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IAC Express 2009
Issue number 800: May 20, 2009
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Contents of this Issue
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  1. Read "Ask the Experts" Q&As about vaccine errors
AAFP, American Academy of Family Physicians; AAP, American Academy of Pediatrics; ACIP, Advisory Committee on Immunization Practices; AMA, American Medical Association; CDC, Centers for Disease Control and Prevention; FDA, Food and Drug Administration; IAC, Immunization Action Coalition; MMWR, Morbidity and Mortality Weekly Report; NCIRD, National Center for Immunization and Respiratory Diseases; NIVS, National Influenza Vaccine Summit; VIS, Vaccine Information Statement; VPD, vaccine-preventable disease; WHO, World Health Organization.
Issue 800: May 20, 2009
1.  Read "Ask the Experts" Q&As about vaccine errors

Many readers of Needle Tips, Vaccinate Adults, and Vaccinate Women consistently rank "Ask the Experts" as their favorite feature in these publications. As a thank-you to our loyal IAC Express readers, we have decided to periodically publish an Extra Edition with new "Ask the Experts" Q&As answered by CDC experts.

IAC thanks William L. Atkinson, MD, MPH, Andrew T. Kroger, MD, MPH, medical epidemiologists, and Donna L. Weaver, RN, MN, nurse educator, at the National Center for Immunization and Respiratory Diseases, CDC, for agreeing to answer the following questions.

All the Q&As in this edition of IAC Express deal with vaccine errors. Unfortunately, vaccine errors occur all too frequently. The result of making such errors can be serious, and can range from possibly causing harm to the incorrectly vaccinated person from a side effect or from increased vulnerability to a disease, to causing inconvenience to the parent/patient, unreimbursed cost to the provider, and possible negative publicity. Avoiding such errors benefits everyone.

We encourage you to reprint any of these Q&As in your own newsletters. Please credit the Immunization Action Coalition and the Centers for Disease Control and Prevention. Information about IAC's preferred citation style can be found at

You can access more "Ask the Experts" Q&As in our online archive at

Editor's note: Information about submitting a question to "Ask the Experts" is provided at the end of this Extra Edition.


Q: We gave a dose of vaccine too soon after the previous dose. When can we give another (valid) dose?

A: ACIP allows a grace period of 4 days (i.e., vaccine doses administered up to 4 days before the recommended minimum interval or age can be counted as valid). However, if a dose was administered 5 or more days earlier than the recommended minimum interval between doses, it is not valid and must be repeated. The repeat dose should be spaced after the invalid dose by the recommended minimum interval.

Likewise, doses administered 5 or more days before the minimum age should be repeated on or after the patient reaches the minimum age and 4 or more weeks after the invalid dose.

Avoid such errors by knowing the minimum intervals and ages for routinely given vaccines. You can look up such information here.

Other useful resources are

Summary of Recommendations for Adult Immunization

Summary of Recommendations for Childhood and Adolescent Immunization


Q: One of our nurses accidentally gave Zostavax IM instead of SC. What do we need to do?

A: You can count the dose as valid. ACIP recommends that vaccines given by the wrong route be counted as valid with one exception: hepatitis B administered by any route other than intramuscular should not be counted as valid and should be repeated. Vaccines should always be given by the route recommended by the manufacturer, but errors do occur. Your practice should put procedures in place to ensure that you give vaccines by the recommended route.

Avoid such errors by using the following resources:

How to Administer Intramuscular (IM) and Subcutaneous (SC) Injections

How to Administer IM and SC Injections to Adults

Administering Vaccines to Adults: Dose, Route, Site, Needle Size, and Preparation

Administering Vaccines: Dose, Route, Site, and Needle Size (includes all vaccines)


Q: For an extended period, the temperature in the vaccine-storage refrigerator in our practice was too cold. We assume all the vaccines given during that period are considered invalid. How should we schedule the revaccinations?

A: If administered vaccine is found to be stored at an inappropriate temperature, the provider should contact the state health department to determine if the vaccine dose is invalid. If the vaccine dose is determined to be invalid, another dose should be given. This applies to inactivated or live vaccines. If the damaged vaccine was a live virus vaccine (e.g., MMR, VAR), you should wait at least 4 weeks after the previous (damaged) dose was given before repeating it. If the damaged vaccine was an inactivated vaccine, you can give the repeat dose on the same day you gave the damaged dose or at any other time. If you prefer, you can perform serologic testing to check for immunity for certain vaccinations (e.g., measles, rubella, hepatitis A, and tetanus).

Q: What should we do if a dose of expired vaccine is given to a patient?

A: The dose should be repeated. If the expired dose is a live virus vaccine, you should wait at least 4 weeks after the previous (expired) dose was given before repeating it. If the expired dose is not a live vaccine, the dose should be repeated as soon as possible. If you prefer, you can perform serologic testing to check for immunity for certain vaccinations (e.g., measles, rubella, hepatitis A, and tetanus).

Avoid vaccine storage and handling errors by using the following resources:

CDC's Vaccine Storage and Handling Toolkit

CDC's Vaccine Management booklet

Checklist for Safe Vaccine Handling and Storage

Don't Be Guilty of These Errors in Vaccine Storage and Handling

Vaccine Handling Tips

Maintaining the Cold Chain during Transport

Emergency Response Worksheet

Temperature Log for Vaccines (Fahrenheit)

Temperature Log for Vaccines (Celsius)

"Do Not Unplug" sign (color)

"Do Not Unplug" sign (black and white)


Q: One of our staff gave a dose of pediatric hepatitis A vaccine to an adult patient by mistake. How do we remedy this error?

A: In general, if you give less than a full age-appropriate dose of any vaccine, the dose is invalid. You should revaccinate the person with the appropriate dose as soon as feasible.

There are, however, two exceptions to the general rule: (1) If a patient sneezes after receiving nasal-spray live attenuated influenza vaccine, count the dose as valid. (2) If an infant regurgitates, spits, or vomits during or after receiving oral rotavirus vaccine, count the dose as valid.

If you give more than an age-appropriate dose, count the dose as valid and notify the patient/parent about the error. Using larger than recommended dosages can be hazardous because of excessive local or systemic concentrations of antigens or other vaccine constituents.

Avoid such errors by checking the vaccine vial label 3 TIMES! The following print pieces are also helpful:

Administering Vaccines: Dose, Route, Site, and Needle Size

Administering Vaccines to Adults: Dose, Route, Site, Needle Size, and Preparation

Hepatitis A & B Vaccines: Be sure your patient gets the correct dose!


Q: We inadvertently gave a dose of Tdap to a 5-year-old instead of pediatric DTaP. What is our next best step to take under this circumstance?

A: First, inform the child's parent that you administered the wrong vaccine. Here are some guidelines for what to do if you inadvertently give Tdap to a child younger than age 10.

(1) Tdap given to child younger than age 7 years as either dose 1, 2, or 3 is NOT valid. Repeat with DTaP as soon as feasible.

(2) Tdap given to child younger than age 7 years as either dose 4 or 5 can be counted as valid for DTaP dose 4 or 5.

(3) Tdap given to a child age 7 through 9 years can be counted as valid for the one-time Tdap dose.

Q: We mistakenly gave a teenage girl pediatric DTaP instead of Tdap. Do we need to revaccinate her with Tdap?

A: No. DTaP given to patients age 7 or older can be counted as valid for the one-time Tdap dose. Inform the girl and her parents that though you administered the wrong vaccine, the DTaP vaccine will provide the same protection against pertussis as Tdap.

Q: We accidentally gave a 47-year-old healthcare worker Zostavax instead of Varivax for work. Does this count?

A: Yes, but this is a serious vaccine administration error because Zostavax vaccine contains about 14 times as much varicella vaccine virus as Varivax. You should document the event and establish procedures to prevent this from happening again. The dose of zoster vaccine can be counted as the first of two doses of varicella vaccine for an adult who is not immune to varicella. The second dose of varicella vaccine should be given 4 to 8 weeks after the first dose.

Q: We mistakenly gave a 60-year-old patient varicella vaccine instead of zoster vaccine. Should we still administer zoster vaccine to the patient? If so, how long an interval should occur between the 2 doses?

A: ACIP states the following: "If a provider mistakenly administers varicella vaccine to a person for whom zoster vaccine is indicated, no specific safety concerns exist, but the dose should not be considered valid and the patient should be administered a dose of zoster vaccine during that same visit. If the error is not immediately detected, a dose of zoster vaccine should be administered as soon as possible but not within 28 days of the varicella vaccine dose to prevent potential interference of 2 doses of live attenuated virus."

Avoid such errors by checking the vial label 3 TIMES to make sure you're administering the product you intended!

Q: We mistakenly gave a 2-month-old PPSV instead of PCV. What should we do?

A: PPSV is not effective or recommended for use in children younger than age 24 months. PPSV given at this age should not be considered to be part of the pneumococcal vaccination series. You should administer PCV as soon as the error is discovered.

Anytime you give the wrong vaccine, you need to notify the parent/patient.


Q: There is more than one provider in our practice who will not administer both MMR and varicella vaccines at the same visit. Their belief is that the vaccines are more effective if given separately.

A: Not giving two or more recommended vaccines on the same visit is a missed opportunity. A missed opportunity to vaccinate allows a person to remain at risk of serious disease. Avoid such missed opportunities by giving all indicated vaccines during the same visit. There is no evidence that simultaneous administration of vaccines either reduces vaccine effectiveness or increases the risk of adverse events. No upper limit has been established regarding the number of vaccines that can be administered in one visit. ACIP and AAP consistently recommend administration of all indicated vaccines.

If you miss giving recommended vaccines at the same visit, follow these guidelines:

(1) Administer any missed inactivated vaccine (e.g., DTaP, Tdap, HPV) at any time before or after a different inactivated or live vaccine (e.g., MMR, VAR, LAIV, RV).

(2) If you miss giving any 2 or more recommended live vaccines atthe same visit, you must wait at least 4 weeks before administering any other routinely recommended live virus vaccine.

Q: I need both Tdap and MMR vaccines but my doctor won't give them to me unless I stop breastfeeding. Is this really necessary?

A: No. Breastfeeding is not a contraindication to the administration of any routinely recommended vaccine, either to the mother or to the child.

Providers also often miss opportunities to vaccinate by assuming contraindications when none exist. Only follow TRUE contraindications and precautions to vaccinations.

Avoid missed opportunities by using the following resources:

Giving All the Doses (Immunization Site Map)

Guide to Vaccine Contraindications and Precautions

Guide to Contraindications and Precautions to Commonly Used Vaccines

Guide to Contraindications and Precautions to Commonly Used Vaccines in Adults

Suggestions to Improve Your Immunization Services


Q: I had my spleen removed as a teenager. I have been getting PPSV vaccine every 5 years because my doctor recommends it, but this doesn't agree with what the IAC website says. Which is right?

A: No more than 2 lifetime doses of PPSV vaccine are recommended for anyone. Unfortunately, many healthcare providers seem to believe that more is better when it comes to PPSV. For the facts, read Pneumococcal Polysaccharide Vaccine (PPSV): CDC Answers Your Questions at

Q: I work with university students and many of them miss coming in on time for their next dose of HPV vaccine. What's the longest interval allowed before we need to start the series over?

A: No vaccine series needs to be restarted because of an interval that is longer than recommended (with the exception of oral typhoid vaccine in certain circumstances). You should continue the series where it was interrupted. If the HPV series is begun when the university student is age 26 or younger, it can be completed after she turns 27.

It's important to rely on the actual recommendations, not urban legends or guesswork. All ACIP recommendations can be accessed at ACIP's "General Recommendations on Immunization" are especially useful:

Other useful resources:

CDC's "Pink Book"

IAC's "Ask the Experts" archive

IAC works with CDC to compile new "Ask the Experts" Q&As for our publications based on commonly asked questions. We also consider the need to provide information about new vaccines and recommendations. Most of the questions are thus a composite of several inquiries.

You can email your question about vaccines or immunization to IAC at As we receive hundreds of emails each month, we cannot guarantee that we will print your specific question in the "Ask the Experts" feature. However, you will get an answer. To see if your question has already been answered, you can first check the "Ask the Experts" online archive at

You can also email CDC's immunization experts directly at There is no charge for this service.

If you have a question about IAC materials or services, email

Please forward these "Ask the Experts" Q&As to your co-workers and suggest they subscribe to IAC Express at

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About IZ Express

IZ Express is supported in part by Grant No. 1NH23IP922654 from CDC’s National Center for Immunization and Respiratory Diseases. Its contents are solely the responsibility of and do not necessarily represent the official views of CDC.

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ISSN 2771-8085

Editorial Information

  • Editor-in-Chief
    Kelly L. Moore, MD, MPH
  • Managing Editor
    John D. Grabenstein, RPh, PhD
  • Associate Editor
    Sharon G. Humiston, MD, MPH
  • Writer/Publication Coordinator
    Taryn Chapman, MS
    Courtnay Londo, MA
  • Style and Copy Editor
    Marian Deegan, JD
  • Web Edition Managers
    Arkady Shakhnovich
    Jermaine Royes
  • Contributing Writer
    Laurel H. Wood, MPA
  • Technical Reviewer
    Kayla Ohlde

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