Storage conditions and stability of official vaccines MCQs With Answer

Introduction

Understanding storage conditions and vaccine stability is essential for B. Pharm students involved in immunization programs, cold chain management, and quality assurance. This topic covers vaccine stability, temperature monitoring, cold chain logistics, vaccine vial monitors (VVMs), lyophilized vs liquid formulations, freeze-sensitive and heat-sensitive vaccines, WHO guidelines, shelf life, potency assays, and stability testing protocols. Practical knowledge of refrigeration (2–8°C), ultra-low temperature requirements, excursion handling, controlled temperature chain (CTC) strategies, and documentation ensures vaccine potency and patient safety. Mastery of these concepts helps prevent loss of efficacy, reduce wastage, and comply with regulatory stability requirements. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the WHO-recommended storage temperature range for most routine refrigerated vaccines?

• −70°C to −20°C
• −20°C to 0°C
• 2°C to 8°C
• 15°C to 25°C

Correct Answer: 2°C to 8°C

Q2. Which device is specifically used on vaccine vials to indicate cumulative heat exposure?

• Data logger
• Freeze indicator
• Thermometer
• Vaccine Vial Monitor (VVM)

Correct Answer: Vaccine Vial Monitor (VVM)

Q3. Which vaccine property is most likely to be damaged by accidental freezing?

• pH stability
• Adjuvant-coated antigen structure (potency)
• Color labeling
• Sterile barrier

Correct Answer: Adjuvant-coated antigen structure (potency)

Q4. Controlled Temperature Chain (CTC) allows selected vaccines to be kept at higher temperatures for limited times. Which of the following is true about CTC?

• All vaccines can be used in CTC without validation
• CTC is typically up to 40°C for an approved duration for specific vaccines
• CTC requires storage below −20°C
• CTC eliminates need for any temperature monitoring

Correct Answer: CTC is typically up to 40°C for an approved duration for specific vaccines

Q5. Which of the following best describes a lyophilized vaccine?

• Liquid vaccine stored at room temperature
• Freeze-dried formulation requiring reconstitution before use
• Always stable at high temperatures
• Vaccine that cannot be refrigerated

Correct Answer: Freeze-dried formulation requiring reconstitution before use

Q6. What is the primary purpose of stability testing for vaccines?

• To reduce manufacturing cost
• To determine shelf life and storage conditions that maintain potency and safety
• To improve labeling aesthetics
• To test marketing strategies

Correct Answer: To determine shelf life and storage conditions that maintain potency and safety

Q7. Which guideline is commonly referenced for stability testing of pharmaceuticals including biologicals?

• ICH Q1A(R2)
• FDA Food Code
• ISO 9001
• Good Manufacturing Practice for cosmetics

Correct Answer: ICH Q1A(R2)

Q8. A vaccine’s Vaccine Vial Monitor (VVM) has reached stage 4. What is the correct action?

• Use the vial immediately
• Quarantine and perform potency testing only
• Discard the vial
• Return vial to manufacturer for reconditioning

Correct Answer: Discard the vial

Q9. Which tool provides continuous, time-stamped temperature records for vaccine storage?

• Alcohol thermometer
• Max-min thermometer without logging
• Temperature data logger
• Paper-based logbook only

Correct Answer: Temperature data logger

Q10. Freeze-sensitive vaccines should be protected from freezing. Which indicator helps detect freezing events?

• VVM
• Freeze indicator (e.g., FreezeWatch)
• pH strip
• Light protector

Correct Answer: Freeze indicator (e.g., FreezeWatch)

Q11. After reconstitution, many vaccines must be used within a limited time. Why?

• Reconstitution improves shelf life indefinitely
• Sterility and antigen integrity decline rapidly after reconstitution
• Labeling becomes invalid
• Date of manufacture changes

Correct Answer: Sterility and antigen integrity decline rapidly after reconstitution

Q12. Which factor is NOT typically considered a critical stability parameter for vaccines?

• Potency (antigen content)
• Sterility
• Color of the vial cap
• pH and appearance

Correct Answer: Color of the vial cap

Q13. What is the correct immediate action when a vaccine refrigerator records a sustained temperature of 10°C for several hours?

• Discard all vaccines immediately without assessment
• Document the excursion, assess affected vaccines using VVMs and manufacturer/WHO guidance
• Move vaccines to a freezer
• Continue to use vaccines as normal

Correct Answer: Document the excursion, assess affected vaccines using VVMs and manufacturer/WHO guidance

Q14. Which vaccine characteristic usually makes it more tolerant to short-term heat exposure?

• Presence of live attenuated virus always increases heat tolerance
• Formulation with stabilizers and thermostable antigen design
• Large vial volume
• Clear glass vials

Correct Answer: Formulation with stabilizers and thermostable antigen design

Q15. Which assay is commonly used as a potency test for many vaccines?

• High performance liquid chromatography (HPLC) exclusively
• Potency assays such as in vivo challenge or in vitro immunoassays (ELISA)
• Visual color comparison only
• pH meter alone

Correct Answer: Potency assays such as in vivo challenge or in vitro immunoassays (ELISA)

Q16. Why are some vaccines stored at ultra-low temperatures (e.g., −70°C)?

• To save on refrigeration energy costs
• Because certain formulations (e.g., mRNA vaccines) require ultra-low temperatures to maintain stability
• To increase vaccine vial weight
• Because they are not biologically active at higher temperatures

Correct Answer: Because certain formulations (e.g., mRNA vaccines) require ultra-low temperatures to maintain stability

Q17. Which documentation is essential to demonstrate compliance with vaccine storage and stability requirements?

• Temperature logs, maintenance records, and excursion reports
• Only purchase invoices
• Marketing brochures
• Patient consent forms only

Correct Answer: Temperature logs, maintenance records, and excursion reports

Q18. Multi-dose vials often have an “open vial policy” guideline. What does this primarily address?

• Stability of unopened vials only
• Duration a vial can be used after opening under specified conditions
• Number of doses per vial
• Pricing strategy

Correct Answer: Duration a vial can be used after opening under specified conditions

Q19. Which regulatory or guidance body provides specific vaccine storage and stability recommendations globally?

• World Health Organization (WHO)
• International Olympic Committee
• World Trade Organization
• American Dental Association

Correct Answer: World Health Organization (WHO)

Q20. Accelerated stability studies are used to predict long-term stability by storing product at elevated temperatures. Which principle underlies this?

• Arrhenius equation relating reaction rate to temperature
• Law of conservation of mass
• Boyle’s law
• Principle of optical rotation

Correct Answer: Arrhenius equation relating reaction rate to temperature

Q21. Which storage equipment is best suited for vaccine transport during outreach campaigns?

• Domestic freezer without temperature control
• Vaccine carrier with ice packs or conditioned cold boxes designed for vaccines
• Cardboard box
• Metal toolbox

Correct Answer: Vaccine carrier with ice packs or conditioned cold boxes designed for vaccines

Q22. Photostability is important for some vaccines. What is the recommended protection?

• Expose to direct sunlight to sterilize
• Protect from light using opaque containers or secondary packaging
• Freeze to protect from light
• Remove labels to allow light penetration

Correct Answer: Protect from light using opaque containers or secondary packaging

Q23. Which statement about vaccine shelf life (expiry dating) is correct?

• Expiry dates are arbitrary and not based on testing
• Expiry is assigned based on stability data demonstrating maintained potency and safety over time
• Expiry can be ignored if VVM is stage 1
• Expiry dates extend automatically after refrigeration

Correct Answer: Expiry is assigned based on stability data demonstrating maintained potency and safety over time

Q24. What is the most appropriate action if a lyophilized vaccine has become wet but is still unopened?

• Reconstitute and use immediately
• Assess per manufacturer/WHO guidance; usually consider it compromised and quarantine or discard
• Freeze the vial to dry it out
• Shake vigorously and use

Correct Answer: Assess per manufacturer/WHO guidance; usually consider it compromised and quarantine or discard

Q25. Which of the following is a common stabilizer used in vaccine formulations to improve thermal stability?

• Sodium chloride only
• Sugars (e.g., sucrose, trehalose) and proteins
• Mercury preservatives
• Hydrochloric acid

Correct Answer: Sugars (e.g., sucrose, trehalose) and proteins

Q26. During a cold chain break, which factor most influences the decision to retain or discard affected vaccine lots?

• Brand popularity
• Duration and magnitude of temperature excursion, vaccine type, and VVM status
• Color of vaccine label
• Time of day the excursion occurred

Correct Answer: Duration and magnitude of temperature excursion, vaccine type, and VVM status

Q27. Which method is commonly used to evaluate antigen integrity in stability studies of protein-based vaccines?

• Bioburden count only
• Immunoassays (e.g., ELISA) or SDS-PAGE and potency assays
• Visual inspection only
• pH test only

Correct Answer: Immunoassays (e.g., ELISA) or SDS-PAGE and potency assays

Q28. What is the role of preservatives in multi-dose vaccine vials?

• Enhance antigen potency
• Prevent microbial contamination after repeated punctures
• Change color to indicate vial age
• Reduce vaccine viscosity

Correct Answer: Prevent microbial contamination after repeated punctures

Q29. For long-term vaccine stability monitoring, which approach is most appropriate?

• Rely only on initial release testing
• Perform real-time stability studies under recommended storage conditions and periodic potency testing
• Store samples at random temperatures
• Discard samples after production

Correct Answer: Perform real-time stability studies under recommended storage conditions and periodic potency testing

Q30. Which practice improves cold chain reliability in low-resource settings?

• Using untreated ice packs indiscriminately
• Implementing temperature monitoring, trained personnel, insulated transport, and WHO-recommended equipment
• Relying on ambient storage during summer only
• Keeping vaccines in patient waiting areas

Correct Answer: Implementing temperature monitoring, trained personnel, insulated transport, and WHO-recommended equipment

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com