Immunization and Vaccine-Preventable Diseases Practice Questions

Q: What is the recommended vaccination strategy for rubella?

Women of reproductive age (15-49 years). ### Explanation The primary objective of Rubella vaccination is not just to prevent the mild, self-limiting infection in children, but to prevent **Congenital Rubella Syndrome (CRS)**. When a non-immune pregnant woman contracts Rubella, the virus can cross the placenta, leading to severe fetal malformations, deafness, and cardiac defects. **Why Option A is Correct:** Targeting **women of reproductive age (15-49 years)** is the most effective strategy to provide immediate protection against CRS. By ensuring this cohort is immune, the risk of vertical transmission during pregnancy is eliminated. In the context of public health and NEET-PG, this is often referred to as the "selective" or "targeted" strategy to reduce the disease burden where it is most devastating. **Why Other Options are Incorrect:** * **B & D (Infants/Children):** While the Universal Immunization Programme (UIP) in India now uses the MR (Measles-Rubella) vaccine for children (9 months to 15 years) to build herd immunity, this is a long-term strategy. The immediate priority for preventing CRS remains the reproductive age group. * **C (Adolescent girls):** While important, this is a subset of the reproductive age group. Targeting the entire 15-49 age bracket ensures a wider safety net for all potential pregnancies. **High-Yield Clinical Pearls for NEET-PG:** * **Vaccine Type:** Live attenuated (RA 27/3 strain is most common). * **Contraindication:** Pregnancy. Women should be advised to **avoid pregnancy for 4 weeks (1 month)** after receiving the Rubella vaccine. * **CRS Triad (Gregg’s Triad):** Cataract, Sensorineural deafness, and Cardiac defects (Patent Ductus Arteriosus). * **Diagnostic Tip:** Rubella is also known as "German Measles" or "3-day measles."

Q: All of the following is true about Hepatitis B Vaccination except?

It is a live attenuated vaccine.. **Explanation:** **1. Why Option C is the Correct Answer (The False Statement):** Hepatitis B vaccine is **not** a live attenuated vaccine. It is a **Recombinant DNA vaccine** (Subunit vaccine). It is produced by inserting the gene for Hepatitis B surface antigen (HBsAg) into common baker’s yeast (*Saccharomyces cerevisiae*). The yeast then produces pure HBsAg, which is harvested and used as the immunogen. **2. Analysis of Other Options:** * **Option A:** Healthcare workers (HCWs), especially surgeons and laboratory staff, are at high risk for occupational exposure to blood-borne pathogens. Vaccination is mandatory to prevent horizontal transmission. * **Option B:** Under the National Immunization Schedule (NIS), a **birth dose** is recommended within 24 hours to prevent mother-to-child (vertical) transmission, which carries a high risk of chronic carrier status. * **Option C:** While routine boosters are not recommended for the general population, a booster dose is indicated for individuals (especially HCWs) who fail to achieve protective antibody levels (**Anti-HBs titres < 10 mIU/mL**) after the primary series. **3. High-Yield Clinical Pearls for NEET-PG:** * **Type:** First-generation vaccines were plasma-derived; current (second-generation) vaccines are recombinant. * **Route & Site:** Intramuscular (IM). In infants, it is given in the **Anterolateral aspect of the thigh**; in adults, the **Deltoid**. *Note: Never give it in the gluteal region as it results in lower immunogenicity due to fat deposition.* * **Schedule:** 0, 1, and 6 months (standard) or as part of the Pentavalent vaccine (6, 10, 14 weeks). * **Efficacy:** Highly effective; 95% of vaccinees develop protective immunity. Non-responders are more common among smokers, the obese, and the elderly.

Q: A 5-day-old neonate presents with shallow breathing, generalized hypotonia, rigidity, occasional spasms, and foul-smelling brown material around the umbilicus. The child was born at 39 weeks gestation via spontaneous vaginal delivery, with no antenatal care received. The parents reported a normal suck and cry after birth. What is the case load for this condition to be considered eliminated?

<1 case/1000 live births. ### **Explanation** **Diagnosis: Neonatal Tetanus** The clinical presentation of a 5-day-old neonate with **generalized hypotonia followed by rigidity, spasms, and an infected umbilical stump** (foul-smelling discharge) is classic for Neonatal Tetanus. The history of no antenatal care (suggesting an unimmunized mother) and a "normal suck and cry" at birth (ruling out congenital defects) followed by a sudden inability to suck around day 3–7 is the hallmark of this condition. **1. Why Option A is Correct:** According to the World Health Organization (WHO), **Neonatal Tetanus Elimination** is defined as a rate of **<1 case per 1,000 live births** in every district of a country. India achieved this milestone and was declared "Maternal and Neonatal Tetanus Free" in May 2015. This target is specific to the district level to ensure equitable healthcare coverage. **2. Why Other Options are Incorrect:** * **Options B, C, and D:** These values (10/1000, 100/10000, or 1000/100000) all mathematically represent a higher prevalence than the elimination threshold. In public health, "Elimination" for most infectious diseases (like Tetanus or Leprosy) is strictly defined by specific numerical benchmarks, and for Neonatal Tetanus, that benchmark is strictly <1/1000. **3. Clinical Pearls for NEET-PG:** * **Incubation Period:** Usually 3 to 14 days. The "Rule of 7" states that the shorter the incubation period (symptoms appearing before 7 days), the poorer the prognosis. * **Pathogenesis:** Caused by *Clostridium tetani* spores entering via an unclean umbilical cord (non-sterile delivery). * **Prevention:** The most effective strategy is the **"5 Cleans"** during delivery and ensuring mothers receive **two doses of Tetanus Toxoid (TT/Td)** during pregnancy. * **First Sign:** Inability to suck (due to trismus/lockjaw), followed by a "risus sardonicus" (grimacing expression) and opisthotonus (backward arching).

Q: How much time does it take for the finding shown below, after BCG vaccination?

6-12 weeks. ***6-12 weeks*** - The **BCG scar formation** occurs at 6-12 weeks post-vaccination, representing the final stage of the immune response and successful immunization. - This timeframe allows for complete **granulomatous inflammation** and subsequent healing, resulting in a characteristic **permanent scar**. *1-2 days* - This represents the immediate **injection site reaction** with minimal inflammation and **erythema**. - Too early for any significant **cell-mediated immune response** or meaningful BCG-related changes. *1-2 weeks* - Shows early **inflammatory response** with **induration** and **erythema** but no ulceration or significant tissue reaction. - Represents the **initial cellular infiltration** phase, not the complete immunological process. *2-4 weeks* - Characterized by **papule formation** and possible **ulceration** as the immune response intensifies. - Still represents an **intermediate stage** before complete healing and scar formation occurs.

Q: Which of the following vaccines is NOT included in the national immunization schedule?

Hepatitis A. **Explanation:** The **National Immunization Schedule (NIS)** in India, under the Universal Immunization Programme (UIP), focuses on protecting the pediatric and obstetric population against high-morbidity and high-mortality vaccine-preventable diseases (VPDs). **Why Hepatitis A is the correct answer:** Hepatitis A is currently **not** part of the National Immunization Schedule in India. While the vaccine is available and recommended by the Indian Academy of Pediatrics (IAP) for individual use, it is not provided free of cost under the government’s routine program. This is primarily due to the high endemicity of Hepatitis A in India, where most children develop natural immunity through subclinical exposure at a young age. **Analysis of Incorrect Options:** * **Tetanus Toxoid (TT):** Now replaced by Tetanus & adult Diphtheria (Td) vaccine, it is a core component of the NIS, administered to pregnant women and at ages 10 and 16 years. * **Oral Polio Vaccine (OPV):** A cornerstone of the Pulse Polio Immunization program, it is given at birth (zero dose) and at 6, 10, and 14 weeks. * **Measles:** Administered as the Measles-Rubella (MR) vaccine under the NIS at 9 months and 16–24 months. **High-Yield NEET-PG Pearls:** * **Hepatitis B** is included in the NIS (Birth dose + Pentavalent vaccine), but **Hepatitis A** is not. * **Rotavirus and PCV (Pneumococcal Conjugate Vaccine)** are the latest major additions to the nationwide NIS. * **Fractional IPV (fIPV)** is given intradermally at 6, 14 weeks, and 9 months. * **JE Vaccine** is included in the NIS but only in **endemic districts**.

Q: All of the following are contraindications to pertussis-containing vaccines EXCEPT?

Egg allergy. **Explanation:** The correct answer is **Egg allergy**. Pertussis-containing vaccines (like DPT or DTaP) are not grown in eggs; they are bacterial vaccines. Therefore, an egg allergy is **not** a contraindication. In contrast, vaccines like Influenza, Yellow Fever, and MMR (though MMR is generally safe) are related to egg proteins. **Analysis of Options:** * **Uncontrolled Epilepsy:** Pertussis vaccine is associated with a risk of febrile seizures. In children with evolving or unstable neurological disorders (like uncontrolled epilepsy), the vaccine is deferred until the condition is stabilized to avoid diagnostic confusion regarding the cause of seizures. * **Anaphylactic Reaction:** This is a universal contraindication for any vaccine. If a patient develops a life-threatening allergic reaction to a previous dose or any component of the vaccine, further doses are strictly prohibited. * **Progressive Encephalopathy:** This is an absolute contraindication. If a child has an undiagnosed, evolving neurological condition or develops encephalopathy within 7 days of a previous dose (not attributable to another cause), subsequent pertussis doses must be withheld. **High-Yield Clinical Pearls for NEET-PG:** * **Absolute Contraindications for Pertussis:** 1. Anaphylaxis to vaccine components. 2. Encephalopathy within 7 days of a previous dose. * **Precautions (Deferral):** Fever >40.5°C, collapse/shock-like state (HIE), or persistent crying (>3 hours) within 48 hours of a previous dose. * **Safe to Administer:** Stable neurological conditions (e.g., well-controlled seizures, cerebral palsy), family history of seizures, and minor acute illnesses. * **Switching:** If pertussis is contraindicated, the immunization series should be completed with **DT (Diphtheria and Tetanus)** instead of DPT.

Q: Open Vial Policy is applicable to which of the following vaccines?

IPV. ### Explanation **Correct Answer: D. IPV** The **Open Vial Policy (OVP)**, introduced by the Government of India under the Universal Immunization Programme (UIP), allows certain multi-dose vaccine vials to be used for up to **28 days** after opening, provided specific storage conditions and potency criteria (VVM) are met. **Why IPV is correct:** The Open Vial Policy applies to vaccines that are **liquid formulations** and contain **preservatives** (which prevent bacterial growth). **Inactivated Poliovirus Vaccine (IPV)**, along with DPT, Pentavalent, Hepatitis B, and Oral Polio Vaccine (OPV), meets these criteria. This policy aims to reduce vaccine wastage by allowing health workers to use the same vial across multiple sessions. **Why the other options are incorrect:** * **A & B (MR and BCG):** These are **lyophilized (freeze-dried)** vaccines. Once reconstituted with a diluent, they lose stability and are highly prone to bacterial contamination because they do not contain preservatives. They must be discarded within **4 hours** (or at the end of the session, whichever is earlier) and are strictly excluded from the Open Vial Policy. * **C (RVV):** Rotavirus Vaccine (specifically the indigenous Rotavac used in India) is a heat-sensitive liquid vaccine but is generally excluded from the standard 28-day OVP guidelines to ensure maximum potency and prevent contamination during repeated administration. ### NEET-PG High-Yield Pearls: 1. **Criteria for OVP:** The vial must not have expired, must be stored at +2°C to +8°C, the VVM must be in the usable stage, and the septum must not have been submerged in water. 2. **Vaccines NOT under OVP:** BCG, Measles/MR, JE (Live), and Rotavirus. 3. **Mnemonic for OVP Vaccines:** "D-H-I-P-O" (DPT, Hep-B, IPV, Pentavalent, OPV). 4. **Note:** While OPV is a live vaccine, it is the only live vaccine included in the Open Vial Policy due to its unique stability profile in liquid form.

Q: Why are the following vaccines coloured?

Because these vaccines are light sensitive. ***Because these vaccines are light sensitive*** - Certain vaccines like **BCG** and **measles** vaccines are stored in **amber-colored vials** to protect them from **UV light degradation**. - Light exposure can reduce vaccine **potency** and **efficacy**, making colored vials essential for maintaining immunogenicity. *For easy recognition of these vaccines* - While colored vials may aid recognition, this is **not the primary purpose** of vaccine coloring. - Vaccine identification primarily relies on **labeling** and **packaging** rather than vial color alone. *Because they are live vaccines* - Not all **live vaccines** are stored in colored vials, and not all vaccines in colored vials are live. - Vaccine storage requirements depend on **light sensitivity**, not just whether they are live or inactivated. *Because these vaccines are darker in colour* - The **solution color** is unrelated to the **vial color** used for storage. - Amber vials are used regardless of the actual **vaccine formulation color** inside.

Question 1

What is the recommended vaccination strategy for rubella?

Accepted Answer

Women of reproductive age (15-49 years)

Answer

Infants

Answer

Adolescent girls

Answer

Children aged 1-14 years

Question 2

All of the following is true about Hepatitis B Vaccination except?

Accepted Answer

It is a live attenuated vaccine.

Answer

Surgeons and healthcare workers must be vaccinated.

Answer

It is recommended to be given immediately at birth.

Answer

Booster dose is indicated if there are poor titres.

Question 3

A 5-day-old neonate presents with shallow breathing, generalized hypotonia, rigidity, occasional spasms, and foul-smelling brown material around the umbilicus. The child was born at 39 weeks gestation via spontaneous vaginal delivery, with no antenatal care received. The parents reported a normal suck and cry after birth. What is the case load for this condition to be considered eliminated?

Accepted Answer

<1 case/1000 live births

Answer

<10 cases/1000 live births

Answer

<100 cases/10000 live births

Answer

<1000 cases/100000 live births

Question 4

How much time does it take for the finding shown below, after BCG vaccination?

Accepted Answer

6-12 weeks

Answer

1-2 days

Answer

1-2 weeks

Answer

2-4 weeks

Question 5

Which of the following vaccines is NOT included in the national immunization schedule?

Accepted Answer

Hepatitis A

Answer

Tetanus Toxoid (TT)

Answer

Oral Polio Vaccine (OPV)

Answer

Measles

Question 6

All of the following are contraindications to pertussis-containing vaccines EXCEPT?

Accepted Answer

Egg allergy

Answer

Uncontrolled epilepsy

Answer

Anaphylactic reaction to a previous dose

Answer

Progressive encephalopathy

Question 7

Open Vial Policy is applicable to which of the following vaccines?

Accepted Answer

IPV

Answer

MR

Answer

BCG

Answer

RVV

Question 8

An 11-month-old child who has received two doses of DPT and polio is due for further immunization 5 months after the last dose. What should be done?

Accepted Answer

Give only the booster dose

Answer

Repeat the whole course

Answer

Repeat the second dose and continue the rest of the course

Answer

Give the third dose and continue the course

Question 9

Why are the following vaccines coloured?

Accepted Answer

Because these vaccines are light sensitive

Answer

For easy recognition of these vaccines

Answer

Because they are live vaccines

Answer

Because these vaccines are darker in colour

Question 10

For which of the following diseases is vaccination contraindicated in pregnancy, even following maternal exposure?

Accepted Answer

Measles

Answer

Rabies

Answer

Typhoid

Answer

Hepatitis

Immunization and Vaccine-Preventable Diseases — MCQs

Immunization and Vaccine-Preventable Diseases — MCQs

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