The coronavirus (COVID-19) raged on; for a whole year, it seemed unstoppable. The number of reported cases at the time of writing this article had crossed 78,000,000 worldwide and more than 1,700,000 sadly lost their lives. Fortunately, after a crazy, hectic year, a tiny ray of hope is shining on the horizon. We have a number of vaccines for this virus, some of which I am sure you are already familiar with, such as Pfizer-BioNTech, Moderna, Oxford-AstraZeneca, and Sinopharm.
The process of developing vaccines is a complicated one, and due to the emergency of the situation it has been speeded up tremendously and we have a number of vaccines now. Due to the different techniques used, for the purposes of this article, we will stick to only two vaccines: Pfizer-BioNTech’s and Sinopharm’s. The Sinopharm vaccine is traditional; it has been developed using the tried and tested method of inactivated viruses. On the other hand, Pfizer-BioNTech uses a new technique: messenger RNA (mRNA). Now, Let us see how both vaccines work.
Traditional vaccines fall under two categories: live attenuated and inactivated. Live attenuated vaccines use viruses that are viable but modified in the lab. The virus can still replicate; after the modifications, however, it produces immunity. Inactivated vaccines like the Sinopharm vaccine use an inactivated version of the virus/germs. Since the virus is inactive, it can be injected without causing an illness. Normally, a number of doses are required for inactivated vaccines to be effective; for Sinopharm, two doses are required. It is stored at standard refrigerator temperature of 2 to 8 degree Celsius. Hepatitis A, Flu, Polio, and Rabies vaccines are among the inactivated vaccines used nowadays.
Pfizer is another popular COVID-19 vaccine available. For this vaccine, no virus is used at all; scientists only utilized the genetic sequence of the virus. For the coronavirus vaccine, researchers used a piece of the spike protein—the structure of the coronavirus surface. Messenger RNA (mRNA) is part of the genetic code; the human body cells can read that genetic code and use it to create a protein. The mRNA gives instructions to the cells to create the virus’s spike protein; the immune system then recognizes that this spike protein does not belong to the body and start attacking it. The immune system keeps a memory of the encounter and attacks the actual coronavirus if caught.
Messenger RNA is so fragile that it is put inside lipid nanoparticles—a coating that can easily melt in room temperature. For this reason, Pfizer vaccine has to be kept in extremely cold temperatures (-70 degree Celsius); this vaccine, thus, has to be stored and transported in special equipment. The messenger RNA vaccines technology is promising; in the future, one vaccine can protect us from various diseases.
Over the years, vaccines have helped us survive and eliminate dangerous diseases. As the coronavirus continues to take lives, vaccination remains our only hope to end the pandemic and return back to normal life. Stay vaccinated. Stay safe.
References
cdc.gov
edition.cnn.com
edition.cnn.com
nytimes.com
vaccines.gov