By Lisa Rapaport

(Reuters Health) – Teens are more likely to get at least one of two recommended doses of the meningococcal vaccine when they receive their first shot by early adolescence, a U.S. study suggests.

Meningococcal disease is a serious bacterial infection that can lead to bloodstream infections and severe swelling in the brain and spinal cord. About 10 percent to 15 percent of people who catch it die, and many survivors have lasting impairments like neurological deficits, loss of limbs or digits and hearing loss.

Under U.S. recommendations for routine childhood vaccinations, children are supposed to get two doses of the so-called MenACWY vaccine that covers four strains of meningococcal bacteria: one dose at age 11 or 12 and a booster at age 16. But less than half of teens have received both the primary and booster doses by age 17, researchers note in the Journal of Adolescent Health.

In the current study, researchers examined vaccination data collected on more than 1 million youth with either private health insurance or coverage through Medicaid, the U.S. health program for the poor.

Overall, younger kids were more likely than older kids to have received at least one dose of the MenACWY vaccine. Among kids aged 10.5 to 13 years with private coverage, 72 percent had received at least one dose, as had 59 percent of kids this age insured by Medicaid, the study found. In comparison, just 49 percent of teens aged 15.5 to 18 years with private insurance and 32 percent with Medicaid got at least one vaccine dose.

“Multiple vaccinations are recommended at ages 11 to 12, providing a distinct and focused opportunity for kids to receive the recommended vaccinations at a single visit,” said lead study author Samantha Kurosky of RTI Health Solutions in Research Triangle Park, North Carolina.

“Health care visits centered around preventive care and with more traditional vaccinating providers (e.g., pediatricians) become fewer and far between during older adolescence, which may result in fewer potential opportunities to vaccinate,” Kurosky said by email.

GlaxoSmithKline, maker of a MenACWY vaccine, hired RTI to do the study and was involved in all stages of the study including the data analysis and publication of the results.

Pediatricians administered most of the vaccinations in the study, and young people who saw other types of providers were less likely to get the vaccine than teens who saw pediatricians.

Both older and younger teens most often received the MenACWY vaccine at preventive checkups and in conjunction with a flu shot or other recommended vaccinations. This was less common for older teens, nearly one-third of whom got the vaccine at visits when they didn’t receive other shots.

One limitation of the study is that it looked at vaccination from 2011 to 2015, and it’s possible the results don’t reflect current vaccination rates. Researchers also didn’t evaluate whether teens received both vaccine doses – the primary shot and the booster shot – that are needed for optimal protection.

Teens who get their first dose on time may be more likely to get fully vaccinated than youth who don’t get that first shot until they’re older, noted Dr. Michael Brady of Nationwide Children’s Hospital and the Ohio State University in Columbus, who wasn’t involved in the study.

“If they would have been routinely getting their annual primary care visit, they would have received the first dose earlier,” Brady said by email. “However, by getting the first vaccine later, they have defined themselves as someone who does not routinely get their annual primary care visit.”

SOURCE: Journal of Adolescent Health, online May 15, 2019.