COVID-19 has set off many unprecedented events that will most likely change the world forever. Fortunately, they haven’t all been bad: the virus led to the remarkable development of vaccines at a pace and scale the likes of which have never before been seen in history. Both the Pfizer-BioNTech vaccine and the Moderna vaccine use a relatively new technology that has been approved for the first time: mRNA vaccines. (The Oxford vaccine instead uses genetic material from what’s known as an adenovirus derived from chimpanzees.)
These incredible developments, naturally, have led many people to dust off those old biology textbooks and try to remember what they learned about mRNA back in Biology 101. What do all those letters in mRNA stand for? How is it different from RNA? For that matter, what even is RNA? Does it have anything to do with DNA? In this article, we will answer all of these questions.
But first, we should quickly answer the most pressing question you might have: is it safe to take the COVID-19 vaccines or any mRNA vaccine? The answer is “Yes.” The new COVID-19 vaccines have gone through the same rigorous testing process as every other vaccine, as will any new mRNA vaccines developed in the future. If you’d like to know more about how the COVID-19 vaccines were tested for safety and approved, you can read about them in more detail as provided by the CDC and the WHO.
What is DNA?
To begin with, we must start with probably the best known of the three macromolecules (“big molecules”) we will be looking at today: DNA.
DNA stands for “deoxyribonucleic acid.” DNA is a large, complex molecule that carries and passes down the genetic code that makes up all living organisms. Because most people are at least somewhat aware of DNA’s very important role in life, DNA has come to metaphorically refer to “the set of nongenetic traits, qualities, or features that characterize a person or thing.” For example, we would say a love of words is part of the DNA of Dictionary.com.
DNA is found in the nucleus of cells of all living organisms. DNA is arranged in the shape of a double helix, which resembles a twisted ladder. The “rungs” of the ladder consist of base pairs of substances known as nitrogen bases. You might remember the four bases from science class: adenine, thymine, guanine, and cytosine. These base pairs are the reason why DNA is so important to life: the ordering of the base pairs results in a specific genetic code called a gene.
DNA consists of many genes and is itself organized into structures known as chromosomes, of which humans have 23 pairs. A fruit fly has four pairs of chromosomes, while a dog has 39 pairs. The genetic code in the genes and DNA tell the body how to make proteins. Proteins are extremely important for the survival of the body and you would be in big trouble if your cells couldn’t make proteins or accidentally made the wrong proteins.
We have merely scratched the surface of the complicated molecule that is DNA. To get a better idea of how important DNA is, here are some vocabulary words that explore concepts that are related to DNA:
RNA (we’ll be getting to this one shortly)
nucleic acid
nucleotides
nitrogen base
genes
genetics
protein
What is RNA?
RNA stands for “ribonucleic acid.” RNA is a large molecule made from a single strand of DNA, and one of its main roles is to transfer the instructions needed to make proteins.
While DNA has the instructions on how to make proteins, it is RNA that actually provides these instructions to the ribosomes, organelles in the cell that act as “protein factories” You see, DNA never actually leaves the cell’s nucleus. The nucleus instead builds a single-threaded molecule called RNA, which has a copy of the DNA’s instructions.
Like DNA, RNA also has nitrogen bases that act as a code that the cell can read. The RNA then takes the copy of the instructions and delivers them to the ribosomes. There, RNA helps the ribosomes properly build the correct proteins that the body needs.
As you might guess, this is a simplified version of what actually happens in the cells. To get a better idea of what is actually going on with RNA, here are some vocabulary words that provide more details on the concepts surrounding RNA:
DNA
transcription
ribosome
protein
amino acid
protein synthesis
mRNA (we’ll be getting to this one)
tRNA
rRNA
DNA vs. RNA.
DNA and RNA are very similar. After all, RNA is supposed to be a copy of DNA. However, there are a few differences between the two molecules.
The biggest difference is in their shape: DNA is a two-stranded molecule in the form of a double helix. RNA, on the other hand, is a single-stranded molecule.The other major difference is in the nitrogen bases: RNA shares three of DNA’s bases but has a substance known as uracil that replaces thymine when the DNA is copied. To put it very simply, uracil requires less energy to maintain than thymine, but the presence of thymine makes DNA more stable.
What is mRNA?
There are several different types of RNA. One type of RNA is known as mRNA, which stands for “messenger RNA.” mRNA is RNA that is read by ribosomes to build proteins.
While all types of RNA are involved in building proteins, mRNA is the one that actually acts as the messenger. It is mRNA specifically that has the recipe for a protein. The mRNA is made in the nucleus and sent to the ribosome, like all RNA. Once it gets there, the mRNA bonds with the ribosome, which reads the mRNA’s nitrogen base sequence. Every three-bond sequence of mRNA relates to a specific amino acid, a “building block” of a protein. Amino acids must be arranged in a certain order to make a specific protein, and the mRNA has the blueprints that tell the ribosome which amino acids to get and how they should be arranged.
Other types of RNA, such as transfer RNA (tRNA) and ribosomal RNA (rRNA), help the ribosome actually build the protein. Once the protein is built, the mRNA’s job is over and it will degrade.
Again, this is a general look at what mRNA actually does. This list of vocabulary terms can help you learn more about mRNA’s job and about the other types of RNA.
RNA
tRNA
rRNA
DNA
transcription
ribosome
protein
amino acid
protein synthesis
How is mRNA used in COVID-19 vaccines?
Everything that has been said here doesn’t just apply to humans. Other organisms, including bacteria and viruses, also have DNA and/or RNA. The recent COVID-19 vaccines actually use mRNA from the virus itself in a rather sneaky way.
Usually, a vaccine uses a weakened or damaged version of a virus so that your body can have a “practice run” of fighting it. Your body will make antibodies that fight this weak form of the virus and thus will be able to recognize this same virus in the future and be able to quickly react to the real virus if ever exposed to it.
An mRNA vaccine works differently. Rather than inject a person with the actual virus, this type of vaccine instead injects the cells with some of the virus’s mRNA. This mRNA contains instructions on how to build “spike protein,” meaning the protein that is found on the spiky surface of a virus. This protein is harmless and has no ill effects on the body.
So, your cells will begin making this harmless spike protein. Your immune system will then recognize that this spike protein doesn’t belong in your body and make antibodies designed to destroy it. Making a long story short, this means your body will be able to recognize the spike proteins used by the actual virus. As a result, your immune system will immediately be able to make antibodies that swarm and kill the virus if it ever detects the spike protein in the body.
Luckily, you don’t have to become an expert in macromolecules for your body to function—or the vaccine to do its job. Your body automatically performs the complex functions described here to keep you alive. (Perhaps mastering some of the key terms associated with them is the least you could do!)
1. Arm yourself with more details about the Oxford vaccine known as ChAdOx1 nCoV-19.
WHAT IS CHADOX1 NCOV-19?
ChAdOx1 nCoV-19 is a potential vaccine for the coronavirus. Early results from trials show that the vaccine is safe and produces an immune response against the virus that causes COVID-19.
Another name for ChAdOx1 nCoV-19 is AZD1222, used especially in the context of the vaccine’s co-development by the University of Oxford, Vaccitech, and AstraZeneca. ChAdOx1 nCoV-19 is especially used in the context of Oxford’s leading role in first developing the vaccine.
WHAT DOES CHADOX1 NCOV-19 MEAN?
Scientists abbreviate the names of vaccines, which can be long, complex, and technical. Even their abbreviations, however, can be confusing or intimidating to laypeople.
ChAdOx1 nCoV-19 is no exception—which, we’ll admit, looks like a computer-generated password or a cyberpunk or gamer screen name if we didn’t know any better.
✅ ChAdOx1 nCoV-19 is a chimpanzee (Ch) adenovirus-vectored vaccine (Ad), whose development was led by the University of Oxford (Ox). It has been shown to stimulate an immune response to nCoV-19, the novel coronavirus first identified in 2019.
Now, let’s unpack the phrase chimpanzee adenovirus-vectored vaccine.
vaccine: a substance introduced into someone’s body to prevent them from getting a specific disease. It usually consists of a small amount of a killed, weakened, or otherwise modified version of a disease (such as a virus or bacterium).
vector: the agent that acts as carrier or transporter of the virus, which is injected into a patient to trigger a response from their immune system to fight off disease pathogens.
adenovirus: a type of that can cause respiratory and other illnesses in humans and other primates, including chimpanzees, from which ChAdOx1 nCoV-19 was specifically derived and is being used as the vaccine vector against COVID-19.
In conjunction with the spin-off biotechnology company Vaccitech, Oxford has developed more than one adenovirus-vectored vaccine, which it refers to as ChAdOx1 and ChAdOx2, hence the numeral 1 in ChAdOx1 nCoV-19.
You may recall that COVID-19 is the name of the disease caused by one type of coronavirus, which was newly detected (novel) in 2019. The name of the specific coronavirus that causes COVID-19 is severe acute respiratory syndrome coronavirus 2, abbreviated as SARS-CoV-2.
EXAMPLES OF CHADOX1 NCOV-19:-
Still more research is ongoing, but it's looking like Oxford Uni's ChAdOx1 nCoV-19 vaccine could be the real deal (should also avoid some of the Big Pharma issues). @GossiTheDog, July 20, 2020.
The AZD1222 vaccine has been adapted from a common cold virus found in chimpanzees, with spike glycoprotein, a genetic material from the new coronavirus, added to it. Al Jazeera, July 21, 2020.
A UK Phase I/II trial began in April testing the Oxford coronavirus vaccine ChAdOx1 nCoV-19. The team started working to develop a vaccine against the global threat that is coronavirus in January 2020 and have been working with unprecedented urgency in a race against the coronavirus. Oxford Vaccine Group, July 20, 2020.
MORE INFORMATION ABOUT CHADOX1 NCOV-19
Vaccines generally take a long time to develop, as scientists need to ensure they are safe (don’t make patients sick) and efficacious (produce the desired immune response). To this end, scientists carry out a three-phase trial to test the vaccine, as the CDC explains:
During Phase I, small groups of people receive the trial vaccine. In Phase II, the clinical study is expanded and vaccine is given to people who have characteristics (such as age and physical health) similar to those for whom the new vaccine is intended. In Phase III, the vaccine is given to thousands of people and tested for efficacy and safety.
ChAdOx1 nCoV-19 is moving into Phase 2 and Phase 3 trials. Oxford University is partnering with the UK-based, international biopharmaceutical company AstraZeneca to scale up testing and manufacturing of the potential COVID-19 around the globe. Populations at high-risk of illness or death from COVID-19, such as people over the age of 65 and hospital workers, will be prioritized for the next trials.
So far, there have been well over 100 vaccine candidates for COVID-19, but none have been approved for prevention. As published online in the medical journal The Lancet on July 20, 2020, the initial results ChAdOx1 nCoV-19 are encouraging, positive news, but much more research is needed to determine how long the vaccine’s immune response lasts, how the vaccine affects vulnerable populations, and whether the vaccine can reduce and prevent infection.
In popular culture, some people have been making jokes about ChAdOx1 nCoV-19 resembles Chad, a slang term for a stereotypically masculine, sexually promiscuous young man.
NOTE. This is not meant to be a formal definition of ChAdOx1 nCoV-19 like most terms we define on Dictionary.com, but is rather an informal word summary that hopefully touches upon the key aspects of the meaning and usage of ChAdOx1 nCoV-19 that will help our users expand their word mastery.
2.DNA.
Genetics. deoxyribonucleic acid: an extremely long macromolecule that is the main component of chromosomes and is the material that transfers genetic characteristics in all life forms, constructed of two nucleotide strands coiled around each other in a ladderlike arrangement with the sidepieces composed of alternating phosphate and deoxyribose units and the rungs composed of the purine and pyrimidine bases adenine, guanine, cytosine, and thymine: the genetic information of DNA is encoded in the sequence of the bases and is transcribed as the strands unwind and replicate.
The set of nongenetic traits, qualities, or features that characterize a person or thing: Humility is just not in her DNA.
3. RNA.
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