What are the Vaccines?
A vaccine is a material containing weakened or killed pathogens and is used to produce immunity to a disease by stimulating the production of antibodies. Vaccines are products made for the purpose of protecting the human body from disease. Vaccines prepare the body to use its immune system so it remembers how to recognize disease-causing germs like viruses or bacteria and responds to try and stop those germs from making someone sick. Immunizations are made with either weakened or dying particles of disease-causing germs, or proteins derived from those germs. A vaccination is injected before a person gets sick. It does not cause disease. Instead, it provides a ‘reminder’ to a person’s immune system to say that if the scary germ we did not like comes back into the body again, go out and fight it!
Vaccines have contributed significantly to the eradication or marked decrease in the number of deadly diseases like smallpox, polio, measles, tetanus, and many other diseases.
The History of Vaccines.
Vaccines have been developed and used for almost two hundred years. The first successful vaccine was invented in 1796 by Edward Jenner from the United Kingdom. The disease smallpox was then a virulent, deadly disease that killed millions. Jenner noticed that cows infected with cowpox did not get human smallpox. Based upon that observation, he vaccinated a child with cowpox material, and when the child was later exposed to human smallpox germs, the child did not get sick – the first successful vaccination in history.
After the development of the vaccine, the idea of vaccines was also further developed. In 1885, the French scientist Louis Pasteur invented a vaccine for rabies, which was another milestone. Pasteur also demonstrated that germs can be a principal cause of disease (Germ Theory), hence vaccines were the best way to develop immunity against germs.
The 20th century will perhaps be best described as the “Golden Age of Vaccines.” During this time, many successful vaccines were developed against very serious diseases:
1920s: Diphtheria, tetanus, and whooping cough vaccines.
1950s: The polio vaccine developed by Dr. Jonas Salk, and later from the disruption of live virus with the Sabin vaccine, saved millions of children from disability across the globe.
1960s: Measles, mumps, and rubella vaccines.
1970s: Smallpox was eradicated completely using vaccination campaigns—the first disease in human history to be wholly eradicated.
1980s: The hepatitis B vaccine appears, and is developed financially and through genetic engineering, establishing the rise of biotechnology.
How do Vaccines work?
Vaccines are a safe and effective way to ‘prime’ our immune system for disease. When we receive a vaccine, we receive the germ in a weakened or inactivated form, or just a part of the germ. This is not harmful to our bodies, but the immune system considers it a foreign invader and starts an immune response to it. The white blood cells in our bodies recognize the substance and produce antibodies against it; antibodies are special proteins that help destroy the original disease germ. As well as creating antibodies, the immune system also remembers, so if it encounters the same original virus or bacteria again in the future, the immune response can be engaged instantly and with greater force of response, called immunological memory. Vaccines prevent us from developing diseases, with the effect of never having the disease in the first place. There may also be vaccines that only need one trocar, or others where the body needs several boosters so that the body reestablishes the memory, and the immune system remains alert. This is why children are routinely given several vaccinations against numerous diseases. Occasionally, after vaccination, you may feel a slight fever, body aches, or malaise — which is perfectly normal and simply means the vaccine is working.
Vaccines benefit not only the individual, but they also protect the entire community. When a majority of individuals get vaccinated, the disease transmission stops, and we call that herd immunity. Herd immunity can protect individuals from vaccination for medical reasons, such as newborns and, in some cases, people with immunocompromised systems. History bears witness to the fact that vaccines have saved mankind from catastrophic diseases. For example, the polio vaccine alone has left hundreds of millions of children unscathed and free from disability, and the smallpox vaccine has eradicated the disease for the entire planet.
During the world’s worst pandemic, we lived through, the COVID-19 vaccines prevented millions of deaths in at least severe to moderate cases of COVID-19. In the future, scientists can make discoveries and advances to make sure we have vaccines that can protect the body against not only diseases, but also more complicated diseases like certain cancers, malaria, and HIV. In conclusion, vaccines are not just medicine; rather, there is the greatest bulwark for the survival of the human race or for helping to maintain a healthy society.
Types of Vaccines.
1. Live Attenuated and Inactivated Vaccines.
Live attenuated vaccines are one of the oldest types of vaccines, and are very effective because they use a weakened version of the actual virus or bacteria. They induce a strong and durable immune response, and they also resemble a natural infection much more closely than an inactive vaccine. Think of the measles, mumps, rubella (MMR) vaccine or oral polio vaccine. In contrast, inactivated vaccines are attracted to pathogens that have been killed or inactivated and cannot cause disease. The inactivated vaccines will depend on the booster response, but they are still safe in people with reduced immune systems. Think inactivated polio vaccine or the hepatitis A vaccine.
2. Subunit, Conjugate, and Toxoid Vaccines.
Some vaccines only contain components of a germ, like either proteins or sugars, as opposed to an entire germ. These vaccines are called “subunit” vaccines. They are safer because they only provide the immune system with the essential antigens. Good examples are the hepatitis B vaccine and the HPV vaccine. Conjugate vaccines are for bacteria that have a protective sugar coating. They bind proteins to sugars to improve vaccine immunogenicity – this is done in the Hib vaccine. Toxoid vaccines immunize against toxic substances released from bacteria instead of immunizing against the pathogenic bacteria themselves. Some examples are diphtheria and tetanus.
3. Modern DNA and mRNA Vaccines.
Biotechnology has seen new vaccines take shape over the past few years. DNA vaccines and mRNA vaccines do not use any part of the live virus. Instead, they provide genetic instructions to cells, telling the cells to make a harmless piece of the pathogen (usually a protein) that triggers the immune system. The best-known examples of this type of vaccine are the Pfizer-BioNTech and Moderna COVID-19 vaccines that use mRNA technology. mRNA vaccines are faster to develop, can be modified for different strains, and are the future of vaccine development.
The Future of Vaccination.
Vaccines are evolving, and with that evolution, there will be new options for preventing and treating diseases. While vaccines used to comprise weakened or inactivated viruses, we have seen the rise of new abilities such as mRNA vaccines. These vaccines can be made in a timely manner and may be used with new pathogens, as we have seen with COVID-19. Researchers hope to change the direction of mRNA technology for diseases such as influenza, HIV, malaria, and even specific cancers.
A similarly exciting area of focus is the development of needle-free vaccines, including the use of nasal sprays, oral formulations, and skin patches. The hope is that these vaccines will be more attractive and therefore less painful, particularly in situations with children or those with aversions to needles, as well as easier to deploy in low-resource settings to provide access to vaccines to help address global vaccination coverage. Researchers are also attempting to develop vaccines that are universal and provide long-lasting immunity to multiple strains, for example, a universal flu vaccine.
In addition to infectious diseases, we may advance vaccines to treat non-communicable diseases: cancer, Alzheimer’s disease, and autoimmune diseases. The future of vaccines may also include personalized vaccines that take into account a patient’s genetic profile or immune system. Conducting vaccination to protect individuals more precisely will be a major advancement. The idea of stopping illness is in the past—the future may be about constantly moving the needle of global health forward, rather than waiting for illness to trigger the need for a medical response.
How Biotechnology is Changing Vaccines.
Biotechnology is changing vaccine development, production, and delivery with new ways of doing things with biotechnology, aside from the traditional alternatives. Vaccines can now be designed and engineered from a genetic basis. mRNA vaccines are the newest type of vaccine to be developed and mark a significant milestone in vaccine development and distribution, because of the speed at which biotechnology can respond to new diseases such as COVID-19. Recombinant DNA technology allows researchers to produce antigens safely, without utilizing the entire pathogen. Bioinformatics is allowing researchers to assess new vaccine targets at astounding speeds. Biotechnology also provides evidence-based personalized vaccines that account for a person’s personalized immune system response or genetic history. Biotechnological advances offer new vaccine delivery methods, for example, edible plant-based vaccines and microneedle patches, which are among the advances made possible through biotechnology. All these advances have made vaccines safer, better, and faster without substantial harm to our planet. This is not only a leap forward in vaccine research and development, but for making vaccines available and accessible internationally. Looking to the future, biotechnology’s growth will not only protect us from infections, but will also extend our health to protect us from chronic diseases such as cancer.
