Immunization in Children - Pediatric OSCE Stations

These are few Practise OSCE station on Pediatric immunizations, vaccines, vaccine schedule, and procedures to store and vaccinate children. Vaccine related question are also very common part in clincal viva-voce.

Station 1- What is VVM and how will you interpret it?

Answer

How to interprete VVM

A vaccine vial monnitor (VVM) is a small label on a vaccine vial that changes color as the vaccine vial is exposed to heat. It gives a visual indication of whether the vaccine has preserved its potency.

VVM on vials

Station 2- How do you store vaccines in the refrigerator?

Answer

The following image illustrates the different storage compartments for common vaccines

How to store vaccines in a refrigerator - ref: WHO 2004

Station 3- Name some contraindications and precautions for vaccination in general.

Answer

Contraindication to vaccination

A contraindication is a condition in a recipient in which a vaccine, increases the chances of a serious adverse reaction that outweighs the therapeutic benefit. eg. - severe allergic reactions

Contraindication to vaccination - ref IAP imm book 2018-19

Precaution

A Condition in the recipient that might increase the chance of serious adverse reaction or might compromise the ability of the vaccine to produce immunity.

Precaution for vaccination of children - ref IAP imm book 2018-19

Station 4- What is a freeze watch indicator?

Answer

Freeze watch indicator for vaccines

A freeze watch indicator is a small vial of red liquid attached to a white card and covered in plastic. Vial breaks if the temperature drops below 0 Celsius for >1 hour.

Freeze sensitive vaccines are

• Diphtheria.
• Tetanus.
• Pertussis.
• Liquid Haemophilus influenzae type b (Hib)
• Hepatitis B.

Station 5- What are special vaccines you would advise for high-risk category children?

Answer

High-risk categories of children include

1. Congenital or acquired immunodeficiency (including HIV)
2. Chronic cardiac, pulmonary, hematologic, renal and liver disease
3. Children on long term steroids, salicylates, immunosuppressive or radiation therapy
4. Diabetes mellitus, CSF leak, Cochlear implant, Malignancies
5. Children with functional/ anatomic asplenia/ hyposplenia
6. Laboratory personnel and healthcare workers
7. Travelers

Recommended vaccines for High-risk children

1. Influenza Vaccine
2. Meningococcal Vaccine
3. Japanese Encephalitis Vaccine
4. Cholera Vaccine
5. Rabies Vaccine
6. Yellow Fever Vaccine
7. Pneumococcal vaccine (PPSV 23)

Station 6- An 11-year-old boy is adopted, no medical records are available and BCG scar is not seen. The adoptive parents want to know what vaccines have to be given. What will you advise?

Answer

1. TDaP vaccine- single dose
2. MMR- 2 doses at 4-8 weeks gap
3. Hep B- 3 doses at 0,1 and 6 months
4. Hepatitis A- 2 doses at 0, 6 months
5. Typhoid- 1 dose every 3 years
6. Varicella- 2 doses at 4-8 weeks

Station 7- About Influenza Vaccine

1. What are the types of influenza vaccines in India?
2. When is a Live Attenuated Influenza vaccine (LAIV) not recommended?
3. What is IAP's recommended target prioritization for influenza vaccines?

Answers

Types of Influenza vaccine

Trivalent inactivated vaccines (TIV) and Live Attenuated Influenza vaccines (LAIV).

LAIV is not recommended in

LAIV is not recommended below 2 years of age, in high-risk individuals, and in pregnant women.

Target prioritization

1. Elderly (> 65 years) / nursing-home residents
2. HIV/AIDS, and pregnant women (especially to protect infants 0–6 months)
3. Other groups: Health care workers, asthmatics, and children from ages 6 months to 2 years.
4. Children, aged 2–5 years and 6–18 years, and healthy young adults.

Where 1 is the highest priority and 4 is the lowest priority.

Station 8- Regarding vaccination in symptomatic HIV cases, answers yes or no for the following

1. Can BCG vaccine be given in symptomatic HIV cases
2. Can OPV be given in symptomatic HIV cases
3. Can measles, MMR and Varicella be given in symptomatic HIV cases

Answer

1. No, BCG vaccine can not be given in symptomatic HIV cases
2. Yes, if IPV is not affordable/available, OPV can be given in symptomatic HIV cases
3. Yes, if CD4+ count > 15%, measles, MMR, and Varicella can be given in symptomatic HIV cases.

Station 9- Regarding BCG vaccination

1. What solution is used to swab the site prior to BCG vaccination?
2. When will you consider the BCG administration technique to be successful?
3. What is the normal reaction at the vaccine site following successful vaccination?
4. What condition is associated with BCG vial contamination?

Answer

1. Normal saline or sterile water
2. A wheal of 5 mm at the injection site
3. A papule develops by 2-3 weeks, increases to a size of 4-8mm by 5-6 weeks, ulcerates and heals with scarring by 6-12 weeks
4. Toxic shock syndrome

Station 10- Which is the Polio vaccine of choice for outbreak control? Which Polio vaccine type is more efficacious – Trivalent OPV or Bivalent OPV? What is enhanced IPV?

Answer

Polio vaccine of choice for outbreak control

OPV

More efficient OPV

Bivalent OPV is more efficacious than Trivalent OPV – as competition between different serotypes is eliminated

Enhanced IPV contains

• type 1 – 40 Ag U
• type 2 – 8 Ag U
• type 3- 32 Ag U

Station 11- What are the conditions that predispose to VDPV? Name the Polio serotypes more frequently associate with VAPP and VDPV

Answer

Conditions that predispose to VDPV are

a) Dropping immunization coverage
b) High population densities
c) Tropical conditions
d) previous eradication of wild poliovirus

Associated serotypes

VAPP – Type 2
VDPV – Type 3

Station 12- What is AEFI and when will you consider it serious? What are the different types?

Answer

AEFI is an adverse event following immunization

An AEFI is considered to be serious if it

1. Results in death
2. Develops life-threatening event
3. Requires in-patient hospitalization or prolongation of existing hospitalization
4. Results in persistent or significant disability/incapacity
5. Results in a congenital anomaly/birth defect or
6. Requires intervention to prevent permanent impairment or damage.

Types of AEFI

1. Vaccine reaction

An event caused by the vaccine or precipitated by the vaccine when given correctly eg. VAPP after OPV

2. Programme error

An event caused by an error in vaccine preparation, handling, or administration. Egs- TSS after measles vaccine due to improper storage

3. Injection reaction

Event from anxiety about, or pain from the INJECTION, rather than the vaccine. Eg abscesses

4. Coincidental

An event that happens after immunization, but is NOT caused by it. Eg SIDS

5. Unknown

The cause of the event cannot be determined.

What are the recommended time limits for using vaccines after reconstitution?

Answer

1. Varicella - 0 mins (and protect from light)
2. MMRV - 30 mins (and protect from light)
3. Yellow fever - 1 hour
4. MEASLES/MMR - 4 to 6 hours
5. Meningococcal PS vaccine -30 mins
6. DTaP/Hib combination - 30 mins

Station 13- What is pre-exposure prophylaxis for rabies and for whom it is advised? What are the advantages of giving it?

Answer

PEP for rabies constitutes three doses of rabies vaccine to be given intramuscularly on days 0, 7 and 28

Pre-exposure prophylaxis for rabies is advised for

1. Children having pets in the home
2. Children perceived with higher threat of being bitten by dogs such as hostellers, risk of stray dog menace while going outdoor
3. Veterinarians, those who work with animals

Advantages

In case of a dog bite, only two doses are to be given on days 0 and 3 and Rabies immunoglobulin (RIG) is not needed after receiving pre-exposure prophylaxis.

Station 14- Regarding Meningococcal Vaccine, What are the categories to be vaccinated as per IAP recommendations?

Answers

Following categories should be vaccinated with Meningococcal Vaccine.

1. A.During disease outbreaks
2. B. Vaccination of persons with high-risk conditions/situations
   1. Complement component deficiencies
   2. Functional/anatomic asplenia/hyposplenia
   3. HIV
   4. Healthcare workers exposed routinely to Neisseria meningitides
   5. Adjunct to chemoprophylaxis
3. C. International travelers – Study abroad/ Hajj/ Sub-Sahara Africa

Station 15- What are the recent updates to the IAP Immunization schedule?

Answer

DTaP:

Preferably be avoided in primary vaccination series (at 6, 10 and 14 weeks)

IPV:

Instead of OPV at 6, 10, 14 weeks and 15 months, So OPV only at birth, 6 months, 9 months and 5 years

Hepatitis B vaccine:

The final (third or fourth) dose in the Hepatitis B vaccine series should be administered no earlier than age 24 weeks and at least 16 weeks after the first dose

MMR vaccine:

At 9 months and 15 months, No need for a booster at 5 years

Typhoid conjugate vaccine:

(TypBar) given at 9 to 12 months, with a booster at 2 years of age

Hepatitis A:

Single-dose for live attenuated H2-strain Hep-A vaccine
Two doses for all killed Hep-A vaccines are recommended at 12 months and 18 months

HPV:

• Only 2 doses of either of the two HPV vaccines for adolescent/pre-adolescent girls aged 9-14 years.
• For girls 15 years and older, and immunocompromised individuals 3 doses are recommended.
• For a two-dose schedule, the minimum interval between doses should be 6 months.
• For 3 dose schedule, the doses can be administered at 0, 1-2 and 6 months