COVID-19 Vaccine: Vaccine Types, How They Work, and More

• Vaccines mimic the viruses they target to aid a patient’s body in building immunity against that particular virus. For example, the flu vaccine targets the influenza virus.

• The Centers for Disease Control and Prevention (CDC) has provided the United States with recommendations on how the COVID-19 vaccines should be made available to the public during the course of the COVID-19 pandemic, usually by age group.

• There are many benefits to receiving the COVID-19 vaccine such as personal health and the protection of those around you because the vaccines have been proven to lower the chances of preventing severe illness as a result of a COVID-19 infection.

• As of 2022, there are now four authorized vaccines available including vaccine booster doses. 

• The CDC recommends anyone six months and older get vaccinated against COVID-19. Those who should not get a COVID-19 vaccine includes people who have experienced severe allergic reactions to any mRNA vaccine.

After the World Health Organization declared the COVID-19 outbreak an official pandemic in 2020, the race to produce a safe and effective vaccine was on. While vaccines normally take a minimum of six years to be developed, studied, and manufactured, the Moderna and Pfizer coronavirus vaccines were readily produced within a year. Due to modern technological advances and past studies linked to gaining immunity over COVID-19, the vaccines were able to be produced at rapid speeds. 

In 2021, the Johnson & Johnson (J&J) vaccine was then given emergency use authorization. Now, in 2022, COVID-19 bivalent vaccine boosters from both Pfizer and Moderna have now become available in order to combat the various strains that have mutated from the original virus strain. Additionally, the Novavax vaccine for COVID-19 is now available under FDA approval using an emergency use authorization as well.

This article will explain everything there is to know about COVID-19 vaccinations including vaccine types, current CDC recommendations, and more. 

There are currently several vaccines available. These include mRNA vaccines from Pfizer and Moderna as well as a vaccine from Johnson & Johnson. As well, there are now booster shots available from both Moderna and Pfizer. A new Novavax vaccine is available as well, making it the fourth vaccine to be authorized for use in the U.S.

Learn more about each type below.

Primary Pfizer-BioNTech Vaccine

During clinical trials, the Pfizer vaccine was proven 95% effective against COVID-19. It’s an intramuscular vaccine given in a patient’s upper arm and patients receive the vaccine in two doses. After the first vaccine dose, the patient should get their second vaccine 21 days later. After the initial two doses, patients may have received an initial (monovalent) booster dose two months after completing their primary series of vaccinations.

Note: Patients must receive the same vaccine (i.e either Pfizer or Moderna) for their initial booster dose. Learn more about vaccine booster doses at this resource.

Ingredients:

Due to the vaccine being stored at extremely cold temperatures, preservatives are not necessary. Eggs and latex are also not ingredients in the Pfizer COVID-19 vaccine. 

• Messenger Ribonucleic Acid (mRNA): this acts as the human body’s blueprint in generating the coronavirus antigens that then trigger the immune system to respond and fight back.

• Lipid Nanoparticle Technology:

  • (4‑hydroxybutyl)azanediyl)bis(hexane‑6,1‑diyl)bis(2‑hexyldecanoate): a phospholipid that mimics native phospholipids in the body to help with drug delivery.

  • 2 [(polyethylene glycol)-2000]-N,N‑ditetradecylacetamide: a phospholipid linked to polyethylene glycol which aids constipation.

  • 1,2‑Distearoyl-sn-glycero-3- phosphocholine: another phospholipid that mimics native phospholipids in the body that compose the cell wall. 

  • Cholesterol: depending on the temperature, this lipid aids in the fluidity or rigidity of the membrane.

• Potassium Chloride: simple salt of potassium and chloride which helps to stabilize the nanoparticle (found naturally in the body).

• Monobasic Potassium Phosphate: potassium salt of dihydrogen phosphate which helps to buffer swings in pH levels (found naturally in the body).

• Sodium Chloride: laboratory-grade table salt to stabilize the nanoparticle.

• Dibasic Sodium Phosphate Dihydrate: sodium salt of dihydrogen phosphate which helps to buffer swings in pH levels.

• Sucrose: laboratory-grade table sugar which helps to stabilize nanoparticles during transport.

Note: To learn more about the ingredients and how they function within the Pfizer COVID-19 vaccine, visit this source.

Who Shouldn’t Get the Pfizer Vaccine:

The Pfizer COVID-19 vaccine cannot be given to those under 6 months of age. Furthermore, anyone who has experienced a mild, severe, or immediate reaction to any mRNA vaccine (including the first dose of Pfizer’s COVID-19 vaccine), polyethylene glycol (PEG), and/​or polysorbate, should not get the Pfizer COVID-19 vaccine.

Note: An immediate reaction means experiencing hives, swelling, or wheezing within four hours of receiving an mRNA vaccine.

Common Side Effects:

During clinical trials, most people got mild to moderate side effects while a few had severe side effects. These side effects are prone to start within one to two days after getting vaccinated and should only last a few days at maximum. The side effects related to the Pfizer COVID-19 vaccine include:

• In Arm:

  • Minor swelling

  • Pain

  • Irritation/​redness

• Throughout Body (common after the second dose):

  • Chills

  • Mild fever

  • Tiredness

  • Headache

Note: If severe side effects occur or moderate side effects persist for longer than a few days, be sure to contact your doctor.

Primary Moderna Vaccine

During clinical trial testing, the Moderna vaccine was proven 94.1% effective against the coronavirus. The vaccine is an intramuscular shot given in the patient’s upper arm and patients receive the vaccine in two doses that are given 28 days apart.

Ingredients:

No eggs, preservatives, or latex are included in the Moderna COVID-19 vaccine. 

• Messenger Ribonucleic Acid (mRNA): The only active ingredient in the vaccine, mRNA contains genetic materials that helps trigger the immune system to produce the antibodies that protect a patient if exposed to COVID-19 in the future.

• Lipids: Helps to coat the mRNA in a slippery exterior so it can better slide inside the body’s cells.

  • SM-102

  • Polyethylene glycol [PEG] 2000 dimyristoyl glycerol [DMG]

  • Cholesterol

  • 1,2‑distearoyl-sn-glycero-3-phosphocholine [DSPC]

• Tromethamine: an acid stabilizer to maintain the vaccine’s stability after it’s manufactured.

• Tromethamine Hydrochloride: an acid stabilizer to maintain the vaccine’s stability after it’s manufactured.

• Acetic Acid: an acid that helps to keep the vaccine stable after it’s manufactured.

• Sodium Acetate: salt that helps to maintain the vaccine’s stability after it’s been produced.

• Sucrose: sugar that helps to maintain the vaccine’s stability after it’s been produced.

Note: To learn more about the ingredients and how they function within the Moderna COVID-19 vaccine, visit this source.

Who Shouldn’t Get the Moderna Vaccine:

The Moderna COVID-19 vaccine cannot be given to those under 6 months of age. Furthermore, anyone who has experienced a mild, severe, or immediate reaction to any mRNA vaccine (including the first dose of Moderna’s COVID-19 vaccine), polyethylene glycol (PEG), and/​or polysorbate, should not get the Moderna COVID-19 vaccine. 

Note: An immediate reaction means experiencing hives, swelling, or wheezing within four hours of receiving an mRNA vaccine.

Common Side Effects:

During clinical trials, most people got mild to moderate side effects while a few had severe side effects. These side effects are prone to start within one to two days after getting vaccinated and should only last a few days at maximum. The side effects related to Moderna’s COVID-19 vaccine include:

• In Arm:

  • Minor swelling

  • Pain

  • Irritation/​redness

• Throughout Body (common after the second dose):

  • Chills

  • Mild fever

  • Tiredness

  • Headache

Note: If severe side effects occur or moderate side effects persist for longer than a few days, be sure to contact your doctor.

Bivalent Booster Doses: Pfizer-BioNTech and Moderna 

Because the nature of the COVID-19 virus is constantly in flux, getting a bivalent booster can help with added protection against the virus. 

Bivalent boosters are called ​“bivalent” because they contain two components: a portion of the original COVID-19 strain as well as a part of the omicron variant. This gives better protection against COVID-19. 

The FDA authorized bivalent versions of the Moderna and Pfizer-BioNTech COVID-19 vaccines. These are given as a single dose. 

Note: Learn more about bivalent boosters at this resource including information on the age groups approved for booster shots.

Johnson & Johnson Vaccine 

The Johnson & Johnson COVID-19 vaccine is known as a viral vector vaccine. This means that a harmless, modified version of a different virus (aka a vector virus) that delivers instructions to the body’s cells for how to fight the virus the causes COVID-19.

It is important to note that the CDC recommends that the J&J vaccine only be used in certain situations due to the possibility of adverse effects. In most cases, the CDC encourages Pfizer-BioNTech, Moderna, or Novavax vaccines over J&J. Learn more at this resource.

Ingredients:

No eggs, preservatives, or latex are included in the J&J COVID-19 vaccine. 

• Recombinant, replication-incompetent Ad26 vector: A harmless version of a virus unrelated to the COVID-19 virus. The ingredient responsible for the immune response that helps the body from falling ill with COVID-19 in the future.

• Sugars, salts, acid, and acid stabilizer: Used to keep the vaccine molecules stable during manufacturing, transportation, and storage. 

  • Polysorbate-80

  • 2‑hydroxypropyl-β-cyclodextrin

  • Trisodium citrate dihydrate

  • Sodium chloride (basic table salt)

  • Citric acid monohydrate (closely related to lemon juice)

  • Ethanol (a type of alco

Who Shouldn’t Get the J&J Vaccine:

Anyone who has experienced a mild, severe, or immediate reaction to COVID vaccine, polyethylene glycol (PEG), and/​or polysorbate, should not get the Johnson and Johnson version of the COVID-19 vaccine. 

Common Side Effects:

The side effects related to the J&J vaccine include:

• Headache

• Fever

• Fatigue

• Nausea

• Muscle aches

• Pain, redness, swelling, or irritation of the injection site

Note: If severe side effects occur or moderate side effects persist for longer than a few days, be sure to contact your doctor.

Novavax Vaccine

The Novavax vaccine is the most recent vaccine approved by the FDA. People 12 and older are able to receive the Novavax vaccine. A Novavax booster can be given six months after the first dose. Americans 12 through 17 who received the Novavax primary series must get a Pfizer-BioNTech bivalent booster. 

Ingredients:

No eggs, preservatives, or latex are included in the Novavax COVID-19 vaccine. 

• SARS-CoV‑2 recombinant spike protein: Responsible for triggering the body’s immune response to prevent illness from COVID-19 in the future. 

• Lipids: Assists the spike protein to enter the cells. 

  • Cholesterol

  • Phosphatidylcholine

• Adjuvant: Activates immune cells. 

  • Fraction‑A and Fraction‑C of Quillaja saponaria Molina extract

• Salts, sugar, and acid: Used to keep the vaccine molecules stable during manufacturing, transportation, and storage. 

  • Disodium hydrogen phosphate heptahydrate

  • Disodium hydrogen phosphate dihydrate

  • Polysorbate-80

  • Potassium chloride (common food salt)

  • Potassium dihydrogen phosphate (common food salt)

  • Sodium chloride (basic table salt)

  • Sodium dihydrogen phosphate monohydrate

  • Sodium hydroxide or hydrochloric acid

  • Water

Who Shouldn’t Get the Novavax Vaccine:

The Novavax vaccine is not recommended for anyone under the age of 12 years. As well, anyone who has experienced a mild, severe, or immediate reaction to the ingredients found in the COVID vaccine should not get the Novavax vaccination.

Common Side Effects:

Side effects related to the Novavax COVID-19 vaccine include: 

• Fatigue

• Malaise

• Muscle pain

• Headache

• Joint pain

• Nausea and vomiting

• Fever

• Chills

Note: If severe side effects occur or moderate side effects persist for longer than a few days, be sure to contact your doctor.

Both COVID-19 vaccines started distribution in December 2020, with the Centers for Disease Control and Prevention (CDC) recommending that the first round of doses go to healthcare personnel and long-term care facility residents. From there, they recommended that frontline essential workers such as firefighters, police officers, U.S. postal workers, etc. and those over 75 years of age should be vaccinated.

Today, vaccination eligibility has expanded greatly.

Many questions have been raised surrounding both vaccines’ safety with those 55+ years old and those with comorbid conditions. However, clinical trials proved that COVID-19 vaccine side effects were actually less common and severe within these populations. One study notes that the vaccine is ​“better tolerated in older adults than younger adults” and that its efficacy is similar across all age groups. 

Note: To read personal accounts from those 55 and older on receiving the COVID-19 vaccine, visit this source.

Getting vaccinated for COVID-19 incites three major benefits: protecting yourself from coronavirus, protecting those around you from coronavirus, and aiding the world in ending the coronavirus pandemic.

Protecting Yourself from COVID-19

Clinical trials have determined that COVID-19 vaccines are highly effective at preventing a patient from contracting the coronavirus. The Pfizer vaccine was proven to be 95% effective against the coronavirus during clinical trials while the Moderna vaccine was proven to be 94.1% effective against the coronavirus during clinical trials. Furthermore, past vaccine research shows that if a patient does get infected, being vaccinated helps to protect the patient from severe disease. 

Protecting Others from COVID-19

When a person is infected with the coronavirus, they’re considered very contagious. It’s possible for an infected person to spread the disease to their loved ones through respiratory droplets when they breathe, sneeze, cough, etc. In order for each individual to protect themselves and the ones they love from being infected, the CDC emphasizes getting vaccinated. While patients who have already contracted and healed from the coronavirus do have natural immunity, experts are unsure how long this immunity will last. Due to this uncertainty, the CDC is recommending that at the appropriate time, those who can, should be vaccinated.

Ending the Coronavirus Pandemic

The overall goal of the COVID-19 vaccine is to end the current global coronavirus pandemic. Over time, as more and more people are vaccinated, the hope is to grow herd immunity to the virus, and have society eventually get back to ​‘normal’.

How were the vaccines developed so quickly?

How were the vaccines developed so quickly?

The COVID-19 vaccines were developed so rapidly due to a variety of factors:

• Previous research demonstrated the role of the spike protein in coronavirus pathogenesis and displayed evidence that proved the importance of neutralizing that protein in order to reach immunity.

• Nucleic acid technology has rapidly evolved, allowing vaccines to be created and manufactured much quicker than in years prior.

• Development activities were able to be conducted in a parallel manner vice sequentially which hastened vaccine testing and manufacturing without putting participants at risk.

Does health insurance include COVID-19 vaccine coverage?

Currently, COVID-19 vaccines are provided free due to government funding. However, this is likely to change in the future. For example, Pfizer will begin to charge for its COVID-19 vaccines once funding from the government for the shots stops. Be sure to stay up-to-date with COVID-19 news to stay informed on potential vaccination costs.

What is considered full vaccination?

In order to be considered as fully vaccinated, one must have received the complete primary series of a vaccine and received the most recent booster vaccination recommended by the CDC.

When can someone receive their booster dose?

The CDC recommends for anyone ages six months or older. COVID-19 vaccine booster doses are recommended for those ages five years and older when eligible. Use the “Find Out When You Can Get Your Booster” tool on this page of CDC website to see when you’re eligble for your COVID-19 vaccine booster shot. Currently, all vaccine manufacturers have booster shots available.

Are COVID-19 vaccines safe?

Yes. In fact, hundreds of millions of Americans have received COVID-19 vaccines under the most intense safety monitoring in the United States.

Note: Learn more about the safety of vaccination for COVID-19 at this resource.

What are the current Centers for Disease Control and Prevention recommendations regarding COVID-19?

Visit the COVID-19 section of the CDC website to stay up-to-date on updated boosters, COVID-19 safety recommendations, and general news about COVID-19.