Vaccines are made of either live or inactivated pathogens or germs, some are made of polysaccharides and some are toxoid vaccines. Vaccines are created by a team of scientists, doctors and researchers to protect people from getting infected by a disease causing germ and suffer its effects. While developing a vaccine, the researchers consider the following factors:
Types of vaccines:
Vaccines are categorized into four major types according to the main ingredient used to keep away the targeted germs.
Live - attenuated vaccines:
Small amount of weakened live virus is injected into the child so that the body produces antibodies against the invasion. Since the virus is not strong, it does not produce severe symptoms like those in the actual disease. But there may or may not be mild symptoms due to the rush of the immunity system’s defense mechanism of producing white blood cells and antibodies. This immunity for vaccine gives immunity against the disease for a lifetime. Measles, rotavirus, smallpox, chickenpox, etc are live vaccines.
Killed version of the germs that cause the disease are inactivated vaccines. Since they do not provide as good immunity as live vaccines, more number of booster doses are required to develop immunity against the diseases. Hepatitis, polio, rabies, etc are inactivated vaccines.
Subunit, recombinant, polysaccharide and conjugate vaccines:
These components may be used in various combinations and are extracted as specific parts of the germ that causes the disease. A protein, sugar or caspid (the covering of the germ) are some of the parts used for making vaccines. This type of vaccine develops strong immunity against the disease and since they do not contain the actual germs, they can be used with people with weakened immunity system too. However, booster shots are required for continuous protection against the disease. Some of the diseases against which such vaccines are used are Human papillomavirus, whooping cough, hepatitis B, meningococcal disease, etc.
The disease causing germ makes a harmful product that is toxic to humans. However, using this harmful product as vaccine with caution can help develop immunity against the toxin that the germ is using against the human body. The immune response is targeted to the toxin instead of the disease causing germ. Diphtheria and tetanus are some of the diseases in which germ-toxins are used as vaccines.
Scientists are working to develop DNA strands in individuals that would produce very strong, life-time immunity. These could be very easy to make and inexpensive too.
Recombinant vector vaccines:
These are also called platform-based vaccines and the vaccines act like the natural infection without causing much damage. The immunity system responds to this near-natural infection and develops antibodies that could last a life-time.
A lot of research and many numbers of trials go into the development of the final product as vaccine to be manufactured in a large scale. Apart from these main ingredients, vaccines contain preservatives and stabilizers to prevent them from losing their strength. The use of preservatives and stabilizers are also researched well to