World Health Organization (WHO) defines immunization as the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine. Vaccines stimulate the body’s own immune system to protect the person against subsequent infection or disease.

Immunization is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert between 2 and 3 million deaths each year. It is one of the most cost-effective health investments, with proven strategies that make it accessible to even the most hard-to-reach and vulnerable populations. It has clearly defined target groups; it can be delivered effectively through outreach activities; and vaccination does not require any major lifestyle change

For details on vaccines and the diseases they prevent in babies, as well as the age at which these vaccines can be given, see the revised Immunization Schedule for Nigerian parents below:



•BCG is the tuberculosis vaccine. Tuberculosis causes pulmonary infection, but can spread to many other organs, causing serious illness, death and disability.

•OPV1 is also called oral polio vaccine. Polio mainly affects children under five years of age. One in 200 infections leads to irreversible paralysis. Among those paralyzed, 5% to 10% die when their breathing muscles become immobilized.

•HEPBO is the Hepatitis B vaccine. Hepatitis B can cause chronic liver disease and put people at high risk of death from cirrhosis of the liver and liver cancer.

6 weeks

OPV1, Pentavalent 1, PCV (optional), Rotavirus 1(optional)

• Pentavalent vaccine is a combination of five vaccines-in-one that prevents diphtheria, tetanus, whooping cough, hepatitis B and haemophilus influenza type B, all through a single dose.

• Diphtheria is a fatal disease. It is a bacteria that causes a severe throat and upper lung infection.

• Tetanus is also a fatal disease. It is a bacteria causes weakness and paralysis when allowed to fester in a deep, dirty wound.

• Whooping cough (also known as pertussis) is a bacteria that causes severe coughing fits. It can lead to fatalities do occur especially in young infants.

• Hepatitis B is a virus that causes severe liver damage. It can be fatal.

• Haemophilus Influenza type B is a bacteria that causes meningitis and bloodstream infections. Most cases are in infants or the elderly. It can be fatal.

• PCV is also called pneumococcal conjugate vaccine. Pneumococcal disease, an infection caused by the bacteria Streptococcus pneumoniae or pneumococcus can lead to bacterial meningitis, pneumonia and bacteremia.

• Rotavirus vaccine is an oral vaccine against rotavirus infection, a common cause of diarrhoea and sickness. Rotavirus typically strikes babies and young children, causing an unpleasant bout of diarrhoea, sometimes with vomiting, tummy ache and fever.

10 weeks

OPV2, Pentavalent 2, PCV (optional)

• See above

14 weeks

OPV3, Pentavalent 3, PCV, Rotavirus 2 (optional)

• See above

9 months


• Measles vaccine is a highly effective vaccine used against measles.

12 months

Yellow fever

• Yellow fever is a potentially fatal viral infection, transmitted by mosquitoes in tropical regions. There is no specific treatment for yellow fever.

15-18 months

MMR, OPV, chicken pox (optional)

• MMR is the measles, mumps and rubella vaccine. Measles, mumps and rubella are very common, highly infectious, conditions that can have serious, potentially fatal, complications, including meningitis, swelling of the brain (encephalitis) and deafness.

• The chickenpox (varicella) vaccine provides protection against the varicella zoster virus that causes chickenpox.

24 months

Meningitis, Thyphoid fever (optional)

•Meningococcal vaccine is a vaccine used against Neisseria meningitidis, a bacterium that causes meningitis, meningococcemia, septicemia, and rarely carditis.

• Typhoid vaccine helps prevent typhoid fever.Typhoid is a serious disease caused by bacteria called Salmonella Typhi. Typhoid causes a high fever, weakness, stomach pains, headache, loss of appetite, and sometimes a rash.