Vaccines

Question 1

Herd immunity

Answer 1

Non-vaccinated individuals are at a decreased risk because the surrounding population has been vaccinated and can’t be carriers!

Question 2

Ideal Vaccine

Answer 2

Safe
Elicits an appropriate immune response
Long-lived, easy to administer
Can be given as a single or double dose
Can be stored and transported easily

Measles vaccine - 2x to prevent outbreaks

Question 3

Passive Immunity

Answer 3

The transfer of antibodies from one person to another (mother passes maternal antibodies to child through placenta/breast milk)

IgG can cross placenta, IgA are found in breast milk

MATERNAL ANTIBODIES LAST UP TO A YEAR - this is why young infants DONT RECEIVE THEIR VACCINES until after a YEAR of age –> these antibodies could interfere with the development of active immunity from a vaccine

Also comes rom homologous-pooled antibody, homologous human hyperimmune globins and monoclonal antibodies

SYNERGIST is an example of a monoclonal vaccine (RSV)

Preformed also given prophylactically (tetanus, botulism, HBV, rabies) after exposure

Question 4

When should passive immunity be used?

Answer 4

Patients can’t generate their own immune response (immunocompromised)

Newborns born to a mother with a recent varicella infection

Newborns with exposure to measles or hep A

Toxin producing microbes already present in patient

If active immunization is not readily available/functioning (premies)

Question 5

Active Immunity

Answer 5

Formation of antigen-specific humoral and cellular immunity post exposure to a foreign pathogen –> results in MEMORY CELL FORMATION and is MUCH LONGER LASTING than passive immunity!

Question 6

Live Attenuated Vaccines

Answer 6

Contain a live virus with DECREASED VIRULENCE

Whole organism is altered, so that when given it causes mild or absent symptoms

Attenuation can result by passing the organism through multiple cell cultures or by genetic reassortment

ROTAVIRUS (#1 cause of infant diarrhea) vaccine – combines bovine and human viruses; BOVINE portion lessens severity, human aspect ensures proper antibody formation!!

MMR, influenza, polio, yellow fever, varicella are all LIVE ATTENUATED (many can also be given as inactivated).

Question 7

Inactivated Vaccines

Answer 7

Contain ONLY VIRAL PARTICLES and ARE NOT ALIVE

Whole cell - contain whole cell pathogens that have been killed by heat shock or chemicals; generally WEAKER and require multiple doses to confer immunity

Toxoid - made of inactivated TOXIN released by the organism and include vaccines for tetanus, diphtheria, botulism, HBV, and rabies – need a BOOSTER later on for full immunity

Or FRACTIONAL – next card

Question 8

Fractional Vaccines

Answer 8

Recombinant, polysaccharide, or conjugated polysaccharide

Recombinant - made through insertion of bacterial plasma into YEAST; yeast is culture and the virulent particles replicated and then made into a vaccine; NO BACTERIAL DNA in the vaccine, so it cannot CAUSE disease

Polysaccharide – contain sugars found on the viral surface and alone do NOT induce a strong immune response; T cell independent (only B cell response; IgM is primary antibody made and little or no IgG produced; kids under 2 are NOT RESPONSIVE TO THESE

But if conjugated to a viral protein, the vaccine is greatly enhanced and a T CELL RESPONSE would be generated

Additionally, conjugated vaccines produce mainly IgG and can be given to kids under 2!

Conjugated include pneumococcus, meningococcus and haemophilus!

Question 9

Live vs. Inactivated?

Answer 9

Adults, perhaps the best is INACTIVATED – since adults have been exposed to these viruses (sometimes) in the past, like influenza, they are more likely to have antibodies already that would bind to the live vaccine, limiting the development of new active immunity!! Use Inactivated

In contrast, young kids do not have as many antibodies, so their body has no response ramping up an immune response when a live vaccine is given!