On 26 December 2018, Sanofi and Merck jointly announced (pdf) FDA approval for a new hexavalent vaccine called Vaxelis. The new vaccine was developed to vaccinate children aged 6 weeks to 4 years old to protect them against diphtheria, tetanus, pertussis (whooping cough), polio, hepatitis B, and Haemophilus influenzae type B (also known as Hib). Sanofi and Merck stated that the companies are setting up production, and the vaccine should be available in the USA by 2020.
This new (for the USA) hexavalent vaccine is intended for intramuscular injection as a 3-dose series given at 2, 4, and 6 months of age. However, the initial dose may be given to infants as early as 6 weeks. The vaccine may be used to complete the hepatitis B immunization series. However, one additional dose of a pertussis-containing vaccine must be added to the 3-dose hexavalent vaccine schedule to complete the immunization against pertussis.
This vaccine will reduce the number of separate vaccinations from at least 4 down to 1. Reducing the number of times an infant needs to receive a shot is a benefit to the child, the parents, and the healthcare workers who perform the vaccinations.
Sanofi, Merck, and GSK have produced various formulations of this hexavalent vaccine outside of the USA since 2000. Merck and Sanofi submitted the application for this vaccine to the FDA in 2014 after completion of phase III clinical trials, which included over 1400 infants. The clinical trial showed that the new vaccine was equivalent, in terms of safety and effectiveness, to the older series of individual vaccines.
As discussed previously, spurious claims that hexavalent vaccines lack antigens and other nonsense have been debunked.
I am not sure why this vaccine took nearly two decades to reach the US market, but I’m sure someone in the anti-vaccine religion will invent some ridiculous conspiracy theory to say why. Nevertheless, this hexavalent vaccine is a very important addition to the list of vaccines available in the USA.
In spite of the FDA approval, the CDC’s Advisory Committee on Immunization Practices will need to review all of the data again before making a recommendation to change the US vaccination schedule. That will probably happen during the next couple of years.
This new hexavalent vaccine is a great benefit to preventing diseases that harm our children. I’m glad it’s coming to the USA.
- Marshall GS, Adams GL, Leonardi ML, Petrecz M, Flores SA, Ngai AL, Xu J, Liu G, Stek JE, Foglia G, Lee AW. Immunogenicity, Safety, and Tolerability of a Hexavalent Vaccine in Infants. Pediatrics. 2015 Aug;136(2):e323-32. doi: 10.1542/peds.2014-4102. PubMed PMID: 26216331.