Answer
-Vaccines produce :
Active Humoral Immunity.
- passive immunity is less satisfactory because :
immunity is temporary they give rapid protection but
immunity is a short lasting
Work Step by Step
Ways of Acquiring Specific Immunity
- immunity may be acquired by the individual either
actively or passively.
1- Active Acquired Immunity
- on exposure to foreign antigen or infective agent the
individual actively produces his own antibodies or
sensitized lymphocytes.
- immunity develops slowly, however it lasts for a long
time due to development of immunologic memory.
- it can be naturally acquired or artificially induced.
a- Natural active :
immunity occurs following clinical or sub clinical
infections e.g. after measles or mumps, in which
immunity is long lasting.
b- Artificial active :
immunity occurs after vaccination with live or
killed infectious agents or their products.
the different types of vaccinations are :
- Killed vaccines e.g
TAB vaccine for typhoid & paratyphoid
Salk vaccine for poliomyelitis
& rabies vaccine for rabies.
- Living attenuated vaccines e.g. sabin vaccine
for poliomyelities, the BCG vaccine for
tuberculosis, the 17-D vaccine for yellow fever
& the MMR vaccine for measels, mumps &
rubella.
- Toxoids : these are vaccines prepared by
detoxifying the toxins of some bacteria e.g.
toxoid vaccines for diphtheria & tetanus.
- Vaccines prepared from bacterial fractions e.g.
meningococcal polysaccharide vaccine.
- Recombinant vaccines prepared by recombinant
DNA technology e.g. hepatitis B virus vaccine.
2- Passive Acquired Immunity
- in which ready made antibodies are transferred to an
individual .
- this gives rapid protection, however immunity is
short lasting .
- there are 2 types :
a- Natural Passive Immunity :
- as occurs when antibodies are transferred from
mother to fetus through the placenta ( IgG ) or in
the colostrum ( IgA ).
- this type of immunity is responsible for protection
of the new born against several diseases during
the first 6 months after birth.
b- Artificial Passive immunity : as in treatment or
prophylaxis against several diseases , for example
- injecting antitoxic serum in prophylaxis &
treatment of diphtheria.
- prophylactic injection of gamma globins to protect
contacts of cases of measles or poliomyelitis