How does a vaccination prevent disease?
The immune system, the body’s defense system that wards off infections with foreign intruders and kills damaged or sick cells in the body, has a way to remember pathogens it has seen before. A vaccination takes advantage of this trait. In a vaccination, the body is given either a weakened version of the live pathogen (live vaccine) or pieces or the killed pathogen. A vaccine does not cause the disease (even a life vaccine is not strong enough for this), but it causes the immune system to go on alert and attack the pathogen pieces in the vaccine.
The immune system builds special protein particles that are called antibodies, that help kill and dispose of the real pathogen, when the body ever encounters it. Antibody responses grow weaker over time, and can become completely undetectable, but a vaccination helps build cells, called memory cells, that remember the original stimulus, and that can produce a lot of specific antibodies, when they encounter the same pathogen again.
A vaccinated person therefore will fend of the infection without becoming sick. The person is said to be “immune” to this illness. Immunity can also be acquired by going through the actual disease like measles, or chickenpox, but these diseases can be dangerous and cause permanent damage or even death, so it is better to become immune through vaccination.
Why should I vaccinate my child?
Vaccinations help protect your child from serious diseases that can causes severe suffering, and even life-long disabilities and death. Some of these diseases are getting less common due to vaccinations like e.g. polio and diphtheria, but without vaccinations these diseases will come back. Only if a disease is completely eradicated a vaccination against this disease is no longer necessary.
This is the case with smallpox, which had been a deadly and feared disease for centuries. After a worldwide vaccination effort, the last natural case occurred in 1977 in Somalia. In 1980 the World Health Organization recommended the cessation of small pox vaccinations.
What are the risks and side effects?
Like all medical treatments, vaccinations carry a risk of side effects and some people with pre-existing medical conditions might not be able to get a certain vaccine. However vaccines are safe for the general population and the risk to have serious complication from vaccination is many thousand times lower than if the actual disease is contracted.
The most common side effects of injected vaccines are redness and/or swelling at the injection site and pain or soreness at the injection site that can radiate into the arm. These can happen in up to 25% of vaccine recipients and will go away without treatment after a few days. Some vaccines can cause fevers in a low number of vaccinate people (for most vaccines no more than 1 in every 10000 recipients).
There are other side effects that can occur with specific vaccines, and like with any foreign substance induced to the body, serious allergic reaction can occur. These are usually very rare and don’t happen more often than 1 in every 1,000,000 of vaccine recipients. In infants, allergic reactions are even rarer. However, if an allergy is known to any of the components of the vaccine, the child should not receive this vaccine.
The mercury-containing preservative Thimerosal that used to be widely used in many vaccines, has received a lot of media coverage for its potential toxicity for brain cells. Claims that it can cause autism have been widely published. However, scientific studies on autism frequencies and vaccination schedules cannot substantiate any link between the use of Thimerosal-containing vaccines and autism.
Nevertheless, it is better to avoid exposure to mercury during brain development. Because of this, and the sheer number of vaccines that are recommended nowadays for children, Thimerosal has been either completely removed or greatly reduced in all but one vaccine that are recommended for children under 6. The only vaccine that still contains Thimerosal which is available for children under 6 is the inactivated influenza vaccine packaged in a multiple-dose vial. A single dose vial of this vaccine contains only trace amounts of Thimerosal.
What vaccinations are advised for newborn infants?
There is only one vaccination recommended to be given at birth. It is the first of four shots of HepB vaccine that protects against the serious liver disease hepatitis B. The HepB vaccine is a shot that is given into the arm. It is a very save vaccine that is made from a part of the HepB virus and the most frequent side effect is that it can cause soreness and pain at the injection side. Serious allergic reactions are extremely rare and occur less than in every 1.1 million vaccine doses given.
At 2 months of age another shot of HepB vaccine is recommended together with various other vaccinations. These consist of the following:
DTaP: a combiniation shot that protects against diphtheria, tetanus (lockjaw), and pertussis. The DTaP vaccine replaces the older
DTP vaccine that protected against the same illnesses, but DTaP is safer than the old vaccine.
PCV: This vaccine protects against infections with the bacterium Pneumococcus that can cause pneumonia, meningitis, sepsis (blood poisoning) and death.
The Hib vaccine protects against infections with the bacterium Hemophilus influenzae Type B, which can cause serious throat infections, meningitis, sepsis and death.
Polio: This vaccine protects against infection with the polio virus that can cause paralysis, permanent disability and death.
RV: Rotavirus infections, against which this vaccine protects, can cause life-threatening diarrhea in infants.
At four months of age babies should receive another round of the same vaccinations as the ones they received at 2 months of age. This vaccination regimen is also scheduled for 6 months of age. Now, the child is fully protected against HepB infections, and this protection most likely will last life-long, so that no more HepB vaccinations are recommended for the future. From 6 months of age on, children can receive the influenza vaccine, which is recommended to be repeated every fall or winter.
It is recommended to give children 1 year and older scheduled booster shots of DTaP, PCV, Hib and influenza vaccinations. Additionally, children one year and older should receive chickenpox, HepA (protects against another virus that can cause hepatitis) and the MMR vaccine which protects against measles, mumps and rubella (German measles).