Routine Immunization Schedule — MCQs
All of the following regarding rotavirus vaccine are correct except?
Which is not given at the time of birth?
Which vaccine is given at birth to provide protection against tuberculosis as per the National Immunization Schedule in India?
Which vaccine is contraindicated in a 6-month-old infant whose sibling is on chemotherapy for leukemia?
Which vaccine is contraindicated in pregnancy?
Which immunization is typically given at 6 months of age?
Which vaccination schedule is correct for PCV (Pneumococcal Conjugate Vaccine)?
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 ?
Which of the following is the aetiological agent most often associated with Epiglottitis in children -
An 80-year-old woman, a retirement home resident, has multiple bouts of pneumonia caused by Streptococcus pneumoniae. In an attempt to prevent such infections, polyvalent vaccines directed at multiple serotypes of the organism have been administered but have not elicited long-acting immunity. Which of the following is the probable explanation for this phenomenon?
Routine Immunization Schedule Indian Medical PG Practice Questions and MCQs
Question 1: All of the following regarding rotavirus vaccine are correct except?
- A. Inactivated vaccine (Correct Answer)
- B. Available as monovalent and pentavalent
- C. Last dose should be completed by 8 months of age
- D. Administered orally
Explanation: ***Inactivated vaccine*** - The rotavirus vaccines (Rotarix and RotaTeq) are **live-attenuated vaccines**, meaning they contain weakened forms of the virus, not inactivated forms. - Live-attenuated vaccines replicate in the host to induce a robust immune response similar to natural infection. - This is the **incorrect statement**, making it the correct answer to this "except" question. *Available as monovalent and pentavalent* - This statement is correct. There are two main types: **Rotarix**, which is a **monovalent** vaccine targeting G1P strains, and **RotaTeq**, which is a **pentavalent** vaccine targeting G1, G2, G3, G4, and P strains. - Both forms provide broad protection against common rotavirus strains. *Last dose should be completed by 8 months of age* - This statement is correct. The first dose should be given between **6-14 weeks**, and the final dose should be administered by **8 months (32 weeks) of age**. - For **Rotarix** (2-dose series): complete by 24 weeks; for **RotaTeq** (3-dose series): complete by 32 weeks. - This age limit is primarily due to a theoretical increased risk of **intussusception** when administered later in infancy. *Administered orally* - This statement is correct. Rotavirus vaccines are given **orally** and are not injectable. - This method of administration makes the vaccine easy to administer and simulates the natural route of rotavirus infection, promoting mucosal immunity.
Question 2: Which is not given at the time of birth?
- A. Hepatitis B
- B. HiB (Correct Answer)
- C. OPV
- D. BCG
Explanation: ***HiB*** - The **Haemophilus influenzae type b (Hib)** vaccine is given as part of the **pentavalent vaccine** starting at **6 weeks of age**, with subsequent doses at 10 and 14 weeks in the Indian National Immunization Schedule. - It is not administered at birth because maternal antibodies present in newborns can interfere with the vaccine's effectiveness, and optimal immune response is achieved when vaccination begins at 6 weeks. *Hepatitis B* - The **Hepatitis B vaccine** is routinely given at birth (Hepatitis B-0), preferably within the first 12-24 hours, to protect against perinatal transmission. - Early vaccination is crucial for preventing chronic infection in infants born to mothers with Hepatitis B infection. *OPV* - The **oral polio vaccine (OPV-0)** is given at birth as a "zero dose" to provide early protection against polio. - This initial birth dose helps establish gut immunity before the standard primary series at 6, 10, and 14 weeks. *BCG* - The **Bacille Calmette-Guérin (BCG) vaccine** for tuberculosis is given at birth in India due to the high prevalence of tuberculosis. - Its purpose is to protect infants and young children from severe forms of the disease, such as tuberculous meningitis and disseminated TB.
Question 3: Which vaccine is given at birth to provide protection against tuberculosis as per the National Immunization Schedule in India?
- A. Measles
- B. BCG (Correct Answer)
- C. OPV
- D. Hepatitis B
Explanation: ***Correct: BCG*** - The **BCG vaccine** (Bacille Calmette-Guérin) is the only vaccine given at birth specifically to protect against **tuberculosis** - It is administered at birth or as early as possible as part of the **National Immunization Schedule** - BCG is particularly important in India due to the high burden of tuberculosis *Incorrect: Measles* - The **measles vaccine** is given at **9 months of age**, not at birth - Early administration is less effective due to the presence of **maternal antibodies** that can interfere with vaccine response *Incorrect: OPV* - While **OPV zero dose (OPV0)** is also given at birth for early polio protection, it protects against **poliomyelitis**, not tuberculosis - OPV is followed by subsequent doses at 6, 10, and 14 weeks *Incorrect: Hepatitis B* - **Hepatitis B birth dose** is also given within 24 hours of birth to prevent **vertical transmission** - However, it protects against **Hepatitis B virus infection**, not tuberculosis
Question 4: Which vaccine is contraindicated in a 6-month-old infant whose sibling is on chemotherapy for leukemia?
- A. Oral polio vaccine (Correct Answer)
- B. Hepatitis B
- C. Rotavirus vaccine
- D. DPT
Explanation: ***Oral polio vaccine*** - The **oral polio vaccine (OPV)** is a live attenuated vaccine containing weakened but live viruses. - It is **absolutely contraindicated** in individuals with immunocompromised household contacts (like a sibling on **chemotherapy**) due to the risk of **vaccine-associated paralytic poliomyelitis (VAPP)** from shedding of the live vaccine virus. - The shed virus can be transmitted to and cause disease in immunocompromised contacts. - This is the primary reason most countries have switched to **inactivated polio vaccine (IPV)**. *Hepatitis B* - The **Hepatitis B vaccine** is an inactivated (non-live) recombinant vaccine. - It poses no risk of transmitting live virus to an immunocompromised individual. - It is safe to administer to an infant with an immunocompromised household contact. *Rotavirus vaccine* - The **Rotavirus vaccine** is also a live attenuated vaccine, and there is a **relative contraindication** when household contacts are severely immunocompromised. - The vaccine virus can be shed in stool for several days after vaccination. - However, compared to OPV, the risk of serious disease transmission is considered much lower, and some guidelines allow its use with precautions (strict hand hygiene, avoiding diaper changes by immunocompromised contacts). - In the context of this question, **OPV has a stronger absolute contraindication** than rotavirus vaccine. *DPT* - The **DPT vaccine** (Diphtheria, Pertussis, Tetanus) is an **inactivated vaccine** containing toxoids and killed bacterial components. - It is safe to administer to an infant with an immunocompromised household contact as there is no risk of shedding live pathogens.
Question 5: Which vaccine is contraindicated in pregnancy?
- A. Influenza
- B. Rubella (Correct Answer)
- C. Tetanus toxoid
- D. Hepatitis B
Explanation: ***Rubella*** - The **rubella vaccine** is a **live attenuated vaccine**, which carries a theoretical risk of fetal infection and congenital rubella syndrome if administered during pregnancy. - For this reason, women are usually screened for immunity and vaccinated **pre-conception** or **postpartum**. *Influenza* - The **influenza vaccine** (inactivated form) is **recommended** during pregnancy to protect both the mother and newborn from severe influenza illness. - It is **safe** and **effective** for pregnant women at any stage of gestation. *Tetanus toxoid* - The **tetanus toxoid vaccine** (Tdap or Td) is **recommended** during each pregnancy to provide passive immunity to the newborn against pertussis (whooping cough), as well as protecting the mother from tetanus and diphtheria. - It is considered **safe** and ideally given between 27 and 36 weeks of gestation. *Hepatitis B* - The **hepatitis B vaccine** is **recommended** for pregnant women who are at high risk of hepatitis B infection, as a protective measure for both the mother and the fetus. - It is an **inactivated vaccine** and has not been shown to cause adverse effects in pregnancy.
Question 6: Which immunization is typically given at 6 months of age?
- A. Measles vaccine
- B. DPT vaccine (Correct Answer)
- C. BCG vaccine
- D. None of the options
Explanation: **DPT vaccine** - The DPT (diphtheria, pertussis, and tetanus) vaccine is administered in multiple doses during infancy as part of the primary immunization series. - At **6 months of age**, the **third dose of DPT** is typically given (following doses at 6 weeks, 10 weeks, and 14 weeks according to the Indian immunization schedule). - Among the options provided, DPT is the only vaccine routinely administered at 6 months of age. - This vaccine protects against three serious bacterial infections: **diphtheria**, which can cause breathing problems; **pertussis (whooping cough)**, a severe respiratory illness; and **tetanus**, which causes painful muscle spasms. *Measles vaccine* - The measles vaccine (given as part of the **MMR vaccine** or as MR vaccine in India) is typically administered at **9 to 12 months of age** for the first dose, and a second dose between 15-18 months or 4-6 years. - It is not routinely given at 6 months, as maternal antibodies can interfere with its effectiveness at this younger age. *BCG vaccine* - The BCG (Bacillus Calmette-Guérin) vaccine protects against **tuberculosis** and is given at **birth** or in early infancy as a single dose. - It is not administered at 6 months of age. *None of the options* - This option is incorrect because the **DPT vaccine** (third dose) is a standard immunization given at 6 months of age according to the Indian immunization schedule. - Multiple vaccines are actually given at 6 months (including OPV, Hepatitis B, Hib, PCV), but among the listed options, only DPT is correct.
Question 7: Which vaccination schedule is correct for PCV (Pneumococcal Conjugate Vaccine)?
- A. 6, 10, 14 weeks, booster at 12 months (Correct Answer)
- B. 2, 4, 6 months
- C. 6, 10, 14 weeks
- D. 2, 4, 6 months, booster at 15 months
Explanation: ***6, 10, 14 weeks, booster at 12 months*** - This is the **standard recommended schedule** for PCV (3+1 schedule) as per **IAP (Indian Academy of Pediatrics) guidelines**. - The initial three doses at 6, 10, and 14 weeks provide **primary immunity**, while the booster at 12 months significantly **enhances and extends protection** against invasive pneumococcal disease. - This schedule is included in the **Universal Immunization Programme (UIP)** in India. *2, 4, 6 months* - This schedule follows the **US CDC** pattern primarily used for DTaP, Hib, and PCV in the United States. - It **lacks the critical booster dose** at 12 months as per Indian guidelines and uses months instead of weeks for the primary series. - Not the standard schedule tested in **Indian Medical PG exams**. *6, 10, 14 weeks* - This provides the **primary series** but omits the crucial **booster dose** typically given at 12 months. - Without the booster, **long-term protection against pneumococcal disease** may be insufficient, leading to waning immunity. - An incomplete vaccination schedule. *2, 4, 6 months, booster at 15 months* - This follows the **US CDC schedule** with a delayed booster. - Indian guidelines recommend the primary series at **6, 10, 14 weeks** (not months) with booster at **12 months** (not 15 months). - Not aligned with **IAP/NTAGI recommendations** for India.
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 ?
- A. Give the infant second dose of DPT/OPV (Correct Answer)
- B. Give the infant DT/OPV
- C. Repeat the first dose counting afresh
- D. Give the infant a booster dose of DPT/Polio
Explanation: ***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.
Question 9: Which of the following is the aetiological agent most often associated with Epiglottitis in children -
- A. Neisseria sp
- B. Moraxella catarrhalis
- C. Haemophilus influenzae type b (Correct Answer)
- D. Streptococcus pneumoniae
Explanation: ***Haemophilus influenzae type b*** - Historically, **_Haemophilus influenzae_ type b (Hib)** was the most common cause of **epiglottitis** in children. - The introduction of the **Hib vaccine** has significantly reduced its incidence, but it remains a crucial consideration. *Neisseria sp* - **_Neisseria_ species** are typically associated with infections like **meningitis** and **gonorrhea**, not primary causes of epiglottitis. - While **_Neisseria meningitidis_** can cause invasive disease, it's not a common pathogen for epiglottitis. *Moraxella catarrhalis* - **_Moraxella catarrhalis_** is a common cause of **otitis media**, **sinusitis**, and **bronchitis**, especially in children. - It is not a principal cause of acute epiglottitis. *Streptococcus pneumoniae* - **_Streptococcus pneumoniae_** is a major cause of **pneumonia**, **otitis media**, **meningitis**, and **sepsis**. - While it can cause respiratory infections, it is not the most frequent pathogen associated with epiglottitis compared to Hib pre-vaccine era.
Question 10: An 80-year-old woman, a retirement home resident, has multiple bouts of pneumonia caused by Streptococcus pneumoniae. In an attempt to prevent such infections, polyvalent vaccines directed at multiple serotypes of the organism have been administered but have not elicited long-acting immunity. Which of the following is the probable explanation for this phenomenon?
- A. The bacterial capsule binds C3b, facilitating activation of the alternative complement pathway, inducing complement-mediated lysis, and preventing immunization.
- B. The capsular polysaccharides of S. pneumoniae have limited hapten potential.
- C. S. pneumoniae evades host immune response by forming capsular coatings composed of host proteins and recognized as "self" antigens.
- D. Memory T lymphocytes respond poorly to polysaccharide antigens. (Correct Answer)
Explanation: ***Correct: Memory T lymphocytes respond poorly to polysaccharide antigens.*** - T cells are activated by **peptide antigens** presented by MHC molecules; they do not recognize **polysaccharide antigens** directly. - Vaccines composed of purified polysaccharide antigens (like in the polyvalent *S. pneumoniae* vaccine) primarily stimulate a **T-cell-independent B-cell response**, which typically results in a weaker immune response, poor memory, and limited class switching, especially in older individuals. - This is why **conjugate vaccines** (polysaccharide linked to protein carriers) were developed—they convert the T-independent antigen into a T-dependent one, generating better memory responses. *Incorrect: S. pneumoniae evades host immune response by forming capsular coatings composed of host proteins and recognized as "self" antigens.* - The capsule of *S. pneumoniae* is composed of **polysaccharides**, not host proteins. - It evades the immune system by being poorly immunogenic and preventing phagocytosis, but not by mimicking "self" antigens. *Incorrect: The bacterial capsule binds C3b, facilitating activation of the alternative complement pathway, inducing complement-mediated lysis, and preventing immunization.* - The **capsule** of *S. pneumoniae* actually **inhibits C3b binding** and prevents activation of the alternative complement pathway, thereby *resisting* complement-mediated lysis and opsonization. - This resistance is a mechanism of immune evasion, not prevention of immunization. *Incorrect: The capsular polysaccharides of S. pneumoniae have limited hapten potential.* - While polysaccharide antigens can be considered haptens in a sense if they require a carrier protein to become fully immunogenic, the primary issue is their inability to activate T cells. - The limitation in hapten potential isn't the most direct or impactful explanation for the lack of long-lasting immunity compared to the T-cell dependence of memory responses.
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