3.2 Contraindications, Precautions & Adverse Effects

Contraindication, precaution, and "not a reason to defer" are three different clinical categories. Mixing them is how children leave the office unvaccinated for no medical reason. Domain I.B tests whether the CPNP-PC can name the short list of true contraindications, defer when a precaution is present, and vaccinate through the myths.

Three buckets

True contraindication — the risk of giving that vaccine clearly outweighs the benefit. Do not give that antigen (or that live product) until the condition resolves, if it ever does. The list is short on purpose.

Precaution — a condition that might increase the chance of a serious adverse reaction, might compromise the immune response, or might confuse attribution of an evolving illness. You weigh benefit versus risk. Moderate or severe acute illness is the most common precaution: defer until the child is improving, then vaccinate. A precaution is not a lifetime ban.

Not a contraindication (invalid excuse) — mild illness, low-grade fever, current antibiotics, convalescence, premature birth (aside from specific hepatitis B birth-dose timing in infants <2,000 g), breastfeeding, a pregnant household contact, a local reaction to a prior dose, penicillin allergy that is not an allergy to a vaccine component, and "the child has a cold." These do not justify skipping indicated vaccines.

Anaphylaxis and components

A severe allergic reaction (anaphylaxis) to a prior dose of that vaccine, or to a listed component, is a contraindication to further doses of that vaccine. It is not a reason to withhold unrelated antigens. Confirm the component in the current package insert rather than guessing (gelatin, neomycin, and yeast appear in different products). Have epinephrine immediately available whenever you vaccinate. A history of anaphylaxis to latex matters if the vial stopper or syringe contains latex; many products are latex-free.

Egg allergy is the classic outdated "component" story. Current CDC/ACIP influenza guidance: most egg-allergic children, including those with a history of severe egg reaction, CAN receive influenza vaccine. Any licensed, age-appropriate influenza vaccine may be used. You do not need to select a special "egg-free" product solely because of egg allergy, and you do not need allergy testing before vaccination. Observe the child as you would after any vaccine (see syncope, below). Do not send every egg-allergic preschooler to a hospital infusion center for a flu shot.

Live vaccines, immunosuppression, and pregnancy

Live-attenuated vaccines (MMR, varicella, LAIV, rotavirus, and travel live vaccines such as yellow fever) are contraindicated in pregnancy and are generally contraindicated in severe immunosuppression — examples include primary immunodeficiencies such as SCID, active chemotherapy, some biologics, high-dose systemic corticosteroids, and advanced untreated HIV with severe CD4 depletion. Use the current ACIP immunocompromised schedule; do not invent a steroid milligram cutoff from memory if the stem does not give one.

Household contacts of pregnant people and of immunocompromised patients should receive indicated MMR and varicella so they do not bring wild-type measles or varicella home. LAIV should not be used when a close contact is severely immunocompromised and requires a protective environment. Inactivated influenza is the default in those households.

SCID is a contraindication to rotavirus. Screen family history of immunodeficiency and newborn-screen results when you start the rotavirus series. A mildly ill, exclusively breastfed 2-month-old with a stuffy nose is still a rotavirus candidate if those true contraindications are absent.

Rotavirus and intussusception; pertussis and encephalopathy

History of intussusception is a contraindication to rotavirus vaccine. A slightly increased risk of intussusception after rotavirus vaccination is why that history matters. It is not a reason to withhold every other infant vaccine at the 2-month visit.

Encephalopathy (coma, decreased level of consciousness, or prolonged seizures) not attributable to another identifiable cause, occurring within 7 days of a previous pertussis-containing vaccine, is a contraindication to further pertussis-containing vaccines. Progressive neurologic disorders are a precaution for DTaP until the condition is clarified. A simple febrile seizure after a prior dose is not that contraindication — do not convert every fever-plus-jerk into a lifetime pertussis exemption.

Other high-yield precautions (not automatic bans): Guillain-Barré syndrome within 6 weeks of a previous influenza or tetanus-toxoid-containing vaccine; an Arthus-type hypersensitivity reaction after diphtheria or tetanus toxoid (defer tetanus-containing vaccines until 10 years have elapsed); recent antibody-containing blood products before MMR or varicella (spacing per the current table). Personal or family history of seizures is a precaution for MMRV as the first dose — use separate MMR and varicella rather than skipping measles protection.

Expected reactions versus serious events

Most children have local pain, redness, or swelling and sometimes low-grade fever, fussiness, or myalgias. Counsel families that these are expected, self-limited, and not reasons to skip the next dose. Antipyretics may be used for comfort after vaccination; they are not required prophylactically, and prophylactic acetaminophen is not used as a routine strategy to "prevent" fever.

Serious adverse events are uncommon. Recognize:

• Anaphylaxis — minutes after the dose; treat immediately (epinephrine), then report.
• Syncope, especially in adolescents after HPV, Tdap, or meningococcal vaccines. Observe for 15 minutes, seated or lying. Injuries occur from the fall, not from the antigen. This is ACIP/CDC practice, not optional courtesy.
• Shoulder injury from too-high intramuscular injection — landmark the deltoid correctly in older children and adolescents.
• Intussusception after rotavirus — counsel on episodic, severe, colicky pain, drawing up the legs, and currant-jelly stool as a reason to seek care.
• Febrile seizures — increased with some live combination products in the second year of life; still not a contraindication to future MMR or varicella.

VAERS, VIS, and VICP — three different tools

Candidates confuse the three "V" systems. They are not three names for the same form.

VIS is before the dose. VAERS is after a suspected event. VICP is compensation, not a clinic reporting portal. Telling a family "I filed VAERS, so you will automatically be paid" confuses VAERS with VICP.

How the CPNP-PC documents and reports

Document as a clinician who may later need the record for school, public health, VAERS, or VICP:

• Vaccine name, manufacturer, lot number, dose, site, route, date and time
• Name and title of the person who administered the dose and the clinic address
• VIS edition date and date the VIS was given
• Any precaution, contraindication, or refusal (see 3.3)
• Immediate reactions and the 15-minute observation for adolescents

If a serious event occurs, treat first, then file VAERS, notify the collaborating physician or medical director per practice policy, and document what was given, the timing, the exam, and the treatment. Do not wait for "proof" of causation. Do not tell a family that a VAERS filing means the vaccine is "guilty." Causation is not implied by a report.

On the exam: a toddler with a cold and a low-grade fever who is finishing antibiotics, whose mother is pregnant and breastfeeding a newborn, still gets indicated inactivated and live vaccines unless a true contraindication exists. Anaphylaxis to a prior dose, SCID, pregnancy in the patient, intussusception (rotavirus), and pertussis-associated encephalopathy are the stops. Everything else is counseling, a possible short deferral for moderate-severe illness, or an invalid excuse.