Question 1

You are about to graduate as a RN. Your final term project is to prepare a presentation on HIV/AIDS. HIV (human immunodeficiency virus) is a retrovirus—it is an enveloped single-stranded virus that has duplicate copies of a single-stranded RNA genome. All retroviruses encode reverse transcriptase, an enzyme that uses an RNA genome as a template to make a complementary DNA strand. HIV can infect a variety of human cell types, but the most important are the helper T cells (also called CD4 cells)—the virus infects these cells and causes their death; their numbers slowly decline until the immune system can no longer resist infections or tumor development. You give your presentation to the class and are asked by your professor at the end of the session to answer some questions that your peers have on diagnosing HIV.
-You explain to the class that ELISA tests may be direct or indirect. Please select the False statement regarding these tests.

Accepted Answer

This statement is false. While ELISA tests are highly accurate, they are not 100% accurate and can yield false positive results. It is recommended that positive ELISA results be confirmed through additional testing such as a Western blot test.

Question 2

You are about to graduate as a RN. Your final term project is to prepare a presentation on HIV/AIDS. HIV (human immunodeficiency virus) is a retrovirus—it is an enveloped single-stranded virus that has duplicate copies of a single-stranded RNA genome. All retroviruses encode reverse transcriptase, an enzyme that uses an RNA genome as a template to make a complementary DNA strand. HIV can infect a variety of human cell types, but the most important are the helper T cells (also called CD4 cells)—the virus infects these cells and causes their death; their numbers slowly decline until the immune system can no longer resist infections or tumor development. You give your presentation to the class and are asked by your professor at the end of the session to answer some questions that your peers have on diagnosing HIV.
-The initial test used to diagnose HIV is the ELISA test. This test is

Accepted Answer

The ELISA test stands for Enzyme-Linked Immunosorbent Assay, and it is a colorimetric assay that uses enzyme-labeled antibodies to detect the presence of HIV antibodies in a patient's blood sample. The test is often conducted in a microtiter plate, and a positive result indicates the presence of HIV antibodies in the patient's bloodstream.

Question 3

Which of the following is NOT True of artificially acquired passive immunity?

Accepted Answer

Artificially acquired passive immunity can provide immediate protection before or after exposure to a pathogen, limit the duration of certain diseases, and block the action of microbial toxins. However, it does not cure certain diseases.

Question 4

Which of the following is NOT True of naturally acquired immunity?

Accepted Answer

Naturally acquired immunity does not involve injecting a person with antibodies produced by other people or animals. This scenario describes artificially acquired immunity through passive immunization.

Question 5

You are very concerned about the  child with leukemia  who was in your office before you saw the measles patient. You know that the two children had been in the same waiting room for at least 20 minutes and that measles is a highly contagious disease. You also know that the patient with cancer has not received his MMRV vaccine because

Accepted Answer

Attenuated vaccines, such as the MMRV vaccine, contain live but weakened disease agents that could pose a risk to immunocompromised individuals who cannot fight off any microbial infection. This is why the child with leukemia has not yet received the MMRV vaccine. In addition, the fact that the child with leukemia and the measles patient were in the same waiting room for at least 20 minutes increases the risk of the leukemia child contracting measles, which could be very dangerous for them.

Question 6

A patient is tested for antibodies to a particular infectious agent and is found to be positive. What would account for the positive result in this person?

Accepted Answer

A positive result for antibodies means that the person was exposed to the infectious agent at some point in the past. The positive result could be due to current infection, past infection, or vaccination. Therefore, option D is the correct choice as it includes all possibilities.

Question 7

You are about to graduate as a RN. Your final term project is to prepare a presentation on HIV/AIDS. HIV (human immunodeficiency virus) is a retrovirus—it is an enveloped single-stranded virus that has duplicate copies of a single-stranded RNA genome. All retroviruses encode reverse transcriptase, an enzyme that uses an RNA genome as a template to make a complementary DNA strand. HIV can infect a variety of human cell types, but the most important are the helper T cells (also called CD4 cells)—the virus infects these cells and causes their death; their numbers slowly decline until the immune system can no longer resist infections or tumor development. You give your presentation to the class and are asked by your professor at the end of the session to answer some questions that your peers have on diagnosing HIV.
-One of your peers asks you to explain the term immunoassay. You tell him that it

Accepted Answer

Immunoassay is an in vitro test in which known antibodies or antigens are used to detect or quantify given antibodies or antigens. In other words, it is a laboratory test that uses specific antibodies to detect the presence of certain proteins or substances in a patient's biological sample.

Question 8

The type of immunity conferred by giving a person a vaccine is

Accepted Answer

Vaccines provide artificial active immunity, because the body produces an immune response and creates memory cells to fight off future infections. Natural immunity refers to immunity gained through exposure to a pathogen, whereas passive immunity refers to the transfer of antibodies from one organism to another. Vaccines do not provide natural or passive immunity.

Question 9

Many inactivated vaccines contain an adjuvant, a substance that enhances the immune response to antigens. An adjuvant that uses a derivative of lipid A has recently been developed. Would lipid A work well as an adjuvant?

Accepted Answer

Lipid A is a component of the outer membrane of Gram-negative bacteria and is recognized by Toll-like receptor 4 (TLR4) in mammalian cells, triggering an immune response. Since lipid A can alert the immune system to the presence of bacteria, it can similarly alert the immune system to the components of a vaccine if used as an adjuvant in the vaccine.

Question 10

Select the False statement regarding artificially acquired passive immunity.

Accepted Answer

The statement "It occurs naturally in response to infections, and artificially in response to vaccination, when antigens are deliberately introduced into the body" describes artificially acquired active immunity, not passive immunity. Passive immunity is acquired through the transfer of pre-formed antibodies from one individual to another.

Question 11

You are about to graduate as a RN. Your final term project is to prepare a presentation on HIV/AIDS. HIV (human immunodeficiency virus) is a retrovirus—it is an enveloped single-stranded virus that has duplicate copies of a single-stranded RNA genome. All retroviruses encode reverse transcriptase, an enzyme that uses an RNA genome as a template to make a complementary DNA strand. HIV can infect a variety of human cell types, but the most important are the helper T cells (also called CD4 cells)—the virus infects these cells and causes their death; their numbers slowly decline until the immune system can no longer resist infections or tumor development. You give your presentation to the class and are asked by your professor at the end of the session to answer some questions that your peers have on diagnosing HIV.
-The Western blot is used to confirm the results of an ELISA test. Which of the following is the correct sequence of steps involved in this procedure?
1) To determine if a patient's serum has antibodies specific for any of the proteins in the sample (in this case HIV proteins), some of that serum is added to the blot, after which unbound antibodies are washed off.
2) The antigen proteins separate according to size. The separated proteins in the gel are then transferred ("blotted") to a nylon membrane to immobilize them in the same positions they were in the gel.
3) A type of gel electrophoresis (SDS-PAGE) is used to separate the proteins of an antigen, which involves loading the sample onto a polyacrylamide gel matrix, and running an electrical current through it.
4) Labeled anti-human IgG antibodies are added, which bind to any serum antibodies that have attached to the proteins. Unbound labeled antibodies are then washed off and attached label is detected.

Accepted Answer

The correct sequence for a Western blot procedure starts with SDS-PAGE to separate proteins (3), followed by transferring these proteins to a membrane (2), then adding patient serum to see if antibodies bind to the proteins (1), and finally adding labeled anti-human IgG antibodies to detect bound antibodies (4).

Question 12

Why does passive immunity not give lifetime protection, while active immunity may?

Accepted Answer

In active immunity, the body produces memory cells that can respond to subsequent exposure to the same antigen, providing long-lasting protection. In passive immunity, the antibodies are already formed and injected, providing immediate but temporary protection as they are not produced by the body's own lymphocytes and do not stimulate the formation of memory cells.

Question 13

You are about to graduate as a RN. Your final term project is to prepare a presentation on HIV/AIDS. HIV (human immunodeficiency virus) is a retrovirus—it is an enveloped single-stranded virus that has duplicate copies of a single-stranded RNA genome. All retroviruses encode reverse transcriptase, an enzyme that uses an RNA genome as a template to make a complementary DNA strand. HIV can infect a variety of human cell types, but the most important are the helper T cells (also called CD4 cells)—the virus infects these cells and causes their death; their numbers slowly decline until the immune system can no longer resist infections or tumor development. You give your presentation to the class and are asked by your professor at the end of the session to answer some questions that your peers have on diagnosing HIV.
-You tell the class that ELISAs and Western blots are performed in a clinic or laboratory. However, there are a variety of tests that can be performed at home. With the oral fluid antibody self-test, a person swabs their own mouth and uses a kit to test the sample. The kit looks similar to a pregnancy test. Saliva is collected on a swab which is then inserted into the "tube" containing a test strip on which certain HIV proteins are bound. The saliva moves up the test strip until it reaches two windows on the tube - one is labeled C and the other is labeled T.  When the saliva reacts with the bound virus proteins, a color change is seen. Results are interpreted as follows: 
No color in the C window-test is not working.
Color in the C window but none in the T window-negative result.
Color in the C window and color in the T window-positive result. 
Given this information, select the False statement.

Accepted Answer

The answer of You are about to graduate as a...

Question 14

You explain to the parent of the child with measles the importance of vaccinations. She responds by saying that measles, mumps, rubella, and varicella are very rare diseases in developed countries and she doesn't want her child to go through getting her shots. She worries about the safety of the MMRV vaccine. Which is the best response regarding this concern?

Accepted Answer

This choice not only addresses the concern about the safety and effectiveness of the MMRV vaccine but also highlights the importance of herd immunity for the protection of vulnerable populations like immunocompromised individuals. It also acknowledges that although these diseases are rare in developed countries, they still exist and can pose a threat with enough susceptible hosts.

Question 15

Which of the following is NOT an example of an inactivated vaccine?

Accepted Answer

Adjuvants are substances that are added to vaccines to enhance the immune response, but they are not vaccines themselves. Inactivated vaccines include toxoid, subunit, conjugate, and virus-like particle vaccines.

Question 16

The MMRV vaccine is an attenuated vaccine, which means that the vaccine

Accepted Answer

The MMRV vaccine is an attenuated vaccine because it is composed of a weakened form of the pathogen that is generally unable to cause disease. This weakened form can still stimulate the immune system to produce an immune response and provide protection against the pathogen.

Question 17

Attenuated vaccines have several advantages. Which of the following is NOT an advantage of these vaccines?

Accepted Answer

Attenuated vaccines require careful storage and transportation because they are live pathogens that can revert to virulence if not properly handled.

Quiz 18: Applications of Immune Responses