The Basics of Pediatric Immunizations

Elizabeth Farren, PhD, RN; Melanie McEwen, PhD, RN


NAINR. 2004;4(1) 

In This Article

Adverse Reactions and Safety Concerns

Adverse events to vaccines are common. Local reactions include pain, swelling, and redness at the injection site. Systemic reactions include fever, irritability, drowsiness, and rash.[18] Allergic reactions and seizures are among the more serious undesired effects of immunizations. Pain and fever can be minimized with acetaminophen, but more serious side effects should be reported immediately to the health care provider administering the vaccine and treated accordingly.

Adverse reaction may occur after any immunization and may be related to the vaccine itself or a vaccine constituent. Adverse reactions may be mild, moderate, or severe and differ depending on the vaccine. Allergic reactions to egg-related antigens are common. For older children these may be anticipated and identified via screening; for infants, who probably have not had eggs, the risk appears to be low, but real. Neomycin and gelatin components of certain vaccines are sometimes implicated in adverse reactions. Other antibiotics are sometimes suspect, but proof of a causal relationship has not been made. For older children, scratch and intradermal testing is possible if there is true suspicion of potential harm.[5]

The AAP warns that "persons administering biologic products or serum should be prepared to recognize and to treat anaphylaxis. The necessary medication, equipment and staff competent to maintain the patency of an airway and to manage cardiovascular collapse must be immediately available."(p 51)[5] In all instances of anaphylaxis, the drug of choice is epinephrine. Mild reactions, such as puritis, erythema, urticaria, and angioedema should be treated with epinephrine first, limiting response, and then may be followed by diphenhydramine or another antihistamine, depending on resolution of symptoms.

As the incidence of vaccine-preventable diseases declined, adverse effects became more visible and lead to a demand by the public that risks to infants be defined and studied. Because of increasing litigation, several manufacturers threatened to stop production of vaccines. As a result, the National Vaccine Injury Act was passed in 1986,[8] to compensate individuals who were injured by childhood vaccines; this released vaccine manufacturers of liability. The Vaccine Adverse Effects Reporting System (VAERS) was also created by this Act. VAERS is managed by the Food and Drug Administrations and the CDC and is responsible for collecting, managing, and evaluating reports of vaccine reactions.[19,20,21] Public and provider concern has increased in recent years because, in every year since the early 1990s, the number of reports of serious side effects has exceeded the reported incidence of all vaccine-preventable childhood diseases combined.[22] Indeed, the number of problems reported by VAERS is approximately 11,000 per year,[18] while there were approximately 10,000 cases of vaccine-preventable illnesses in children in 2000 (excluding varicella and hepatitis B, which is rare in children).

VAERS is a passive surveillance system for clinical events that occur following immunization. Manufacturers, health care professionals, state health coordinators, and parents of vaccinated children can submit VAERS reports. There are several limitations to VAERS, however. First, it receives only information regarding vaccinated individuals who have generally severe adverse events. Also, underreporting is a big problem and results from incomplete reports, lack of consistent diagnostic criteria, simultaneous administration of multiple vaccines, and reporting bias.[21]

Known adverse events to a specific vaccine can be found in the ACIP recommendations for that vaccine and the VIS, mentioned previously. Any potentially serious adverse event or side effect following administration of a vaccine should be reported. An isolated event alone may give little indication of causation without further research. Therefore, the report of any adverse event is important as a stimulus to studies attempting to prove causal relationships through epidemiologic research.

The VAERS system, despite its known weaknesses, has shown considerable success, as indicated by the adoption and then subsequent removal of the Rotavirus vaccine. The Rotavirus vaccine was licensed in August 1998 and recommended for the routine vaccination of healthy infants. In July 1999, use of the vaccine was suspended following reports to the VAERS of intussuseption in several infants who had recently received the vaccine. Then, in October 1999, the ACIP withdrew its recommendation and the rotavirus vaccine was withdrawn from the market.[21]

The National Vaccine Injury Compensation Program is a no-fault system in which persons thought to have experienced an injury as the result of a vaccine may seek compensation. Each matter involving a covered vaccine is adjudicated through the federal program before civil litigation may take place. This program is meant to protect clients, as well as to ensure a stable source of vaccine availability.

"To the modern parent and increasingly to health providers, the relative likelihood of having personal experience with an adverse event (real or coincidental) now exceeds that of having an experience with the disease."[23] In recent years, a large number of providers and public health professionals have recognized that concerns related to the safety of vaccines are becoming increasingly common.[24,25] Marshall and Gellin[26] conducted a survey of pediatricians and family physicians and reported that the overwhelming majority had families in their practice that refused one or more of the recommended vaccines out of concern for safety of the vaccine.

The public expects a high level of safety for vaccines because they are given to healthy persons to prevent disease. Thus, tolerance of adverse reactions resulting from products given to healthy infants and children is lower than that for products administered to persons who are ill.[19] Furthermore, concerns regarding adverse events can lead to a loss of public confidence in immunization[21] and the potential to refuse immunization. Some of the main safety concerns are summarized in Table 3 .

Chronic illnesses recently linked with vaccinations include asthma, autism, diabetes, and multiple sclerosis. Known attributable risks include febrile seizures (DT, DTap, DTP, and MMR), hypotonic-hyporesponsive episodes (DT, DTaP, and DTP), anaphylaxis (hepatitis B and MMR), and vaccine-associate paralysis (OPV).[28] Complications caused by vaccine components, including adjuvants, preservatives or contaminates, have also been described as problematic. Aluminum is added to some vaccines for diphtheria, tetanus, hepatitis A, and hepatitis B. Aluminum has been associated with macrophagic myofacitis, arthromyalgias, and chronic fatigue as well as demyelanitating central nervous system disorders.[29]

Thimerosal is a mercury-based preservative previously used in hepatitis B vaccines, some DTaP, all DTP, and some Hib vaccines. Although it had been a vaccine component for decades, it was removed in 2000 due to concerns of mercury toxicity. Depending on the particular vaccine formulation and schedule, an infant might have received a cumulative mercury dose as high as 187.5 micrograms during the first six months of life; exceeding the maximum dose recommend by guidelines of methyl mercury intake.[29] It should be noted, however, according to a recent report by the Institute of Medicine,[14] no studies have established a causal link between vaccines and these diseases.


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