What are pediatric vaccines?
Pediatric vaccination involves exposing children to dead or otherwise inactive viruses or viral antigens, spurring their immune systems to develop immunity to the disease in question before exposure in the field.
Pediatric vaccines are injections given to children to immunize them to certain diseases caused by germs. Administration of pediatric vaccines begins at birth and continues until 18 years, based on the immunization schedule recommended by the Centers for Disease Control and Prevention (CDC).
Vaccines are prepared from disease-causing germs, and contain a weakened form of the pathogens or their inactivated components. Vaccines activate the immune system, which generates antibodies to the specific diseases and protect children from contracting those diseases if exposed to them in their daily lives.
Most of the pediatric vaccines are administered in three or four doses spread over a specified time period. In addition to routine childhood vaccines, children also require travel vaccines before travelling to certain countries, to protect them from diseases that are prevalent in those regions.
Why do children need vaccination?
Vaccines protect children from contracting and spreading many infectious diseases that have led to severe illness, disability and death in the past. Young children are more susceptible to microbial infections than adults, as their immune systems are not fully developed.
Since the advent of vaccination, the incidence of many debilitating childhood diseases is drastically reduced. Some deadly diseases such as smallpox and polio have been eradicated in most parts of the world, thanks to the availability of vaccination.
What vaccines are given in childhood?
Following is a list of pediatric vaccines given in childhood in the United States (US):
Hepatitis B virus vaccine
The hepatitis B virus (HBV) vaccine is primarily given in three-dose series, though there are exceptions. The first dose is given within 24 hours of birth in medically stable infants born to HBV negative mothers. HBV vaccine is also given to high-risk populations and as a travel vaccine.
Two HBV vaccines are available in the US:
- Engerix-B: A four-dose series given at birth, and ages one, two and 12 months.
- Recombivax HB: A two-dose series for children of age 11-15 years.
Pneumococcal conjugate vaccines
Pneumococcal conjugate vaccines (PCVs) are given in two-dose or three-dose primary vaccination, plus a booster. The PCV available in the US is:
- Prevnar-13: Contains antigens of 13 strains of pneumococci.
Varicella virus vaccine
The varicella virus vaccine (VAR) is a weakened live vaccine that protects against Varicella zoster virus, which causes chickenpox and shingles. In the United States, VAR is recommended for all children under 13 who have not had the infection, as well as adolescents and adults who lack immunity to it. The varicella virus vaccine available in the US is:
- Varivax: Given as two-dose series.
Measles, mumps and rubella vaccine
The measles, mumps and rubella (MMR) vaccine is used as a combination vaccine for children. The MMR vaccine available in the US is:
- M-M-R II: Given in two doses with the first one in 15-18 months and a second dose at four to six years of age.
Haemophilus influenzae type B vaccine
Haemophilus influenzae type B (HIB) bacteria causes several diseases such as pneumonia and meningitis in children below five years of age. The HIB vaccine schedule may be two or three-dose series and is started in 6-week-old children. Children over a year old receive only one dose and the vaccine is not usually given to healthy children over five years old.
The HIB vaccine available in the US is:
- ActHIB: Given in four dose-series.
Polio vaccines
Polio virus is of three types, known as wild poliovirus (WPV) type 1, 2 and 3. The WPV2 has been eradicated globally, with the last case of occurring in 1999. Countries where polio has been eradicated have low polio risk, and inactivated polio vaccine (IPV) is given as an injection. IPV, also known as Salk vaccine, contains all three poliovirus strains in inactivated form.
Many countries administer oral polio vaccine (OPV) which contains live weakened poliovirus. In 2017 the entire world switched from trivalent OPV (containing three strains) to bivalent OPV, dropping WPV2 from the vaccine, as it was no longer necessary and also interfered with the immune response to the other two types of poliovirus.
In countries where OPV is given, the World Health Organization (WHO) recommends one shot of IPV in addition to bivalent OPV, to maintain the eradication of WPV2. The polio vaccine administered in the US is:
- IPOL: Given as a four-dose series of injections in the arm or leg.
Diphtheria/tetanus/pertussis vaccines
Diphtheria, tetanus and pertussis (DTP) vaccines are given in three doses within the first year of a child, and two more boosters at the age of one and six. Tetanus booster shots are recommended every 10 years, and in the last trimester for pregnant women.
The DTP vaccines in the US contain only acellular (inactivated) pertussis bacteria. Two types of vaccines are available in the US:
Diphtheria, tetanus and acellular pertussis (DTaP) vaccine:
Tetanus, reduced diphtheria toxoids and acellular pertussis (TDaP) vaccine:
- Adacel
- Boostrix
Human papilloma virus vaccines
Worldwide there are two types of human papilloma virus (HPV) vaccines:
- Quadrivalent HPV vaccine: Protects against four viruses, two of which cause genital warts and two that can cause precancerous lesions and cervical cancer in women, and anal cancer in men.
- Nonavalent HPV vaccine: Protects against an additional five virus strains, nine strains in total.
HPV vaccine can be initiated at 9 years of age, even in the absence of high-risk. CDC recommends a two-dose series HPV vaccine if started before the age of 15, and three-dose series if initiated after 15, except for immunocompromised adolescents, who require three doses whatever the age of vaccine initiation.
The HPV vaccine available in the US is:
- Gardasil-9: A nine-valent HPV vaccine approved by FDA for both females and males from age nine to 45.
Rotavirus vaccine
Rotavirus vaccine protects against rotavirus gastroenteritis. The WHO recommends the inclusion of the rotavirus vaccine in the immunization programs of all nations. The rotavirus vaccine is initiated at six months but not recommended in children older than two years.
The two available rotavirus vaccines in the US are:
- Rotarix: A two-dose series of oral suspension
- Rotateq: A three-dose series of oral solution
Hepatitis A vaccine
Routine hepatitis A (HepA) vaccination starts at the age of one, but any person who has not been vaccinated for hepatitis A should get vaccinated, including adults. Infants of age six to 11 months and everyone over one year old should be vaccinated before international travel, in particular, to countries with endemic hepatitis A.
The hepatitis A vaccines are two-dose series of injections administered six to 18 months apart. Hepatitis A vaccines available in the US are:
A combination vaccine for hepatitis A and B that is available in the US is:
- Twinrix: Three or four-dose series for unvaccinated adolescents of 18 years or older.
Meningococcal vaccines
Meningococcal A vaccines
Meningococcal A vaccines protect against meningococcal bacteria types A, C, Y and W-135. Routine vaccination is administered at 11-12 years with the booster dose at 16-18 years of age. Meningococcal vaccination may be given in infancy to children who are at high risk, which includes the following conditions:
- Absence of pancreas
- Sickle cell disease
- Human immunodeficiency virus (HIV) infection
- Deficiency in the complement immune system
Meningococcal A vaccines available in the US are:
- Menactra
- Menveo
- Menhibrix: A combination vaccine with
- HIB vaccine
- Tetanus vaccine
- Meningococcal B vaccines
Meningococcal B vaccines
Routine meningococcal B vaccines are recommended at 10 years for children with certain genetic deficiencies with the complement immune system. Young adults up to the age of 23 may be vaccinated in the event of a meningococcal B disease outbreak.
Two vaccines available in the US are:
- Bexsero: Two-dose series given at least a month apart.
- Trumenba: Given as a three-dose series.
The two products are not interchangeable, and the same product must be given for both initial and booster doses.
Japanese encephalitis vaccine
The WHO recommends that Japanese encephalitis (JE) vaccine must be given as a routine childhood immunization in regions where it is prevalent. The JE vaccine is given to adults and children older than two months. The JE vaccine available in the US is:
- Ixiaro: A two-dose series of primary vaccination 28 days apart. A third booster dose may be given in case of continued exposure to JE virus.
Cholera vaccine
In countries where cholera is endemic, the cholera vaccine is administered in populations in high-risk areas. In the US, the cholera vaccine has been approved in 2016 for adults of age 18 to 24, who are travelling to cholera-affected regions. The cholera vaccine available in the US is:
- Vaxchora: A single oral dose.
Typhoid vaccines
Typhoid immunization is important for children in regions where typhoid is prevalent, especially where the antibiotic-resistant Salmonella typhi strain is present. In the US, typhoid vaccine is recommended before travel to typhoid-endemic areas. Two products are available in the US:
- Typhim Vi: A single dose injection for anyone over two years old, given at least two weeks before travel.
- Vivotif/Vivotif Berna: Oral pills that can be taken by people over six years of age. A four-dose series taken on alternate days and completed at least a week before travel.
Yellow fever vaccine
The WHO recommends yellow fever vaccine as a routine pediatric vaccine in countries where it is endemic. In the US, the yellow fever vaccine is administered to anyone who is nine months or older, and is travelling to yellow fever-prevalent areas.
YF-VAX: A single dose injection provides life-long immunity to yellow fever, but a booster shot after 10 years is recommended for vulnerable groups such as HIV-infected, particularly if travelling to high-risk areas.
Tick-borne encephalitis vaccine
Tick-borne encephalitis (TBE) is endemic in parts of Europe and Asia. The WHO recommends TBE vaccine as a part of routine immunization for children in TBE-affected regions. There are no TBE vaccines licensed or available in the US.
Rabies vaccine
The WHO recommends rabies vaccine as a preventive measure (prophylaxis) for people who are at continual risk for rabies exposure because of place of residence or occupations such as:
- Veterinarians
- Research lab workers
- Wildlife officials
Post-exposure to rabies, the wound must be thoroughly cleansed. Post-exposure, a four-dose series of rabies vaccine injections are administered to unvaccinated persons, and a two-dose series for previously immunized people.
The rabies vaccines available in the US are:
- Imovax Rabies
- RabAvert
Mycobacterium bovis bacillus Calmette-Guerin vaccine
Mycobacterium bovis bacillus Calmette-Guerin (BCG) vaccine protects against tuberculosis (TB) and is part of the pediatric immunization schedule in countries with high prevalence of TB.
BCG vaccine must not be given to children who are HIV-positive or whose HIV status is unknown, as it can interfere with TB skin test and show a false-positive reaction. BCG vaccine is not in use in the US.