Situation: A nurse handles the under-five clinic of a Barangay Health Station (BHS). A 4-month-old with HIV, who is clinically well and immunologically stable on antiretroviral therapy, did not receive BCG at birth. According to the National Immunization Program guidelines, which plan is CORRECT?

Two rules apply at once. BCG can still be given up to 1 year of age, and it is given to infants with HIV who are clinically well and immunologically stable on antiretroviral therapy. OPV, however, is a live oral vaccine and is contraindicated in HIV, so IPV is used instead.

Core rationale
This question tests two separate immunization rules that must be applied together. The first concerns BCG timing and eligibility in an infant with HIV. The second concerns the choice between bOPV and IPV in the same infant. The correct plan gives BCG today and replaces bOPV with IPV.

BCG eligibility in this infant
BCG is a live attenuated vaccine, so the decision to give it is based on the infant’s current immune status rather than HIV status alone. In this case, the infant is 4 months old, clinically well, and immunologically stable on antiretroviral therapy. Under the National Immunization Program, BCG may still be given up to 1 year of age when it was missed at birth. The key qualifier is that the infant must be clinically well and immunologically stable on ART; if those conditions are met, BCG is not permanently withheld. This is why options that say “withhold BCG permanently” are incorrect.

The evidence base adds an important caution. BCG-related complications, including regional BCG-itis and disseminated BCG-osis, occur preferentially in immunocompromised hosts ^[1][2]. In addition, BCG-related immune reconstitution inflammatory syndrome can emerge after ART initiation, typically presenting as ipsilateral axillary lymphadenitis at the vaccination site ^[3][4]. These risks explain why BCG is not given to every HIV-infected infant without qualification. However, the infant in this scenario is already stable on ART and clinically well, which is the precise situation in which BCG can be considered. The risk of BCG disease is highest in infants with untreated or advanced HIV, not in those who are immunologically stable ^[1][2].

Why IPV replaces bOPV
bOPV is a live oral polio vaccine. Because it contains live attenuated virus, it is contraindicated in infants with HIV, regardless of how clinically stable they appear. The safer alternative is IPV, an inactivated injectable polio vaccine that does not carry the same risk of vaccine-derived infection in an immunocompromised infant. Therefore, the polio series continues, but with IPV instead of bOPV.

Applying both rules together
The correct plan must satisfy both conditions simultaneously. Giving BCG today is appropriate because the infant is under 1 year of age and immunologically stable on ART. Continuing bOPV is not appropriate because live oral polio vaccine is contraindicated in HIV. The only option that combines BCG today with IPV substitution is the correct answer.

Component	Correct decision	Reason
BCG	Give today	Age under 1 year; clinically well and immunologically stable on ART
Polio vaccine	IPV instead of bOPV	bOPV is live and contraindicated in HIV; IPV is inactivated and safe

Watch out! Do not assume that HIV status alone permanently contraindicates BCG. The decision hinges on age, clinical status, and immunologic stability on ART. Key point! Live oral polio vaccine is never the correct choice for an HIV-infected infant; IPV is the required substitute.