Immunization and Vaccine-Preventable Diseases — MCQs

Which of the following regarding the vaccine vial monitor (VVM) is true? 1. It is used for monitoring heat exposure of the vaccine by healthcare workers in primary healthcare. 2. It shows cumulative exposure of the vaccine to the heat. 3. It can be used to assess the potential efficacy of the vaccine 4. Calculation of the expiry date can be done using VVM. 5. The expiry date of the vaccine can be relaxed if VVM is an acceptable range. 6. If the square and the circle are the same in color, then the vaccine can be safely used.

Q378

Recommended HPV vaccination schedule for 9 to 14-year-olds according to WHO SAGE guidelines is:

Q379

Which is not a contraindication for OPV?

Q380

Yellow fever vaccine is valid for?

Immunization and Vaccine-Preventable Diseases Indian Medical PG Practice Questions and MCQs

Question 371: Which one of the following statements regarding sequential administration of Inactivated Polio Vaccine (IPV) and Oral Polio Vaccine (OPV) is NOT correct?

A. Intestinal mucosal immunity is lost due to IPV administration (Correct Answer)
B. The combined schedules of IPV and OPV appear to reduce or prevent Vaccine Associated Paralytic Polio (VAPP)
C. It will be cost effective in developing countries for Polio prevention
D. IPV and OPV together may optimize both the humoral and mucosal immunogenicity of Polio vaccine

Explanation: ***Intestinal mucosal immunity is lost due to IPV administration*** - This statement is **incorrect** and is the answer to this "NOT correct" question. - IPV (given parenterally) does NOT cause "loss" of pre-existing mucosal immunity; rather, it **fails to stimulate intestinal mucosal immunity** because it doesn't reach the gut mucosa. - IPV primarily induces **systemic humoral immunity** with high levels of serum antibodies, providing excellent protection against paralytic polio but minimal intestinal immunity. - The absence of mucosal immunity means IPV recipients can still be infected and shed wild poliovirus in their intestines if exposed, though they remain protected from paralysis. *The combined schedules of IPV and OPV appear to reduce or prevent Vaccine Associated Paralytic Polio (VAPP)* - This statement is **correct**. VAPP is a rare complication (1 in 2.4 million doses) associated with OPV due to reversion of the live attenuated virus. - Using IPV first (which contains killed virus and cannot cause VAPP) followed by OPV reduces VAPP risk because the initial doses carry no reversion risk. - This sequential strategy maintains the benefits of OPV (mucosal immunity) while minimizing VAPP occurrence. *It will be cost effective in developing countries for Polio prevention* - This statement is **correct**, though context-dependent. Sequential IPV-OPV schedules represent a balance between optimal immunogenicity and practical implementation. - While IPV alone is more expensive than OPV, using **limited IPV doses followed by OPV** (as recommended by WHO) is cost-effective because it reduces VAPP while maintaining the transmission-blocking benefits of OPV. - Many developing countries have successfully implemented fractional-dose IPV in sequential schedules, making this approach feasible and cost-effective for polio eradication programs. *IPV and OPV together may optimize both the humoral and mucosal immunogenicity of Polio vaccine* - This statement is **correct** and represents the scientific rationale for sequential schedules. - **IPV provides robust systemic humoral immunity** (high serum IgG antibodies), protecting against paralytic disease and viremia. - **OPV stimulates strong intestinal mucosal immunity** (secretory IgA), preventing viral replication and shedding in the gut, thereby interrupting transmission. - Sequential administration leverages the complementary strengths of both vaccines for comprehensive individual and community protection.

Question 372: Pentavalent vaccine provides protection against which of the following diseases?

A. Diphtheria, Pertussis, Tuberculosis, Measles and Hepatitis B
B. Diphtheria, Pertussis, Tetanus, Hepatitis B and Hib (Correct Answer)
C. Diphtheria, Pertussis, Tetanus, Hepatitis B and Rubella
D. Diphtheria, Pertussis, Measles, Hepatitis B and Hib

Explanation: ***Diphtheria, Pertussis, Tetanus, Hepatitis B and Hib*** - The **Pentavalent vaccine** is a combination vaccine that provides protection against five common childhood diseases. - These five diseases are **Diphtheria**, **Pertussis** (whooping cough), **Tetanus**, **Hepatitis B**, and infections caused by **Haemophilus influenzae type b (Hib)**. *Diphtheria, Pertussis, Tuberculosis, Measles and Hepatitis B* - While it includes **Diphtheria**, **Pertussis**, and **Hepatitis B**, this option incorrectly lists **Tuberculosis** and **Measles** as components. - The vaccine for Tuberculosis is **BCG**, and Measles is part of the MMR vaccine, not the pentavalent vaccine. *Diphtheria, Pertussis, Tetanus, Hepatitis B and Rubella* - This option correctly identifies **Diphtheria**, **Pertussis**, **Tetanus**, and **Hepatitis B** but incorrectly includes **Rubella**. - **Rubella** is typically part of the **MMR vaccine**, not the pentavalent vaccine. *Diphtheria, Pertussis, Measles, Hepatitis B and Hib* - This option correctly includes **Diphtheria**, **Pertussis**, **Hepatitis B**, and **Hib**, but incorrectly lists **Measles**. - **Measles** is administered as part of the **MMR vaccine**, not as a component of the pentavalent vaccine.

Question 373: Which statement is TRUE regarding the relationship between HPV vaccination and cervical cancer screening?

A. Vaccinated women require less frequent screening than unvaccinated women
B. Screening recommendations are currently the same regardless of vaccination status (Correct Answer)
C. HPV vaccination eliminates the need for cervical cancer screening
D. Screening should begin at a younger age in vaccinated women

Explanation: ***Screening recommendations are currently the same regardless of vaccination status*** * Current guidelines recommend the same cervical cancer screening schedule for all eligible individuals, **regardless of their HPV vaccination status**. * This is because the HPV vaccine does not protect against all oncogenic HPV types, and individuals may have been exposed to HPV prior to vaccination. *Vaccinated women require less frequent screening than unvaccinated women* * This statement is incorrect because there is **no evidence to support less frequent screening** for vaccinated women. * The persistence of **high-risk HPV types not covered by the vaccine** and the possibility of prior exposure necessitate consistent screening. *HPV vaccination eliminates the need for cervical cancer screening* * This is incorrect; HPV vaccination significantly reduces the risk of cervical cancer but **does not eliminate it completely**. * Vaccines protect against the most common high-risk HPV types but **not all of them**, making continued screening essential. *Screening should begin at a younger age in vaccinated women* * This is incorrect; current guidelines recommend the **same starting age for cervical cancer screening** (typically 21 or 25, depending on the guideline) for both vaccinated and unvaccinated women. * There is **no clinical rationale to initiate screening earlier** in vaccinated individuals.

Question 374: Which of the following vaccines should be stored at the lowest level in an Ice-Lined Refrigerator (ILR)?

A. OPV (Correct Answer)
B. DPT
C. Hep B
D. Rota

Explanation: ***OPV (Oral Polio Vaccine)*** - **OPV** is a **heat-sensitive** vaccine that requires storage at the **coldest temperature** to maintain its potency. - In the traditional ILR storage protocol, OPV is stored at the **lowest level** (bottom shelf) where the temperature is coldest (0-2°C). - This positioning helps prevent heat degradation of the live attenuated virus. - **Note:** OPV has been largely replaced by IPV in India's routine immunization, but this remains a standard exam concept. *DPT (Diphtheria, Pertussis, Tetanus)* - DPT is a **freeze-sensitive vaccine** that should NOT be stored at the coldest parts of the refrigerator. - Freezing can cause **flocculation** and loss of potency, particularly affecting the pertussis component. - Stored in the **middle shelves** to avoid both freezing and excessive heat. *Hepatitis B* - Hepatitis B vaccine is **highly freeze-sensitive** and can lose efficacy permanently if frozen. - The aluminum adjuvant aggregates when frozen, reducing immunogenicity. - Stored in the **middle or upper shelves**, away from the coldest zone. *Rotavirus Vaccine* - Rotavirus vaccine is **freeze-sensitive** and must be protected from sub-zero temperatures. - Freezing can damage the viral particles and reduce vaccine effectiveness. - Stored in the **middle or upper shelves** of the ILR. **Key Principle:** In ILR storage, heat-sensitive vaccines (OPV, measles) go at the bottom (coldest), while freeze-sensitive vaccines (DPT, Hep B, IPV, Rota) go in the middle/upper shelves to prevent freezing damage.

Question 375: In an outbreak of encephalitis in a community, according to the Universal Immunization Schedule, what is the route of administration for the vaccine likely used for the infection?

A. Live & subcutaneous
B. Killed & intramuscular
C. Live & intramuscular (Correct Answer)
D. Killed & subcutaneous

Explanation: ***Live & intramuscular*** - The most common cause of encephalitis in outbreaks included in the Universal Immunization Schedule is **Japanese Encephalitis (JE)**, for which the **live attenuated SA 14-14-2 vaccine** is administered **intramuscularly**. - As per the **National Immunization Schedule of India (current UIP)**, JE vaccine is given via **IM route** at 9-12 months of age. - **Live attenuated vaccines** stimulate a strong, long-lasting immune response, often with a single dose. *Incorrect: Live & subcutaneous* - While the older **inactivated JE vaccine** (used before 2013) was given subcutaneously, the **current live attenuated SA 14-14-2 vaccine** used in India's UIP is administered **intramuscularly**. - Subcutaneous route was appropriate for the older killed vaccine formulation but not for the current live vaccine. *Incorrect: Killed & intramuscular* - The current JE vaccine in India's UIP is **live attenuated, not killed**. - While killed vaccines are often given intramuscularly (e.g., inactivated polio), the primary vaccine for encephalitis outbreaks is the **live SA 14-14-2 vaccine**. - Killed vaccines typically require **multiple doses** and boosters to achieve adequate immunity. *Incorrect: Killed & subcutaneous* - Although the **older inactivated (killed) JE vaccine** was given subcutaneously before 2013, this has been replaced in the UIP. - The **current standard** is the live attenuated vaccine given intramuscularly, which provides better immunogenicity and requires fewer doses.

Question 376: In a 10-year-old school child under the school health program, which vaccine should be administered?

A. DPT
B. BCG
C. Td (Correct Answer)
D. MMR

Explanation: ***Td (Tetanus-Diphtheria)*** - For a 10-year-old child under the school health program in India, the recommended vaccination is a booster dose of **Td (tetanus-diphtheria)**. - This ensures continued **protection against tetanus and diphtheria**, as immunity from the primary series may wane over time. - **Td is preferred over TT** (tetanus toxoid alone) as it provides protection against both tetanus and diphtheria. - This is administered at **10 years and 16 years** as per the Indian Academy of Pediatrics immunization schedule. *DPT* - **DPT (diphtheria, pertussis, tetanus)** is administered in infancy and early childhood (at 6, 10, and 14 weeks, with boosters at 16-24 months and 4-6 years). - The **pertussis component is not given** in later childhood or adolescence due to increased reactogenicity in older children. *BCG* - **BCG (Bacille Calmette-Guérin)** vaccine protects against tuberculosis and is given **at birth** in endemic areas like India. - It is **not routinely administered** to a 10-year-old unless there are specific risk factors or documented non-vaccination status. *MMR* - **MMR (measles, mumps, rubella)** vaccine is given as **two doses**: first at 9-12 months and second at 16-24 months (or 4-6 years). - A 10-year-old child would have **already completed** their MMR vaccination schedule.

Question 377: Which of the following regarding the vaccine vial monitor (VVM) is true? 1. It is used for monitoring heat exposure of the vaccine by healthcare workers in primary healthcare. 2. It shows cumulative exposure of the vaccine to the heat. 3. It can be used to assess the potential efficacy of the vaccine 4. Calculation of the expiry date can be done using VVM. 5. The expiry date of the vaccine can be relaxed if VVM is an acceptable range. 6. If the square and the circle are the same in color, then the vaccine can be safely used.

A. 1,2,3,4,5
B. 3,4
C. 1,2 (Correct Answer)
D. 5,6

Explanation: ***Correct: Statements 1, 2*** **Statement 1 - TRUE**: The VVM is primarily designed for **healthcare workers** to monitor vaccine heat exposure at all levels, including primary healthcare settings. This is a key WHO tool for cold chain monitoring. **Statement 2 - TRUE**: VVMs provide a **cumulative record** of time and temperature exposure, reflecting the total heat stress a vaccine has experienced throughout its journey from manufacturer to administration. *Statement 3 - FALSE* - While VVMs assess heat exposure that affects vaccine stability, they do **not directly measure vaccine efficacy** or provide quantitative measures of immune response potential. - Heat damage indicated by VVM indirectly suggests reduced potency, but the VVM itself cannot assess efficacy. *Statement 4 - FALSE* - VVMs are **not used to calculate expiry dates**. Manufacturing expiry dates are determined through stability studies under controlled conditions by the manufacturer. *Statement 5 - FALSE* - The **expiry date cannot be relaxed or extended** based on VVM status. The manufacturer's stated expiry date must always be respected regardless of how favorable the VVM reading is. *Statement 6 - FALSE* - This is the **opposite** of how VVM works. If the **inner square is the same color or darker than the outer circle**, the vaccine has been exposed to excessive heat and **should NOT be used**. - The vaccine is safe when the inner square is lighter than the outer circle.

Question 378: Recommended HPV vaccination schedule for 9 to 14-year-olds according to WHO SAGE guidelines is:

A. 1 or 2 doses (Correct Answer)
B. 3 doses
C. 3 or 4 doses
D. 4 doses

Explanation: ***1 or 2 doses*** - The **WHO Strategic Advisory Group of Experts (SAGE)** on Immunization recommends a simplified **one- or two-dose schedule** for girls and boys aged 9–14 years. - This recommendation, updated in April 2022, is based on evidence demonstrating comparable efficacy of **single-dose HPV vaccination** to multi-dose regimens in this age group, while improving accessibility and uptake. - **Key advantage**: Reduced doses improve vaccination completion rates and reduce programmatic costs without compromising protection. *3 doses* - A **three-dose schedule** (0, 1-2, 6 months) was the original recommendation but is **no longer recommended** for the 9–14 age group. - Three doses are now reserved for **immunocompromised individuals** or those starting vaccination at older ages in some guidelines. - Maintaining a three-dose schedule would increase costs and reduce completion rates unnecessarily. *3 or 4 doses* - **Four doses** have never been part of any WHO HPV vaccination recommendation. - This option represents an excessive and unsupported schedule that would create unnecessary barriers to vaccination coverage. *4 doses* - **Four doses** are not recommended by WHO SAGE for any age group or clinical scenario. - This would represent over-vaccination without evidence of additional benefit and would significantly impair program implementation.

Question 379: Which is not a contraindication for OPV?

A. Leukemia
B. Malignancy
C. Immunocompromised
D. Diarrhoea (Correct Answer)

Explanation: ***Diarrhoea*** - **Diarrhoea** is not considered a contraindication for OPV; while it may reduce vaccine efficacy, the vaccine should still be administered. - Minor illnesses, including mild **gastrointestinal upset**, are not reasons to defer vaccination. *Leukemia* - **Leukemia** is a **malignancy** of the blood cells, leading to an **immunocompromised state**. - Live vaccines like OPV are generally **contraindicated** in individuals with leukemia due to the risk of vaccine-associated paralytic poliomyelitis (VAPP). *Malignancy* - Children with **malignancies**, especially those undergoing treatment like **chemotherapy** or **radiation**, are often **immunocompromised**. - Live oral vaccines are typically **contraindicated** in these patients to prevent serious infections from the live attenuated virus. *Immunocompromised* - Being **immunocompromised**, whether due to disease (e.g., HIV, primary immunodeficiency) or medication (e.g., high-dose corticosteroids), is a **contraindication** for live attenuated vaccines like OPV. - The weakened immune system cannot effectively clear the vaccine virus, leading to a higher risk of **serious infection** or **vaccine-associated paralysis**.

Question 380: Yellow fever vaccine is valid for?

A. 20 years
B. 5 years
C. Lifelong (Correct Answer)
D. 10 years

Explanation: ***Life long*** - As per the **International Health Regulations (IHR) 2005**, a single dose of yellow fever vaccine provides **lifelong protection**, eliminating the need for booster doses. - This change in policy reflects robust evidence demonstrating sustained immunity beyond 10 years, making previous 10-year validity periods obsolete. *20 years* - While reflecting a prolonged period of protection, **20 years** is not the officially recognized validity period. - The latest WHO recommendations state **lifelong validity**, superseding previous duration estimates. *5 years* - A 5-year validity period was used historically but is now outdated. - **Evidence has shown long-term immunity**, supporting a much longer, effectively lifelong, protection. *10 years* - The **10-year validity** was the standard for many years, necessitating booster doses for travelers. - This has been updated to **lifelong validity** based on conclusive data proving persistent protective immunity.

Practice by Chapter

Principles of Immunization

Practice Questions

Types of Vaccines

Practice Questions

Universal Immunization Program

Practice Questions

Cold Chain System

Practice Questions

Vaccine Storage and Handling

Practice Questions

Adverse Events Following Immunization

Practice Questions

National Immunization Schedule

Practice Questions

Polio Eradication

Practice Questions

Measles Elimination

Practice Questions

Tetanus Control

Practice Questions

New and Underutilized Vaccines

Practice Questions

Vaccination Coverage Assessment

Practice Questions

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