Pediatric Hexavalent Combination Vaccine Approved by FDA

The US Food and Drug Administration has approved a hexavalent combination vaccine (Vaxelis) that is indicated for immunization to prevent diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B, and invasive disease due to Haemophilus influenzae type b in children younger than 5 years old.

The vaccine is approved as a 3-dose series, which consists of a 0.5 mL intramuscular injection, administered at 2, 4, and 6 months of age.

Contraindicated in children with a history of anaphylaxis to any ingredient in the vaccine, health care officials are also advised not to administer Vaxelis to anyone with a history of encephalopathy, within 7 days of a pertussis-containing vaccine, that is not attributable to another identifiable cause. The vaccine is also not to be administered to anyone with a history of progressive neurologic disorder until a treatment regimen has been established and the condition has stabilized.

A statement from Sanofi advised health care officials to "carefully consider benefits and risks before administering Vaxelis to persons with a history of:

• fever of 105°F or higher,
• hypotonic-hyporesponsive episode or persistent, inconsolable crying lasting 3 or more hours within 48 hours after a previous pertussis-containing vaccine,
• seizures within 3 days after a previous pertussis-containing vaccine.”

The adverse reactions following any dose were irritability (≥55%), crying (≥45%), injection site pain (≥44%), somnolence (≥40%), injection site erythema (≥25%), decreased appetite (≥23%), fever ≥38.0°C (≥19%), injection site swelling (≥18%), and vomiting (≥9%). This vaccine does not constitute a primary immunization series against pertussis.

Sanofi and Merck, who developed the vaccine as part of a joint partnership, are working to maximize production of the vaccine to allow for a sustainable supply to meet anticipated demand, but commercial supply is not expected until 2020.