VACCINATION

T

he processes of administration of a substance into the body for the purpose of prevention of disease is called as Vaccination. Traditionally it consists of killed microorganisms or live attenuated microorganisms.

Vaccination works by generating an immune response, that enables the memory cells to respond the next time when same organism enters the body.

The term vaccination is derived from the Latin word Vacca which means “COW”, and Benjamin Jesty and Edward Jenner later showed that Vaccination with Cowpox could give protection with Smallpox.

Fig 1.0 Edward Jenner, English Physicist.

Edward Jenner took the fluid from the pustule of woman who had cowpox and injected that into a healthy boy who had neither cowpox or smallpox. Six weeks later, he injected the boy with smallpox fluid taken from an infected person and he didn’t develop anything. By 1980, smallpox was totally eradicated.

Milestones in the history of vaccination –

a.     1879 – Louis Pasteur against chickenpox

b.    1881 – Louis Pasteur against anthrax

c.     1885 – Louis Pasteur against Rabies

d.    1886 – Edmund Salmon and Theobald Smith    against Cholera (heat killed vaccine)

e.     1927 – BCG vaccination against Tuberculosis

f.      1927 – Tetanus

g.    1935 – Yellow fever

Post world war certain vaccines were developed.

a.     1955 – Injectable Polio Vaccine (IPV)

b.    1962 – Oral Polio Vaccine (OPV)

c.     1964 – Measles

d.    1967 – Mumps

e.     1970 – Rubella

f.      1981 – Hepatitis B

Today vaccination is available for approximately 34 of the 400 known pathogens that cause diseases.

Immunity

Resistance exhibited by the host to the pathogenic organism itself or their products entering the body.

There are two types of Immunity –

a.     Acquired immunity

b.    Innate immunity

Innate immunity is resistance possessed by an individual by birth or is inherited. It has 3 levels – Species immunity, Individual immunity and Racial Immunity. It depends upon the age, hormones and nutrition of the person. Both infants and old age people are at risk of developing diseases; because infants have immature immune system and old age shows weakened immune system because of weakened immune response.

People with drugs like corticosteroids have weakened immunity because of the drugs action. People with diabetes have less immune response. Malnourished children have weakened immune response.

Innate immunity works as a 1^st line of defence and thus can function by –

1.    Epithelial surfaces

2.    Antimicrobial substances

3.    Cellular factors

4.    Inflammation

5.    Fever

6.    Acute Phase proteins

Acquired immunity is by acquiring by the individual along the course of his/her life. It acts as 2^nd line of defence. It is characterised by –

1.    Antigen specificity

2.    Diversity

3.    Immune memory

4.    Self/non-self-recognition

Acquired immunity is of 2 types –

a.     Active

b.    Passive

Active immunity is also known as adaptive immunity. Resistance is developed by the antigen stimulation. This is used in vaccination and thus is a prophylaxis. This is of 2 types –

a.     Natural active immunity

b.    Artificial active immunity

In Passive immunity, the persons immune system plays no importance, i.e. readymade immunity. It is of 2 types –

a.     Natural passive immunity

b.    Artificial passive immunity

Active Immunity	Passive Immunity
Produced by host.	Readymade
Induced by infections or immunogens.	Readymade or preformed antibodies.
Long lasting and effective.	Short lived and relatively less effective.
Takes time for immunity to develop.	Immediate.
Booster effect on subsequent dosage.	Subsequent dose is less effective.
Negative Phase may occur.	No negative phase.
Not applicable in immune-deficit person.	Applicable in immune-deficit person.

Table 1.0 Difference between active and passive immunity.

Combined immunization is another phenomenon where immediate action is required hence active and passive both immunities are done. Example, a person who is not immune to tetanus is met with an accident and open wound is observed; we administer TIG (Tetanus Immunoglobulin) on one arm and other arm is injected with tetanus toxoid. This is followed by the full course of tetanus vaccination.

Herd Immunity – plays a vital role in community and is relevant for epidemic disease prevention.

VACCINATION IN INDIA

In India Vaccination is carried out with immense importance because of increasing population and certain endemic diseases.

Government of India has carried out certain programmes for immunization like pulse polio week, etc where immunization is done.

Centres like Anganwadi, Public Health Centre (PHC) provide immunization to everyone in the country and makes sure that each and every person receives immunization. One such famous Programme is “MISSION INDRADHANUSH”.

INDRADHANUSH – Means Rainbow and since rainbow has seven colours, the vaccination carried under this programme included seven vaccines –

a.     Diphtheria

b.    Tetanus

c.     Whooping cough

d.    Poliomyelitis (polio)

e.     Tuberculosis

f.      Measles

g.    Hepatitis B

In addition to these other vaccines that are being provided in selected states like Bihar, Orrisa, etc are

a.     Japanese Encephalitis

b.    Haemophilus Influenzae B

Mission indradhanush was started on 25^th December 2014.

On October 08, 2017, Government started to further intensity the mission and launched Intensified Mission Indradhanush (IMI). To boost the immunization further the Health minister of India, Dr, Harsh Vardhan introduced Intensified Mission Indradhanush 2.0 (IMI – 2.0) that would run from December 2019 till march 2020.

Ministry of Women and Child Development, Panchayati Raj, Ministry of Urban Development, Ministry of Youth Affairs and others have come together to ensure the benefits of vaccines reach the last mile.

Fig 1.1 Mission Indradhanush.

There is one programme that is carried out nation wide and it is followed according to the National Immunization Schedule.

The below table shows the national Immunization schedule.

Vaccine	When to give	Max age	Dose	Diluent	Route	Site
For Pregnant Women
TT - 1	Early Pregnancy	----	0.5 ml	-- NA --	Intramuscular	Upper arm
TT – 2#	4 weeks after TT – 1	----	0.5 ml	-- NA --	Intramuscular	Upper arm
TT – Booster#	If received TT doses in pregnancy within last 3 years	----	0.5 ml	-- NA --	Intramuscular	Upper arm
Vaccine	When to give	Max age	Dose	Diluent	Route	Site
For Infants
BCG##	At birth or as early as possible	Till 1 year of age	0.1 ml (0.05 ml until 1 month of age)	Sodium Chloride	Intradermal	Left upper arm
Hepatitis B – birth dose ##	At birth or as early as possible	Within 24 hours	0.5 ml	--	Intramuscular	Anterolateral side of Left mid-thigh
OPV – 0**	At birth or as early as possible	Within the first 15 days	Two Drops	--	Oral	--
OPV – 1, 2, and 3	At 6, 10 & 14 weeks	Till 5 years of age	2 Drops	--	Oral	--
Rotavirus Vaccine*	At 6, 10 & 14 weeks	Till 1 year of age	5 Drops	--	Oral	--
IPV	At 14 Weeks	Up to 1 year of age	0.5 ml	--	Intramuscular	Anterolateral side of Right mid-thigh
Pentavalent** 1, 2, 3	At 6, 10 & 14 weeks	Till 1 year of age	0.5 ml	--	Intramuscular	Anterolateral side of Left mid-thigh
Measles – 1st dose	9 – 12 months completed	Till 5 years of age	0.5 ml	Sterile water	Subcutaneous	Right Upper arm
Japanese Encephalitis*** – 1st dose	9 – 12 months completed	Till 15 years of age	0.5 ml	Phosphate buffer	Subcutaneous	Left Upper arm
Vitamin A – 1st dose	At 9 months completed with measles	Till 5 years of age	1 ml ( 1 Lakh IU)	--	Oral	--
For Children
DPT booster – 1	16 – 24 months	7 years	0.5 ml	--	Intramuscular	Anterolateral side of left mid-thigh
Measles 2nd dose	16 – 24 months	Till 5 years of age	0.5 ml	Sterile water	Subcutaneous	Right upper arm

OPV booster	16 – 24 months	Till 5 years of age	2 drops	--	Oral	--
Japanese Encephalitis*** – 2nd dose	16 – 24 months	--	0.5 ml	Phosphate buffer	Subcutaneous	Left Upper arm
Vitamin A – 2nd to 9th dose	16 months, then 1 dose every 6 months	Till 5 years of age	2 ml ( 2 Lakh IU)	--	Oral	--
DPT booster – 2	5 - 6 years	7 years	0.5 ml	--	Intramuscular	Left Upper arm
TT	10 years and 16 years	--	0.5 ml	--	Intramuscular	Upper Arm

# - Give TT – 2 or booster doses before 36 weeks of pregnancy. However, give these even if more than 36 weeks have passed,

Give TT to a woman in labour, if she has not previously received TT.

## BCG: there is no need to revaccinate the child if scar is not formed after BCG vaccination.

### Hepatitis B: Birth dose is given only within 24 hours after birth as it helps to prevent perinatal transmission of Hepatitis B.

OPV – 0 dose is given within 15 days after birth. OPV can be given till 5 years of age.

*   In selected states.

** Pentavalent vaccine contains a combination of DPT, Hepatitis B and Hib. Hepatitis B dose and booster dose of DPT will continue as before.

*** Japanese Encephalitis vaccine is introduced after the campaign in selected endemic districts of Uttar Pradesh, West Bengal, Karnataka, Assam and Bihar.

Children who have not received a single vaccine coming after 1 year, will be given 3 doses of DPT at an interval of 4 weeks,

Measles – 1^st dose and Japanese Encephalitis 1^st dose(wherever applicable) up to 2 years of age.

Minor cough and cold are not a contraindication for vaccination.

If the child has diarrhoea, give a dose of OPV, but do not count the dose and ask the mother to return in 4 weeks for the missing dose.

  

To make Vaccines stay effective with little wastage, Open vial policy was brought in action, which states that open vials can be used to draw doses until they are stored correctly. Multi – Dose vials of OPV, DPT, TT, Hep B, etc can be reused if stored correctly and these conditions have met –

a.     Expiry has not passed

b.    Stored in appropriate cold chains

c.     Vaccine septum not stored under water.

d.    Aseptic conditions were followed for removal of vial contents.

e.     The Vaccine Vial Monitor (if attached) has not reached the discard point.

But Vials of BCG and Measles should be discarded at the end of immunization and not used for more than 6 hours. All vials should be discarded immediately if they are suspected to be contaminated and or no aseptic conditions were followed while immunization.

Fig 1.2 Vaccine Vial Monitor labels on the vaccine vials.

This image show the stages of vaccine vial monitor and the colour change indicates the lifetime of the vaccine in the vial.

Fig 1.3 VVM interpretation.

But other than this the storage of vaccine is also of utmost importance. It is done by Cold Storage.

These are the following components of cold storage –

a.     Storage

b.    Transportation

c.     Association

d.    Temperature monitoring.

                                                                                                                                                                                                                                                                                                                                  This Chart shows the types of vaccines present.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         SOME IMPORTANT INSTRUMENTS REGARDING VACCINATION                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

Fig 1.4 Ice pack ( Water to be filled up till the level marked on the pack as water later expands on cooling)

  

Fig 1.5 Vaccine carrier box.

   

Fig 1.6 Walk in Freezer

   

Fig 1.7 Walk in cooler

 

Fig 1.8 Ice lined Refrigerator