Immunization and Vaccine-Preventable Diseases Practice Questions

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: Minimum threshold level of herd immunity for Pertussis is?

90%. ***90%*** - Pertussis, due to its **high R-naught (R0)**, requires a very high vaccination coverage to achieve herd immunity. - An estimated 92-94% vaccination coverage is often cited as necessary to prevent outbreaks. *80%* - While 80% might be sufficient for some less contagious diseases, it's **too low a threshold** for a highly transmissible infection like pertussis. - This level would likely still allow for significant localized outbreaks, especially in unvaccinated pockets. *70%* - A 70% threshold is generally considered **insufficient** for controlling the spread of highly contagious respiratory infections. - This level of immunity would mean a higher proportion of susceptible individuals, leading to a greater risk of widespread transmission. *50%* - A 50% herd immunity level is **grossly inadequate** for a disease like pertussis, which is one of the most contagious vaccine-preventable diseases. - This low level of immunity would offer minimal protection against widespread transmission and outbreaks.

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: 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: Ideal temperature for DPT storage?

4 to 8°C. ***4 to 8°C*** - The ideal temperature for DPT (diphtheria, pertussis, tetanus) vaccine storage is between **+2°C and +8°C** (or 35°F and 46°F), which is the standard refrigerator temperature range. - This temperature range is crucial for maintaining the **potency** and **efficacy** of the vaccine, preventing **degradation** due to excessive heat or cold. *Room temperature* - Storing DPT vaccines at **room temperature** (typically 20-25°C or 68-77°F) for extended periods can lead to a **loss of potency** as heat can degrade vaccine components. - While short-term excursions within this range might be permissible under specific conditions (e.g., during transport), it is not the ideal long-term storage solution. *0 to - 20°C* - DPT vaccines, particularly the **whole-cell pertussis (wP)** component, can be **damaged by freezing**. - Temperatures below 0°C can cause the **adjuvant** (usually aluminum salt) to separate, leading to a loss of efficacy and potential local reactions at the injection site. *None of the options* - This option is incorrect because **4 to 8°C** is indeed the established and recommended ideal storage temperature for DPT vaccines.

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: 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: 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: 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: Dukoral is:

Oral cholera vaccine. ***Oral cholera vaccine*** - Dukoral is a **killed oral whole-cell vaccine** against *Vibrio cholerae* O1 and O139, often combined with a recombinant B subunit of cholera toxin. - It provides protection against **cholera**, an acute diarrheal illness caused by bacterial infection of the small intestine. *Oral rotavirus vaccine* - Oral rotavirus vaccines (e.g., Rotarix, RotaTeq) provide protection against **rotavirus**, the most common cause of severe diarrhea in infants and young children. - These vaccines are usually given in multiple doses to infants and are distinct from cholera vaccines. *Oral typhoid vaccine* - An oral typhoid vaccine, such as Ty21a, is used for the prevention of **typhoid fever**, caused by *Salmonella Typhi*. - It is a **live attenuated vaccine** administered in several doses over a week, differing significantly from Dukoral's mechanism and target. *Ready to use therapeutic food* - **Ready-to-use therapeutic food (RUTF)** is a high-energy, micronutrient-rich paste used for the treatment of **severe acute malnutrition (SAM)**, especially in children. - It is a nutritional intervention, not a vaccine, and helps in weight gain and recovery for malnourished individuals.

Question 1

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 2

Minimum threshold level of herd immunity for Pertussis is?

Accepted Answer

90%

Answer

80%

Answer

70%

Answer

50%

Question 3

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

Accepted Answer

2010

Answer

2008

Answer

2009

Answer

2011

Question 4

Which vaccine is contraindicated in pregnancy?

Accepted Answer

Measles vaccine

Answer

Cholera vaccine

Answer

Typhoid vaccine

Answer

Meningococcal vaccine

Question 5

Ideal temperature for DPT storage?

Accepted Answer

4 to 8°C

Answer

Room temperature

Answer

0 to - 20°C

Answer

None of the options

Question 6

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 7

Antiserum is available for passive immunization against ?

Accepted Answer

Rabies

Answer

Typhoid

Answer

Mumps

Answer

Measles

Question 8

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 9

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 10

Dukoral is:

Accepted Answer

Oral cholera vaccine

Answer

Oral rotavirus vaccine

Answer

Oral typhoid vaccine

Answer

Ready to use therapeutic food

Immunization and Vaccine-Preventable Diseases — MCQs

Immunization and Vaccine-Preventable Diseases — MCQs

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