Immunization and Vaccine-Preventable Diseases Practice Questions

Q: Which one of the following vaccines is known to interfere with the Yellow Fever vaccine if administered within 3 weeks of each other?

Measles vaccine. ***Correct: Measles vaccine*** - **Measles vaccine (MMR)** is a **live attenuated viral vaccine** that can interfere with yellow fever vaccine immune response - Both are live viral vaccines and CDC/WHO guidelines recommend they be administered **simultaneously OR separated by ≥4 weeks** - When live viral vaccines are given too close together (but not simultaneously), immune interference can reduce antibody response to the second vaccine - This is due to **interferon production** from the first vaccine suppressing replication of the second vaccine virus *Incorrect: Typhoid vaccine* - While **oral typhoid vaccine (Ty21a)** is live attenuated, it is a **bacterial vaccine** and does not have the same viral interference pattern - Can generally be co-administered with yellow fever vaccine without significant spacing requirements - Main concern with oral typhoid is interference from **antibiotics and antimalarials**, not other vaccines *Incorrect: Tetanus toxoid* - **Inactivated vaccine** that does not interfere with live vaccines - Can be given simultaneously or at any interval with yellow fever vaccine - No immune competition with live viral vaccines *Incorrect: Cholera vaccine* - Currently available **oral cholera vaccines** (CVD 103-HgR or killed whole-cell vaccines) do not have documented interference with yellow fever - No specific spacing requirements with yellow fever vaccine - Can be co-administered or given at any interval **Note:** This question is from UPSC-CMS 2022. The original exam key may have listed typhoid, but current CDC and WHO immunization guidelines identify measles (MMR) as the primary vaccine requiring spacing with yellow fever due to live viral vaccine interference.

Q: Which of the following is a rare vaccine reaction known to occur with BCG vaccine in immunocompetent individuals?

Osteitis. ***Osteitis*** - **Osteitis** (inflammation of bone) is a **rare complication** of the BCG vaccine, occurring in **immunocompetent individuals**, particularly infants. - Incidence: approximately **1-30 cases per million doses**. - It results from the **dissemination of live attenuated *Mycobacterium bovis*** (the strain used in BCG) to bone tissue. - Typically presents months after vaccination with localized bone pain and swelling. *Guillain-Barré syndrome* - **Guillain-Barré syndrome** is a rare neurological disorder characterized by rapid-onset muscle weakness. - While it can be triggered by various infections and, rarely, by some vaccines (e.g., influenza vaccine), it is **not specifically associated with the BCG vaccine**. *Suppurative lymphadenitis* - **Suppurative lymphadenitis** (inflammation and pus formation in lymph nodes) is a **relatively common adverse reaction** to the BCG vaccine, not a rare one. - Incidence: **0.01-4.3%** of vaccinees. - It typically occurs in regional lymph nodes draining the injection site and usually resolves with conservative management or needle aspiration. *Disseminated infection* - **Disseminated BCG infection** is an **extremely rare** complication (0.06-1.56 per million doses). - It occurs **primarily in immunocompromised individuals** (e.g., severe combined immunodeficiency, HIV). - This is a contraindication-related complication rather than a typical vaccine reaction in the general population. - The question specifies immunocompetent individuals, making **osteitis** the most appropriate answer as it represents the classic rare complication in normal hosts.

Q: What is the shelf life of Dukoral (wc-rBS) oral vaccine used for cholera prevention, when stored at a temperature of 2 °C to 8 °C?

2 years. ***2 years***- Dukoral (wc-rBS) oral vaccine, when stored correctly at **2 °C to 8 °C**, maintains its efficacy and stability for **2 years**. - This is the manufacturer-specified shelf life that ensures the vaccine remains potent and safe for use. - The vaccine contains inactivated whole-cell V. cholerae and recombinant cholera toxin B subunit, with a validated 2-year stability period. *3 years*- A 3-year shelf life is an **overestimation** for Dukoral under standard refrigerated storage conditions. - Beyond the validated 2-year period, the vaccine's potency cannot be guaranteed. - This could lead to administration of potentially ineffective vaccine. *6 months*- A 6-month shelf life is significantly **underestimated** for Dukoral, indicating a lack of understanding of vaccine stability. - Such a short duration would lead to premature discarding of usable vaccine and increased waste. - Most modern refrigerated vaccines have longer shelf lives than this. *5 years*- A 5-year shelf life is a significant **overestimation** for Dukoral (wc-rBS). - This duration exceeds the manufacturer's validated stability data for this oral vaccine. - Using vaccine beyond its validated shelf life poses risks of reduced immunogenicity.

Q: As a part of the Universal Immunization Programme in India, the Inactivated Polio Vaccine (IPV) given as fractional IPV by intradermal route is first administered at what age?

6 weeks. ***6 weeks*** - In the Universal Immunization Programme (UIP) in India, the first dose of **fractional Inactivated Polio Vaccine (fIPV)** is administered to infants at **6 weeks of age** via the **intradermal route**. - This timing coordinates with other routine vaccinations given at 6 weeks, such as the first dose of the **pentavalent vaccine** (diphtheria, pertussis, tetanus, Hepatitis B, and Hib). *14 weeks* - The second dose of **fIPV** is typically administered at **14 weeks of age** within the UIP schedule. - This dose also aligns with other scheduled vaccinations at 14 weeks, reinforcing immunity against polio. *9 months* - At **9 months of age**, infants receive the first dose of **measles and rubella (MR) vaccine** and **Vitamin A supplementation** under the UIP. - No polio vaccine doses are scheduled at 9 months. *Birth* - At birth, infants are given the **oral polio vaccine (OPV0)**, **Hepatitis B birth dose**, and **Bacille Calmette-Guérin (BCG) vaccine**. - While initial polio immunization begins at birth, the **IPV is not administered at this stage**.

Q: Toxic shock syndrome occurs after one of the following vaccinations :

DPT. ***DPT*** - Toxic shock syndrome has been **extremely rarely reported in isolated case reports following DPT** (diphtheria, pertussis, tetanus) vaccination, though it is **not a recognized or established complication** in standard medical literature. - The association is controversial and based on very limited data. Any potential link may be related to coincidental bacterial infection rather than a direct vaccine effect. - Among the options listed, this has the most (though minimal) reported association with **TSS-like reactions** in historical case reports. *Measles vaccine* - The measles vaccine is a **live attenuated vaccine** and does not cause toxic shock syndrome. - Its adverse effects are usually related to a mild form of the disease or allergic reactions, not **bacterial toxin-mediated illnesses like TSS**. *BCG vaccine* - The BCG (Bacille Calmette-Guérin) vaccine is used against tuberculosis and is a **live attenuated vaccine**. - Adverse effects are commonly local reactions or disseminated BCG disease in immunocompromised individuals, not **toxic shock syndrome**. *Recombinant DNA Vaccine against Hepatitis B* - Recombinant DNA vaccines, like the Hepatitis B vaccine, are highly purified and contain **no live pathogens or bacterial toxins**. - They are associated with very few severe adverse events, none of which include **toxic shock syndrome**.

Q: A 9-month-old infant is brought to you for immunization. The infant has previously received the first dose of OPV and DPT. What will you do ?

Give the infant second dose of DPT/OPV. ***Give the infant second dose of DPT/OPV*** - As per the **Expanded Programme on Immunization (EPI)** guidelines, even if there's a delay, one should **continue the vaccination schedule** from where it left off, rather than restarting. - The 9-month-old is due for the **second dose of DPT and OPV**, as the first dose has already been administered. *Give the infant DT/OPV* - **DT (Diphtheria and Tetanus)** vaccine is generally given to older children who have contraindications to the pertussis component of DPT or as part of a different schedule. - At 9 months, the infant still requires the **pertussis component** for protection against whooping cough. *Repeat the first dose counting afresh* - There is **no clinical or immunological basis** for restarting the vaccination schedule (counting afresh) simply because of a delay. - Antibodies from the first dose are still present and contribute to the immune response upon subsequent doses; hence, previous doses are **considered valid**. *Give the infant a booster dose of DPT/Polio* - A **booster dose** is typically given much later in childhood (e.g., at 18 months or 5 years) to enhance and prolong immunity after the primary series is completed. - The infant first needs to **complete the primary series** of DPT and OPV, which involves a second and third dose.

Q: In which of the following diseases is post-exposure immunisation prescribed?

Rabies. ***Rabies*** - **Rabies post-exposure prophylaxis (PEP)** is critical with documented or suspected exposure, given its near 100% fatality rate once symptoms appear. - PEP consists of both **rabies vaccine** and **rabies immunoglobulin** administered as soon as possible after exposure. *Poliomyelitis* - Poliovirus vaccination is a **pre-exposure intervention** aimed at preventing infection in the first place through herd immunity. - There is no specific post-exposure immunization strategy for polio once exposure has occurred. *Yellow fever* - The yellow fever vaccine is a highly effective **pre-exposure preventive measure** for individuals traveling to or living in endemic areas. - While it provides long-lasting immunity, it is not used as a post-exposure treatment. *Cholera* - Cholera vaccines are primarily used for **pre-exposure prevention**, especially for travelers or populations in endemic areas. - Post-exposure management of cholera focuses on **rehydration therapy** and antibiotics, not immunization.

Q: Consider the following statements regarding Vaccine Vial Monitor (VVM) on the vial of oral polio vaccine : The vaccine is not potent and should be discarded 1. if the colour of the small square within the circle is lighter in colour than that of the circle 2. if the small square within the circle is of the same colour as the circle 3. if the small square within the circle is darker in colour than the colour of the circle Which of the statements given above is/are correct?

2 and 3. ***2 and 3*** - A vaccine vial is considered **not potent and should be discarded** if the inner square is the **same color as or darker than** the outer circle, as this indicates **heat exposure** reducing vaccine efficacy. - **Statement 2** (same color) indicates the vaccine has reached the **discard point** due to cumulative heat exposure, and **statement 3** (darker color) indicates the vaccine is **beyond the discard point**, both requiring immediate disposal. - VVMs are crucial for ensuring **cold chain integrity**; the color change of the inner square relative to the outer circle signifies cumulative heat damage and loss of potency. *2 only* - While statement 2 correctly identifies that a vaccine should be discarded when the inner square is the **same color** as the outer circle, this option **omits statement 3**. - Statement 3 (darker inner square) also correctly indicates the vaccine should be discarded, making this option **incomplete**. *1 only* - This statement is **incorrect** because a **lighter inner square** compared to the outer circle indicates that the vaccine has been exposed to **minimal heat**, meaning the vaccine is **still potent and safe to use**. - A lighter inner square is the **ideal state** for a VVM, signifying a correctly maintained cold chain; the vaccine should **NOT be discarded** in this scenario. *1 and 2* - Statement 1 is **incorrect** because when the inner square is **lighter** than the outer circle, the vaccine remains **potent and should continue to be used**, not discarded. - Only statement 2 is correct in this combination, but statement 3 is also correct and should be included, making this option wrong.

Question 1

Which one of the following vaccines is known to interfere with the Yellow Fever vaccine if administered within 3 weeks of each other?

Accepted Answer

Measles vaccine

Answer

Tetanus toxoid

Answer

Cholera vaccine

Answer

Typhoid vaccine

Question 2

Which of the following is a rare vaccine reaction known to occur with BCG vaccine in immunocompetent individuals?

Accepted Answer

Osteitis

Answer

Guillain-Barre syndrome

Answer

Suppurative lymphadenitis

Answer

Disseminated infection

Question 3

What is the shelf life of Dukoral (wc-rBS) oral vaccine used for cholera prevention, when stored at a temperature of 2 °C to 8 °C?

Accepted Answer

2 years

Answer

3 years

Answer

6 months

Answer

5 years

Question 4

Which of the following statements regarding the Open Vial Policy, 2015 are correct?

1. It applies only for DPT, TT, Hepatitis B, OPV and Liquid Pentavalent vaccine.
2. Vaccine vials opened in session-site can be used again provided a vaccine vial monitor has not reached the discard point.
3. Open vial should never be submerged in water.
4. Open vials of BCG, Measles and JE should be preserved till the next immunization session.

Accepted Answer

2. Vaccine vials opened in session-site can be used again provided a vaccine vial monitor has not reached the discard point.

Answer

4. Open vials of BCG, Measles and JE should be preserved till the next immunization session.

Answer

3. Open vial should never be submerged in water.

Answer

1. It applies only for DPT, TT, Hepatitis B, OPV and Liquid Pentavalent vaccine.

Question 5

As a part of the Universal Immunization Programme in India, the Inactivated Polio Vaccine (IPV) given as fractional IPV by intradermal route is first administered at what age?

Accepted Answer

6 weeks

Answer

14 weeks

Answer

9 months

Answer

Birth

Question 6

The order of priority of immunization strategy to prevent congenital rubella infection from first to last is :

Accepted Answer

Infants → children 1-14 years → women of reproductive age group

Answer

Women of reproductive age group → children 1-14 years → Infants

Answer

Infants → women of reproductive age group → children 1-14 years

Answer

Women of reproductive age group → Infants → children 1-14 years

Question 7

Toxic shock syndrome occurs after one of the following vaccinations :

Accepted Answer

DPT

Answer

Measles vaccine

Answer

BCG vaccine

Answer

Recombinant DNA Vaccine against Hepatitis B

Question 8

A 9-month-old infant is brought to you for immunization. The infant has previously received the first dose of OPV and DPT. What will you do ?

Accepted Answer

Give the infant second dose of DPT/OPV

Answer

Give the infant DT/OPV

Answer

Repeat the first dose counting afresh

Answer

Give the infant a booster dose of DPT/Polio

Question 9

In which of the following diseases is post-exposure immunisation prescribed?

Accepted Answer

Rabies

Answer

Poliomyelitis

Answer

Yellow fever

Answer

Cholera

Question 10

Consider the following statements regarding Vaccine Vial Monitor (VVM) on the vial of oral polio vaccine :
The vaccine is not potent and should be discarded

1. if the colour of the small square within the circle is lighter in colour than that of the circle

2. if the small square within the circle is of the same colour as the circle

3. if the small square within the circle is darker in colour than the colour of the circle
Which of the statements given above is/are correct?

Accepted Answer

2 and 3

Answer

1 only

Answer

1 and 2

Answer

2 only

Immunization and Vaccine-Preventable Diseases — MCQs

Immunization and Vaccine-Preventable Diseases — MCQs

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