nothing that happens during its lifetime (with a few exceptions) will affect the genetics it passes on to its children.

 

[sona1177]

The viruses/disease-causing organisms keep changing, so we must change them with them or eventually go extinct. They change by the second so any genes for immunity your parents pass on through thousands and thousands of generations will likely not completely protect you from all pathogens.

 

[CoolBeans]

Thanks guy's that cleared things up, however if two people naturally had an immunity to a certain strain of a virus it would then be reasonable to assume that the child is likely to have that same immunity right?

 

[sona1177]

No because remember that genes are passed on randomly. Parents only pass on 23 chrosomes, they give either the recessive or dominant allele. Also, you can not inherit features but only these genes. For instance,
Just because you are diabetic does not mean your child will be diabetic. It only PREDISPOSES them to being diabetic (meaning passing on genes that make the person more vulnerable). It also depends on lifestyle. If things went the way you were saying, the human race would be in trouble lol. But I haven't taken genetics yet so I'm sorry if this doesn't entirely answer your question.

 

[CoolBeans]

No that's alright, thanks for the response it answer my question well.

 

[Pythagorean]

At this point we should also consider gene expression. You may share a lot of genes with your relatives that just aren't being expressed by your cells currently (and may never be expressed by the time you die).

If I recall correctly, changes in gene expression only occur under significant conditions of stress on the biological system, but I'm a bit sketchy here.

 

[RiDK]

CoolBeans, in terms of the child being likely to inherit the immunity, the simple answer is yes. The more complicated answer being provided by sona1177.

Under the overly broad assumption that a single, specific pair of non-sexual alleles directly causes the immunity. The child has at least a 75% chance to inherit the trait. If it is a dominant trait, and both parents have a dominant and recessive allele, (immune+non-immune) the child has to inherit a non-immune allele from each parent to not have the immunity, which will only happen 25% of the time. If it is a recessive trait, neither parent has a non-immune allele, so the child will have the trait barring the minute chance of a mutation damaging the portion of the allele that causes the immunity.

This assumes there are no complicating factors such as sona1177 describes, which may cause the gene to not be expressed because of a dependence on other genes or external factors.

As a touch more detail with regards to your original question: a vaccine causes the immune system to produce antibodies to fight the disease. The ability to produce these antibodies is genetic, and thus is passed on to the child. However, the immune system only produces antibodies for diseases it is actively fighting or has fought in the past. Thus, the child will not begin producing antibodies to a disease until given a vaccine (which simulates catching the disease) or until the child actually gets the disease. The idea being that a vaccine can look like a disease without actually attacking the body, whereas the disease may kill the child before its body reacts and produces enough antibodies to fight off the disease.

 

[fedaykin]

CoolBeans: Humoral immunity and cell-mediated immunity are largely not inherited. The mechanisms to produce them are, but the antibodies and receptors themselves are not.
There may be a predisposition to develop responses to certain antigens though.

I don't remember the timeframe too well on the following; seems I need to brush up.

In a sense, you're born with all of the different types of antibodies you can ever make. The lymphocyte progenitors undergo a series of recombinations as they divide that makes millions of different types of antibody proteins. A lymphocyte will express only one. These are stored until an antigen is presented to the lymphocytes. A lymphocyte that expresses an antibody that binds that antigen will be selected to proliferate thereby producing an immune reaction to that antigen eventually.

For more information, look up VDJ recombination and clonal selection/proliferation.

Edit: Also, that's not a stupid question.

 

[russ_watters]

Thanks guy's that cleared things up, however if two people naturally had an immunity to a certain strain of a virus it would then be reasonable to assume that the child is likely to have that same immunity right?

I don't think anyone answered this directly, so I'll say it: Immunizations do not cause genetic change in the people who are immunized. Therefore, there is nothing from them for parents to pass along to their children's DNA.

 

[Pythagorean]

I don't think anyone answered this directly, so I'll say it: Immunizations do not cause genetic change in the people who are immunized. Therefore, there is nothing from them for parents to pass along to their children's DNA.

ooh, ooh! me me! post #2!

 

[russ_watters]

Oh, sorry - I guess I probably missed it for the same reason the OP missed it! (skimming too fast):

You pass genes on to your kids and immunizations don't directly affect genes.

 

[Pythagorean]

No worries, I probably could have been more articulate.

 

[nismaratwork]

I would just add that our immune system, bolstered by our mothers, our adenoids as children, or by a vaccination vary in terms of how long it remains ready to render you "immune" to a particular pathogen. We DO have adaptations to deal with many diseases, but our adaptations do not usually render us immune (to some %) in the way that a vaccine does. Thus the need for booster shots, even when the pathogen in question has not mutated/adapted.