COVID-19: What is mRNA vaccine and how does it work? Watch explainer video

Pfizer/BioNTech and Moderna have developed an entirely new type of vaccine based on mRNA [Messenger RNA vaccines] to combat the coronavirus. A UK-based university, with the help of a two-minute-long video, has explained how the mRNA vaccine targets the immune system to eliminate COVID-19. The coronavirus vaccines, when injected in the upper arm sends the mRNA into the bloodstream. The virus makes copies of itself by entering into the healthy host cells using protein spike structures that are made out of RNA and DNA. The mRNA from the vaccine contains the synthetic version of the RNA that tricks the immune system that the virus is present, thereby accelerating the anti-body-making process. 

When injected, the mRNA component acts as an instructor for the immunity cells directing them to interpret the protein spike structure of the coronavirus which kick starts the immunity mechanism in the body. While the coronavirus attacks the healthy cells, makes copies of itself, and rapidly multiplies, the mRNA prepares these cells to fight in advance. The messenger RNA injected from the vaccine performs a "crucial task" in the body by tricking the healthier cells against the ‘spike protein’ and by teaching our immune system what that virus actually looks like. This prepares the immune system to vigorously attack the actual virus. 

According to Barry Bloom of Harvard T.H. Chan school of public health, SARS-CoV-2 uses DNA or RNA that wraps itself on the coat of proteins altering it into a specific structure. As mRNA enters the blood, the immunity cells become more aware of these spike protein structures that are also composed of RNA.  This is much different from the mechanism of traditional vaccines. “In the case of COVID-19, a piece called the spike protein is the critical piece,” scientists explain. And hence, the mRNA vaccine instructs the immune system cells to gobble up the critical piece of protein, kill the virus, and ramp up the defense against the virus. The mRNA plays a vital role in educating the immune cells to get rid of the actual virus. Once the cells recognize the protein spike structure due to the mRNA, it starts to build an immune response and makes antibodies. 

Read: COVID-19: Johnson And Johnson's Single-dose Vaccine 'offers Strong Protection', Says FDA

Read: In Bid To Battle Covid, AIIMS' Dr Randeep Guleria Pitches Vaccine-aided Herd Immunity

[SARS-CoV-2. Credit: Twitter/@MediosTec21_Vva]

New vaccines, but known previously

mRNA vaccines that have been researched for the COVID-19 were manufactured earlier for ailments like flu, Zika, rabies, and cytomegalovirus (CMV). Scientists have used traditional vaccines for over several years against illnesses like polio and measles. After the coronavirus pandemic hit the world, German company BioNTech, and company in Massachusetts Moderna commenced rigorous research to alter the right mRNA sequence for it to combat more complicated illnesses like COVID-19. For this, the researchers had to first identify the coronavirus. Once the genes that make the spike protein in the SARS-CoV-2 virus were identified, scientists began working on an mRNA vaccine to pave way for widespread immunization again COVID-19. 

Read: Elderly Receive Vaccine In Argentina Amid Scandal

Read: Indian Envoy: 'I Am Glad That Mongolia's First COVID-19 Vaccine Is Made In India'