Vaccination and HIV infection

Vaccination of children with proven HIV infection should take into account their clinical and immunological categories according to the table: N1, N2, N3, A1, A2, АЗ...С1, С2, СЗ; if the child's HIV status is not confirmed, the letter E is used before the classification (for example, EA2 or ЕВ1, etc.).

The National Calendar describes the vaccination method for HIV-infected children, but omits mention of BCG for these children - obviously. This vaccine is not administered to HIV-infected children, however, it does not describe how to vaccinate HIV-uninfected children from HIV+ mothers.

The main route of HIV infection in children is perinatal, however, with modern therapy of HIV-infected pregnant women, no more than 5-10% of newborns are infected. Since newborns, regardless of whether they are infected or not, have maternal antibodies to HIV in their blood, which can persist for 18 months, the diagnosis of HIV infection before this age is made on the basis of detection of the virus or its p24 antigen in the blood. Thus, children of an HIV-infected mother represent one heterogeneous group for the vaccinator, which poses a number of significant problems, in particular, the safety and efficacy of different vaccines in children with perinatal HIV infection (according to ICD B23), as well as the effectiveness of vaccination of HIV-uninfected children (according to ICD R75), the development of whose immune system, at least theoretically, could be affected in the body of an HIV-infected mother.

Clinical categories of HIV infection in children under 13 years of age

Category	Manifestations
Asymptomatic - N	None
Low-symptom -A	Lymphadenopathy, hepatosplenomegaly, mumps, dermatitis, recurrent otitis, chronic diarrhea
Moderately expressed - B	First episode of bacterial meningitis, pneumonia or sepsis, cardiomyopathy, hepatitis, opportunistic infections (CMV, candidiasis, herpes simplex or herpes zoster, complicated chickenpox, toxoplasmosis, leiomyosarcoma, lymphoid pneumonitis, anemia with Hb<80 g/l, neutropenia <1000 in 1 μl, thrombocytopenia <100,000 in 1 μl for 1 month or more)
Heavy - C	Bacterial infections of multiple localization or repeated, severe herpes virus infection, Pneumocystis pneumonia, disseminated forms of tuberculosis, histoplasmosis and coccidioidomycosis, deep mycosis, brain lymphoma, Kaposi's sarcoma, leukoencephalopathy, wasting syndrome

Killed vaccines

All inactivated vaccines (including toxoids), recombinant vaccines are administered to children born to HIV-infected mothers, including HIV-infected children, regardless of the stage of the disease and the number of CD4+ lymphocytes. In both groups of children, they are safe, the number of side effects does not differ from that of healthy children. The immune response to IPV, diphtheria and, especially, tetanus toxoids in HIV+ children differs little from those in children of HIV-uninfected mothers. The immune response to HBV in HIV-infected children can be reduced: even at a dose of 20 mcg according to the 0-1-6 schedule, vaccination did not provide protective levels of antibodies in 22% of children. Thus, DPT and HBV should be administered to all children of HIV-infected mothers on schedule, regardless of the severity of clinical manifestations and immunological classification. In addition to calendar vaccinations, it is strongly recommended to carry out active prevention of Hib infection (starting from the age of 3 months), pneumococcal infection (after 2 years) and influenza. The response to the Act-Hib vaccine in all children of HIV-infected mothers did not differ from that in healthy children. Antibodies to pneumococcal polysaccharides in HIV-infected children are often initially elevated (due to higher morbidity); after the introduction of Pneumo23, their titer increased in 81% of children (in uninfected children - 91%), although to a lesser extent than in other groups. Vaccination reduces the risk of pneumococcal infection by more than 2 times.

In response to the influenza vaccine, HIV-infected children produce antibodies as often as their uninfected peers, although their antibody levels are somewhat lower.

Immunization with live vaccines

Live vaccines are administered to children with a confirmed diagnosis of HIV infection after an immunological examination to exclude an immunodeficiency state. In the absence of immunodeficiency, live vaccines are administered in accordance with the Calendar. In the presence of immunodeficiency, the administration of live vaccines is contraindicated.

Six months after the initial administration of live vaccines against measles, mumps, and rubella to HIV-infected individuals, the level of specific antibodies is assessed and, if absent, a repeat dose of the vaccine is administered with preliminary laboratory monitoring of the immune status.

The safety of vaccination against measles, as well as rubella and mumps in HIV-infected individuals, was confirmed by the absence of serious adverse reactions. However, the seroconversion rate in HIV-infected children was only 68%, antibody titers were significantly lower than in the control and were lost after 6 months. The reduced immune response to the vaccine was the basis for the recommendation to administer a second dose. The vaccine is contraindicated in children with moderate and severe immunosuppression, as well as clinical category C.

The seroconversion rate after rubella vaccine administration is little different from that in uninfected individuals, but their antibody levels are lower. Children in the N1 and A1 categories tolerate the varicella vaccine well and produce an adequate immune response.

WHO does not recommend vaccinating HIV-infected children with BCG. Although perinatally infected HIV-infected children remain immunocompetent for a long time, in case of progression of the process, generalized BCG-itis may develop. Moreover, as shown by the experience of countries where BCG is vaccinated en masse, including to children from HIV+ mothers, during chemotherapy of HIV-infected children, 15-25% develop "inflammatory syndrome of the immunological constitution with multiple granulomatous foci." WHO does not object to the introduction of BCG to children before their HIV status is determined in regions with a high incidence of tuberculosis in the absence of the possibility of identifying HIV-infected children, however, for regions with such possibilities, it is recommended to refrain from administering BCG until the HIV status of the child is determined.

The existing experience of vaccinating children of HIV-infected mothers went smoothly, but the new WHO data cannot be ignored. At the same time, given the high incidence of tuberculosis in HIV-infected children in such families.