Bacteria-Related Pediatric Deaths in France Linked to Late Vaccination

One in four deaths caused by pediatric community-onset severe bacterial infections (COSBIs) could have been prevented if vaccines had been administered in a timely fashion.

ChristFle Gras-Leguen, a pediatrician in the Pediatric Emergency Department at Nantes University Hospital in Nantes, France, presented data from an area in West France that is known for vaccine hesitancy at the 2017 Pediatric Academic Societies Meeting (PASM) in San Francisco, California, held from May 6-9. He introduced the issue stating, “Despite a context of vaccine controversy in France, we have a paucity of data on the morbidity and mortality of community-onset severe bacterial infections and the portion of those deaths that are vaccine-preventable.” To address the scarcity of data, they evaluated a subset of children in the French county of Pasteur, where, Dr. Gras-Leguen said, “vaccine hesitancy has resulted in suboptimal coverage regarding meningococcal C vaccine (MnC) and pneumococcal conjugate vaccine (PCV).” Vaccine hesitancy does not always equate to non-vaccination, but it does often lead to delays in vaccination or “untimely vaccinations” that occur 15 days to 1 month after the recommended dates.

The Centers for Disease Control and Prevention (CDC) has published an official “catch-up schedule” for infants and children who are more than 1 month behind on their vaccinations. However, in young children such as those included in this French study, where the median age was just over two years, it is possible that the entire catch-up process would not have been completed even if parents had opted to begin vaccination after the delay. This is because, in some cases, vaccine schedules must be permanently adjusted if the delay is too long, since first-dose ages have maximum as well as minimum values. For example, in the case of pneumococcal vaccines, a child may receive the first dose at the prescribed dosage at 6 weeks of age, and receive a second dose weeks later, depending on recommendations. However, if the child receives the first dose at 24 months of age or older, he or she would not receive a second dose. In cases like this, the entire vaccine schedule is permanently altered from a potential 4 total doses to 1 or 2 depending on the perceived health of the child and the age at which they were vaccinated. This can contribute to impaired immunity in some cases, as well.

The group categorized vaccine-preventable COSBIs as infections that would have been prevented had the child been vaccinated on time. Severe sequelae of these infections include: “paralysis, ataxia, neuropathic pain, sensory deficit, hypotonia, hydrocephaly, epilepsy, and necrotic skin lesions requiring engraftment or amputation or resulting in organ failure.” The group evaluated the results of 262 children with COSBIs who were admitted into intensive care units (ICUs) or who died before admission between 2009 and 2014; this accounted for more than 1 in 10 of the entire French pediatric population during this time. Of those children, 124 were infected with meningococcus or pneumococcus, and 38 of the 100 patients with pneumococcus infections had received untimely vaccinations, as had 41 of the 61 patients with meningococcus infections. Of those with meningococcal infections, 10 patients died and 7 developed sequelae. Of those with pneumococcal infections, 10 patients died and 5 developed sequelae. Of those with meningococcal infections, 11 were theoretically vaccine-preventable, including 4 of the deaths and 2 sequelae, said the researchers, while 7 of the pneumococcal infections were theoretically vaccine-preventable, including 1 death and 1 sequelae.

The median age of the children included in the study was 25 months, and 63 of the patients them had comorbidities. Twenty-eight study patients eventually died, and another 25 had severe sequelae at the time of ICU discharge. Given that Neisseria meningitidis and Streptococcus pneumoniae are the main pathogens in France responsible for COSBIs and that the former is the cause of 72% of all deaths and sequelae, France’s low levels of vaccine coverage for these infections is particularly troubling.

“No vaccine failure was observed,” said Dr. Gras-Leguen, concluding, “Mortality rates could be reduced by better implementation of vaccine programs in France.”