This document summarizes immunizing agents and vaccines. It describes the classification of immunizing agents as vaccines, immunoglobulins, and antisera. It provides details on the types of vaccines including live, inactivated, subunit, conjugate, combined, and components added to vaccines. The document also includes India's immunization schedule and provides specific information on commonly used vaccines like BCG, hepatitis B, polio, pentavalent, rotavirus, measles-rubella, diphtheria-pertussis-tetanus, and Japanese encephalitis.

1. IMMUNIZING AGENTS
Immunization is the process by which an individual is exposed to an agent that is designed to
fortify his or her immune system against that agent.
Immunizing agents are the substances which when introduced or injected into the body causes
production of antibodies to fight against the disease.
Classification:
Vaccines: These are immune-biological substances designed to produce specific protection
against diseases by stimulating production of protective antibody or other immune mechanisms.
Immunoglobulins: These are readymade antibody preparations, obtained from the human
beings. They produce immunity instantaneously.
Antisera: These are the specific immunoglobulins prepared from the plasma of immunized
animals, such as horses. Immunity lasts for about 2 to 3 weeks.
Types of Vaccines:
 Live (attenuated) – the disease causing agent is purified after its attenuation under sub
optimal conditions. Eg: BCG, OPV, MMR, varicella, rotavirus.
 Inactivated (killed) – the disease causing agent is inactivated by thermal or chemical
treatment and then purified to destroy their virulence property but retain their
immunogenicity or antigenicity and induce active immunity. Eg: IPV, Pertussis, Rabies,
Hepatitis A, JE.
 Subunit vaccines –made of single or multiple antigenic components of a microorganism that
are capable of stimulating a specific immune response sufficient to protect from the relevant
pathogen infection or from the clinical manifestation of the disease. Different types of
subunit vaccines are:
o Toxoids – the toxins produced by the organisms are detoxicated. Eg: Tetanus, Diphtheria.
o Protein vaccines – protein based vaccine is produced using purified single protein or a
combination of proteins from a pathogenic microorganism. Eg: Acellular pertussis
vaccine, influenza vaccine.
o Recombinant protein vaccines - expression of protective protein antigens in heterologous
expression systems to produce cleaner vaccine with better safety profile. Eg: Hepatitis B
vaccine.
o Polysaccharide based vaccines – these are vaccines against capsulated bacteria, prepared
by stimulation of an antibody response against the surface polysaccharide of pathogenic
bacteria. Eg: Hib vaccine, vaccine for Salmonella typhyi muruim and pneumoniae.
o Conjugate vaccines: antigens are chemically linked to a protein that T-cells recognize and
further elicit strong immune response and immune memory in young children.
Eg. Vaccines for Hepatitis B, Hib, Pneumococcal, Meningococcal, Influenza (inj), HPV.

2.  Combined/ mixed - more than one kind of immunizing agent is included in the vaccine.
Eg: DPT, DT, MMR, Pentavalent vaccine.
Components of vaccine:
Agents added to the antigen to make them a viable and effective pharmaceutical. It preserves the
active parts of the vaccine (the antigens).
- Immune enhancer (adjuvant) – substance is added to a vaccine to enhance the immune
response by degree and/or duration. Eg: Aluminium salts (Aluminium hydroxide, Aluminium
phosphate or potassium Aluminium sulfate), MF59 (hydrocarbon emulsion)
- Antibiotics – used during manufacturing process to prevent bacterial contamination of the
tissue culture cells in which viruses are grown. Eg: Neomycin.
- Preservatives – to inactivate viruses, detoxify bacterial toxins, and to prevent serious
secondary infections. Eg: 2 Phenoxyethanol, Phenol, Thiomersal, Formaldehyde
- Stabilizers – to maintain product quality or stability, compounds are added for variety of
manufacture related issues like :
• Controlling acidity: buffers ( potassium or sodium salts, lactose),
• Stabilizing antigens: MgCl2 (for OPV), MgSO4 (for measles), lactose-sorbitol and
sorbitol-gelatine.
• Preventing antigens from adhering to sides of vials: polysorbate 20 and 80.
Immunization schedule
Age Vaccines
Infants
At birth BCG, bOPV-0, Hep B
6 weeks
bOPV-1, Pentavalent-1, Rotavirus vaccine-1,
fIPV-1, PCV-1
10 weeks bOPV-2, Pentavalent-2, Rotavirus vaccine-2
14 weeks
bOPV-3, Pentavalent-3, Rotavirus vaccine-3,
fIPV-2, PCV-2
9 months MR, JE, Vit A, PCV booster
Children
16 – 24 months JE, DPT booster, MR booster, OPV booster
5-6 years DPT booster
10 and 16 years dT
Pregnancy
Early in pregnancy dT
4 weeks after first
dose
dT
Note: JE and PCV are administered in places where applicable.

3. Vaccine details
BCG (Bacilli Calmette Guerin)
• Bacterial Live attenuated freeze dried vaccine
• Strain: Danish 1331, M. bovis strain.
• Dosage:
- 0.05ml at Birth in all hospital deliveries
- 0.1ml, if child is >1 month, up to 1 year
• Route and site of administration: Intradermal, Left Upper Arm (Deltoid).
Note: Alcohol should not be used to wipe the skin.
• Diluent: Sodium Chloride/ Normal saline
• Immunity: 15-20 years of age against meningeal tuberculosis and miliary TB.
• Adverse reactions: local reaction, suppurative lymphadenitis, BCG osteitis, disseminated
BCG infection
• Contraindications: Immunodeficiency disorders, generalized eczema, Pregnancy, Child born
to AFB positive mother.
Hepatitis-B Vaccine
• Recombinant subunit vaccine. Formalin inactivated vaccine.
• Prepared from plasma of human carrier of hepatitis (HBsAg)
• Route and site of administration: Intramuscular route over deltoid region or Antero lateral
aspect of thigh.
• Dosage:
- In Children, 0.5ml each
Given at Birth (within 24 hours)
Given at 6th
, 10th
and 14th
week (as Pentavalent)
- In Adults, 3 doses of 1ml each
Given as 0, 1 and 2 ‘OR’ Given as 0, 1 and 6
• Adverse reactions: local reactions, fever, anaphylactic reactions
• Contraindications: Presence of HBs Antigen
OPV (Oral Polio Vaccine - Sabin)
• Live attenuated Bivalent vaccine
• Preparation:3 lakhs TCID50 of Type I and III.
• Stabilizing agent: Magnesium chloride
• Dosage: 2 drops Orally
- Given at Birth, 6th
week, 10th
week & 14th
week
- Booster dose at 16-24 months and 5 years
• Adverse reactions: None
• Contraindications: immunocompromised state, malignancy and leukaemias.
• Immunity: Life long

4. IPV (Inactivated Polio Vaccine – Salk)
• Inactivated vaccine (formalin killed preparation in MKC)
• Preparation: Total 80 Units of D-antigen of Type 1 (40 U), Type 2 (8 U) and Type 3 (32 U)
• Dosage: As per the National Immunization Schedule, 2 fractional doses of 0.1ml each
- Given at 6th
and 14th
week
• Route: Intradermal, over Right Upper Arm
• Indicated in immunocompromised individuals, HIV infection and disease.
Pentavalent Vaccine
• Conjugated vaccine with Aluminium Phosphate as Adsorbent
• Preparation: Diphtheria toxoid 20 Lf, whole cell killed pertussis 20,000 million units, tetanus
toxoid 0.5 Lf, Plasma derived Hepatitis-B vaccine and conjugated Hemophilus Influenzae-B
vaccine.
• Dosage: 0.5ml each
- Given at 6th
week, 10th
week & 14th
week
• Route: Intramuscular over the anterolateral aspect of thigh.
• Adverse reactions: Redness, swelling and pain at site of injection.
• Contraindications: Persons allergic to any component of vaccine.
Rotavirus Vaccine:
• Live attenuated vaccine
• Composition: live attenuated human strains of rotavirus serotypes G1, Gl, G3, G4 and G9.
• Types:
- The monovalent human rotavirus vaccine (Rotarix™) : 2 - dose schedule (2 and 4
months of age)
- The pentavalent bovine-human, reassortant vaccine (Rota Teq ™): 3 – dose schedule
(6, 10, 14 weeks of age)
Note: Potentially higher risk of intussusception when the first dose of these vaccines is given
to infants aged > 12 weeks. Maximum age for any dose is 24 weeks of age for Rotarix and 32
weeks for RotaTeq.
• Dose: 2.5 ml
• Route of Administration: Orally in cheek.
• Diluent: distilled water
• Adverse reactions: intussusception if 1st
dose is given > 12weeks of age
MR (Measles-Rubella) Vaccine
• Live attenuated freeze dried vaccine
• Preparation:
- Measles: 1000TCID50 Edmonston Zagreb strain HDC cultured,
- Rubella: 1000 TCID50 RA 27/3 strain HDC
• Diluent: Sterile Water
• Route: Subcutaneous over Right Upper Arm (Triceps)
• Dosage: 2 doses of 0.5ml each
- 1st
dose, only after completion of 9 months and before 12 months of child age

5. - Booster dose, after completion of 18 months and before 24 months of age
• Adverse reactions: pain and tenderness at site of administration, fever, transient rash.
• Contraindications: High fever, serious disease, pregnancy, history of reaction to neomycin,
gelatin or components of vaccine, immunocompromised state.
DPT Vaccine
• Combined vaccine
• Composition: Diphtheria toxoid (25 or 30 Lf), whole cell killed pertussis vaccine (20,000 or
32,000 million) and tetanus toxoid (5 or 10 Lf).
• Adsorbent is Aluminium Phosphate, preservative used is Thiomersal (0.01%).
• Dosage: 2 booster doses of 0.5ml each
- at 16-24 months and 5 years
• Route: Intramuscular over the anterolateral aspect of thigh or gluteal region
• Adverse reactions: Severe pain at the site, Convulsions, rarely Shock
• Contraindications: Hypersensitivity to previous dose, Progressive neurological disorder,
temperature above 40 deg.C.
dT (Diphtheria Toxoid)
• Adsorbed vaccine with Aluminium Phosphate
• Preparation: it contains TT and adult dose (2 Lf) of diphtheria toxoid.
• Route: Intramuscular, over Upper Arm
• Dosage:
- In Children, 0.5 ml each at 10 and 16 years
- In case of unimmunized individuals- 0.5ml each, first 2 doses at an interval of 4-6
weeks, 3rd
dose after 1 year
- Booster dose is given every 5 years
- For pregnant women:
1st
dose at 16-20 weeks of pregnancy
2nd
dose at 24-32 weeks of pregnancy
• Adverse reactions: local reactions, fever, malaise, non-specific symptoms, anaphylaxis.
Vitamin A prophylaxis
• Oily preparation
• Composition: retinol palmitate (110 mg in 2.00,000 IU)
• Route of administration: oral
• Dose:
- 1 lakh IU at 9 months
- 2,00,000 IU each at 15 to18, 24, 30 and 36 months of age.
• Adverse reaction: Nausea, vomiting.

6. Japanese Encephalitis Vaccine
• Live attenuated cell culture vaccine
• Preparation: SA 14-14-2 strain of JE virus
• Diluent: Phosphate Buffered Saline
• Route: Subcutaneous over Left Upper Arm
• Dosage: 2 doses of 0.5ml each
- 1st
dose, only after completion of 9 months and before 12 months of child age
- 2nd
dose, after completion of 18 months and before 24 months of age
• Adverse reactions: local reactions, fever, GI upset, neurological events.
• Contraindication: history of hypersensitivity reactions to a previous dose.
Pneumococcal conjugate vaccine
• Polysaccharide conjugated vaccine
• Preparation: 25 microgram of individual serotype capsular polysaccharide antigen from
pneumococcus.
• Types:
- PCV 10: serotypes 1, 4, 5, 6B, 7F, 9V, 14, 18C, 19F, 23F
- PCV13: all serotypes in PCV10 plus serotype 3, 6A and 19A.
• Route of administration: intramuscular, antero-lateral aspect of mid thigh- right
• Dosage: each dose of 0.5ml at 6 and 14 weeks and booster dose at 9 completed months of
age.
• Indicated in children with HIV infection, sickle cell disease or who are otherwise
immunocompromised.
• Adverse reactions: irritability, crying, swelling and tenderness at injection site, transient
fever.
• Contraindications: severe allergic reaction to prior dose.