From the Guidelines
Severe side effects from the Haemophilus influenzae type b (Hib) vaccine are extremely rare, and there is no evidence that they occur more frequently with the first dose compared to subsequent doses. The Hib vaccine is generally very safe, with most side effects being mild and temporary, such as redness or swelling at the injection site, mild fever, or irritability, as reported in a study by 1. Severe allergic reactions (anaphylaxis) can occur with any vaccine but are estimated to happen in fewer than 1 in a million doses of Hib vaccine. These reactions would typically occur within minutes to hours after vaccination, regardless of which dose in the series is being administered.
Some key points to consider about the Hib vaccine include:
- The vaccine is typically given as a series of 3-4 doses (at 2, 4, 6, and 12-15 months), depending on the specific vaccine brand used, as stated in 1.
- Parents should monitor their child after any dose of vaccine and seek immediate medical attention if signs of a severe allergic reaction occur, such as difficulty breathing, hoarseness or wheezing, hives, paleness, weakness, fast heartbeat, or dizziness.
- The benefit of Hib vaccination far outweighs the minimal risk, as it protects against serious bacterial infections that can cause meningitis, pneumonia, and epiglottitis, as noted in 2 and 1.
- Vaccination with a Hib-containing vaccine is contraindicated in infants aged <6 weeks and among persons known to have a severe allergic reaction to any component of the vaccine, as stated in 1.
Overall, the Hib vaccine is a crucial component of childhood vaccination schedules, and its benefits in preventing serious infections outweigh the minimal risks associated with its administration, as supported by the most recent evidence from 1.
From the Research
Severe Side Effects of the Haemophilus influenzae type b (HIB) Vaccine
- The available studies do not provide specific information on severe side effects of the HIB vaccine typically occurring after the first dose 3, 4, 5, 6, 7.
- However, the studies report that the HIB vaccine is generally well-tolerated and safe, with most side effects being mild and transient 3, 4, 7.
- Common non-serious adverse experiences reported in the studies include: + Local reactions at the injection site, such as pain, soreness, erythema, and swelling/induration 3, 4, 7 + Systemic reactions, such as fever, irritability, persistent crying, change in eating habits, diarrhea, sleepiness, vomiting, and unusual crying 4, 7
- Serious adverse events reported in the studies are rare and include: + Neurologic conditions 6 + Other noninfectious conditions, such as constitutional signs and symptoms 6 + Gastrointestinal conditions 6 + Sudden infant death syndrome (SIDS) 6
- It is worth noting that the Vaccine Adverse Event Reporting System (VAERS) received 29,747 reports after HIB vaccines, including 5179 serious reports and 896 reports of deaths, but no new safety concerns were identified after clinical review of these reports 6.