Is it safe to administer vaccines stored at a temperature of 1.5 degrees Celsius (hypothermia)?

Vaccine Storage Temperature Excursion Management

Vaccines stored at 1.5°C are safe to administer as this temperature falls within the recommended storage range of 2-8°C (36-46°F), though it is slightly below the lower limit. 1

Understanding Vaccine Storage Temperature Requirements

Proper vaccine storage is critical for maintaining potency and effectiveness. The guidelines for vaccine storage temperatures are:

• Standard refrigerated vaccines: 2°C to 8°C (36°F to 46°F)
• Frozen vaccines: Below -15°C (for vaccines requiring freezer storage)

Temperature Excursion Assessment

When evaluating a temperature excursion to 1.5°C:

1. Severity: A temperature of 1.5°C represents only a minor deviation (0.5°C) below the recommended lower limit
2. Duration: The impact depends on how long vaccines were exposed to this temperature
3. Vaccine type: Different vaccines have different temperature sensitivities

Vaccine-Specific Considerations

Inactivated Vaccines

Most inactivated vaccines and toxoids are primarily sensitive to freezing rather than mild cold exposure 2:

• These vaccines typically maintain potency at temperatures slightly below 2°C as long as they do not freeze
• The temperature of 1.5°C does not represent a freezing condition

Live Attenuated Vaccines

For live attenuated vaccines such as LAIV (Live Attenuated Influenza Vaccine):

• LAIV must be stored at 2°C to 8°C and can be stored for up to 60 hours after thawing 1
• A brief exposure to 1.5°C would not significantly impact potency

Clinical Decision-Making

When faced with vaccines stored at 1.5°C:

1. Document the excursion in vaccine storage logs
2. Check duration of the temperature excursion
3. Verify no freezing occurred (most inactivated vaccines are damaged by freezing, not by mild cold)
4. Proceed with administration if the excursion was minor and brief

Common Pitfalls and Caveats

• Do not confuse with freezing: A temperature of 1.5°C is not freezing temperature (0°C or below)
• Avoid unnecessary wastage: Discarding vaccines exposed to minor temperature excursions leads to unnecessary vaccine wastage 3
• Distinguish between vaccine types: While most vaccines can tolerate brief exposure to 1.5°C, always verify specific storage requirements for individual vaccines
• Monitor for equipment issues: Temperature excursions often indicate equipment problems that should be addressed to prevent future occurrences 4

Practical Recommendations

1. Continue using the vaccines stored at 1.5°C as this represents only a minor deviation from recommended storage temperatures
2. Check refrigerator settings to ensure temperature returns to the recommended 2-8°C range
3. Review cold chain management procedures to prevent future temperature excursions
4. Document the incident according to local protocols

In conclusion, vaccines stored at 1.5°C remain safe and effective to administer, as this temperature represents only a minor deviation from recommended storage parameters and does not compromise vaccine potency or safety.