To control the COVID-19 coronavirus pandemic, society needs public health measures (e.g., masks, physical distancing, hand washing), treatments for infection, and vaccines to prevent infection or serious disease. In 2020, several manufacturers developed COVID-19 vaccines in less than a year. Before that, the fastest a vaccine had been developed was in four years.

As the most trusted profession, nurses have a responsibility to educate patients and the community about the facts and science behind the vaccines. This reference sheet will help guide those conversations and will be updated as new information is released.

What We Know 

Both the U.S. government and private industries have been working to develop COVID-19 vaccines. The government-supported program is known as Operation Warp Speed. U.S. Congress directed almost $10 billion to the effort in 2020 through supplemental funding, including the CARES Act. 

As of December 2020, several manufacturers’ vaccines have either emergency use authorization (EUA) or are in clinical trials. Pfizer’s vaccine received U.S. Food and Drug Administration (FDA) an EUA on December 11, 2020. 

Manufacturers are working on three main types of COVID-19 vaccines: 

  • mRNA vaccines contain material from the virus and instruct cells to make a harmless protein that is unique to the virus then destroy the vaccine’s genetic material. The body’s immune system recognizes the protein as foreign and produces T and B lymphocytes against COVID-19. 

  • Protein subunit vaccines include pieces of the virus, which the immune system recognizes as foreign and produces T lymphocytes and antibodies.  

  • Vector vaccines contain a weakened version of a different live virus that has genetic material from COVID-19 inserted into it. This is called a viral vector, and it instructs cells to make a protein that is unique to COVID-19, prompting production of T and B lymphocytes. 

Pfizer and Moderna-BioNTech’s mRNA vaccines were the first ones FDA reviewed for EUA in December 2020. Although mRNA vaccines are new for human vaccination, the National Institutes of Health began investing in that type of vaccine in the 1990s. mRNA vaccines do not use a live virus, nor do they enter the cell nucleus or change cellular DNA.  

More than 74,000 people enrolled in the Moderna and Pfizer COVID-19 vaccine clinical trials. Eight participants in the Pfizer trial's vaccine arm developed COVID-19 compared to 162 in the placebo arm, which is an overall effectiveness of 95%. Moderna's trial saw 11 cases of COVID-19 in the vaccine arm compared to 185 in the placebo arm for an effectiveness of 94%.

The vaccines require two doses by intramuscular injection: an initial dose followed by a second dose three to four weeks later. The most common side effects observed during the trials were sore arm at the injection site and mild flu-like symptoms, including fatigue. 

What We Don’t Know 

What are the vaccine’s short- and long-term side effects? Because of the small number of people studied in vaccine trials, healthcare providers should monitor people who have received the COVID-19 vaccine and report observations through the following methods: 

  • V-safe is the Centers for Disease Control and Prevention’s (CDC’s) smartphone app that sends text messages to vaccine recipients to assess for side effects.  

  • VAERS (Vaccine Adverse Event Reporting System) was created by the Health and Human Services, CDC, and FDA. Providers can use it to report side effects directly, and V-safe will activated it if a patient reports a side effect in the text message responses. 

How do we know if we develop enough antibodies after vaccination? The clinical trials for five vaccines have entered phase III and will follow all participants for two years. They will report more information about antibody response as well as length of effectiveness over time.  

How do data from COVID-19 vaccine trials translate to the pediatric population as well as people who are pregnant or lactating? The EUA for the Pfizer vaccine applied to use in people aged 16 and over. It did not make recommendations for people who are pregnant or lactating, leaving that decision to patients and their healthcare providers. Clinical trials excluded children younger than 16 as well as people who are pregnant or lactating. The vaccine response in those populations is being studied in ongoing and new clinical trials.  

Is it possible to get reinfected with COVID-19 after vaccination? Clinical trials are ongoing but have not yet identified how long immunity will last. 

What type of vaccine is safest and most effective? More information about the safety and efficacy of the other types of vaccines will be available as the clinical trials data are reported.