CDC Guidelines for Protecting the Cold Chain: Key Points for the Pharmacist

In May 2014, the Centers for Disease Control published a guideline document to help pharmacists and other health care professionals avoid common pitfalls of vaccine cold-temperature storage that may affect the efficacy and safety of vaccines.

In May 2014, the Centers for Disease Control published a guideline document to help pharmacists and other health care professionals avoid common pitfalls of vaccine cold-temperature storage that may affect the efficacy and safety of vaccines.

Training, transport, and management are all important components of the cold chain protocol, and extends from the manufacturer, to the distributor, to the delivery service, and finally to the pharmacist and provider.

Even a single excursion beyond a narrow range of temperatures will render some vaccines useless. Other vaccines, particularly those that contain aluminum adjuvants, may lose potency when frozen (see appendix below).

The CDC recommends that temperature monitoring devices should continuously monitor the storage temperature of vaccines. Before using a new freezer unit or refrigerator unit, 1 week of temperature readings should be available to ensure that the unit is functioning properly.

It is important for pharmacists to be aware that thin layers of frost on the inside of a freezer will not affect a freezer's performance, but that a thick layer may affect the freezer's ability to maintain cold temperatures. Regularly defrosting a freezer or (preferably) using a freezer with an automatic defrost function minimizes the risk of damage to frozen vaccines.

Adding sealed water bottles or cooling packs to the refrigerator top shelf, floor, and in door racks helps stabilize temperature fluctuations. Separate freezer and refrigerator and units are preferable to combined units, but it is important to note that dormitory- or bar-style combined refrigerator/freezer units should never be used for storage of any vaccine.

Refrigeration units should be placed in an area with good air circulation. To maintain air circulation, refrigerators should be positioned at least 4 inches from any adjoining wall, and should sit at least 1 to 2 inches above the floor. Additionally, the motor compartment of the refrigerator, which is usually on the back of the unit, should not be obstructed.

Refrigerator temperature should be calibrated before any refrigerated medications are added to the unit. The CDC recommends placing a sign near temperature controls with the following text: “Do NOT adjust refrigerator (or freezer) temperature controls. Notify (insert name) if adjustments are necessary.”

Use of digital data loggers for temperature recording is recommended by the CDC. At a minimum, loggers should be able to display the current, minimum, and maximum temperature. In addition, probes should preferably be encased in a thermal buffer solution to simulate the actual temperature of vaccines—not just the temperature of the refrigerator air.

Ensuring the potency of vaccines is an important responsibility of pharmacists. With a better understanding of what can go wrong with the cold chain, and with procedures and protocols in place, pharmacists can help safeguard against expensive losses through simple preventive action. For more on the CDC guidelines, please consult the full document at the CDC website here.


Centers for Disease Control and Prevention. Vaccine storage & handling toolkit. Published May 2014. Accessed December 2014.


An Overview of Vaccine Storage Requirements

Vaccines that lose potency when frozen due to the presence of aluminum adjuvants include the following:

  • Adacel
  • Boostrix
  • Cervarix
  • Comvax
  • Daptacel
  • Decavac
  • Engerix-B
  • Gardasil
  • Havrix
  • Infanrix
  • Kinrix
  • Pediarix
  • PedvaxHIB
  • Pentacel
  • Prevnar 13
  • Recombivax HB
  • Tenivac
  • Twinrix
  • Vaqta

Certain vaccines must be protected from light. These include the following:

  • Varivax
  • Zostavax
  • ProQuad
  • M-M-R II
  • Hiberix
  • Gardasil
  • Afluria
  • Agriflu
  • Fluarix
  • Flublok
  • Flucelvax
  • FluLaval
  • Fluvirin
  • IPOL
  • MenHibrix
  • Menveo
  • Rotarix
  • RotaTeq

All varicella-containing vaccines should be stored in a freezer between —58°F and 5°F, including:

  • Varivax
  • Zostavax
  • ProQuad

The following vaccines should be stored in a refrigerator between 35°F and 46°F:

  • Hepatitis A Havrix Vaqta
  • Hepatitis B Recombivax HB Engerix-B
  • Hepatitis A—Hepatitis B Twinrix
  • Haemophilus influezae B PedvaxHIB Hiberix
  • Haemophilus influenzae B—Hepatitis B Comvax
  • Human papillomavirus (HPV2, HPV4, and HPV9)
  • Influenza (live attenuated influenza vaccine, inactivated influenza vaccine, recombinant influenza vaccine)
  • Inactivated polio gaccine
  • Meningococcal-containing (Hib-MenCY, MCV4, MPSV4)
  • Pneumococcal (PCV13 and PPSV23)
  • Rotavirus (RV1 and RV5)
  • All diphtheria toxoid—, tetanus toxoid–, and pertussis-containing vaccines

The following vaccine be either stored in a freezer or refrigerated (but the diluent should never be frozen):

  • M-M-R II