The term for receiving the full dosages of vaccines that scientists have determined is the amount needed to build the body’s immunity against SARS-CoV-2, the pathogen known to cause COVID-19.
Deeper dive
As the SARS-CoV-2 virus as mutated, the Centers for Disease Control and Prevention has modified its recommendations for vaccination necessary to develop immune protection from the virus. As of July 2022, the agency recommends Americans 6 months and older should be ‘up-to-date’ with their vaccines, meaning they should receive the amount of vaccine, based on the latest data, that is necessary to induce immune protection.
When vaccines were initially introduced at the end of 2020, the CDC counted someone fully vaccinated two weeks after the day individuals received a second dose of their Moderna or Pfizer vaccine or a dose of Johnson & Johnson vaccine. As of July 2022, the CDC defines ‘up-to-date’ as 2 doses of Moderna or 3 doses of Pfizer for children 6 months to 4 years old. For those five and older, a booster dose of vaccine is recommended. If immunocompromised, potentially a 4th dose of the vaccine is recommended.
The definition ‘fully’ causes confusion because the CDC still says an individual who has had just 2 doses of Moderna or Pfizer vaccine and 1 dose of Johnson & Johnson is “fully vaccinated.” Vaccines also never work 100% of the time. A vaccine’s effectiveness depends on a person’s immune system and whether a pathogen has evolved to escape defenses built by the vaccine.