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How Does the Body React to the COVID-19 Vaccine?

First appearing in China near the end of 2019, COVID-19 spread to North America and Europe by February 2020. By November 2020, two major pharmaceutical manufacturers had developed vaccines that were shown to be about 95% effective, which means vaccinated test subjects were 95% less likely to get COVID-19 than unvaccinated ones. The U.S. Food and Drug Administration (FDA) approved these vaccines for use within about a year of their inception. Prior to this, the shortest time in which a vaccine had been both developed and FDA approved was four years: for the mumps vaccine, introduced in 1967. At time of writing, there are three primary vaccines in use in the United States, generally known by the names of their manufacturers: Pfizer, Moderna and Johnson & Johnson.  

mRNA vs. Viral Vector Vaccines 

The available COVID-19 vaccines were developed independently of one another and function in different ways. The Pfizer and Moderna vaccines are both examples of what’s referred to as a messenger RNA or mRNA vaccine.  

RNA, ribonucleic acid, is a molecule that “carries the genetic instructions for many viruses.” For these vaccines, a genetically engineered version of mRNA was used to instruct cells to create a protein that’s part of the virus. When a person is vaccinated, their body’s immune system begins to create that protein, followed by antibodies that can fight the COVID-19 virus, should that person subsequently be infected with the disease. Both the Pfizer and Moderna vaccines require an initial injection and a second dose delivered several weeks later. 

The Johnson & Johnson vaccine, delivered in a single injection that has shown about 66% efficacy, arrived shortly after the Pfizer and Moderna vaccines. It’s what’s called a viral vector vaccine, a type that has also been used to fight HIV, the flu and viral epidemics predating COVID-19. The Johnson & Johnson vaccine was created by introducing genetic material from COVID-19 into another type of virus. The resulting combination is injected into a person’s bloodstream, where the genetic material catalyzes cells to produce a protein. This protein causes the person’s immune system to produce infection-fighting antibodies and white blood cells. AstraZeneca has a similar viral vector vaccine, though it is not approved for use in the United States as of this writing. 

Potential Vaccine Side Effects 

So, what happens to a human body after receiving a COVID-19 vaccine? That depends on a number of factors. An individual’s age, overall health, allergies, gender and other factors can influence what side effects the COVID-19 vaccine might have on their body. Some reports suggest that women suffer side effects at a much higher rate than men, but this is generally true for all vaccines. Overall, the occurrence of side effects indicates that the vaccine is working. 

Systemic Side Effects 

After vaccination, people may experience these systemic effects: 

  • Headaches 
  • Muscle aches 
  • Fatigue 
  • Nausea 
  • Chills  
  • Fever 

 Local Side Effects 

Vaccinated people may also experience the following symptoms at the injection site, which is typically the upper arm: 

There have been reports of a few deaths occurring after vaccinations for COVID-19, though according to the Centers for Disease Control (CDC), “A review of available clinical information including death certificates, autopsy and medical records revealed no evidence that vaccination contributed to patient deaths.” 

Gain a Deeper Understanding of How the Body Works and Reacts to Disease and Drugs 

While a cough and fever are among the most common COVID-19 symptoms, the disease can progress into pneumonia and acute respiratory distress syndrome (ARDS), an accumulation of fluid in the lungs that makes respiration difficult and diminishes the oxygen supply to the body’s organs. ARDS may ultimately compromise the respiratory, renal and cardiovascular systems of a COVID-19-infected person.  

The University of Florida’s acclaimed College of Medicine offers programs that focus on how these vital systems work under normal conditions and how they respond to diseases and drugs. Our programs are offered entirely online, enabling you to finish class assignments and tests at your own pace, virtually anywhere.  

Master of Science in Medical Sciences with a concentration in Medical Physiology and Pharmacology 

In our online master’s degree in medical physiology and pharmacology program, you’ll gain a broader scientific understanding of the major systems of the human body and how they’re affected by various drugs. This program also helps you prepare for the National Board, MCAT and other exams that can help you advance to the next level of a medical career. Once you’ve finished your master’s degree, you will have earned a respected graduate-level credential that can position you for more advanced roles within the medical profession. 

If you’ve completed either our Graduate Certificate in Medical Physiology or Graduate Certificate in Medical Physiology with a specialization in Cardiovascular/Renal Physiology (see more details below), you’ve already completed half of your master’s degree. Our 30-credit master’s degree program allows you to transfer up to 15 credits from your graduate certificate program. And that’s just one of the many benefits of UF’s master’s degree in medical physiology and pharmacology. You can also: 

  • Graduate in as little as one year. 
  • Study on your own schedule. 
  • Gain the clinical knowledge you’ll need to thrive in medical school. 
  • Skip the GRE. 
  • Take advantage of multiple financial aid options, should you need them. 
  • Earn a career-transforming education credential. 

Graduate Certificate in Medical Physiology 

One of our two career-boosting graduate certificate options, the Graduate Certificate in Medical Physiology explores the essentials of medical physiology and examines the individual human body systems. This is a 9- to 14-credit program that enables you to take up to six courses. However, you only need to complete 9 credits to earn your certificate, which means you can finish in as little as one semester. 

Graduate Certificate in Medical Physiology with a specialization in Cardiovascular/Renal Physiology 

The second of our medical physiology graduate certificates is the 12-credit Graduate Certificate in Medical Physiology with a specialization in Cardiovascular/Renal Physiology. This program provides advanced instruction in cardiovascular and renal physiology and pathophysiology research that can prove invaluable in a clinical setting. 

Discover how the body works and reacts to various treatments in an entirely online University of Florida medical physiology program. 

 

Sources: 

https://www.biospace.com/article/a-timeline-of-covid-19-vaccine-development/
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/how-they-work.html#:~:text=Once%20vaccinated%2C%20our%20bodies%20recognize,one%20that%20causes%20COVID%2D19
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/expect/after.html
https://www.doh.wa.gov/Emergencies/COVID19/VaccineInformation/HowVaccinesWork 
https://annalsofintensivecare.springeropen.com/articles/10.1186/s13613-019-0552-5