Why Proper Vaccine Storage Matters?
Vaccines contain biologically active components that lose effectiveness if exposed to temperature fluctuations, light, or contamination.
Proper storage ensures potency and safety.
1) Temperature Ranges
Refrigeration (2°C to 8°C): Most routine bacterial and viral vaccines (e.g., DPT, Hib, Hepatitis B, some influenza formulations).
Frozen (-15°C or colder): Certain live vaccines (e.g., varicella, zoster) are often kept frozen until use.
Ultralow Freezer (-50°C to -80°C) or -70°C to -90°C: Some newer mRNA COVID-19 vaccines.
2) Light Sensitivity
Many vaccines are light-sensitive (e.g., measles-containing vaccines) and must be protected from direct sunlight or fluorescent light.
3) Shelf Life
Depends on the vaccine. Many have a shelf life of 1–3 years if stored under recommended conditions.
Freeze-dried (lyophilized) vaccines often have longer shelf lives compared to liquid forms, but once reconstituted, they typically must be used within a short timeframe (e.g., within hours).
4) Post-Reconstitution Stability
Certain lyophilized vaccines (e.g., BCG, MMR) must be used promptly (often within 6–8 hours) after reconstitution, as they rapidly lose potency at room temperature.
5) Monitoring
Vaccine Vial Monitors (VVMs): Some vials have heat-sensitive indicators to show exposure to excessive heat.
Cold Chain Maintenance: Continuous monitoring of temperature (cold chain) from manufacturer to end-user clinic is essential.
6) Disposal
Expired or compromised vaccines (exposed to temperatures outside recommended range) must be discarded properly as per biosafety guidelines.
General Storage Guidelines
Vaccine Type | Storage Temperature | Stability Notes |
Live Attenuated Vaccines | -15°C or lower | Must be kept frozen (e.g., MMR, varicella) |
Inactivated Vaccines | 2–8°C | Never freeze (e.g., Hepatitis A, IPV) |
Toxoids | 2–8°C | Light-sensitive, should not be frozen |
Antitoxins & Immunoglobulins | 2–8°C | Stable for months but should not be frozen |
Factors Affecting Stability
Temperature fluctuations can degrade proteins.
Light exposure can reduce potency (e.g., toxoids).
Contamination risks due to improper handling.
