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Recommendations for Practitioners to Prevent Vaccine Errors Part 2: Analysis of ISMP Vaccine Errors Reporting Program (ISMP VERP)

While the risk of adverse reactions to vaccines has been given considerable attention in recent years, the study of adverse events associated with vaccine errors has been much less extensive. Despite this, the World Health Organization (WHO) emphasizes that adverse events due to vaccine errors are more common than adverse events due to the vaccines themselves.1,2 Also, the opportunity for vaccine errors is immense—30 or more vaccines will be administered to fully immunize a child in the US by the age of 6, accounting for a large number of opportunities each year for vaccine-related errors to occur during childhood vaccinations alone.1 

To collect the details needed to understand vaccine errors and their causes, ISMP partnered with the California Department of Public Health in September 2012 to develop the ISMP National Vaccine Errors Reporting Program (ISMP VERP). This is the only national vaccine error-reporting program in the US. ISMP sends all reports submitted to VERP to the Vaccine Adverse Event Reporting System (VAERS) used by the US Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC).  The primary purpose of the VAERS is to assess adverse events associated with vaccines. Outside of the error reports received from the ISMP VERP, the VAERS contains a very small number of reports that detail vaccine errors.3,4    

In the December 4, 2014 newsletter, we published Part 1 of a 2-year analysis of nearly 1,000 reports submitted to the ISMP VERP.5 From that analysis, the vaccines most frequently reported to be involved in errors included the following, in descending order:

  • Influenza (IIV3, IIV4, RIV3, ccIIV3, or LAIV4)
  • Diphtheria and tetanus toxoids, acellular pertussis adsorbed, and inactivated poliovirus (DTaP-IPV)
  • Hepatitis A (HepA)
  • Tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis adsorbed (Tdap)
  • Human papillomavirus, recombinant (4vHPV, 2vHPV)
  • Diphtheria and tetanus toxoids, and acellular pertussis adsorbed (DTaP)
  • Measles, mumps, rubella, and varicella (MMRV)
  • Hepatitis B (HepB)
  • Diphtheria and tetanus toxoids, acellular pertussis adsorbed, inactivated poliovirus, and Haemophilus influenzae type b conjugate (DTaP-IPV/Hib)
  • Haemophilus influenzae type b conjugate (Hib)

Among all vaccine errors in the 2-year VERP data set, the most common contributing factors were as follows:

  • Mistakes in choosing age-specific formulations of vaccines intended to prevent the same diseases
  • Unfamiliarity with the vaccine, particularly its dose, dosing schedule, age specifications, route of administration, and a vaccine’s components (e.g., combination vaccines; diluent and powder)
  • Failure to check or verify the vaccination schedule and the patient’s age, health record, or state immunization information system to avoid invalid doses administered too soon, or missed opportunities to vaccinate
  • Confusion due to similar vaccine names and abbreviations        
  • Confusion due to similar and ambiguous vaccine labeling and packaging
  • Administering diluents without vaccines, and/or one component of two-component vaccines
  • Using the wrong vaccine diluent
  • Unsafe storage (e.g., too close to similar-looking vaccines, temperature excursions, expired vaccines)
  • Wrong patient errors due to sibling confusion

In Part 2 of this newsletter feature, we provide recommendations to reduce the risk of vaccine errors based on the contributing factors identified in the 2-year data set. The contributing factors are highlighted in red, and the recommendations are listed under each contributing factor. Some recommendations will reduce the risk of errors associated with several different contributing factors. To avoid duplication, these recommendations appear under a single contributing factor but are highlighted with an asterisk (*) to note their ability to address other causative factors.

Errors with age-specific formulations

  • Prior to prescribing, dispensing, or administering a vaccine, verify the patient’s age by asking the birth date (if the patient is available) and referencing the patient’s health record, immunization record, and/or medication administration record (MAR). Also, compare the patient’s current age with information on the applicable immunization schedule and Vaccine Information Statement (VIS) from the CDC. 
  • Affix auxiliary warning labels to vaccines when first received in the pharmacy to draw attention to products with different formulations for neonatal, pediatric, adolescent, and/or adult patients.
  • Investigate purchasing differing age-specific formulations of the same vaccine from different manufacturers to help distinguish them.

Wrong patient errors due to confusion between siblings

  • If multiple children, adults, or an adult and child are being seen at the same time for vaccinations in the same immediate vicinity, structure the appointment to vaccinate one patient at a time. Moving siblings to separate treatment rooms when possible is one way to approach the problem.1 If more than one patient remains together, bring only one patient’s vaccines into the treatment area at a time, labeled with the vaccine name and intended patient’s name on each container. If more than one vaccine must be administered to a patient, keep them separate (e.g., separate trays; separate vaccine administration stations).* 
  • Verify the intended patient’s identity using two unique identifiers (e.g., name and birth date) before administering each vaccine.

Invalid doses (given too soon) or missed opportunities to vaccinate

  • Prior to vaccination, verify the patient’s current immunization status by checking the patient’s health record and vaccination record to avoid omissions and/or duplicate vaccine doses. If possible, build an alert into the electronic MAR or vaccination record to remind staff to review the patient’s immunization record or discuss prior immunizations with the patient or parent.
  • Locate missing vaccination records whenever possible by contacting previous healthcare providers and reviewing state or local immunization information systems. If records cannot be located, patients should be started on an age-appropriate vaccination schedule.
  • Post up-to-date, easy-to-read immunization schedules for infants, children, teens, and adults that staff can quickly reference in clinical areas where vaccinations may be prescribed and administered.6  If possible, link the immunization schedule to an electronic MAR and/or vaccination record.* 
  • Provide parents/caregivers, teens, and adults with easy-to-read immunization schedules  so they know what vaccine(s) they or their child should be receiving during visits to a healthcare provider.6*
  • If a child or teen misses a particular vaccination(s), create an individualized catch-up schedule of immunization and provide it to the parent or caregiver.6*
  • For frequently administered vaccines, establish standard order sets or protocols, which include:7*
    • The full generic name, brand name (if applicable), and standard abbreviation.8
    • Criteria for screening patients to determine the need for vaccination, indications, contraindications, and precautions.
    • Directions for administering the vaccine, including the route and any special procedures required to enhance safety.
    • Information regarding any required follow-up doses.
    • Details regarding what (e.g., lot number, expiration date) and where (e.g., vaccination record, immunization registries) to document vaccine administration.
    • An emergency protocol to follow if the patient develops an adverse reaction.
  • Integrate an ambulatory clinical pharmacist into the healthcare team in pediatric primary care and public health clinics, and other inpatient and ambulatory settings where vaccines are frequently administered. Pharmacists are uniquely positioned to reduce the barriers to appropriate and safe vaccine use. When pharmacists work directly in patient care areas, significant reductions in vaccine errors, invalid vaccine doses, and missed opportunities to vaccinate have been documented.9*
  • Implement a “universal birth dose policy” to ensure that every newborn receives the first dose of HepB vaccine at birth, or no later than at discharge from the hospital.10 Establish a reliable system of informing pediatricians or primary care physicians about a birth dose of HepB administered (or not) to a newborn.

Wrong route errors caused by unfamiliarity with the vaccine

  • Post a quick reference for clinicians to verify the route of administration for all vaccines. An excellent chart is available from the Immunization Action Coalition (IAC).11
  • Highlight the route of administration on MARs by using boldface type.
  • Highlight the route of administration on vaccine carton labels by circling or using color to bring attention to the information as necessary, or by affixing an auxiliary label to vaccines prone to administration by the wrong route—influenza; rotavirus; measles, mumps, rubella; and varicella vaccines.
  • When possible, purchase vaccines in packaging or containers that are less likely to mislead clinicians regarding the correct route of administration (e.g., purchase ROTATEQ instead of ROTARIX to avoid accidental injection of the oral vaccine).

Errors with combination vaccines or vaccines with diluents

  • On order sets, MARs, and vaccination records, list the brand names and all components of combination vaccines.
  • Only use the vaccine diluents supplied and packaged by the manufacturer with vaccines that require reconstitution. Vaccine diluents are not interchangeable, and stock vials of sterile water or normal saline should not be used as a substitute.
  • Clearly label or distinguish (e.g., circling or highlighting pertinent label information) diluents if the manufacturer’s label could mislead staff into believing the diluent is the vaccine itself.
  • Establish a process to keep two-component vaccines together, and to keep diluents and their corresponding vaccines together if storage requirements do not differ. Dispense the products together in a bag with an auxiliary label to remind staff to use both vials.
  • Document the NDC number, lot number, and expiration date of each vial in the vaccination record or log before administration to confirm selection or preparation of both components of two-component vaccines. Documenting actual administration of the vaccine should always occur after it is given.*
  • Establish ongoing education of clinical staff who might dispense and administer vaccines,* which includes discussion of safety issues with two-component vaccines and vaccines with specific diluents. Staff should understand the differences between two-component vaccines and vaccines packaged with specific diluents.
  • Barcode scanning prior to vaccine administration* could help catch an error if only one vial was being inadvertently used and the system required scanning the barcodes on both vials of two-component vaccines or diluents and corresponding vaccines.

Wrong vaccine errors related to vaccine nomenclature

  • When feasible, circle or highlight with a marker the brand names on carton labels of vaccine products that have long generic names, to promote correct product recognition.
  • Differentiate the appearance of similar vaccine names on computer screens and MARs by highlighting dissimilarities and including full product names, starting with the brand name (if applicable) first, followed by the generic name, especially for multi-component vaccines (e.g., PENTACEL).*   
  • Prescribe vaccines with look-alike generic names using brand names, not by the CDC-approved abbreviation alone.*
  • If vaccine abbreviations are permitted, allow only current, standard, CDC-approved abbreviations to be used.11 Follow the CDC recommendations to list both the full generic name (and brand name) along with the approved abbreviation on all electronic and preprinted forms to reinforce the product identity and the correct use of abbreviations.  
  • Use patient vaccination records with enough space to list full vaccine names.
  • Avoid listing the conjugate with polysaccharide vaccines on order entry and automated dispensing cabinet (ADC) computer screens, pharmacy labels, MARs, vaccination records, and shelf/storage area labels. For example, do not include tetanus toxoid when listing the generic name of ActHIB, which appears on the label as Haemophilus b conjugate vaccine (tetanus toxoid conjugate).  
  • Prohibit the use of coined or informal names for vaccines.
  • Read back verbal orders to the prescriber for clarification. 

Wrong vaccine and dose errors related to labeling and packaging

  • In hospitals and birthing centers, separate newborn medications from those typically used for mothers in perinatal areas.
  • Whenever possible, administer infant medications in an area that is separate from where medications are administered to the mother.*
  • Reduce the risk of look-alike vaccine mix-ups by purchasing vaccine products from different manufacturers so they do not look as similar.*
  • Store vaccines with similar packaging or names on different refrigerator or freezer shelves to lessen the risk of errors.*
  • Unless the vaccine is prepared in front of the patient and administered immediately, vaccines prepared in syringes must be labeled. Peel-off labels to use for this purpose may be available on some, but not all, manufacturer’s vaccine vials. So it is difficult to standardize a process that includes them. The peel-off labels can also be used to document administration of a vaccine on vaccination records.*

Errors related to unsafe vaccine storage

  • Consult the CDC Vaccine Storage and Handling Toolkit to ensure the use of proper vaccine storage units and equipment, temperature ranges, temperature monitoring, placement of vaccines in storage units, and recommended actions. This will help  to minimize conditions that could compromise proper handling.12 
  • Purchase refrigeration and freezer units large enough to store and organize labeled stock.
  • If possible, store vaccines in their own, dedicated refrigeration and freezer units. 
  • Separate vials and syringes into bins or other containers according to vaccine type and formulation. Never store different vaccines in the same containers.
  • Do not store vaccines with similar labels, names, abbreviations, or overlapping components (e.g., DTaP, DT, Tdap, Td) immediately next to each other or on the same shelf.*
  • Separate the storage areas of pediatric and adult formulations of vaccines, and affix auxiliary labels to the vaccines and/or storage areas to draw attention to the specific ages for these vaccines.*
  • Label the specific locations where vaccines are stored to facilitate correct, age-specific selection and to remind staff to combine the contents of vials. Examples of vaccine labels for storage areas are provided by the CDC.13
  • Do not draw a single vaccine or batches of vaccines into syringes in advance of immunization clinics. Draw up vaccines only at the time of administration. As a safer alternative, use commercially available, prefilled and labeled syringes of vaccines from manufacturers whenever possible.
  • If not using manufacturer’s prefilled syringes in hospitals, the pharmacy should prepare each vaccine in a clearly labeled syringe and dispense it for immediate administration when possible. If vaccines are prepared outside of the pharmacy, each dose should be prepared in a syringe immediately prior to administration.*
  • Although predrawn syringes are discouraged, a limited amount of vaccine may be drawn into syringes in advance for large immunization clinics if:12
  1. Only one type of vaccine is being administered (or separate vaccine administration stations have been set up for each vaccine).
  2. The vaccines are transported at the proper temperatures in the original packaging.
  3. The vaccines are drawn up onsite, not offsite hours ahead of time.
  4. Each clinician draws up only 10 doses or fewer from the multiple-dose vial, and each syringe is individually labeled.
  5. The vaccines are maintained at proper temperatures that are monitored.
  6. Patient flow is monitored to avoid preparation of unneeded doses.
  7. Unused doses are discarded at the end of the workday.

Administration of an expired drug

  • Check for expired vaccines weekly and when vaccines are removed from stock. Rotate the stock based on the expiration date to prevent unnecessary waste by placing vaccines first to expire in the front.
  • Be aware of the short shelf life of live, attenuated influenza vaccine and implement measures to avoid administering an expired vaccine. 
  • Remove expired vaccines from units and storage areas/refrigerators/freezers where viable vaccines are stored. Label the vaccines as expired and sequester them away from in-date medications and drug preparation areas.
  • If an expired vaccine has been administered in error, revaccination with a valid dose is advised.14

Involve the patient in the verification process

  • Provide all patients, parents, or legal guardians with a VIS in their native language prior to vaccination. Time to read the VIS before vaccination should be provided. Document in the patient’s record the publication date of the VIS and the date it was given to the patient, parent, or guardian.*
  • Link the VIS (in the most predominant languages of the population served) to the electronic MAR or vaccination record so they are readily accessible.
  • Hold discussions with patients, parents, or legal guardians about the vaccines being administered and answer any questions. The VISs are not a substitute for direct conversation between the provider and patient regarding the risks and benefits of vaccination.
  • Ask patients or parents to participate in the verification process prior to vaccine administration by reading the VIS and verifying that the patient is within the specific ages for the intended vaccine, and by simultaneously comparing the name of the vaccine on the VIS to the vaccine name stated by the clinician and listed on the vaccine label. Immunization records and/or vaccine logs in which the vaccine name, dose, lot number, and expiration date have been recorded immediately before vaccination can also be verified by the patient or parent as the information on the vaccine label is read aloud by the clinician.*
  • Remind parents that a fever in young children may occur after vaccination, but the CDC Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics do not recommend the prophylactic use of an analgesic/antipyretic medication such as acetaminophen before or at the time of vaccination.15 


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  2. Jodar L, Duclos P, Milstien JB, Griffiths E, Aguado MT, Clements CJ. Ensuring vaccine safety in immunization programmes—a WHO perspective. Vaccine. 2001;19(13-14):1594–605.
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  4. Varricchio F, Reed J, VAERS Working Group. Follow-up study of medication errors reported to the vaccine adverse event reporting system (VAERS). South Med J. 2006;99(5):486-9.
  5. ISMP. Confusion abounds! 2-year summary of the ISMP National Vaccine Errors Reporting Program (part 1). ISMP Medication Safety Alert! 2014;19(24):1-6.
  6. CDC. Immunization schedules. January 26, 2015.
  7. Immunization Action Coalition (IAC). Handouts: clinical resources. Standing orders for administering vaccines. January 21, 2015.
  8. CDC. ACIP abbreviations for vaccines. February 23, 2015.
  9. Hass-Gehres A, Sebastian S, Lamberjack K. Impact of pharmacist integration in a pediatric primary care clinic on vaccination errors: a retrospective review. J Am Pharm Assoc (2003). 2014;54(4):415-8.
  10. IAC. Hepatitis B: What hospitals need to do to protect newborns. July 2013.
  11. IAC. Administering vaccines: dose, route, site, and needle size. Item #P3085. January 2015.
  12. CDC. Vaccine storage & handling toolkit. May 2014.
  13. CDC. Vaccine label examples. February 25, 2013.
  14. Haber P, Schembri CP, Lewis P, Hibbs B, Shimabukuro T. Notes from the field: reports of expired live attenuated influenza vaccine being administered—United States, 2007-2014. Morb Mortal Wkly Rep. 2014;63(35):773.
  15. Prymula R, Siegrist CA, Chlibek R, et al. Effect of prophylactic paracetamol administration at time of vaccination on febrile reactions and antibody responses in children: two open-label, randomised controlled trials. Lancet. 2009;374(9698):1339-50.