Childhood Immunization

1. To establish an efficient system of surveillance and programme monitoring activities to ensure reliable systemic procurement of vaccine.
2. To foster intersectoral co-operation and community involvement and participation in these activities at all levels, and thus enhance the ability of the programme to sustain itself effectively.
3. To achieve 80% immunization coverage of the target population by the year 1990 and a midterm goal of 60% by 1987.
4. To reduce, by 1990, by at least 50% the incidence of the target diseases i.e tuberculosis, diphtheria, pertussis, tetanus, polio and measles through immunization and other preventive measures.

• EPI was launched in Nigeria in 1978.
• Revised in 1984
• Attained the universal childhood immunization target of 80% by 1990.
• EPI was renamed NPI in 1996 by the Nigerian government as a way of reawakening national consciousness and demonstrate a sense of ownership.

• Contains a version of the living microbe that has been weakened in the lab, so it can’t cause disease.
• It’s the closest thing to a natural infection.
• Elicits stronger cellular and antibody responses.
• Often confer life-long immunity with one or two doses.
• There’s the remote possibility of the microbe reverting to its virulent form.
• Not safe for everyone (HIV patients, pregnant women).
• Need to be frozen to stay potent. Stored at temp of -25 to -15 degrees Celsius.
• Easy to create for viruses difficult for bacteria.
• Examples are
• Measles
• Rubella
• Mumps
• Oral polio (Sabin)
• Small pox
• BCG and
• Yellow fever vaccines

[MR. MOSBY]

• Others include Rotavirus vaccine, Influenza vaccine (nasal spray), oral typhoid vaccine, varicella vaccine

• The disease causing organisms are killed with heat, chemicals or radiation.
• Safer and more stable than live vaccines.
• No chances of mutation.
• No need to be frozen.
• Can be stored in freeze dried form, making them accessible to people in developing countries.
• Stimulates a weaker immune response than live vaccines.
• Booster shots are required.
• Examples include
• Pertussis
• I.M polio (Salk)
• Cholera
• Rabies
• I.M typhoid and
• Hepatitis A vaccines

• For bacteria that secrete toxins, this is the answer.
• The toxin secreted by the disease causing bacteria is inactivated using formalin.
• Examples are
• Diphtheria and
• Tetanus Toxoids.

• Rather than the entire microbe, subunit vaccines include only the antigen that best stimulate the immune system.
• This antigen is then produced and introduced to the body to elicit an appropriate immune response.
• Lower chances to adverse reaction.
• Example
• I.M Influenza vaccine
• Acellular pertussis vaccine
• Recombinant vaccines like HBV and HPV vaccines

• Some bacteria possess an outer polysaccharide coat. The polysaccharide coat disguises the bacterium antigen so that the immature immune system can’t recognize or respond to it.
• Conjugate vaccine links the antigen or carrier protein from a microbe that an infant’s immune sys. can recognize to the polysaccharide coating hereby creating a defence against the disease causing bacterium.
• Examples:
• HiB
• Pneumoccocal, and
• Meningococcal vaccines.

• Said to be the future of vaccines.
• These vaccines dispense with both the whole organism and its part to get right to its genetic material.
• They use the genes that code for those all-important antigens.
• The body’s own cells become vaccine making factories.
• It’s being tested against Herpes.

• This could be classified into common minor reactions and rare serious reactions.
• Minor reactions include local reaction, fever and systemic symptoms.
• Rare reactions include hyper pyrexia, seizures, anaphylaxis, and brachial neuritis.

• Acute illness accompanied by fever >38⁰c.
• Immunodeficiency diseases.
• History of severe adverse effect.
• History of allergic reactions.
• Children with neurological disorders e.g. infantile spasms, progressive encephalopathy.

There are two types of polio vaccine—

• Sabin (oral polio vaccine) and
• Salk (I.M polio vaccine).

Both are trivalent vaccines.

Sabin is a live vaccine, it’s recommended for developing countries because it’s simpler and easy to administer, has better acceptability by the population, inexpensive and effective in conferring intestinal as well as systemic immunity.

Disadvantages of the OPV include its high sensitivity to heat and light, possibility of reversion and the fact that at least 3 doses are required to provide protection.

Salk is a killed vaccine. It is given I.M. 2 doses are required to give protection. It does not confer intestinal immunity. Booster dose is required.

A VVM is a label containing a heat-sensitive device which is placed on a vaccine vial to register cumulative heat exposure over time.

The combined effect of time and temperature causes the inner square of the VVM to darken gradually and irreversibly.

Apart from transportation facilities and cold room, there are other equipments and materials used in cold chain.

Cold chain equipment both electrical and none electrical, is used for storing vaccines and/or transporting them at appropriate temperature.

All cold chain equipment must be protected from rain, kept at least 10cm away from walls, level and on wooden boxes.

Electrical equipment include ice lining refrigerators, ice pack refrigerators, deep freezers, generators.

None electrical equipment include cold boxes, vaccine carriers, Ice packs, thermometers, temperature monitoring strips.

Spare parts of these equipment are also very important.

It is a system of storing and transporting unused vaccines and samples at recommended temperatures from the point of collection to the central store or laboratory.

It is maintained when transporting unused vaccines back to the central cold store.

Maintained when transporting stool specimen of suspected polio cases to the lab.