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Covid 19 Vaccines: Top 3 Vaccines that Might Save Us from Covid-19



covid 19 vaccines

The number of coronavirus cases currently stands close to 77 million. The rapid rise in infections has caused deaths and significantly changed global operations. However, scientists have been in a race to develop covid 19 vaccines to help combat the spread of this viral infection. In this article review, we look at the top three covid 19 vaccines and their efficacy.

Top 3 Covid 9 Vaccines

As of late 2020, three covid 19 vaccines have been approved for use. Below is an overview of each one of them based on how they work and their success rate?  

1. Pfizer-BioNtech Covid Vaccine

Pfizer-BioNtech Covid Vaccine

Both Pfizer and BioNTech companies develop it. BioNTech is a German biotechnology company, while Pfizer is an American multinational pharmaceutical corporation.

How It Works

The Pfizer covid vaccine was the first covid 19 vaccine which authorizes for use in the US. It consists of two shots that should be given three weeks apart. 

It should be noted that this is one of the first vaccines that has been designed based on the messenger RNA technology ever approved for human use by the FDA. So, it’s a great scientific milestone. 

Therefore, its functionality is different from the traditional vaccines that are normally designed to work using a dead or a weakened version of the virus.  

Pfizer-BioNTech uses a synthesized piece of genetic information. This gene data is protectively wrapped in a fat layer to prevent it from disintegrating. So, when you are injected with the vaccine in the muscles of the upper arm, the molecular instructions in the vaccine will tell your body cells to generate a protein that will trigger an immune response. 

It should be noted that this immune response is directed to the spike protein found on the surface of the coronavirus. So, in case the virus tries to invade your immune system, it will be effectively-prepared to eliminate the pathogen. 

Success Rate

The available data regarding this vaccine for covid indicates that its 97 percent effective. This makes it one of the three covid 19 vaccines with a high level of efficacy.  

2. Moderna Covid Vaccine


This is one of the top 3 covid 19 vaccines that has been recommended for use by the public—Moderna covid vaccine developed by Moderna. According to business insider, it only took 2 days to design this vaccine.

How it Works 

The Moderna and Pfizer covid 19 vaccines work in similar ways. These two companies did their covid 19 trials by studying the spike proteins.  

The coronavirus is studied with spike proteins that it uses to access and enter the human cells. Moderna vaccine is designed to target the spike protein. The vaccine uses a messenger RNA (mRNA), a genetic material containing information about the spike protein. 

The vaccine provides the body with instructions to produce a small amount of this protein. The immune system will definitely detect this protein, and it will lead to a protective antibody response. 

Note: Even though both Moderna and Pfizer covid 19 vaccines function in a similar way, Moderna’s covid vaccine doesn’t need the same ultra-cold storage as Pfizer’s. 

Success Rate 

Moderna’s covid 19 vaccines have a 94.5% efficacy when it comes to protecting people against COVID-19. While its efficacy may drop over time, scientists believe that the vaccine should protect 9 in 10 people.  

3. AstraZeneca Covid Vaccine

AstraZeneca Covid-Vaccine

It’s one of the recommended covid 19 vaccines. AstraZeneca Covid vaccine trial indicates that it’s safe and effective in the prevention of COVID-19. This vaccine’s development involved a partnership between the University of Oxford and AstraZeneca, a British-Swedish company.  

How It Works

The Oxford-AstraZeneca vaccine is based on the virus’s genetic instructions for building the spike proteinFor effectiveness, the researchers added the gene for the coronavirus spike protein to adenovirus, another type of virus. Ishould be noted that adenoviruses are viruses that are commonly found in colds or flu. The team used a modified version of a chimpanzee adenovirus. After the vaccine is injected into a person’s arm, the adenoviruses (which have the ability to replicate) will bump into cells and latch onto the proteins on their surfaces. 

Eventually, the cell engulfs the virus into a bubble and pulls it inside. But once inside, the adenovirus will escape from the bubble and travel to the nucleus where the cell’s DNA is stored. The cell’s DNA will be pushed into the nucleus. 

While the adenovirus can make copies of itself, the gene for coronavirus spike can be read by the cell and copied into an mRNA Molecule. The mRNA will leave the nucleus, and the cell’s molecules will read its sequence and start to assemble spike proteins. 

Some of the produced spike proteins by the cell will form spikes that will later migrate to the cell’s surface and stick their tips. The vaccinated cells will also break some proteins into segments, which they will present on their surface. 

Interacting with the Immune System

The combination of the protruding spikes and the spike protein fragments is something that the immune system will recognize. The adenovirus essentially provokes the immune system by triggering the cell’s alarm systems. So, the cell will send out an alarm to activate the immune cells nearby. This will cause a stronger reaction to the spike proteins. 

After the vaccinated cell dies, its debris will obviously contain the spike proteins as well as the protein fragments. They will be taken up by an immune cell that’s known as the antigen-presenting cell. There is also the Helper T-cell that can detect these fragments and help to enhance the immune response. The body will thereafter manage to build antibodies that can latch onto the coronavirus spikes. This means that the vaccine is effective in destroying the coronavirus spikes but also preventing further infections 

Success Rate

A one dosing regimen indicates that the Oxford covid vaccine has an efficacy rate is 70%. 

Covid 19 vaccine

The Testing Process of a Covid 19 Vaccines

The testing process for vaccines is usually done during the development stage. It’s important for clinical research and studies. Besides that, vaccine testing helps determine the side effects and the adverse reactions that users can potentially suffer from.  

It should also be noted that the vaccine’s approval process and the development of future vaccines depend on testing. But before testing, here is what it involves in the development of new vaccines: 

The Exploratory Stage

It’s an exploration phase that generally lasts between 2-4 years. However, the period can change (in the case of the covid-19 vaccine, it was shorter). During this time, there is basic research and identification of natural or synthetic antigens.  

Pre-Clinical Stage 

This stage is used to determine how the vaccine will workIt’s generally research-intensive because the foreign substances that induce the body’s chemical reaction have to be foundThe process of identifying the antigen or antigens can take up to four years. 

One scientist who had been investigating candidates for a potential SARS-CoV-2 vaccine since January 2020 said by March 30 that the researching company had been able to find a lead in finding a vaccine with two backups. This process was accomplished in a matter of months and not years! 

The Clinical Development 

This is usually a three-phase process. Phase 1 involves small groups of volunteers who will receive the trial vaccine. Phase II involves the expansion of the clinical study, and the vaccine is normally given to people who have characteristics similar to those for whom the new vaccine is intended for. 

And number III involves the distribution of the vaccine to thousands of people. It should be noted that the vaccine will still be tested to determine its safety and efficacy. 

Regulatory Review and Approval 

This is where the FDA and CDC come in. If Phase III is successful, then the vaccine manufacturer will submit an application to the regulatory body. In the US, it’s the FDA, while in Europe, it’s the European Commission. If the vaccine becomes approve, then the manufacturing process needs to begin. 

Manufacturing and Quality Control 

These are the last stages. The vaccine has to manufacture for distribution to the larger public. However, quality control and monitoring are still important. This is because the vaccine can cause adverse reactions in some people.

Covid 19 Vaccines: Safety Measures

Before the Covid 19 vaccines were released for use, they had to undergo comprehensive testing process. Generally, licensed and recommended vaccines have to undergo years of safety testing. This usually includes: 

  • Testing and evaluating the vaccine before it’s licensed by the FDA and recommended for use by the CDC. 
  • Monitoring of the vaccine’s safety after it’s recommended for infants, children, or adults.

The covid vaccine progress has been one of the quickest in the history of vaccines. It has been developed, tested, and approved for use in less than 10 months. However, the covid vaccine update in places like the UK indicates that breastfeeding moms haven’t been approved for use. 

While covid 19 vaccines are under tests in labs, the FDA normally uses the information derived from such tests to decide whether the vaccine is effective.  

During the clinical trial, the vaccine is normally tested on volunteers. Generally, clinical trials start with between 20 to 100 volunteers. However, thousands of volunteers will be eventually included in the clinical trials. For safety purposes, the tests used to take several years. But the improved technology in the 21st century that the period can be shortened. 

  • Apart from safety, tests help to determine: 
  • The dose or amount of vaccine that works the best 
  • How people with different immune systems will react to it

Throughout the testing process, the FDA will work closely with the company producing the vaccine. This is done to evaluate the vaccine’s safety and effectiveness. If any safety concerns arise, then the company producing the vaccine must address it before the FDA licenses it. 

Covid 19 Vaccines: Every Batch of the Vaccine is Tested 

Once the FDA has licensed the vaccine, its quality and safety will continue to be tested. The manufacturing company will be responsible for carrying out the vaccine tests in batches to ensure that: 

  • Its potent and will therefore work the way it’s supposed it. 
  • It’s safe and pure without contaminants. 
  • Its sterile and doesn’t have any germs. 

The FDA will continuously review the tabulated results regarding the tests. It will also continue to inspect the factories where the vaccine is made. This helps to ensure that everything meets the stipulated quality and safety standards. 

What Happens if a Vaccine is Recommended? 

Well, once a vaccine has been recommended to the public, the CDC, FDA, and other federal agencies will continue to monitor its safety. At the moment, the FDA is investigating allergic reactions to Pfizer covid vaccine reported in multiple states. 

Overall, there are many parts of the national vaccine monitoring system. It should be noted that the US has one of the most advanced systems in the world for tracking the safety of vaccines. Each system has its own guidelines. As a result, they use different types of data to carry out research. They include: 

  • The Vaccine Adverse Events Reporting System (VAERS) 
  • The Vaccine Safety Datalink (VSD) 
  • Post-licensure Rapid Immunization Safety Monitoring System (PRISM) 
  • Clinical Immunization Safety Assessment Project (CISA) 

Are These Covid 19 Vaccines Safe?

While the appropriate governing bodies such as the FDA have authorized the use of these vaccines, the vaccines’ safety is still being monitored. For instance, some of those who got the Pfizer covid vaccination during the clinical trials end up with unpleasant but tolerable side effects. It included: 

  • Muscle pain 
  • Joint pain 
  • Chills and fever 
  • Fatigue 
  • Headache 

Final Thought

Pfizer-BioNTech, Moderna, and AstraZeneca are the top three covid 19 vaccines. They had been developing within a short time frame, all these thanks to science and technology. These vaccines are expected to reduce the spread of covid 19 infections by facilitating the development of herd immunity. 

Currently, the vaccines are being rolled out to the public in different states, especially in the US and the UK. However, the public still needs to follow all covid-19 precautions to minimize a spike in infections.

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