Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus.
Most people infected with the virus will experience mild to moderate respiratory illness and recover without requiring special treatment. However, some will become seriously ill and require medical attention. Older people and those with underlying medical conditions like cardiovascular disease, diabetes, chronic respiratory disease, or cancer are more likely to develop serious illness. Anyone can get sick with COVID-19 and become seriously ill or die at any age.
The best way to prevent and slow down transmission is to be well informed about the disease and how the virus spreads. Protect yourself and others from infection by staying at least 3 feet apart from others, wearing a properly fitted mask, and washing your hands or using an alcohol-based rub frequently. Get vaccinated when it’s your turn and follow local guidance.
The virus can spread from an infected person’s mouth or nose in small liquid particles when they cough, sneeze, speak, sing or breathe. These particles range from larger respiratory droplets to smaller aerosols. It is important to practice respiratory etiquette, for example by coughing into a flexed elbow, and to stay home and self-isolate until you recover if you feel unwell.
How well COVID-19 vaccines work
Vaccines reduce the risk of COVID-19, including the risk of severe illness, hospitalization, and death among people who are fully vaccinated.
Updated COVID-19 boosters can both help restore protection that has decreased since previous vaccination and provide broader protection against newer variants. The updated boosters target the most recent Omicron subvariants, BA.4 and BA.5, that are more contagious than earlier subvariants by providing more specific antibodies for protection.
CDC will continue to provide updates as we learn more.
Types of COVID-19 Vaccines Available
There are four approved or authorized vaccines in the United States used to prevent COVID-19. Pfizer-BioNTech and Moderna are COVID-19 mRNA vaccines. You can also get the Novavax COVID-19 protein subunit vaccine. Otherwise, you may get Johnson & Johnson’s Janssen (J&J/Janssen) COVID-19 viral vector vaccine in some situations.
These vaccines are given as a shot in the muscle of the upper arm or in the thigh. None of them affect or interact with our DNA in any way. COVID-19 vaccine ingredients are considered safe for most people. Nearly all of the ingredients in COVID-19 vaccines are ingredients found in many foods—fats, sugar, and salts. They all have:
No preservatives like thimerosal or mercury or any other preservatives.
No antibiotics like sulfonamide or any other antibiotics.
No medicines or therapeutics like ivermectin or any other medications.
No tissues like aborted fetal cells, gelatin, or any materials from any animal.
No food proteins like eggs or egg products, gluten, peanuts, tree nuts, nut products, or any nut byproducts (COVID-19 vaccines are not manufactured in facilities that produce food products).
No metals like iron, nickel, cobalt, titanium, rare earth alloys, or any manufactured products like microelectronics, electrodes, carbon nanotubes or other nanostructures, or nanowire semiconductors.
No latex. The vial stoppers used to hold the vaccine also do not contain latex.
After the body produces an immune response, it discards all of the vaccine ingredients, just as it would discard any substance that cells no longer need. This process is a part of normal body functioning.