Preventing Vaccination Administration Errors

A partner post from the Colorado Department of Public Health and Environment

Immunization is one of public health’s greatest achievements. The success of any vaccination program (including the COVID-19 vaccination program) depends not just on the number of vaccines that are administered, but how they are stored, prescribed, and handled. Providers and staff administering vaccines should be prepared to manage vaccines according to CDC best practices, and take steps to mitigate the risk for vaccine-related errors.

In an effort to ensure that each vaccine dose is successfully administered, providers and staff should be vigilant to prevent the risk for vaccination errors that can lead to inadequate immunity, increased cost, and reduced confidence in the healthcare delivery system.

The best ways to prevent COVID-19 vaccination errors are:

  • Use the correct site. Always administer the vaccine into the deltoid muscle. Train staff to identify the correct position on the arm by using appropriate landmarks to identify the center of the deltoid muscle to administer the vaccine. An acceptable alternate location is the anterolateral thigh muscle. Also, make sure staff are using the proper technique for giving intramuscular (IM) injections.
  • Use the correct vaccine/interval. Check the Colorado Immunization Information System (CIIS) and available resources before administering vaccines to verify if the patient is due for vaccine and which vaccine should be administered. Make sure that the correct intervals between the doses of either the Pfizer vaccine (21 days) or Moderna vaccine (28 days) are observed. An additional primary dose of an mRNA vaccine for individuals with altered immunocompetence should be administered 28 days after the completion of the primary 2-dose series. Third doses are administered five (5) months from the last dose of mRNA (Pfizer or Moderna) vaccine, or two months after the primary dose of Johnson & Johnson vaccine.
  • Use the correct diluent. The Pfizer vaccine requires being mixed with the sterile 0.9% sodium chloride (normal saline, preservative free) only. Bacteriostatic normal saline or any other diluent should not be used. The sterile 0.9% sodium chloride for injection comes in 10 ml single use vials. After use, discard diluent vial and any remaining diluent.
  • Use the correct diluent volume. The orange cap Pfizer vials require 1.3 ml of diluent for dilution. The Pfizer gray cap does not require dilution. It is crucial to use the correct amount of diluent for the correct vaccine, to ensure proper dosage for a patient’s age. All efforts should be made to ensure that staff are properly trained to reconstitute and properly draw up vaccine.
  • Use the correct dose. Vaccinators should confirm a patient’s date of birth to ensure they receive the correct vaccine and age appropriate dose.
  • Properly store vaccines.
    • Store vaccines with adequate space between them in the storage unit to prevent vaccine mix-ups.
    • Store vaccines away from other refrigerated medications to prevent medications being administered in place of the vaccine.
    • Once a vaccine has been thawed, it cannot be refrozen.
    • Review vaccine beyond use and expiration date to ensure the vaccine is still good to use prior to drawing up the vaccine to administer.
  • Ensure vaccine competency. Make sure staff are trained prior to preparing and administering vaccines. They should know how to screen individuals, understand storage and handling, preparation and administration of vaccines, as well as how to identify the appropriate site to administer the vaccine. Additionally, everyone should know how to identify and treat anaphylaxis should it occur. Vaccinators should have the up-to-date fact sheets to refer to as needed during the day. Staff should also be comfortable with recommending when the next dose is due for scheduling. Also, staff should know when and how to report errors to VAERS and ISMP VERP.
  • Document the administration properly. All doses of COVID-19 vaccine administered must be reported to CIIS, either through an interface between CIIS and your Electronic Health Record, or manual data entry into the system. Vaccine documentation requires: lot number, manufacturer, date of vaccination, site of vaccination (LD, RD, etc), signature and title of the vaccinator, and address of the clinic where the vaccine was administered. Because Pfizer and Moderna vaccines require a second dose, (and they are not interchangeable) reporting the initial doses is very important, so that the next time the patient seeks a vaccination, vaccine type and dates can be verified for the proper interval.

If you have questions or need additional resources related to vaccine administration errors please email