2. LIVE ATTENUATED VACCINES (LAV)
Attenuation (bacterial or viral) represents the process of elimination or greatly
reducing the virulence of a pathogen
Achieved by
1. Growing a pathogenic bacterium or virus for prolonged periods under
abnormal culture conditions.
2. Chemical Treatment or heat
This selects mutants that are better suited for growth in the abnormal culture
conditions than in the natural host.
For example, an attenuated strain of Mycobacterium bovis
Bacillus Calmette-Guerin (BCG) was developed by growing medium
containing increasing concentrations of bile.
After 13 years, this strain had adapted to growth in strong bile and had
become sufficiently attenuated that it was suitable as a vaccine for
tuberculosis.
4. BCG VACCINE
Bacillus Calmette Guerin
Live attenuated vaccine against
Tuberculosis
Induces Cell mediated immunity
Available as lyophilised (freeze dried)
powder ,Reconstituted with sterile
normal saline
Dose – 0.05ml (neonates) , 0.1ml
(infants and children)
Route of administration – intradermal
Papule at site of injection (2-3weeks)
Permanent tiny round scar 4-8mm
diameter
5. ORAL POLIO VACCINE
Poliovirus family of Picornaviridae.
The virus invades the nervous system and can cause permanent paralysis
Types of Oral Polio Vaccines
Trivalent OPV, Bivalent OPV, Monovalent OPV
Sabin vaccine - growth in monkey kidney epithelial cells.
Route of administration – Oral.
Vaccine
The first dose- 2 months
second dose -4 months
Third dose- 6 through 18 months
The fourth dose- 4 through 6 years
6. MMRV VACCINE
Measles Mumps Rubella Chickenpox
Rubeola parotitis (german measles) Varicella
family
Paramyxoviridae
family
Paramyxoviridae
family
Togaviridae;
family
Orthopoxvirus
highly contagious
skin
disease
contagious disease contagious disease
that occurs
primarily in
children
five to nine years
of age
acute, contagious,
and sometimes
fatal disease
The skin rash
normally lasts about
5 to 10 days. Lesions
of the oral cavity
include the
diagnostically useful
bright-red Koplik’s
spots
Mumps affects the
parotid
glands,swelling
salivary glands below
and in front of the
ears
A rash of small red
spots
A red, itchy skin rash
with blisters
Fever
Feeling tired
Not feeling hungry
Headache
7. first dose 12 - 15 months
second dose 4 - 6 years
Children ages 1 - 12 years can get the
MMRV vaccine, which is a combination
vaccine that also protects against
measles, mumps, rubella, and
chickenpox.
Vaccine :
CHICKENPOX
9. YELLOW FEVER
acute viral haemorrhagic disease
Family Flaviviridae
"yellow" in the name refers to the jaundice
caused by a virus that is spread through mosquito bites