Vaccines

Main topics:

Introduction

Vaccination is the administration of an antigen (vaccine) to produce immunity to a disease. Vaccination is generally considered to be the most effective method of preventing infectious diseases. The material administered can either be live but weakened forms of pathogens (bacteria or viruses), killed or inactivated forms of these pathogens, or purified material such as proteins.

How Vaccines Work

Every day, the body is bombarded with bacteria, viruses and other germs. When a person is infected with a disease-causing germ, the immune system mounts a defense against it. In the process, the body produces substances known as antibodies against that specific germ. The antibodies eliminate the germ from the body. The next time the person encounters the germ; the circulating antibodies quickly recognize it and eliminate it before signs of disease develop. This is why a child who has had chickenpox will only rarely develop the disease again. The immune system has memory. The next time the child encounters the virus that causes chickenpox, the antibodies destroy the virus before disease causes sickness.

A vaccine works in a similar way. However, instead of one natural infection, for immunity to develop after a vaccine it usually takes several doses over several months or years. The vaccine contains an inactivated (killed), weakened form of the germ, or a germ component. When introduced into the body, the dead or harmless germ causes an immune response without causing the disease. The immune system develops antibodies that will effectively kill or neutralize the germ if exposed to it in the future. The antibodies circulate in the bloodstream. Vaccination protects a child against infection with a germ without the child ever suffering through the disease.

Types of Vaccine

The safety and effectiveness of a vaccine depends on how it is made and what it contains. There are four main ways to develop vaccines:

• Live attenuated vaccines contain bacteria or viruses that have been altered so they can't cause disease e.g. Measles vaccine (as found in the MMR vaccine),Mumps vaccine (MMR vaccine), Rubella (German measles) vaccine ( MMR vaccine), Oral polio vaccine (OPV), Varicella (chickenpox) vaccine,

• Killed vaccines contain killed bacteria or inactivated viruses e.g. Inactivated polio vaccine (IPV), which is the shot form of the polio vaccine and influenza vaccine

Toxoid vaccines contain toxins (or poisons) produced by the germ that have been made harmless e.g. Diphtheria toxoid vaccine (may be given alone or as one of the components in the DTP, or dT vaccines)Tetanus toxoid vaccine (may be given alone or as part of DTP, or dT)

• Component vaccines contain parts of the whole bacteria or viruses e.g. Haemophilus influenzae type b (Hib) vaccine, Hepatitis B (Hep B) vaccine, and Hepatitis A (Hep A) vaccine

When to go for Vaccination

Staff Members – Monday – Friday during clinic operating hours

Dependants (above five years) – Tuesday afternoon 2pm – 4pm - Friday 1100 am – 1 pm
 

Dependants Below five (5) years

Children below five (5) years should go to their own paediatrician They can also go to Gertrude’s Garden Children’s Hospital in Muthaiga

Precautions

• Certain Vaccines are not recommended during Pregnancy. Inform medical personnel if you are Pregnant

• Vaccines may cause problems for people with certain allergies. Inform the medical personnel if your have any allergies

Possible common side effects of vaccines

Like any medication, vaccine can cause side effects. For the most part these are minor, for example, pain, redness and swelling at the sight of injection, low-grade fever, and headache. These disappear within a few days. Serious allergic reactions are very rare. A decision not to get vaccinated involves a risk that can put you and your family at risk of contracting a potentially deadly disease.

Mandatory Vaccine – Yellow Fever Vaccine

Yellow fever vaccine entry requirements are established by countries to prevent the importation and transmission of yellow fever virus, and are allowed under the International Health Regulations (IHR).

Travelers must comply with these to enter the country, unless they have been issued a medical waiver. Certain countries require vaccination from travelers arriving from all countries, while some countries require vaccination only for travelers coming from “a country with risk of yellow fever transmission.

Yellow Fever vaccine is mandatory for travellers to Africa, Asia and some countries in Latin America.

It is given to children aged from six (6) months to adults up to age sixty (60) years.

It should be given ten (10) days before travel.

Who Pays

Most agencies have subscribed for vaccinations to be given to their staff members. Find out from your administrative officer if your agency has subscribed. If your agency has subscribed, you will be required to pay. You will be given an invoice which you will submit and pay at the UN Coop Office. They will issue a receipt. The cost of vaccine will vary from one vaccine to another.

UNJMS Recommended Vaccines

Immunization Dose Adult Dose Children Route Validity Schedule Comments
Vaxigrip 0.5 mls children and adults aged from 36/12 0.25 mls 6–35/12 I/M or deep under the skin on deltoid the muscle 1 year   Wait for 20 minutes after the administration of the vaccine The vaccine will not protect you against the common cold, even though some of the symptoms are similar to flu
Tetanus 0.5 mls     10 years    
Polio 3 drops 3 drops Under the
tongue
10 years    
Typhoid 0.5 mls 0.5 mls from age
2 years
IM/Subcutaneous 3 Years    
Menactra (Meningitis
ACYW 135)
0.5 mls 0.5 mls
Adults and Children
from over 2
years
Deltoid Muscle
in older children,
adolescents and
adults
Life    
Hepatitis A 0.5 mls 0.5 mls
Pediatric
I/M - deltoid
muscle
Life Primary
vaccination
Booster in 6-8
months
If one dose is
missed there is
no immunity
Hepatitis B 1.0 mls
From 16 years
0.5 mls
(Pediatric)
dose for neonates,
infants, and children
aged up to
and including 15
years
Intramuscular
use only
Life 1st dose elected
date
2nd dose 1 month
after 1st dose
3rd Dose 6 months
after 1st dose
If one dose is
missed there is
no immunity built
Yellow Fever 0.5 mls 0.5 mls
Children from 6
months
Intramuscular Life   10 days before
travel
Rabies 0.5 mls 0.5 mls Intramuscular
only
5 years after 1st booster 1st Booster: 1
Year later
Subsequent
boosters:
every 5 years
Pre exposure:
D0, D7, D28
Post exposure:
D0, D7, D21
None Immunized:
D0, D3, D7, D14,
D28

Other Vaccines

Pneumovax
  • Prevents severe and disseminated disease
  • Indicated for persons aged 65 yrs ( and above) and also for those aged 19-64 yrs who have chronic pulmonary disease, chronic cardiovascular disease, DM, alcoholism, chronic liver disease, cerebrospinal fluid leaks, cochlear implants.
  • May be administered concurrently with other vaccines such as influenza vaccine but at separate sites
Gardasil (cervical cancer vaccine)
  • The vaccine is relevant for ages between 9 and 26yrs. Candidates are required to provide a pap smear report from approved health institutions indicating no disease before the vaccine is administered
  • Adult females through age 26 years and adult males through age 21 years who have not received any HPV vaccine should receive a 3-dose series of HPV vaccine at 0, 1–2, and 6 months. Males aged 22 through 26 years may be vaccinated with a 3-dose series of HPV vaccine at 0, 1–2, and 6 months
Shancol Cholera Vaccine
  • Reduces the risk of becoming ill with diarrhea caused by enterotoxigenic E.coli ( ETEC) or cholera by vibrio cholera
  • Length of protection is 3yrs
  • Given orally 2 doses 2 weeks apart
  • Typhoid vaccine should be separated by 8 hrs
  • Food may affect efficacy of the vaccine avoid 1hr before and 1hr following the vaccine
  • Vaccination should never replace standard hygiene, infection prevention and control measures.