COVID-19 vaccines: here's how it works 2022-Green World

 COVID 19 vaccine-2022

There are more people who will be vaccinating at the same time in the COVID-19 pipeline than ever before in an infectious disease. They are all trying to achieve the same thing - immunity to the virus, while others can also stop the transmission. They do this by stimulating the body's response to the antigen, a molecule found in the virus. In the case of COVID-19, the antigen is usually a spike protein found on the surface of the virus, which is often used to help it attack human cells.

Many common vaccines use complete antibodies to trigger an immune response. There are two main ways. Decreased vaccines use a weaker version of the virus that can still replicate itself without causing illness. 

Ineffective vaccines use viruses that have damaged genes to prevent them from replicating, but they can still trigger an immune response. Both species use stable technologies and methods of legalization, but those that live less can be more likely to cause disease in people with weakened immune systems and often require careful cold storage, making their use more challenging in low-income countries. Ineffective vaccines can be given to people with compromised immune systems but may also require cold storage....

Subunit vaccines use pathogen fragments - usually fragments of protein - to initiate the body's response. Doing so reduces the risk of side effects, but also means that the immune system may be weakened. This is why they often need adjuvants, to help boost the immune response. An example of a sub-unit vaccine is the hepatitis B vaccine...

Nucleic acid vaccines use genes - RNA or DNA - to give cells instructions for antigen production. In the case of COVID-19, this is usually a viral spike protein. When this gene enters the human cell, it uses the protein industry in our cells to make an antigen that will stimulate the immune response. The beauty of these vaccines is that they are easy to make, and cheap. As antigen is produced within our cells and in large quantities, the body's response must be strong. What is worse, though, is that to date, no DNA or RNA standards have been licensed for human use, which could result in many legal barriers. In addition, RNA targets need to be kept at high temperatures, -70C or below, which can be a challenge for countries that do not have cold storage equipment, especially low- and middle-income countries...

Viral vector vaccines also work by giving cells genetic instructions to produce antigens. But they are different from nucleic acid vaccines because they use a harmless virus, which, different from the target, to deliver these instructions to the cell. Another type of virus commonly used as a vector is the adenovirus, which causes the flu. Like nucleic acid vaccines, our cell phones are hijacked to produce antigen in those instructions, in order to trigger an immune response. Viral vector vaccines can mimic a viral infection and should trigger a strong immune response. However, as there is a possibility that many people may already be exposed to viruses used as vectors, others may not be immune to them, making the vaccine less effective.....