explain elaborately with scientific knowledge on how the covid vaccine is invented, and its components

The development of a COVID-19 vaccine involves several steps, each of which is crucial to ensuring its safety and effectiveness. Here's a step-by-step breakdown:

1. Virus Identification: The process begins with the identification of the virus. In the case of COVID-19, the virus is SARS-CoV-2. Scientists quickly sequenced the genome of the virus and shared it globally, which kickstarted the vaccine development process.

2. Preclinical Testing: Scientists test a potential vaccine on cells and then on animals such as mice or monkeys to see if it produces an immune response.

3. Phase 1 Clinical Trials: The vaccine is then given to a small number of people to test its safety, confirm it stimulates the immune system in the right way, and determine the right dosage.

4. Phase 2 Clinical Trials: The vaccine is given to hundreds of people split into groups, such as children and the elderly, to see if the vaccine acts differently in them. These trials further test the vaccine’s safety and ability to stimulate the immune system.

5. Phase 3 Clinical Trials: The vaccine is given to thousands of people to confirm its effectiveness - that it does protect against COVID-19 - and monitor side effects. In some instances, participants are split into groups, one receiving the vaccine and the other a placebo, to compare results.

6. Approval: If the vaccine passes all these stages, it is approved by regulatory authorities like the FDA (Food and Drug Administration in the U.S.) or EMA (European Medicines Agency in Europe) for use.

7. Manufacturing: Once approved, the vaccine is produced on a large scale.

8. Distribution and Administration: The vaccine is then distributed and administered to the public.

As for the components of the COVID-19 vaccines, it varies depending on the type of vaccine. The Pfizer-BioNTech and Moderna vaccines, for example, are mRNA vaccines. They contain a small piece of the SARS-CoV-2 virus's mRNA that instructs cells in the body to produce the virus's distinctive "spike" protein. Once the protein is produced, it triggers an immune response, including the production of antibodies. These vaccines do not contain the live virus that causes COVID-19 and therefore cannot give you COVID-19.

The Johnson & Johnson’s Janssen COVID-19 Vaccine, on the other hand, is a viral vector vaccine. It uses a harmless adenovirus to deliver a piece of the DNA from the SARS-CoV-2 virus to cells in the body, which then produce the spike protein and trigger an immune response.

All COVID-19 vaccines also contain other ingredients, such as lipids (which protect the mRNA), salts, sugars, and stabilizers to help preserve the vaccine and boost its performance.