High-Yield One-Liners in Pediatric Immunology and Vaccines

Types of Organisms

• Viruses, Candida, P.jirovecii and Bacterial infections: T-cell defects.
• Enteroviruses, giardia, cryptosporidium, mycoplasma, and capsulated bacteria: B-cell defects.
• Staph, Pseudomonas, salmonella, Nocardia, candida and Aspergillus indicate phagocytic defects.
• Graft versus host disease due to non-irradiated blood transfusion, primarily indicating T-cell defects.
• Association with oculocutaneous albinism: Chediak-Higashi Syndrome.
• Whenever there is delayed falling of the umbilical cord, there will be Leukocyte Adhesion Defects (LAD) which can be seen in all three forms but are always present in type-1 leukocyte adhesion defects.
• Eczema will indicate Wiskott Aldrich Syndrome and hyper IgE Syndrome.
• Patients with erythroderma: Omenn syndrome, and SCID
• Inability to kill catalase positive bacteria is seen in Chronic Granulomatous Disease.
• The maximum risk of giardiasis is seen in CVID.

IgG Subclass Deficiency

• IgG1 type deficiency: Increased risk of diphtheria and tetanus
• IgG2 type deficiency: Increased risk of encapsulated bacteria (MC in children)
• IgG3 type deficiency: Increased risk of viral infection (MC in adults)
• IgG4 type deficiency: Increased risk of parasitic infections

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New Vaccines approved by IAP ACIP 2020-21

• Tetraxim: DPT + IPV: Approved for use as booster at 4-6 years of age
• Pneumosil: A new 10-valent pneumococcal vaccine, for use at 6, 10, 14 wk and booster at 15 months, the so-called 3+1 regimen. No approved above 2 year of age for catch-up vaccination
• Typhibev: A typhoid conjugate vaccine: Single dose, approved by use between 6 months and 45 years of age
• Menveo: The quadrivalent conjugate meningococcal vaccine covering serogroup A, C, Y and W-135, approved for use in the age group 2-55 years, only in the high-risk group.

What are Interferonopathies?

Interferonopathies are also called Type I Interferonopathies. Refer to a group of inherited auto-inflammatory disorders that are characterized by dysregulation of the Type I IFN pathway. Recent research indicates some autoimmune disorders, such as monogenic forms of SLE, may have disturbances in the Type I IFN pathway.

Conditions to be Fulfilled for Open Vial Policy

• The expiry date should not have passed
• The vaccines should be stored under appropriate cold chain conditions both during transportation and storage in cold chain storage point
• The vaccine vial septum should not have been submerged in water or contaminated in any way
• Aseptic technique used to withdraw vaccine doses
• The vaccine vial monitor (VVM) should not have reached/crossed the discard point.

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Additional Key Points 

• Vaccines that are never given according to NIS above one year of age: pentavalent vaccine, BCG, and rotavirus vaccine ± Hep B
• The type of OPV used in NIS: Bivalent OPV which is active against P1 and P3 strains.
• The dose of BCG vaccine
• If the child's age is less than one month, the dose will be 0.05 ml intradermally.
• If the child's age is at or above one month, those will be 0.1 ml.
• The protection of BCG or efficacy ranges between 0 to 80%. It protects against CNS TB and disseminated tuberculosis but is poor against pulmonary tuberculosis.
• The type of PCV introduced in NIS is PCV13 and the type of regime we follow is two doses given at 6 weeks and 14 weeks, followed by a booster at 9 months.

Sensitivity of Vaccine

Important Questions Answers Regarding Vaccines

Q. Which IgG subclass deficiency is associated with deficiency in IgA?

Ans. IgG2 subclass deficiency.

Q. Where is the BCG vaccine given, and why?

Ans. BCG vaccine is given intradermally in the left upper arm as a part of the regime or protocol.

Q. Why is less dose of BCG given in the neonatal period?

Ans. In the neonatal period, they have thin skin, and sometimes if a 0.1 ml dose is given, the vaccine can enter into deeper structures. It can lead to the development of abscess and tender local lymphadenopathy.

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Q. Why is BCG given only till 1 year of age?

Ans. By one year, the child has been exposed to tuberculosis already and would have developed a clinical or subclinical infection. With partial immunity similar to what BCG gives, you need not give BCG studies.

Q. If no scar appears on giving BCG, should you repeat the dose?

Ans. No.

Q. When to breastfeed if OPV has been given just now?

Ans. The mother can immediately breastfeed after giving OPV.

Q. Can oral Rota/Vit A drops be given at the same time if OPV has been given just now?

Ans. Yes.

Also read: INI-CET Pediatrics: High-Yield Image-Based Questions and Clues

Q. What is the purpose of giving HPV-0 dose at Birth?

Ans. The zero dose decreases the chances of perinatal transmission.

Q. The unvaccinated child comes at 9 months of age, mother asks to give only 1 injection. Which vaccine will you favor?

Ans. MR vaccine along with OPV as well as Vitamin A and advice, the child also needs to be given BCG and pentavalent or DPT, whichever is available.

Q. Which vaccines do you give to an unvaccinated child aged 1-5 years who comes to you in the OPD? Follow the following schedule:

Ans. 1st Visit: DPT-1, OPV-1, MR-1, Vitamin A 2 ml orally.

• DPT and OPV 2nd and 3rd doses at a gap of 1 month each from the 1st visit
• MR-2 as per schedule or at least after 6 months of the initial dose
• A booster dose of OPV/DPT at least 6 months after OPV-3/DPT-3
• Vitamin-A 2ml every 6 months till 5 yr age.

Q. Which vaccines do you give to an unvaccinated child aged 5-7 years who comes to you in the OPD?

Ans. DPT-1, 2, and 3 at monthly intervals. Booster dose of DPT at least 6 months after DPT-3 and No dose of DPT to be given if age crosses 7 years, can give Td instead of DPT above 7 yr age children. OPV-Not given above 5 years of age.

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Q. Why avoid spirit swabs before immunization?

Ans. In general, we use normal saline as it may destroy the live component in the vaccine.

Q. The child received 1st vaccination at 4 months of age. He received Pentavalent 1, OPV-1, and BCG and was lost to follow-up. Now comes to OPD at 10 months of age. What to give?

Ans. Pick up from the last vaccination. Then it administers Pentavalent-2, OPV-2, MR-1, and Vitamin A.

Q. Why is the anterolateral thigh preferred over the gluteal region for DPT/ Pentavalent injections?

Ans. To Avoid Sciatic Nerve Injury. The gluteal region has more fat around the muscle, and when DPT is given here, it elicits weaker immune systems.

Q. Child due for routine immunization has a Cough/ Sore throat/ Moderate grade fever/ Watery stools without dehydration. What should be done?

Ans. Give the vaccine as scheduled.

Q. Why is the MR vaccine given in the right arm?

Ans. Protocol Regimen. If JE is due, it is given subcutaneously in the left arm.

Also read: NEET PG 2025 - High-Yield Topics For Pediatrics

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