Immunity (Nursing)

00:01 Let's talk about immunity.

00:03 Immunity allows us to tolerate the presence of an agent, such as a bacteria or virus.

00:09 It's our ability to resist infection. There are several types of immunity that prevent infectious disease.

00:16 So let's talk about those different types.

00:18 First, we have passive immunity.

00:22 Passive immunity occurs when a person is given immunity.

00:26 Now, this is short-term immunity that provides resistance to a specific disease-causing agent.

00:31 There are two different ways that one can be given immunity.

00:35 One is through maternal antibody transfer.

00:38 This is the transfer of antibodies from a mother to a newborn.

00:41 It can take place in two different ways, through the placenta or through breastmilk.

00:46 So, in this instance, it's like the newborn is borrowing immunity from the mother.

00:51 The second way that one can be given passive immunity is through receiving immunoglobulin therapy.

00:58 This means transferring immunity through the administration of immunoglobulin in a healthcare facility.

01:04 So, let's say for example someone's bitten by a venomous snake. They receive antivenom.

01:08 So, let's say for example someone's bitten by a venomous snake. They receive antivenom.

01:10 This is really just a combination of antibodies against that snake's venom.

01:14 The best part about passive immunity is that it's immediate.

01:18 However, it only lasts for a short period of time.

01:22 The second type of immunity is active immunity.

01:26 Active immunity is a result of production of antibodies in our immune system as a result of exposure to an infectious agent.

01:34 Active immunity is long-term immunity.

01:37 It can be acquired either naturally, through infection with the actual disease, or artificially, through vaccination against the disease.

01:46 Either way, this type of immunity occurs as a result of an exposure to disease organism.

01:52 This exposure triggers the immune system to produce antibodies to that disease in the moment, and in the future.

01:59 Then we have herd immunity.

02:02 Herd immunity is also sometimes called community immunity.

02:05 This is the level of immunity required to resist a particular disease in a specific population.

02:11 Now, in this image, we have the peach population.

02:15 They're non-immunized but still healthy.

02:18 The red represents those who are non-immunized, sick, and contagious.

02:23 If herd immunity is low, meaning that few people in the community are immune, spread of disease is more likely.

02:31 So, here, on the left, we see the majority of people in this community are healthy, but because they're not immunized, even just a few cases of infection in the community can result in high levels of community infection.

02:44 But, also, recognize that those who are immunized and healthy, here, the green population, they remain healthy and not contagious.

02:54 On the other hand, once a large majority of the population are vaccinated and are immune, there's less opportunity for the spread of disease.

03:03 Herd immunity protects the unvaccinated and those with compromised immune systems from getting infection.

03:09 As I mentioned earlier, vaccinations are one way in which people acquire active immunity.

03:15 Vaccinations are cost-effective public health intervention that have had an incredible impact on life-expectancy in the 20th century.

03:23 There are a wide variety of diseases that are vaccine-preventable.

03:27 Some examples are hepatitis B, measles, influenza.

03:32 There are also diseases such as polio that we've almost forgotten about due to the impact of vaccines.

03:38 Most vaccines are developed using either a live organism or an inactivated form of the organism.

03:45 Live attenuated vaccines are made from weakened virus organisms that can still replicate but are too weak to make a person ill.

03:54 This initiates an immune response and the individual builds immunity against the virus for future exposure.

04:01 Next, inactive vaccines, are made from viral organisms that have been inactivated by either chemicals or by heat.

04:11 The viruses in inactivated vaccines cannot replicate, however, they initiate that immune response.