Systemic Reactions to Vaccination

Fever, malaise, myalgia, and other systemic symptoms can occur after vaccination with inactivated vaccine and most often affect persons who have had no previous exposure to the influenza virus antigens in the vaccine (e.g., young children) (189,190). These reactions begin 6–12 hours after vaccination and can persist for 1–2 days. Recent placebo-controlled trials demonstrate that among older persons and healthy young adults, administration of split-virus influenza vaccine is not associated with higher rates of systemic symptoms (e.g., fever, malaise, myalgia, and headache) when compared with placebo injections (12,184–186).
Less information from published studies is available for children, compared with adults. However, in a randomized cross-over study among both children and adults with asthma, no increase in asthma exacerbations was reported for either age group (187). An analysis of 215,600 children aged <18 years and 8,476 children aged 6–23 months enrolled in one of five health maintenance organizations reported no increase in biologically plausible medically attended events during the 2 weeks after inactivated influenza vaccination, compared with control periods 3–4 weeks before and after vaccination (191). In a study of 791 healthy children (71), postvaccination fever was noted among 11.5% of children aged 1–5 years, 4.6% among children aged 6–10 years, and 5.1% among children aged 11–15 years. Among children with high-risk medical conditions, one study of 52 children aged 6 months–4 years reported fever among 27% and irritability and insomnia among 25% (80); and a study among 33 children aged 6–18 months reported that one child had irritability and one had a fever and seizure after vaccination (192). No placebo comparison was made in these studies. However, in pediatric trials of A/New Jersey/76 swine influenza vaccine, no difference was reported between placebo and split-virus vaccine groups in febrile reactions after injection, although the vaccine was associated with mild local tenderness or erythema (81).
Limited data regarding potential adverse events after influenza vaccination are available from the Vaccine Adverse Event Reporting System (VAERS). During January 1, 1991–June 30, 2004, VAERS received 1,895 reports of adverse events among children aged <18 years, including 479 reports of adverse events among children aged 6–23 months. The number of influenza vaccine doses received by children during this entire period is unknown (CDC, unpublished data, 2005). A recently published review of VAERS reports of trivalent inactivated influenza vaccine (TIV) in children aged 6–23 months documented that the most frequently reported adverse events were fever, rash, injection-site reactions, and seizures. The majority of the small total number of reported seizures appeared to be febrile Because of the limitations of passive reporting systems, determining causality for specific types of adverse events, with the exception of injection-site reactions, is usually not possible by using VAERS data alone. A population-based study of TIV safety in children aged 6–23 months indicated no vaccine associated adverse events that had a plausible relationship to vaccination (194).
Health-care professionals should promptly report to VAERS all clinically significant adverse events after influenza vaccination of children, even if the health-care professional is not certain that the vaccine caused the event. The Institute of Medicine has specifically recommended reporting of potential neurologic complications (e.g., demyelinating disorders such as Guillain-Barré syndrome [GBS]), although no evidence exists of a causal relationship between influenza vaccine and neurologic disorders in children.
Immediate — presumably allergic — reactions (e.g., hives, angioedema, allergic asthma, and systemic anaphylaxis) rarely occur after influenza vaccination (195). These reactions probably result from hypersensitivity to certain vaccine components; the majority of reactions probably are caused by residual egg protein. Although current influenza vaccines contain only a limited quantity of egg protein, this protein can induce immediate hypersensitivity reactions among persons who have severe egg allergy. Persons who have had hives or swelling of the lips or tongue, or who have experienced acute respiratory distress or collapse after eating eggs should consult a physician for appropriate evaluation to help determine if vaccine should be administered. Persons who have documented immunoglobulin E (IgE)-mediated hypersensitivity to eggs, including those who have had occupational asthma or other allergic responses to egg protein, might also be at increased risk for allergic reactions to influenza vaccine, and consultation with a physician should be considered. Protocols have been published for safely administering influenza vaccine to persons with egg allergies
Hypersensitivity reactions to any vaccine component can occur. Although exposure to vaccines containing thimerosal can lead to induction of hypersensitivity, the majority of patients do not have reactions to thimerosal when it is administered as a component of vaccines, even when patch or intradermal tests for thimerosal indicate hypersensitivity When reported, hypersensitivity to thimerosal usually has consisted of local, delayed hypersensitivity reactions

Homeopathic medications are not a replacement for standard care and/or
the prevention by vaccinations when appropriate.