A coronavirus disease 2019 (COVID-19) vaccine can help you develop immunity to SARS-CoV-2, the virus that causes COVID-19, without getting ill. While each type of vaccine works in a different way, all COVID-19 vaccines prompt an immune response so that your body remembers how to fight the virus in the future.
The safety of the COVID-19 vaccines is being closely monitored by the U.S. Centers for Disease Control and Prevention and the U.S. Food and Drug Administration (FDA). Even after a vaccine is authorized for use, vaccine safety monitoring systems continue to watch for side effects.
Here's what you need to know about the different COVID-19 vaccines:
What vaccines are available?
Pfizer-BioNTech vaccine
- mRNA vaccine
- 95% effective at preventing the COVID-19 virus with symptoms
- FDA emergency use authorization
- Greater than 89% effective in preventing people with health conditions, such as diabetes or obesity, from developing the COVID-19 virus with symptoms
- Doesn't contain eggs, latex or preservatives
Moderna vaccine
- mRNA vaccine
- 94% effective at preventing the COVID-19 virus with symptoms
- FDA emergency use authorization
- Greater than 90% effective in preventing people with health conditions, such as diabetes or obesity, from developing the COVID-19 virus with symptoms
- Doesn't contain eggs, latex or preservatives
Janssen/Johnson & Johnson
- Vector vaccine
- 66% effective at preventing the COVID-19 virus with symptoms
- 85% effective at preventing the COVID-19 virus with severe illness
- FDA emergency use authorization
- Doesn't contain eggs, latex or preservatives
How many doses are needed, and when does protection start?
Pfizer-BioNTech vaccine
- Two doses are needed, 21 days apart (or up to six weeks apart, if needed)
- Some protection provided after the first dose
Moderna vaccine
- Two doses are needed, 28 days apart (or up to six weeks apart, if needed)
- Some protection provided after the first dose
Janssen/Johnson & Johnson
- One dose is needed
- Some protection provided two weeks after vaccination
Who should or shouldn't get the vaccine?
Pfizer-BioNTech vaccine
People age 16 and older should get the vaccine
Moderna vaccine
People age 18 and older should get the vaccine
Pfizer-BioNTech and Moderna:
- People who've had an immediate or severe allergic reaction to any of the vaccine's ingredients or after a prior dose of the vaccine shouldn't get the vaccine
- People who've had an immediate allergic reaction to any vaccine or injectable medication should be cautious about getting the vaccine
Janssen/Johnson & Johnson
- People age 18 and older should get the vaccine
- People who've had a severe allergic reaction to any of the vaccine's ingredients and people who are allergic to polysorbate shouldn’t get the vaccine
What are the vaccine's possible side effects?
Pfizer-BioNTech vaccine
Injection site pain, fatigue, headache, muscle pain, chills, joint pain, fever, nausea, feeling unwell and swollen lymph nodes
Moderna vaccine
Injection site pain, fatigue, headache, muscle pain, chills, joint pain, swollen lymph nodes in the arm that was injected, nausea, vomiting and fever
Janssen/Johnson & Johnson
Injection site pain, headache, fatigue, muscle pain, chills, fever and nausea
https://www.mayoclinic.org/coronavirus-covid-19/vaccine/comparing-vaccines
Different types of COVID-19 vaccines: How they work
Curious about how mRNA vaccines and other types of COVID-19 vaccines can help you develop immunity to the COVID-19 virus? Understand how different technologies work with the immune system to provide protection.
By Mayo Clinic StaffA coronavirus disease 2019 (COVID-19) vaccine can help you develop immunity to SARS-CoV-2, the virus that causes COVID-19, without getting ill. But how exactly do the different types of COVID-19 vaccines work?
Vaccines prompt an immune response so that your body remembers how to fight a virus in the future. Some vaccines use a whole virus to cause your immune system to respond. Other vaccines use parts of the virus or genetic material that provides instructions for making specific proteins like those in the virus.
Many COVID-19 vaccines involve a spikelike structure on the surface of the COVID-19 virus called an S protein. The S protein helps the virus get inside your cells and start an infection.
Manufacturers around the world are working on different types of vaccines. The main types of COVID-19 vaccines currently available in the U.S. or in large-scale clinical trials include:
Messenger RNA (mRNA) vaccine. This type of vaccine uses genetically engineered mRNA to give your cells instructions for how to make a harmless piece of the S protein found on the surface of the COVID-19 virus. After vaccination, your immune cells begin making the S protein pieces and displaying them on cell surfaces. This causes your body to create antibodies. If you become infected with the COVID-19 virus, these antibodies will fight the virus.
After the mRNA helps your cells make the protein pieces, the mRNA is immediately broken down. It never enters the nucleus of your cells, where your DNA is kept. Both the Pfizer-BioNTech and the Moderna COVID-19 vaccines use mRNA.
Vector vaccine. In this type of vaccine, genetic material from the COVID-19 virus is inserted into a different kind of weakened live virus, such as an adenovirus. The weakened virus (viral vector) serves as a delivery system. When the viral vector gets into your cells, it delivers genetic material from the COVID-19 virus that gives your cells instructions to make copies of the S protein. Once your cells display the S proteins on their surfaces, your immune system responds by creating antibodies and defensive white blood cells. If you become infected with the COVID-19 virus, the antibodies will fight the virus.
Viral vector vaccines can't cause you to become infected with the COVID-19 virus or the viral vector virus. Also, the genetic material that's delivered doesn't become part of your DNA. The Janssen/Johnson & Johnson COVID-19 vaccine is a vector vaccine. AstraZeneca and the University of Oxford are also working on a vector COVID-19 vaccine.
Protein subunit vaccine. Subunit vaccines include only the parts of a virus that best stimulate your immune system. This type of COVID-19 vaccine contains harmless S proteins. Once your immune system recognizes the S proteins, it creates antibodies and defensive white blood cells. If you become infected with the COVID-19 virus, the antibodies will fight the virus.
Novavax is working on a protein subunit COVID-19 vaccine.
In the U.S., the U.S. Food and Drug Administration has given emergency use authorization to the Pfizer-BioNtech, Moderna and Jansssen/Johnson & Johnson COVID-19 vaccines. More types of vaccines are expected to be authorized for use in the coming months.
A COVID-19 vaccine might prevent you from getting COVID-19 or from becoming seriously ill or dying due to COVID-19. Consult your local health department for the latest information on how and when you can receive a vaccine.
https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/different-types-of-covid-19-vaccines/art-20506465
