Immunization Faqs

Monica Madvariya
MD. Associate Editor, Pediatric Oncall, Mumbai, India
First Created: 01/10/2001  Last Updated: 02/19/2016

Patient Education

What is immunizations?

Immunization or vaccinations are the processes of giving vaccines to children as well as adults to protect them from specific infectious diseases. Normally when germs enter the body, they produce disease. The body tries to recover by mounting an immune response. This immune response gives protection against the disease. A vaccine is nothing else but whole or part of the disease germ, which has been processed or modified in such a way than it has lost its capacity to produce disease but it can still induce immunity or fighting power by the body when administered in the body. Hence by vaccination one develops immunity without suffering from the disease. Subsequently, if the person is ever exposed to the actual disease, the immunity is already in place and the body fights the germs. Thus no disease occurs.

What are the types of vaccines?

Vaccines can be in form of drops that have to be put in the mouth like the oral polio vaccine, rotavirus vaccine, or oral typhoid vaccine. They can also be in form of injections that may be given in the thighs or the arms. Earlier one vaccine used to protect against one infection e.g. measles vaccine. However, with now vaccines available for many diseases, it would be difficult to give vaccines at a time for a single disease. Thus, a combination of more than one vaccine like the MMR vaccine (which acts against meals, mumps & rubella) or the DPT vaccine (which acts against diphtheria, pertussis & tetanus) is now available.

Are vaccines safe?

Yes. Vaccines are very safe. There are inherent systems in place ensuring the safety of vaccines. Prior to their launch in markets, vaccines are tested both on animals and human volunteers, for any possible adverse effects. Millions of children are safely vaccinated each year.

Don’t babies have natural immunity? Isn’t natural immunity better than vaccine induced immunity?

Mothers’ have protective immunity for various diseases either due to natural infection or due to previous vaccines. Babies may get some temporary immunity from their mothers in the last few months of pregnancy. Immunity can also be transmitted from mom to child also through breast milk. These antibodies from the mother do not last long in the baby leaving the infant vulnerable to disease. Thus, protection in form of vaccines is necessary for the child.

Natural immunity occurs when your child gets a disease due to infection from a germ. Natural immunity may cause a better antibody response but the infection may also cause problems and complications in the child for e.g diphtheria may lead to serious complications in a child that may lead to difficulty in breathing whereas the vaccine may only cause a minor fever.

How effective are vaccines?

Vaccines are highly effective. They give protection in 85% to 99% of cases. They greatly reduce risk of serious illness.

Why do vaccines given so early in life?

Children are vaccinated early because they are susceptible to diseases at a young age, and the consequences of these diseases can be very serious.

How long does immunity last after getting a vaccine?

Some vaccines give life-long immunity e.g. measles or hepatitis B. Some vaccines may give protection for only a limited time and then would require booster shots to have continued protection e.g. tetanus, diphtheria, pertussis. It's important to keep a record of vaccinations so the doctor knows when your kids are due for a booster.

What are the common side effects caused by immunization?

Most of the vaccines are very safe. Not all the vaccines lead to reactions. Not all the children develop reaction nor does it develop with each dose of vaccine. Child can get pain, redness, swelling at the injection site. Rarely a nodule may form which remains for few weeks especially following DPT. Sometimes, there may be mild to moderate fever, which usually responds to paracetamol. Rarely child can develop fussiness, irritability, vomiting, diarrhea, excessive crying etc. especially after DTP injection.

In rare cases, immunizations can trigger more serious problems, such as seizures or severe allergic reactions which must be reported immediately to the doctor.

In which patients, vaccines should not be given?

Patients with severe reactions to previous immunization should not receive same vaccine again. Patients with severe egg allergies should not be given measles or MMR vaccine. Patients with poor immunity like advanced HIV or AIDS, patients on steroids and those on cancer chemotherapy should be vaccinated only as suggested by the physician as certain vaccines like live vaccines should be avoided in them.

Can getting a number of vaccines at one time harm my baby?

Apart from the pain due to the shots, there is no serious adverse effect of receiving multiple vaccines at one time. Babies have strong immune systems, and they do handle more germs from environmental exposure on a daily basis than what they receive from vaccines. Any number of vaccines can be given on same day at separate sites but if not given on same day there should be gap of 4 weeks between two vaccines in general. This practice is based on extrapolation of data from multiple studies showing that most vaccines can be administered at the same time without compromising safety or immunogenicity. Thus, DTP, Hib, IPV, hepatitis B, pneumococcal conjugate vaccine, MMR, varicella, and rotavirus vaccines can be administered simultaneously. Live virus vaccines should be given either simultaneously or at least 1 month apart. MMR and BCG should not be given together.

Is it true, MMR causes autism?

This is a popular myth and numerous studies have found no link between vaccines and autism.

What about thiomersal (a type of mercury derivative that is used as a preservative in the vaccines)? Is it safe?

Thiomersal at the dose that is present in the vaccines is not harmful. However, thiomersal has been removed from most vaccines now. And recent studies have shown that there is no cognitive or behavioral problems in babies who might have received these thimerosal-containing vaccines.

Is intussusception a problem with the rotavirus vaccine?

Rotavirus is one of the most common causes of diarrhea in young children. In 1999, a rotavirus vaccine was taken off the market because it was linked to an increased risk for intussusception. However, the new rotavirus vaccines called RotaTeq and Rotarix are safe and not found to have this increased risk.

Why does my child need to be immunized if the disease has been eliminated, like polio?

Polio has recently been eliminated in India, but still exists in other parts of the world, like Pakistan, Afghanistan and Nigeria. Doctors continue to vaccinate against polio because it's easy to come into contact with illnesses through travel or visiting travellers.

It's only safe to stop vaccinations for a particular disease when that disease has been eradicated worldwide, as in the case of smallpox.

Can a vaccine be given when a child is sick?

Minor illness like mild cough, cold, loose stools, vomiting or even mild fever is not a contraindication for vaccination. However if a child is suffering from severe diseases, high fever, severe loose stools, pneumonia or any other illness needing investigation or admission to a hospital, vaccination should be postponed till full recovery.

What precautions should one take before vaccination?

Foremost is to complete the schedule in time. Do tell the doctor about any adverse effects seen to previous immunization. One can feed the child including breast feeds before & after any vaccination. There is no need to starve the child before vaccination. Maintain properly the vaccination card & take it along during each vaccination for the doctor to see record.

What precautions should be taken after vaccination?

Keep firm pressure for few minutes at the injection site with a spirit swab. Do not massage or rub at the injection site. Wait in the consulting room for another 30 minutes should any reaction develop following vaccination. Note down carefully when to come back for next vaccination. Inform the doctor immediately if the child develops any reaction or abnormal behavior or habits following vaccination in the next few days.

Immunization Faqs Immunization Faqs 2016-02-19
Disclaimer: The information given by is provided by medical and paramedical & Health providers voluntarily for display & is meant only for informational purpose. The site does not guarantee the accuracy or authenticity of the information. Use of any information is solely at the user's own risk. The appearance of advertisement or product information in the various section in the website does not constitute an endorsement or approval by Pediatric Oncall of the quality or value of the said product or of claims made by its manufacturer.
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0