All about Vaccines

In Sri Lanka we have a well established island wide immunization programme to prevent diseases. Government hospitals provide vaccines for free of charge. However there can be lot of question on vaccination and this is to educate you on vaccination.

What is vaccination? Vaccination is a preventive treatment developed for bacterial or viral infections.

Do all infections have vaccines? No, Vaccines are mainly developed for the diseases with high morbidity and mortality rate or to prevent epidemic conditions. Our immune system and medical care can easily cure many other infections.

Do vaccines contain live viruses? Yes, there are several types of vaccines and following are the commonly found:

• Live attenuated, uses weakened live viruses which cannot produce the disease in a healthy human

• Inactivated, uses killed viruses or parts of the killed virus
• Toxoids, uses inactivated toxins produced by the microorganisms examples are tetanus and diphtheria vaccines

How vaccination prevents infections? When live attenuated/toxoids or inactivated viruses in the vaccine enter in to the body our immune system activates and develops antibodies and memory. When an immunized person is exposed to actual infection the immune system easily fights and eliminates the viruses before harming the body.

How vaccines are administrated: Most common ways are subcutaneous, intramuscular and oral administration.

Does every one develop desired immunity after vaccination? No, usually booster doses are given after the first dose to immunize the most of the population.

Do vaccines provide long lasting immunity? Not all, it depends on the vaccine. Period of protection may vary and some vaccines required periodic administration.

Can someone get infected by vaccination? Rarely Yes, since some vaccines use live organisms, rarely a person with inadequate immunity may be infected and have a chance to develop symptoms and complications similar to actual exposure. However vaccines that use inactivated viruses cannot infect the receiver.

Are there any side effects? Yes mild side effects (i.e. swelling near the injected site, low fever, headache, stomach problems etc.)  are common for any vaccine. These do not need special medical treatments other than mild antipyretics (for fever) and subside within few days.

Though it is uncommon some may develop moderate to severe side effects such as high fever, rashes and breathing difficulties in which the medical treatments are required.

In rare cases some people develop hypersensitivity reactions which can be life threatening.

What are hypersensitivity reactions? They are undesirable reaction to the ingredients of the vaccine by the immune system. It should be noted that it is not a fault of the vaccine or the person administrated.

Can hypersensitivity reactions are preventable? Sometimes not, some people develop hypersensitivity reactions for the first time for a particular vaccine. Therefore it may not be predictable. But emergency medical treatments can prevent the complications. 

Hypersensitivity reactions come soon as less than 60 minutes after vaccination and the symptoms can be severe. Immediate administration of the adrenalin and respiratory support can save the patient. Government or private immunization clinics should have these facilities and trained staff.

Unfortunate rubella vaccine incidents occurred in Sri Lanka most likely to be hypersensitivity reactions.

• It is better to immunize yourself/children at a facility with emergency medical care.
• It is also important to stay at the place at least 30 minutes before leaving.

To be continued .....http://www.blogs.lk/2011/08/all-about-vaccines_25.html