The human race has been faced with different ailment from beginning of time. Some were dealt with without serious damages while some threatened the foundation of the human race before it was crushed. As there are diseases in human communities, they are also present in other life forms. The continued dependence of all life forms on one another for survival since the age of agriculture to the modern age of technology has brought with it various challenges, including diseases.
Since the early days, when people were living in caves, eating raw foods; living at the mercy of nature, people have continued to face threats of infectious diseases. Histories of Mankind, disease and medicine have come a long way. The Early history of fighting infectious diseases was largely curative rather than prevention, but modern age continue to seek ways at preventing it. Human efforts at preventing infectious diseases lead to discovery of vaccines. Essentially, vaccines are being developed to help humanity curtail spread of any known contagious disease.
What is a vaccine and how does it work?
The idea of vaccine develops from the old medicine practice of fighting poison with poison. It has been practiced by people in different cultures at different times. The concept is to kill or weaken germs known to cause a particular infection and use it to make a vaccine. It is believed that human body has the capacity and ability to fight off germs. To fight germs effectively, human antibody needs to prepare before it can effectively combat and stop germs from destroying its host. By introducing dead germs into the body, the immunity system develops necessary antibodies against it, which prepares it to stop any live germs that eventually get in the body.
Therefore, vaccine is a catalyst for immune body building to prepare against an outbreak of certain germs. Usually, a person who receives the vaccine develops protective substances called antibodies to defend the body against the germs. Think of vaccines as a motivation for the body to prepare itself for protection against external attacks.
Once the body has been able to develop an antibody to fight off the vaccine germs, it stays in the body for a fairly long time. These antibodies now understand this particular type of disease and how to deal with them. So, when the real germ no enters the body, the antibody already understands how to fight them off. But, to continue to be strong against this type of germs, your antibody needs a booster in the form of re-vaccination.
Types of vaccines
Scientist’s knowledge about a type of microbe will dictate the approach to design a vaccine. It is the approach taken in the making of a vaccine will define the type of vaccine. Below are some approaches in the design of vaccines:
• Live, attenuated vaccines: Live, attenuated vaccines contain a live version of the microbe in a weakened form. This type of vaccines gives the body the opportunity to produce very strong antibody against the disease with lifelong immunity. Examples of vaccines designed this way include – Measles, Rotavirus, Rubella (MMR combined vaccine) Varicella (chickenpox), mumps, Influenza (nasal spray) etc. Live, attenuated vaccines require careful handling in a refrigerated state to make it safe for use.
• Inactivated vaccines: Inactivated vaccines are a type of vaccine with a dead microbe. It is produced by killing the live microbe with chemical or heat. Inactivated vaccines can be transported without refrigeration and are safer for use, unlike live vaccines. Examples of inactivated vaccines include Polio (IPV), Hepatitis A, etc.
• Sub-unit vaccines: Sub-unit vaccines contain only an essential part of the microbe called antigen that can best stimulate the immune system. The advantage of subunit vaccines is that it has a lower risk of adverse reactions. An example includes Human papillomavirus (HPV).
• Toxoid vaccines: Toxoid vaccines are designed to use bacteria toxins as a trigger for immune buildup. This vaccine stimulates the immune system to learn how to fight off similar natural germ when present in the body. The body immunity produces antibodies that block the toxin. Toxoid vaccines are produced by inactivating toxins using formalin. Examples are Diphtheria, tetanus (part of DTaP combined immunization).
• Conjugate vaccines: Many harmful bacteria do form outer coating of sugar molecules known as polysaccharides and disguised as bacterium antigen to deceive the immune system in infants. Thus, the conjugate vaccines are produced to get around this decoy to help body immune system recognize and destroy them. Conjugate vaccines are special types of a subunit vaccine. The conjugate vaccine is effective against Haemophilus influenza type B (Hib).
• DNA vaccines: Scientists aims at developing vaccines using their knowledge of a micro gene to create a DNA vaccine. Although DNA vaccine is still at experimental stages, there is high hope it will become a success with time. It is expected would invoke strong antibody against free floating antigen secreted by germ cells.
• Recombinant vector vaccines: Recombinant vector vaccines, like the DNA vaccines, are at experimental stages. This vaccine uses an attenuated virus or bacterium to get microbial DNA to the cell of the body. Research efforts at developing a more effective version of recombinant vector vaccines are still ongoing.
How safe are vaccines?
Vaccines are safe for use. The reason they are produced was to help people live a healthy life free of certain diseases. Therefore, extra cares are taken to ensure they are safe before approved for use. However, relevant health authorities continue to monitor a vaccine’s safe use even after approval.
How vaccines have helped in the fight against diseases?
Vaccines have helped immeasurably in a global fight against diseases. Diseases such as Polio were very vicious and debilitated at the start, punctuating lives of many promising children. Polio was all over the world and was very worrying at the beginning. But the discovery of polio vaccines helped to stem the destructive current of polio sweeping across the world.
In the USA for instance, polio was eliminated in 1979 after sustained vaccination efforts. Polio has since been tackled headlong across the world with cheering news of successes. Similar diseases like polio have been confronted and defeated with the use of vaccines.
Maternal mortality and other serious life threatening cases are been confronted with vaccines with greater successes. The continued efforts at producing more effective vaccines promise greater support towards a healthier society.