Immunization and Vaccine-Preventable Diseases Practice Questions

Q: 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?

Live & intramuscular. ***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.

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

Td. ***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.

Q: 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.

1,2. ***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.

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

1 or 2 doses. ***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.

Q: Which is not a contraindication for OPV?

Diarrhoea. ***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**.

Q: Yellow fever vaccine is valid for?

Lifelong. ***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.

Q: Management of non-immunized diphtheria contacts includes all except:

Daily throat swab culture. ***Daily throat swab culture*** - **Daily throat swab cultures** are not part of standard management for non-immunized diphtheria contacts as they are impractical, resource-intensive, and unnecessary. - Standard practice involves a **single throat/nasal culture** at the time of contact identification to detect carriers, not repeated daily cultures. - Daily clinical surveillance (visual examination) is sufficient for monitoring symptom development. *Daily throat examination* - **Daily clinical throat examination** is a crucial component of contact management for early detection of membrane formation or pharyngitis. - This allows prompt isolation and treatment if symptoms develop during the incubation period (2-5 days). - Visual inspection is practical and cost-effective for daily monitoring. *Prophylactic penicillin* - **Prophylactic antibiotics** (benzathine penicillin single dose IM or 7-10 days of oral erythromycin) are essential for all diphtheria contacts regardless of immunization status. - This eradicates potential colonization with *Corynebacterium diphtheriae* and prevents disease development. - Reduces transmission risk during the incubation period. *Weekly throat swab examination* - While **not part of routine management**, weekly swabs are more reasonable than daily cultures if extended monitoring is needed in special circumstances. - Standard protocol involves a **single culture** at identification, not repeated weekly sampling. - The key distinction: daily cultures are clearly excessive, making this the correct answer for what is NOT included in standard management.

Q: Mass vaccination is ineffective in inducing 'herd immunity' for:

Tetanus. ***Tetanus (Correct Answer)*** - **Herd immunity** relies on reducing person-to-person transmission, which is not applicable to tetanus as it is acquired through **environmental exposure** (soil contaminated with *Clostridium tetani* spores), not human contact - Vaccination against tetanus provides **individual protection only** and does not prevent disease spread within a population, making mass vaccination ineffective for herd immunity - Tetanus is a **non-communicable disease** - immunity in others does not protect unvaccinated individuals *Poliomyelitis (Incorrect)* - Mass vaccination for poliomyelitis has been highly effective in establishing **herd immunity**, leading to near-global eradication - The vaccine prevents viral shedding and breaks the chain of transmission - High vaccination coverage protects unvaccinated individuals through reduced viral circulation *Measles (Incorrect)* - Mass vaccination against measles is extremely effective in inducing **herd immunity** due to its high transmissibility (R₀ = 12-18) - Requires **~95% vaccination coverage** to maintain herd immunity - Classic example where high vaccination rates protect vulnerable individuals who cannot be vaccinated *None of the options (Incorrect)* - This is incorrect because tetanus is a clear example where mass vaccination does **not** induce herd immunity - The disease's environmental transmission pattern makes herd immunity irrelevant for disease control

Q: Regarding BCG vaccine, which of the following is untrue?

Orally administered. ***Orally administered*** - The **BCG vaccine** is not administered orally; it is typically given via an **intradermal injection**, usually in the upper arm. - Oral administration is a route used for some vaccines, but not for BCG. *T.B. vaccine* - The **BCG vaccine** is indeed a vaccine against **tuberculosis (TB)**, making this statement true. - It works by using a live, attenuated strain of *Mycobacterium bovis* to provide immunity against *Mycobacterium tuberculosis*. *All of the options* - Since the statement "Orally administered" is untrue, this option cannot be correct. - The BCG vaccine is not administered orally, which makes that specific claim false. *live vaccine* - The **BCG vaccine** is a **live attenuated vaccine**, meaning it contains a weakened form of the *Mycobacterium bovis* bacterium. - This characteristic allows it to stimulate a strong immune response, making this statement true.

Q: A mother brings her 9 month old child for vaccination. Which of the following statements is false regarding immunization of Japanese encephalitis?

Live vaccine SA 14-14-2 is administered intramuscularly. ***Live vaccine SA 14-14-2 is administered intramuscularly*** - The live attenuated **JE vaccine SA 14-14-2** is approved for subcutaneous (SC) administration, not intramuscular (IM). - While some vaccines are given IM, the specific instructions for this live JE vaccine specify the **subcutaneous route**. *2 doses are recommended at age 9 months and 18 months* - This statement is **true** for the live attenuated Japanese Encephalitis vaccine, as two doses at 9 and 18 months provide good long-term protection. - This schedule is commonly adopted in JE-endemic regions for comprehensive immunization. *The live attenuated vaccine can be given to adolescents* - This statement is **true**, as the live attenuated JE vaccine is approved for use across a wide age range, including adolescents, for primary immunization or as a booster. - The vaccine is generally well-tolerated and effective in this age group. *The strain used for live vaccine is JE strain SA 14-14-2* - This statement is **true**; the **SA 14-14-2 strain** is the most widely used and well-characterized live attenuated Japanese Encephalitis vaccine globally. - It has demonstrated high efficacy and a good safety profile in preventing JE caused by various genotypes.

Question 1

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?

Accepted Answer

Live & intramuscular

Answer

Live & subcutaneous

Answer

Killed & intramuscular

Answer

Killed & subcutaneous

Question 2

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

Accepted Answer

Td

Answer

DPT

Answer

BCG

Answer

MMR

Question 3

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.

Accepted Answer

1,2

Answer

1,2,3,4,5

Answer

3,4

Answer

5,6

Question 4

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

Accepted Answer

1 or 2 doses

Answer

3 doses

Answer

3 or 4 doses

Answer

4 doses

Question 5

Which is not a contraindication for OPV?

Accepted Answer

Diarrhoea

Answer

Leukemia

Answer

Malignancy

Answer

Immunocompromised

Question 6

Yellow fever vaccine is valid for?

Accepted Answer

Lifelong

Answer

20 years

Answer

5 years

Answer

10 years

Question 7

Management of non-immunized diphtheria contacts includes all except:

Accepted Answer

Daily throat swab culture

Answer

Daily throat examination

Answer

Prophylactic penicillin

Answer

Weekly throat swab examination

Question 8

Mass vaccination is ineffective in inducing 'herd immunity' for:

Accepted Answer

Tetanus

Answer

Poliomyelitis

Answer

None of the options

Answer

Measles

Question 9

Regarding BCG vaccine, which of the following is untrue?

Accepted Answer

Orally administered

Answer

T.B. vaccine

Answer

All of the options

Answer

live vaccine

Question 10

A mother brings her 9 month old child for vaccination. Which of the following statements is false regarding immunization of Japanese encephalitis?

Accepted Answer

Live vaccine SA 14-14-2 is administered intramuscularly

Answer

2 doses are recommended at age 9 months and 18 months

Answer

The live attenuated vaccine can be given to adolescents

Answer

The strain used for live vaccine is JE strain SA 14-14-2

Immunization and Vaccine-Preventable Diseases — MCQs

Immunization and Vaccine-Preventable Diseases — MCQs

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