Immunologic mechanisms responsible for adverse reactions to routine immunizations in children

Cervical lymph node diseases in children

The lymph nodes are an essential part of the body’s immune system and as such are affected in many infectious, autoimmune, metabolic and malignant diseases. The cervical lymph nodes are particularly important because they are the first drainage stations for key points of contact with the outside world (mouth/throat/nose/eyes/ears/respiratory system) – a critical aspect especially among children – and can represent an early clinical sign in their exposed position on a child’s slim neck.

Involvement of the lymph nodes in multiple conditions is accompanied by a correspondingly large number of available diagnostic procedures. In the interests of time, patient wellbeing and cost, a careful choice of these must be made to permit appropriate treatment. The basis of diagnostic decisions is a detailed anamnesis and clinical examination. Sonography also plays an important role in differential diagnosis of lymph node swelling in children and is useful in answering one of the critical diagnostic questions: is there a suspicion of malignancy? If so, full dissection of the most conspicuous lymph node may be necessary to obtain histological confirmation.

Diagnosis and treatment of childhood cervical lymph node disorders present the attending pediatric and ENT physicians with some particular challenges. The spectrum of differential diagnoses and the varying degrees of clinical relevance – from banal infections to malignant diseases – demand a clear and considered approach to the child’s individual clinical presentation. Such an approach is described in the following paper.

Will the current measles vaccines ever eradicate measles?

Measles virus is the most infectious transmissible agent causing human disease and has probably been responsible for the deaths of more children than any other single cause. In addition, infection with the natural virus causes many severe complications, including encephalitis, deafness and pneumonia. The introduction of live attenuated vaccines, either singly or as the measles-mumps-rubella combined vaccine, has dramatically reduced the occurrence of disease and in countries where vaccine uptake is high, indigenous disease has been virtually eliminated. Even though the current vaccines are very efficient, they do have their limitations. Children are most at risk during the first year of life and for most of this period, maternal antibodies prevent effective immunization. In addition, the current measles vaccines are relatively heat labile which causes difficulty in tropical areas. In recent years, vaccination rates in some industrial countries have been adversely affected by fears that measles vaccines are linked to inflammatory bowel diseases and autism. Although there is no conclusive evidence to support these fears, they still remain and probably contribute to poor vaccine uptake in some regions and sections of society. Although severe complications from vaccination are extremely rare, mild local reactions are more common. Consequently, in countries where measles is declining or has been eliminated, the fear of side effects of vaccination may encourage the development of vaccines that do not rely on virus replication to take effect.

Comparative safety of tetanus-diphtheria toxoids booster immunization in students in Grades 6 and 9

BACKGROUND

Tetanus-diphtheria toxoids (Td) booster immunization is generally recommended for Grade 9 students (14- to 16-year-olds) but targeting younger students may enhance vaccine uptake or facilitate simultaneous vaccinations. However, earlier vaccination might cause greater side effects. This study was undertaken to compare the safety of Td vaccinations in students in Grade 6 (11 to 12 years old) and Grade 9.

METHODS

A controlled, sequential assessment of Td vaccine, adsorbed, was conducted in one urban school district, starting with Grade 9 students. Grade 6 students were given Td concurrently with Dose 3 of hepatitis B vaccine. Adverse effects were assessed during visits 2 days after vaccination. Participation criteria, immunization technique and assessment procedures were standardized.

RESULTS

Of 410 students vaccinated, 204 in Grade 9 and 206 in Grade 6, 391 (95.4%) were assessed in person. Nineteen missed follow-up visits but telephone interviewers established that none missed school because of vaccine side effects. At follow-up Grade 6 students more often reported deltoid pain with arm movement (35.2% vs. 10.8%, P < 0.001). Injection site redness > or = 50 mm in diameter was present in 12.2% of Grade 6 and 3.6% of Grade 9 students (P < 0.001) whereas swelling > or = 50 mm diameter was present in 22.4 and 10.8%, respectively (P < 0.01). Fewer than 10% of subjects took analgesics for injection site pain. Only 5 students (1.3%) rated Td site morbidity as severe/unacceptable. Hepatitis B site morbidity was minimal in comparison.

CONCLUSION

Td boosters were moderately reactogenic in adolescents. Younger students more often experienced injection site morbidity but considered it bearable. Booster immunizations can reasonably be offered within the age range of 11 to 16 years.

DTP and DTP-inactivated polio vaccines: comparison of adverse reactions and IGG, IGM and IGA antibody responses to DTP

Adverse reactions and anti-DTP antibody responses were compared between DTP- or DTP-inactivated-polio-vaccinated children. The material consisted of 380 children whose adverse reactions were registered by detailed questionnaires given to the parents. IgG-, IgM- and IgA-anti-DTP antibodies of 42 children were quantified using enzyme-linked immunosorbent assay (ELISA). Fever, restlessness and local reactions were the most frequent adverse reactions observed. DTP-polio vaccine induced significantly more restlessness than DTP. This was the only significant difference in adverse reactions between the vaccines. An enhancement of IgG-anti-DTP antibody responses at the age of 6 months was observed in the DTP-polio group. The enhancement was transient in antitoxin responses but still present in pertussis antibodies at 8 months of age. Very low and mostly undetectable levels of IgM- and IgA-anti-DTP antibodies were observed in both groups.