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: 

• Soreness 
• Redness 
• Inflammation 
• Rash (aka “COVID 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://annalsofintensivecare.springeropen.com/articles/10.1186/s13613-019-0552-5  

Our organs keep us alive, individually and in combination with other organs. There are about 78 organs in the human body, and each performs one or more vital functions. But do we really need all of those, or are there organs we can live without? 

 As it turns out, we don’t exactly need all of our organs in order to survive. Let’s look at a few “unnecessary” organs, their purpose and why you can live without them. 

Appendix 

What It Does
The appendix is somewhat of a mystery organ, as doctors and scientists aren’t 100% sure of its purpose. One common theory is that this little appendage to the large intestine is where the body stores good bacteria. It may also assist our immune system.  

Why You May Have to Have It Out
When a person develops appendicitis, it means the appendix has become infected. In most cases, doctors will recommend surgical removal of the appendix, known as an appendectomy. 

Why You Can Live Without One
After an appendectomy, patients typically go on to live with no measurable change in their quality of life. 

Gallbladder  

What It Does
Located in the upper abdomen, the gallbladder acts as a storage bag for bile, which the liver creates to help us digest fatty foods. 

Why You May Have to Have It Out
The gallbladder can sometimes develop gallstones, a painful condition that’s usually treated by removal of the organ. 

Why You Can Live Without One
While many doctors recommend a low-fat diet for patients who’ve had their gallbladder removed, this typically only needs to be temporary. Most people experience no complications from life without a gallbladder. 

Kidney  

What It Does
The kidneys perform a variety of important functions, such as filtering waste and excess water out of our blood, producing hormones and regulating the balance of sodium and other chemicals in our bodies. 

Why You May Have to Have It Out
Conditions including cancer and injury may necessitate the removal of a kidney.

Why You Can Live Without One
As vital as kidneys are, most people have two of them and can continue to live a normal life if they have to give one up. In fact, some people have donated one of their kidneys to help a patient with unhealthy kidneys, and both parties have gone on to live healthy lives. 

Lung   

What It Does
Lungs take in oxygen, which moves into the bloodstream, and take carbon dioxide back out of the bloodstream. This waste gas is then expelled (exhaled) out of the body. In short, they’re what we breathe with. 

Why You May Have to Have It Out
Pneumonectomy, or removal of a lung, is performed when cancer or injury has damaged the lung beyond repair.  

Why You Can Live Without One
As with kidneys, we have two lungs, and can live without one of them when necessary. A person with one lung has to adjust their lifestyle somewhat, exerting themselves less due to their decreased intake of oxygen. 

Spleen  

What It Does
The spleen stores and filters blood, destroying damaged or old red blood cells but saving healthy elements for the body to use again.

Why You May Have to Have It Out
A swollen, ruptured or torn spleen will often be removed with a procedure called a splenectomy. 

Why You Can Live Without One
In the absence of a spleen, the lymph nodes and liver will typically adapt to undertake the spleen’s functions. 

 Tonsils  

What They Do
Part of the immune system, the tonsils fight viruses and bacteria that come into the body through the mouth. This can also make them more susceptible to becoming infected or swollen. 

Why You May Have to Have Them Out
When someone develops tonsillitis, it means their tonsils are inflamed. Unlike other conditions we’ve discussed, this is a contagious condition. A tonsillectomy, or removal of the tonsils — they come in and are removed in pairs — may be necessary when the inflamed tonsils can’t be treated any other way. 

Why You Can Live Without Them
Tonsils are less likely to be removed than they once were, with many doctors preferring alternate treatments. Some studies show an increased risk of respiratory disease in patients who’ve had them removed during childhood. But people do live without tonsils and many even experience some benefits in terms of sleep apnea reduction.  

Risks of Removal 

While people can live without the aforementioned organs and others, removal surgery, like any surgery, poses risks for complications and side effects. These can range from minor to severe and life threatening, depending on the organ and complication. Our original organs are best left alone, provided they’re healthy and functioning properly. However, when they’re not, it’s reassuring to know we may not need some of them. 

Online Programs Dedicated to Human Organ Systems 

The University of Florida’s renowned College of Medicine offers entirely online programs focused on human body systems and the organs that comprise them. All of these programs enable you to complete coursework anywhere, 24/7, at your own pace. Having a family or career doesn’t mean having to forego earning a career-boosting education credential! Our programs include:  

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

Prepare for medical school and related exams (National Board, MCAT) as you explore how drugs and other factors affect the body’s systems. If you’ve taken either of the certificate programs below, you’ve already met 15 credits of this program’s 30-credit requirement! No GRE is required for admission, and you may be able to graduate in as little as one year. 

Graduate Certificate in Medical Physiology  

Learn the essentials of medical physiology and the individual human body systems. You can finish this 9- to 14-credit program in as little as one semester. 

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

Gain an advanced understanding of cardiovascular and renal physiology and pathophysiology research that will benefit you in clinical settings. You may be able to complete this program in as little as two semesters. 

Master human physiology and pharmacology in an online degree or certificate program from the University of Florida. 

Sources:
https://www.livescience.com/how-many-organs-in-human-body.html