From the Guidelines
Infants with high fever after vaccination should be evaluated for other causes if the fever does not begin until 24 hours after vaccination or persists for more than 24 hours, and acetaminophen may be given to lessen fever and irritability, as recommended by the Advisory Committee on Immunization Practices (ACIP) 1. When considering the management of infant high fever after vaccine administration, it's crucial to differentiate between expected immune responses and potential complications.
- Fever is a common reaction to vaccines, typically a normal immune response, and can be managed with acetaminophen at a dose of 10-15 mg per kg of body weight every 4-6 hours, or ibuprofen (for babies over 6 months) at 5-10 mg per kg every 6-8 hours.
- However, fever that does not begin until greater than or equal to 24 hours after vaccination or persists for more than 24 hours after vaccination should not be assumed to be due to DTP vaccination and should be evaluated for other causes, such as otitis media or meningitis, to prevent delayed treatment for serious conditions 1.
- Contact a doctor immediately if the infant's fever reaches 100.4°F (38°C) or higher for babies under 3 months, or 102.2°F (39°C) or higher for older infants, or if the baby shows signs of unusual fussiness, lethargy, poor feeding, or a rash.
- The use of fever-reducing medications, such as acetaminophen, can help with discomfort but does not interfere with the vaccine's effectiveness, as noted in the recommendations for vaccine use and other preventive measures 1.
- It's also important to keep the baby comfortable with light clothing and ensure they stay hydrated with regular breast milk or formula feedings.
- Moderate-to-severe systemic events, including high fever, persistent crying, collapse, or short-lived convulsions, although infrequent, should be monitored and reported to healthcare professionals, as they may be associated with vaccine administration 1.
From the Research
Infant High Fever After Vaccine
- High fever in infants after vaccination is a common concern for parents and caregivers 2, 3, 4, 5, 6
- Studies have shown that fever is a frequent systemic adverse event following immunization, especially in infants and young children 3
- The time pattern of fever attributable to immunization has characteristic features depending on the vaccine used 3
Prevention and Management of Fever
- Antipyretic analgesics are commonly used to prevent and treat adverse events following immunizations, but current practice discourages routine use due to possible blunting of vaccine immune responses 4, 5
- Prophylactic administration of antipyretic drugs at the time of vaccination should not be routinely recommended since antibody responses to several vaccine antigens were reduced 2
- Acetaminophen and ibuprofen may reduce the incidence of adverse reactions in young infants receiving certain vaccines, but their use is not recommended prophylactically to prevent vaccine-associated adverse reactions 5
Measurement and Interpretation of Fever
- The definition and means of assessment of fever in vaccine safety studies should be standardized to permit comparability of data and improve understanding of its importance as an adverse event following immunization 6
- Fever is a generally benign, albeit common, clinical sign, and its role as a physiologic reaction to invading substances is not fully understood 6