VACCINATION- What It Is, Classification, Vaccine-Preventable Diseases and More

important information on vaccination

Your immune system performs the function of recognizing micro-organisms that invade the body and protect against them by producing antibodies.

Vaccination, also known, as immunization is the injection of weakened or killed micro-organisms into the body to stimulate the immune system.

A majority of the diseases that can be prevented by vaccines and can be fatal if the individual hasn’t been vaccinated.

Vaccines are medications, used in vaccinations, that boost your ability to fight off certain diseases.

Classification of Vaccines

Based on the  are two classes of vaccines:

  • Live ‘Attenuated’ Vaccines: These are made from live viruses that have been weakened. When given, they lead to a strong immune response with symptoms similar to, but milder than the disease caused by the virus.
  • Inactivated ‘Killed’ Vaccines: These are produced by growing the microbes (bacteria or viruses) and then killing it with chemicals or heat. They are safer than attenuated vaccines but tend to provide less protection than the former.

Examples of Vaccines

Live Vaccines


Measles- Mumps – Rubella (MMR)

Oral polio

Oral typhoid




Yellow fever


Inactivated Vaccines

Acellular pertussis




Haemophilus influenza type b

Hepatitis A

Hepatitis B

Human papillomavirus

Influenza shot




Polio shot




Typhoid shot

Diseases That Have Vaccines


Cholera is an acute diarrheal disease caused by a gram-negative rod-shaped bacterium called Vibrio cholerae. According to WHO, there are about 1.3 – 4.0 million cases with 21,000 – 143,000 deaths worldwide each year. Cholera is endemic in Nigeria.

Cholera spreads via stool or vomit and is transmitted by the ingestion of contaminated water or food. Outbreaks are common in slums, camps, and densely populated areas where there are poor hygiene and inadequate access to safe water.

Vaccines Available For Cholera

The oral cholera vaccine (OCV). It helps in the prevention of cholera together with the other preventive measures.

The Cholera Vaccine (OCV) is recommended for use in areas with endemic cholera, during cholera outbreaks and in humanitarian crises with the risk of cholera.

There are various forms of oral cholera vaccine made available by different manufacturers. The Dukoral® being for people from 2 years and above with the difference between the 1st and 2nd dose being not less than 7 days or more than 6 weeks. Children from 2 – 5 years will require a 3rd dose. Protection is for 2 years.

The Shanchol™ and Euvichol-Plus® are almost the same but are made by different manufacturers, administered to individuals one year and above, with a minimum of 2 weeks maintained between the two doses. Its protection is for 3 years and it is the one available for mass vaccination.

In 2016, the Vaxchora which is a single dose cholera vaccine was approved in the US by the FDA for people travelling to cholera endemic areas. It is for people from 6 years and only available in the EU. It is a live attenuated vaccine in a powdered form that is reconstituted with water.

Frequently Asked Questions About The Vaccine

•          Is the vaccine effective?

Yes, its effectiveness is about 65-75%

•          Is the vaccine safe?

Yes, it is safe and has no serious side effects.

•          Is it safe for use in pregnancy?

In theory, the OCV is safe in pregnancy but is not yet recommended. Conclusive studies in pregnancy are yet to be carried out. The Vaccine may be administered during pregnancy with an appropriate weighing of the benefit against the risk.

•          Are other preventive measures still necessary after taking the vaccine?

Yes, as a large dose of the bacteria can overwhelm the immunity. Consumption of safe water and personal hygiene should also be maintained.


Diphtheria is a serious bacterial infection that affects the mucous membranes of the throat and nose. A type of bacteria called Corynebacterium diphtheriae causes diphtheria

The condition is typically spread through person-to-person contact or through contact with objects that have the bacteria on them, such as a cup or used tissue. It could also be acquired when in close contact with an infected person when they sneeze, cough, or blow their nose.

Vaccine Available for Diphtheria

DTaP vaccine, giving a single shot along with vaccines for pertussis and tetanus.

Immunization Schedule

The vaccines are given to children aged 2 months, 4months, 6 months, 15 to 18 months, 4 to 6 years.

The vaccine lasts for 10 years and as such is advisable children get vaccinated again at 12years

Relevant facts about the vaccine

  • DTaP vaccine is given oy to children below 7 years.
  • It is taken with strict precautions in persons with allergic reactions, seizure episodes, has had a coma or decreased level of consciousness in the past 7days, has ever had Guillain Barr Syndrome, has had severe pain or swelling after a previous dose of any vaccine that protects against tetanus or diphtheria.


Pertussis is also known as whooping cough. It is a highly contagious respiratory tract infection that can lead to severe breathing problems, especially in children. It is caused by a type of bacteria called Bordetella pertussis and is easily preventable by vaccine.

Besides a cough that sounds like “whoop”, symptoms include a runny nose, nasal congestion and sneezing and it can be spread by airborne respiratory droplets (coughs or sneezes), by saliva (kissing or shared drinks and cups) or by skin-to-skin contact (handshakes or hugs).

Vaccines Available For Pertussis

There are two vaccines that include protection against whooping cough:

  • The TDaP vaccine protects young children and infants from diphtheria, tetanus, and whooping cough.
  • The DTaP vaccine protects preteens, teens, and adults. The vaccine is only available in combination with tetanus and diphtheria vaccines. Vaccinating the mother during pregnancy may protect the baby.

There are two main types: whole-cell vaccines and acellular vaccines. (Hence TDap means Tetanus, Diphtheria and Acellular Pertussis). The whole-cell vaccine is about 78% effective while the acellular vaccine is 71–85% effective. The effectiveness of the vaccines appears to decrease by between 2 and 10% per year after vaccination with a more rapid decrease with the acellular vaccines.

Schedule for Immunization

The World Health Organization and Center for Disease Control and Prevention recommend all children be vaccinated for pertussis and that it be included in routine vaccinations.

Young children need a dose of the vaccine at 2 months, 4 months, 6 months, 15 through 18 months and 4 through 6 years.

Older children (preteens and teens between 7 and 18 years) need 1 booster shot of the Tdap vaccine at age 11 or 12 as part of their routine vaccine schedule.

 If your child misses the booster shot, talk with your child’s doctor about scheduling a catch-up shot.

Adults 19 years and older, if they missed the TDap booster as a teen, they’ll need to get a Tdap booster to ensure protection from whooping cough.

Pregnant women should get the vaccine during each pregnancy. Vaccination is recommended between 27 and 38 weeks of pregnancy even if they have previously received Tdap vaccine. Health workers or caretakers of infected patients should also take the vaccine.

TDap is typically given once during a lifetime (except during pregnancies). However, you may need routine booster shots of the vaccine every 10 years to adequately protect you against tetanus and diphtheria.

Frequently Asked Questions

  • Does having pertussis give you immunity?

If your doctor confirms that you have pertussis, your body will have a natural defence (immunity) to future pertussis infections. Some observational studies suggest that pertussis infection can provide immunity for 4 to 20 years.

  • Can you get pertussis more than once?

Reinfection appears to be uncommon but does occur. With natural infection, immunity to pertussis will likely wane as soon as seven years following disease; reinfection may present as a persistent cough, rather than typical pertussis.

·         Do pertussis vaccines protect from serious disease?

If you get pertussis after getting pertussis vaccines, you are less likely to have a serious infection. For example, when vaccinated children get pertussis, fewer have apnoea (life-threatening pauses in breathing), cyanosis (blue/purplish skin colouration due to lack of oxygen), and vomiting.

·         Should I delay travel to an area that is having a pertussis outbreak?

No, but those travelling to an area with a pertussis outbreak should make sure they are up to date on their pertussis vaccines. People who did not get all the recommended pertussis vaccines, including babies too young to be vaccinated, are putting themselves at risk for catching pertussis.

Where To Get Vaccinated In Nigeria

No 30 Raymond Njoku St, Ikoyi, Lagos


Pretty Health Care

No 43a Abba Johnston Crescent, Akora villa Adeniyi Jones, Ikeja, Lagos



Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic liver disease. The virus is most commonly transmitted through direct contact with infected blood and contact with other body fluids e.g semen. It can also be transmitted from mother to child during birth. Sexual transmission of hepatitis B may occur, particularly in unvaccinated men who have sex with men and heterosexual persons with multiple sex partners or contact with sex workers.

Vaccine available for Hepatitis B

Hepatitis B Vaccine (Brand Names – Engerix B, Heplisav-B, Recombivax HB)

Immunization Schedule

For infants

First shot: If a newborn’s mother carries the hepatitis B virus in her blood, the baby must get the vaccine within 12 hours after birth. The baby also needs another shot — hepatitis B immune globulin (HBIG) — to protect against the virus right away.

If a newborn’s mother doesn’t have the virus in her blood, the baby can get the vaccine within 24 hours after birth.

Second shot: This should be taken at 1–2 months of age

Third shot: This should be taken at 6–18 months of age

For Adults

Heplisav-B (Dynavax) is a two-dose vaccine approved for use in adults aged 18 and older. The vaccine is administered as two doses given one month apart.

Content of The Vaccine

Hepatitis B vaccines (HBV) are composed of highly purified preparations of hepatitis B “s” antigen (HBsAg).

Early vaccines were prepared by harvesting HBsAg from the plasma of people with chronic infection (plasma-derived vaccine) while more recent ones are obtained by expressing plasmids containing the corresponding gene in yeast or mammalian cells (recombinant DNA vaccine). An adjuvant, aluminium phosphate or aluminium hydroxide, is added to the vaccines that are also preserved with thiomersal when used in multi-dose vials.

Frequently Asked Questions About Hepatitis B Vaccine

  • What should be done if the hepatitis B vaccine series was not completed?

Talk to your doctor to resume the vaccine series as soon as possible. The series does not need to be restarted. If the series is interrupted, the next dose should be given as soon as possible.

  • Are booster doses of the hepatitis B vaccine necessary?

It depends. A “booster” dose of hepatitis B vaccine is a dose that increases or extends the effectiveness of the vaccine. Booster doses are not recommended for most healthy people.

Booster doses are recommended only in certain circumstances and the need for booster doses is determined by a certain blood test that looks for hepatitis B surface antibody (anti-HBs).

  • Can I get the hepatitis B vaccine at the same time as other vaccines?

Yes. Getting two different vaccines at the same time is not harmful.

  • Is the hepatitis B vaccine safe?

Yes, the hepatitis B vaccine is safe. Soreness at the injection site is the most common side effect reported.

  • Who should get vaccinated against hepatitis B?

Hepatitis B vaccination is recommended for:

  • All infants
  • All children and adolescents younger than 19 years of age who have not been vaccinated
  • People at risk for infection by sexual exposure
  • People at risk for infection by exposure to blood
  • People who are immunocompromised e.g. People living with HIV/AIDS


Measles is a highly contagious infectious disease caused by the measles virus. It that lives in the nose and throat mucus of an infected person and is transmitted through coughing and sneezing.

The infection makes a person immune for the rest of their life; that means they cannot get it again.

Vaccine Available For Measles

The MMR vaccine – protects children and adults from measles, mumps, and rubella.

Immunization Schedule

The first dose should be given between the age of 9-15 months and the second dose between 15 months- 6 years.

Content Of The Vaccine

Each dose of the vaccine is calculated to contain sorbitol (14.5 mg), sodium phosphate, sucrose (1.9 mg), sodium chloride, hydrolyzed gelatin (14.5 mg), recombinant human albumin (≤0.3 mg), fetal bovine serum (less than one part per million), other buffer and media ingredients and approximately 25 micrograms of neomycin.

Where To Get Vaccinated In Nigeria                            

 Primary Healthcare Centres across the country


Mumps is a systemic viral infectious disease caused by Paramyxovirus and affects primarily the salivary glands. It is transmitted by respiratory droplets from an infected person when they cough or sneeze. A child can also be infected from contaminated surfaces or utensils. It can be spread via saliva example when an infected person kisses a child.

It is now rare due to vaccination.

Vaccine Available For Mumps

The Mumps vaccine is given along with that of measles and rubella – MMR vaccine.

It is given to children within 15-18 months. A second dose is recommended at 4-6years.

Frequently Asked Questions About The Vaccine

  • Won’t this vaccine make my child sick?

It does not cause disease in healthy people. Mumps vaccine is very safe though some mild side effects can be seen such as swollen injection site, non-infectious red rash, fever.

  • Will the vaccine protect a person for life?

The vaccine protects 88% of people and protects children. The immunity wanes with time but by then if a person gets the disease it won’t likely be severe.

  • Can’t we give the vaccine separately?

Measles and rubella are two other harmful diseases for children with complications. Giving it together is a result of scientific research and has shown to be effective. It also reduces the number of injections the child has to take.

  • I heard that it causes autism. Is it true?

Truly this information was being spread at a time, however, there is no proof that it causes autism. This news has been debunked several times and it is safe and recommended to give your child.

  • What other complications can occur if a child is not immunized?

Deafness, pneumonia, brain infection, other disabilities and in extreme cases death if untreated.

  • Are adults allowed to take this vaccine?

Adults who are at risk, travelling to areas with an outbreak or who have not been vaccinated can also get the vaccine. It not given to people who have a weak immune system like those who have cancer, are pregnant, have serious allergies, kidney disease or other severe diseases.


Poliomyelitis, shortened to polio is a disabling and often life-threatening disease. It is caused by one out of 3 types of poliovirus (which are members of the enterovirus genus).

These viruses spread through contact from person to person, by nasal or oral secretions and by contaminated faeces. It may also be spread by food or water containing human faeces.

Vaccines Available For Polio

There are 2 types of vaccine that can prevent polio:

  • The Inactivated Polio vaccine (IPV): This is given as an injection in the leg or arm, depending on the patient’s age
  • The Oral Poliovirus vaccine (OPV): This is commonly administered.

Immunization Schedule

For everyone, it is recommended that using Oral polio (sabin) vaccine, a dose of 2 drops is used.

Infants and children

A total of 3 doses of Polio sabin (oral) multidose are given. Each dose is given on a separate visit.

First Dose: Given at 2 months of age

Second Dose: Given at 4 months of age

Third Dose: Given at 6 months of age


3 doses are also given in total:-

First Dose: is given at an elected date

Second Dose: Given 4-8 weeks after the first dose.

Third Dose: Given 4-8 weeks after the second dose.

Booster Doses

Children are given routine booster doses to ensure long term protection against poliovirus – this is normally given at age 4.

Adults at ongoing risk of infection are advised to have a booster dose of polio vaccine every 10 years.

In Nigeria, polio vaccines are given at birth, and ages 2 months, 3rd-month 4th month, a year and 6 months and at 4 years.

Content Of The Vaccine

The active ingredient of polio Sabin (oral) multidose vaccine is 3 live but weakened poliovirus of type 1, 2 and 3.

The inactive ingredients in the vaccine are magnesium chloride (stabilizer), neomycin B sulfate (trace amount), polymyxin B sulfate (trace amount), L-arginine, polysorbate 80 and water

Frequently Asked Questions About The Vaccine

  • Is the oral polio vaccine safe?/ effective for eradication?

Yes, it is. The WHO recommended polio vaccination for its eradication. In many countries, UNICEF supplies all polio vaccine for Polio National Immunization Day.

  • Why do some children still get polio vaccine even after several doses of the vaccine?/ isn’t routine immunization sufficient?

Temperate countries with a clean environment, excellent sanitation and health systems improve an increased child’s ability to convert oral polio vaccine into immunity.

Tropical environments or parts of the world that are less developed, and children are malnourished with poor sanitation systems. For these, it can take more doses to ensure a child reaches the same level of immunity.

  • What is VVM and how does it work?

The oral polio vaccine is sensitive to high temperature and it loses its potency if exposed to heat for a prolonged period. The vaccine vial monitor (VVM) is a label placed on a vaccine which allows health workers to know how long the vaccine has been exposed to heat.


Rabies is a disease that is transmitted from animals to humans caused by the rabies virus within the family Rhabdoviridae. Domestic dogs are the most common reservoir of the virus, with more than 99% of human deaths caused by dog-mediated rabies. This virus attacks the brain and nervous system.

The good news is that Rabies is a 100% vaccine-preventable disease.

Vaccines Available For Rabies

  • Human diploid cell rabies vaccine
  • Rabies immune globulin
  • Purified chicken embryo cell vaccine
  • Purified Vero cell rabies vaccine

Immunization Schedule

    Primary vaccination with either type of rabies vaccine consists of 3 intramuscular doses (deltoid injection only), one injection per day on days 0, 7, and 21 or 28.

      A booster dose as often as every 6 months to 2 years may be required for a person at highest risk for exposure to the rabies virus, such as persons who work with rabies virus in research laboratories or vaccine production facilities, veterinarians and staff, and animal control and wildlife officers. Persons with infrequent exposure and persons vaccinated before international travel do not require routine booster doses but may require postexposure prophylaxis if exposed.

Contents Of The Rabies Vaccine

One dose of reconstituted vaccine contains ≤12 mg polygeline (processed bovine gelatin)

≤0.3 mg of human serum albumin.

1 mg potassium glutamate

0.3 mg sodium EDTA.

Relevant Facts About The Rabies Vaccine

According to the World Health Organization (WHO), these are some relevant facts about the vaccine.

  • Vaccination against rabies saves lives: Vaccination for travellers may be recommended before visiting rabies-affected areas. Individuals should consult with their healthcare provider.
  • Vaccinating dogs reduces human infection: Giving vaccines to all dogs, including roaming and strays, prevents rabies being passed to humans and stop other dogs becoming infected.


Chickenpox also called varicella is a highly contagious viral infection caused by varicella zoster virus (VZV). It is highly contagious to those who haven’t had the disease or been vaccinated against it.

It is spread by airborne respiratory droplets (coughs and sneezes,) saliva, skin to skin contact, touching contaminated surfaces or mother to baby by pregnancy, labour or nursing.

Vaccine Available For Chickenpox

Varicella vaccine or chickenpox vaccine (Brand Names: Varivax, Varilrix)

Immunization Schedule

It is given in two doses subcutaneously (just under the skin)

A child should have the 1st dose at ages 12-18 months.

The second dose (booster shot) should be given at ages 4-6 years.

Older children and adults should have 2 doses, with 4-8 weeks between the first and second dose (or 3months apart).

Content Of The Vaccine

The vaccine contains a live strain of the varicella-zoster (chickenpox) virus which has been weakened (attenuated). This stimulates the immune system but does not cause disease in healthy people.

Inactive Ingredients: sucrose, hydrolyzed gelatin, sodium chloride, monosodium L-glutamate, sodium phosphate dibasic, potassium phosphate monobasic, potassium chloride, residual components of MRC-5 cells including DNA and protein, sodium phosphate monobasic, EDTA, neomycin, fetal bovine serum.

Frequently Asked Questions About Varicella Vaccine

  • Can varicella be given before 12 months?

The minimum age for the first dose is 12 months. Doses administered before age 12 months should not be counted and the child should be revaccinated at 12 through 15 months of age (and ≥3 months after the initial dose) The second dose may be administered earlier than age 4 years (e.g. during a varicella outbreak).

  • Do adults need varicella booster?

All adults who have never had chickenpox or received the vaccination should be vaccinated against it. Two doses of the vaccine should be given at least four weeks apart.

  • Does the chickenpox vaccine protect you for life?

It is not known how long a vaccinated person is protected against varicella. But, live vaccines, in general, provide long-lasting immunity. Several studies have shown that people vaccinated against varicella had antibodies for at least 10 to 20 years after vaccination.

  • Does the vaccine have side effects?

Side effects are rare and occur mostly in those with poor immune function.

Common side effects include: Pain at the site of infection, fever, rash

Where To Get Vaccinated In Nigeria

Local health or primary health care centres.

Child health clinics

Protection against diseases via immunization is important for all people. Some of the vaccines are readily accessible in Nigeria (some are free too) while others are not. However, most of these vaccines can be found.

It is important to complete every vaccination schedule.

Got any questions? Do ask in the comments and we will answer!