There is no doubt that Covid-19 is on the top of major concerns in human health in 2021. Scientists, researchers, and health care professionals from all around the globe are working hard to develop a vaccine to eradicate this disease. The tremendous war between our bodies and the virus left us with question marks on how a vaccine can work to stop the spread of the pandemic. Therefore, it is significant to know how our bodies respond to infections and how a vaccine can help in this manner.
Imagine your body as a city getting attacked by foreigners of different shapes and sizes. The city is surrounded by soldiers who work hard to defend it from any kind of danger. This is how our innate immunity works. The causative agent of the disease is called an antigen. In response to this antigen, our immune system takes time to produce an antibody that targets this antigen. Meanwhile, the body gets sick. This produced Ab works with the rest of the immune system to fight the disease. As well, our bodies produce memory cells that help in this war in case of a second response.
A vaccine is a therapeutical application that simulates this war in our bodies. The only difference is that the vaccine contains weakened parts of the antigen that do not cause disease but enough to produce antibodies and memory cells. The importance of the vaccine can go far beyond establishing herd immunity. In this sense, immunocompromised patients who are unable to be vaccinated can also be protected.
According to WHO, there are three main approaches to designing a vaccine. For instance, using a whole virus, parts of the germ that trigger the immune system, or just the genetic material of the virus. First of all, in the whole virus approach, the vaccine might be inactivated, live attenuated, or viral vector vaccine. The inactivated vaccine contains killed Coronavirus in the same way that flu and poliovirus were made. However, requiring special conditions as well as being a time-consuming technique put it aside. In addition, the Live attenuated vaccine has a similar technology but depends on using a weakened version of the virus. In a different manner, the viral vector vaccine requires a safe virus that includes specific parts of coronavirus protein which triggers the immune system when it enters the body.
Besides, the subunit approach depends on using specific parts of the virus that triggers the immune system similar to childhood vaccines as tetanus and diphtheria.
Finally, the nucleic acid vaccine got much concern after covid-19. Because it is based on a genetic approach, it works in a different manner. As it depends on using parts of the virus genetic materials that provide instructions for a specific protein either DNA or mRNA. In this sense, it produces the target protein for the immune response. To that end, research in this particular area has developed fast and some MRNA viruses got the approvals by national authorities to be used in urgent settings.
- Who.int. 2021. How do vaccines work?. [online] Available at: <https://www.who.int/news-room/feature-stories/detail/how-do-vaccines
- Who.int. 2021. The effects of virus variants on COVID-19 vaccines. [online] Available at: <https://www.who.int/news-room/feature-stories/detail/the-effects-of-virus-variants-on-covid-19-vaccines