Immunization and Vaccine-Preventable Diseases Practice Questions

Q: Which vaccine is contraindicated in pregnancy?

Measles vaccine. ***Measles vaccine*** - The measles vaccine is a **live attenuated vaccine**, which carries a theoretical risk of causing infection in the fetus. - Live vaccines are generally **contraindicated during pregnancy** due to this potential risk of congenital infection. *Cholera vaccine* - The cholera vaccine is generally considered **safe during pregnancy** if indicated, especially for travel to endemic areas. - While administration in pregnancy should be based on risk-benefit, it is not consistently contraindicated like live vaccines. *Typhoid vaccine* - Both inactivated and live attenuated typhoid vaccines are available; the **inactivated (killed) vaccine** is generally preferred if vaccination is necessary during pregnancy. - The risks of the disease usually outweigh the vaccine risks, and it is not a universal contraindication. *Meningococcal vaccine* - **Meningococcal vaccines** are generally considered safe and can be administered during pregnancy if there is a significant risk of exposure or during outbreaks. - The benefits of maternal and potential fetal protection from meningococcal disease outweigh theoretical risks.

Q: What is the schedule of intradermal rabies vaccine?

2-0-2-0-1-1. ***2-0-2-0-1-1*** - This schedule represents the **Thai Red Cross (TRC) regimen** for intradermal rabies vaccination that was standard at the time of this exam (2013). - The numbers indicate the number of vaccine doses administered at different sites: **2 doses on day 0** (bilateral deltoids), **0 doses on day 3**, **2 doses on day 7** (bilateral deltoids), **0 doses on day 14**, **1 dose on day 28**, and **1 dose on day 90**. - This was the **answer expected for NEET 2013** based on the guidelines prevalent at that time. - **Note:** Current WHO guidelines (post-2013) recommend the updated 2-2-2-0-1-1 schedule (4-site ID regimen) which includes doses on days 0, 3, 7, and 28. *2-2-0-1-0-1* - This schedule is **not a recognized** intradermal rabies vaccination protocol. - Does not match any standard WHO-approved regimen for intradermal administration. *2-2-2-0-1-1* - While this may appear incorrect for the 2013 exam context, this schedule actually represents the **current updated Thai Red Cross (4-site ID) regimen** recommended by WHO in recent guidelines. - This regimen provides doses on **days 0, 3, 7, 28, and 90**, which is now the preferred intradermal schedule. - However, for the NEET 2013 exam, the older 2-0-2-0-1-1 schedule was the expected answer. *8-4-4-1-0-1* - This schedule is **not a standard regimen** and involves an impractically high number of doses. - No recognized intradermal rabies protocol uses this many doses on initial days. - Would be **unnecessary and impractical** for effective post-exposure prophylaxis.

Q: According to the immunization schedule, how many doses of influenza vaccine should children under 9 years of age receiving the vaccine for the first time typically receive?

2 doses at 4 weeks interval. ***2 doses at 4 weeks interval*** - Children **under 9 years of age** receiving the influenza vaccine for the **first time** require **two doses** administered at least **4 weeks (28 days) apart**. - This two-dose priming schedule is essential to ensure adequate immune response and protection against circulating influenza strains. - This recommendation is consistent across **IAP (Indian Academy of Pediatrics)** and **CDC guidelines**. - Children 9 years and older, and younger children who have been previously vaccinated, require only **1 dose annually**. *3 doses at 4 weeks interval* - The standard protocol for influenza vaccination does **not involve three doses**. - A three-dose schedule is typically seen with vaccines like **Hepatitis B**, **DTaP**, or **Hib**, but not for influenza. *2 doses at 4 weeks interval with a booster dose for high-risk children* - While high-risk children (chronic lung disease, heart disease, immunocompromised) are priority groups for influenza vaccination, the schedule remains **two initial doses** for first-time recipients under 9 years. - There is **no additional booster dose** beyond the two-dose series within the same influenza season, even for high-risk children. - Subsequent years require only **1 dose annually**. *None of the options* - This is incorrect as the standard recommendation is clearly established in immunization guidelines. - The **two-dose schedule at 4-week intervals** for first-time recipients under 9 years is well-documented by IAP and international guidelines.

Q: Antiserum is available for passive immunization against ?

Rabies. ***Rabies*** - **Antiserum** (or rabies immune globulin, RIG) provides immediate **passive immunity** against rabies, neutralizing the virus before the body can mount an active immune response. - It is administered in conjunction with the **rabies vaccine** for post-exposure prophylaxis, especially in severe exposures. *Typhoid* - **Typhoid fever** is primarily prevented through vaccination (active immunization) and improved sanitation. - There is no routinely available antiserum for **passive immunization** against *Salmonella typhi* infection. *Measles* - **Measles** is prevented through active immunization with the MMR (measles, mumps, rubella) vaccine. - While immune globulin can be used for passive protection in exposed, immunocompromised individuals, it's not commonly referred to as "antiserum" in the same context as rabies. *Mumps* - **Mumps** is prevented by active immunization with the MMR vaccine. - Similar to measles, there is no commonly used specific antiserum for **passive immunity** against mumps in the clinical setting.

Q: India started 2-dose vaccination strategy for measles, in -

2010. ***2010*** - India implemented the **two-dose measles vaccination strategy** as part of its Universal Immunization Program starting in **2010**. - This decision was based on recommendations to improve immunity and reduce measles incidence, moving from a single-dose to a more effective **two-dose schedule**. *2008* - While important immunization initiatives were ongoing, the specific policy of a **two-dose measles vaccination strategy** had not yet been introduced in India during 2008. - At this time, the focus was primarily on ensuring high coverage of the **first dose** of measles vaccine. *2009* - The year 2009 saw continued efforts to strengthen the Universal Immunization Program, but the official launch of the **two-dose measles vaccination strategy** in India occurred later. - Discussions and planning for the transition were likely underway, but implementation began in the subsequent year. *2011* - By 2011, the **two-dose measles vaccination strategy** was already being implemented across India, having been introduced in 2010. - This year marked a period of expanding coverage and consolidation of the new 2-dose schedule rather than its initial introduction.

Q: To achieve neonatal tetanus elimination, the incidence of neonatal tetanus per 1000 live births should be reduced to less than:

1.0. ***1.0*** - The international target for **neonatal tetanus elimination (NTE)** as defined by WHO/UNICEF is an incidence rate of **less than 1 case per 1,000 live births per year** in every district of a country. - This is the globally recognized threshold for declaring that neonatal tetanus has been eliminated as a public health problem. - Countries achieving this target at the district level are considered to have achieved NTE. *0.1* - While 0.1 per 1,000 live births represents an extremely low incidence, this is not the WHO-defined threshold for **neonatal tetanus elimination**. - The elimination target is less stringent at <1 per 1,000 live births, making disease control achievable while still representing a major public health success. *0.2* - An incidence of 0.2 per 1,000 live births, though very low, is not the internationally recognized threshold for **neonatal tetanus elimination**. - The established WHO/UNICEF target is <1 per 1,000 live births in every district. *0.5* - An incidence of 0.5 per 1,000 live births indicates excellent control of neonatal tetanus but is not the specific cut-off value. - The WHO criterion for elimination is less than 1 case per 1,000 live births per year at the district level.

Q: Which of the following is the primary component of the AFP (Acute Flaccid Paralysis) case definition used in polio surveillance?

Onset of acute flaccid paralysis. ***Onset of acute flaccid paralysis*** - The primary component of the **AFP case definition** for polio surveillance is the acute onset of **flaccid paralysis** in a child under 15 years, or paralytic illness in a person of any age when polio is suspected. - This definition is crucial for identifying all potential cases of polio, regardless of the cause, to ensure thorough investigation and prevent outbreaks. *Stool specimen positive for poliovirus* - A positive stool specimen for poliovirus is a **laboratory confirmation** of polio infection, but it is not the primary component of the initial case definition. - The AFP case definition aims for **high sensitivity** to capture all possible cases for investigation, even before laboratory results are available. *Presence of residual paralysis after 60 days* - Residual paralysis after 60 days is an important indicator for **classifying a confirmed polio case** and understanding the long-term impact. - However, it is a **follow-up criterion** used after the initial detection of AFP, not the primary component that triggers the initial surveillance. *All of the above* - While laboratory confirmation and residual paralysis provide further information about a case, the **initial identification relies specifically on the clinical presentation** of acute flaccid paralysis. - The broad clinical definition ensures that no potential polio case is missed, initiating an immediate public health response.

Q: Which vaccine is associated with a risk of encephalopathy?

Measles. ***Measles*** - Among the options provided, **measles vaccine** has been reported to have a very rare association with **post-vaccination encephalitis/encephalopathy** (approximately 1 per million doses). - **Important note:** The **pertussis vaccine (particularly whole-cell DTP)** is the vaccine most classically associated with encephalopathy risk, but it is not among the options here. - The risk of encephalopathy from the measles vaccine is significantly lower than the risk from natural measles infection itself. - Modern measles vaccines are highly purified and safer than earlier formulations. *OPV* - **Oral Polio Vaccine (OPV)** is associated with **vaccine-associated paralytic poliomyelitis (VAPP)**, not encephalopathy. - VAPP occurs at a rate of approximately 1 case per 2.4 million doses due to reversion of the attenuated virus to a neurovirulent form. - Manifests as flaccid paralysis, not encephalopathy. *Rubella* - **Rubella vaccine** (component of MMR) is very safe with no significant association with encephalopathy. - Rare adverse effects include transient arthralgia (especially in adult women), mild rash, or lymphadenopathy. - Severe neurological complications are extremely rare. *BCG* - **Bacillus Calmette-Guérin (BCG) vaccine** protects against tuberculosis and is not associated with encephalopathy. - Common adverse effects are local reactions: induration, ulceration, scarring, and rarely lymphadenitis. - Disseminated BCG infection can occur in immunocompromised individuals but is distinct from encephalopathy.

Q: At what age is the BCG vaccination administered in India?

At birth. ***At birth*** - In India, the **BCG vaccine** is routinely administered to infants **at birth** or as early as possible thereafter as per the **Universal Immunization Programme (UIP)**. - This early vaccination aims to provide protection against **severe forms of tuberculosis (TB)**, particularly **tuberculous meningitis** and **disseminated (miliary) TB** in young children. - Early administration is crucial as infants are at highest risk of developing severe TB if exposed. *Incorrect: 1 year* - While other vaccinations might be given at 1 year (such as MMR), the BCG vaccine is specifically recommended at or soon after birth. - Delaying BCG vaccination until 1 year increases the risk of early exposure to TB before immunity can be established, defeating its protective purpose. *Incorrect: 2 years* - The recommended schedule for BCG vaccination in India does not include administration at 2 years of age. - By 2 years, potential exposure to TB may have already occurred, and the vaccine's efficacy in preventing severe forms of the disease would be compromised. *Incorrect: 6 weeks* - At 6 weeks, other vaccines like OPV, DPT, Hepatitis B, Hib, and Rotavirus are administered as part of the UIP schedule. - BCG is specifically given at birth, not at 6 weeks, to provide early protection against severe childhood tuberculosis.

Q: What is the appropriate diluent for the BCG vaccine?

Sterile distilled water. ***Sterile distilled water*** - **Sterile distilled water** is the recommended diluent for the **BCG vaccine** to ensure proper reconstitution and antigen stability. - Using the correct diluent is critical for maintaining the **efficacy** and safety of the vaccine. *Sterile normal saline* - **Sterile normal saline** (0.9% NaCl) can be used as a diluent for some vaccines, but it is **not appropriate for BCG** as it can negatively impact vaccine viability. - The **salt concentration** in saline can affect the live attenuated organisms in the BCG vaccine. *Sterile dextrose solution* - **Dextrose solutions** are generally avoided as vaccine diluents due to their potential to support **bacterial growth** or alter vaccine stability. - They are primarily used for **intravenous fluid administration** and not for vaccine reconstitution. *Colloid solutions* - **Colloid solutions** like albumin or dextran are never used as vaccine diluents as they can interfere with the **vaccine antigens** and cause adverse reactions. - These solutions are typically used for **plasma volume expansion** and have no role in vaccine preparation.

Question 1

Which vaccine is contraindicated in pregnancy?

Accepted Answer

Measles vaccine

Answer

Cholera vaccine

Answer

Typhoid vaccine

Answer

Meningococcal vaccine

Question 2

What is the schedule of intradermal rabies vaccine?

Accepted Answer

2-0-2-0-1-1

Answer

2-2-0-1-0-1

Answer

8-4-4-1-0-1

Answer

2-2-2-0-1-1

Question 3

According to the immunization schedule, how many doses of influenza vaccine should children under 9 years of age receiving the vaccine for the first time typically receive?

Accepted Answer

2 doses at 4 weeks interval

Answer

2 doses at 4 weeks interval with a booster dose for high-risk children

Answer

3 doses at 4 weeks interval

Answer

None of the options

Question 4

Antiserum is available for passive immunization against ?

Accepted Answer

Rabies

Answer

Typhoid

Answer

Mumps

Answer

Measles

Question 5

India started 2-dose vaccination strategy for measles, in -

Accepted Answer

2010

Answer

2008

Answer

2009

Answer

2011

Question 6

To achieve neonatal tetanus elimination, the incidence of neonatal tetanus per 1000 live births should be reduced to less than:

Accepted Answer

1.0

Answer

0.1

Answer

0.5

Answer

0.2

Question 7

Which of the following is the primary component of the AFP (Acute Flaccid Paralysis) case definition used in polio surveillance?

Accepted Answer

Onset of acute flaccid paralysis

Answer

All of the above

Answer

Stool specimen positive for poliovirus

Answer

Presence of residual paralysis after 60 days

Question 8

Which vaccine is associated with a risk of encephalopathy?

Accepted Answer

Measles

Answer

OPV

Answer

Rubella

Answer

BCG

Question 9

At what age is the BCG vaccination administered in India?

Accepted Answer

At birth

Answer

1 year

Answer

2 years

Answer

6 weeks

Question 10

What is the appropriate diluent for the BCG vaccine?

Accepted Answer

Sterile distilled water

Answer

Sterile normal saline

Answer

Sterile dextrose solution

Answer

Colloid solutions

Immunization and Vaccine-Preventable Diseases — MCQs

Immunization and Vaccine-Preventable Diseases — MCQs

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