Have COVID-19 Vaccine Doubts? Learn How It Is Developed

How Is The COVID-19 Vaccine Developed? - DoctorOnCall

The world is still plagued by the COVID-19 epidemic. Scientists around the world are working hard to find the best treatment, to restore pre-pandemic life. A few pharmaceutical companies are also competing to develop antiviral drugs to treat COVID-19 patients either creating new drugs or experimenting with existing drugs that have been used before for other infections. Studies for vaccines continued and are expected to be used as a preventive measure for COVID-19 infection. 

However, when the vaccine has now been successfully developed and began to be distributed all around the world, many are skeptical and doubting the ability and safety of this vaccine that they refuse to take it. So, through this article, we will explain the process of COVID-19 vaccine development from the beginning until it reaches the consumer.

What Are The Important Steps In Covid-19 Vaccine Development?

According to the World Health Organization (WHO), there are a number of important steps that need to be taken to ensure that a new vaccine is safe and effective. The important steps in this process are as follows:

  • Pre-Clinical Studies

For efficacy and safety, vaccines are tested in several studies on animals and also by challenge studies.

  • Phase I: Clinical Trial 

Small group of healthy adult volunteers receive the vaccine in order to test the safety of the vaccine. 

  • Phase II: Clinical Trial 

Vaccines are given to people with characteristics (such as age and physical health) that are similar to those who are the main target of the vaccine development.

  • Phase III: Clinical Trial

Vaccines are given to thousands of people and their efficacy and safety are tested more accurately.

  • Phase IV: Post-Marketing Surveillance

Ongoing studies after vaccines are approved and licensed, to monitor side effects. Additionally, the long-term effects of vaccines in the population are also being studied. 

  • Human Challenge Studies

Studies in which the vaccine is given with the pathogen of the disease. This type of study is less practical as many ethical challenges that need to be overcome. 

In a regular vaccine study, a group of volunteers at risk of getting the disease were given an experimental vaccine, while another group was not. Then, researchers will monitor these two groups from time to time and compare the results to see if the vaccine is safe and effective.

In human challenge studies, after a healthy volunteer has been vaccinated, these volunteers will be exposed to the organism or pathogen that causes the disease. This aims to see if the vaccine really works. Some scientists believe that this approach can accelerate the development and production of the COVID-19 vaccine, as it requires far fewer volunteers than regular vaccine studies.

However, there are some important ethical considerations that must be followed especially for new diseases like COVID-19, which we have not fully understood and are still learning treat effectively. This is one of the big challenges for the medical community and volunteers, to estimate the risk if they are involved in the human challenge studies for the COVID-19 vaccine.

Why Are There So Many Types of COVID-19 Vaccine in Development?

To fulfill the worldwide demand for COVID-19 vaccines, it is impossible for production to the sole responsibility of a single company. Therefore, scientists and pharmaceutical companies around the world are working on research simultaneously at an unprecedented rate, with the best and most promising results being used by the world community. This simultaneous production is also very important to ensure that vaccine demand for the population around the world can be met including the less affluent countries. 


In conclusion, the process of developing COVID-19 vaccine is a tough challenge. Especially in this challenging era of pandemics, the rapid production of vaccines is essential. However, safety and efficacy aspects remain the highest standards in the process. 

Boost your immune system and have a healthy life!


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