Study Guide 4-8 Acquired Immunity and Vaccines

Identify five diseases that may be eradicated and the specific challenges that each presents:

polio measles mumps rubella pork tapeworm

Define vaccine

preparation of microbes or their components that induces immunity

Define vaccination

the administration of a micro-organism of a disease to bring about an immune response

Define variolation

the deliberate inoculation of individuals with infectious material from scabs or pustules of smallpox victims.

Describe the major misconceptions about vaccines and the evidence regarding these:

- Multiple vaccines at once can overload the immune system (this concern first began to appear as the recommended childhood immunization schedule expanded to include more vaccines, and as some vaccines were combined into a single shot) -Vaccination against diseases that have disappeared from the US is not necessary -During an outbreak, more vaccinated people get sick than the unvaccinated (This is not because vaccines are ineffective, but because there are so few people who avoid vaccination in the first place.) -Hygiene and better nutrition are responsible for the reduction in disease rates, not vaccination -Natural immunity is better than vaccine-acquired immunity.

Characterize inactivated or killed vaccines

-Consist of whole virus/cells that have been inactivated by heat or chemicals. -Pros: the microbe can't revert, can't replicate and can't spread. -Cons: less stimulation of immune responses; requires multiple injections; greater risk of side effects.

Characterize live attenuated vaccines:

-composed of living (weakened) pathogen -produce HIGH immunity because the microbe REPLICATES in the body. -There is a possibility that the weakened pathogen could revert to a more pathogenic state.

Characterize toxoid vaccines

-contain inactivated bacterial toxins, called toxoids. -used to prevent diseases in which bacterial toxins play an important role in pathogenesis.

Explain the measures taken that resulted in the eradication of smallpox:

-focused surveillance-quickly identifying new smallpox cases- and ring vaccination. Ring vaccination meant that anyone who could have been exposed to a smallpox patient was tracked down and vaccinated as quickly as possible.

Describe the common side effects that are associated with vaccines:

-mild: soreness, swelling, or redness at site of injection. -Fever, rash, and achiness -Serious: seizure or allergic reaction

Characterize conjugate vaccines

-modified form of subunit vaccine. -consists of a protein conjugated to a capsule polysaccharide. (antigen coupled with protein) -have been developed to enhance the efficacy of subunit vaccines against pathogens that have protective polysaccharide capsules that help them evade phagocytosis, causing invasive infections.

Characterize subunit vaccines

-only expose the patient to the key antigens of a pathogen-not whole cells or viruses. -risk of side effects is relatively low.

List the reasons why smallpox was a good candidate for eradication:

-there are very visible signs with smallpox -it has a short incubation time -human reservoir only -lifelong immunity from the disease -highly effective vaccine

Characterize each of the following and give examples of each: 1. Naturally acquired active immunity 2. Naturally acquired passive immunity 3. Artificially acquired active immunity 4. Artificially acquired passive immunity

1. Natural active immunity: develops after natural exposure to a pathogen (catching a cold) 2. Natural passive: Antibodies enter a person in a natural manner from another organism (antibodies cross the placenta into the fetus, antibodies transferred via breastmilk.) 3. Artificially Active: The pathogen is introduced into the body as a vaccine. (being immunized or vaccinated for polio) 4. Artificially passive: Antibodies from another person or animal are injected into a person (anti-tetanus infections)

Discuss the difficulty encountered with establishing that a vaccine is the cause of a side effect or adverse event:

Each year, American babies receive more than 10 million vaccinations. During the first year of life, a significant number of babies suffer serious, life-threatening illnesses and medical events, such as Sudden Infant Death Syndrome (SIDS). Additionally, it is during the first year that congenital conditions may become evident. Therefore, due to chance alone, many babies will experience a medical event in close proximity to a vaccination. This does not mean, though, that the event is in fact related to the immunization. The challenge is to determine when a medical event is directly related to a vaccination.

Identify the hypotheses proposed regarding linkage between autism and vaccines and discuss findings from studies regarding these hypotheses:

MMR vaccine- Thimerosal- Number of vaccines- Aluminum adjuvant in vaccines-

Explain how adverse effects are monitored:

Vaccine Adverse Event Reporting System (VAERS) collects information on side effects and adverse events following vaccination. The goal is to detect possible signals of adverse events associated with vaccines.

What is herd immunity?

When a majority of a population are vaccinated against a disease. This means that even people who have not been vaccinated are less likely to get it because there are fewer people to catch it from.

Define immunization

Immunization is the process of conferring specific immunity by artificial means and can involve the use of vaccines, toxoids or immune serum. If vaccines or toxoids are used, active immunity is induced, but if immune serum is used, the immunity is passive.