Kids with Sickle Cell Disease Aren’t Receiving Key Vaccines, Michigan Study Finds

A significant proportion of children with sickle cell disease (SCD) are not receiving key recommended vaccines on time or at all, according to a new study examining pneumococcal and meningococcal vaccinations among children in Michigan.

The study, “Pneumococcal and Meningococcal Vaccination among Michigan Children with Sickle Cell Disease,” was published in the Journal of Pediatrics.

The researchers sought to determine the proportion of children with SCD compared to kids without the condition in Michigan who were vaccinated according to pneumococcal vaccination recommendations and, secondarily, to examine meningococcal vaccination.

The study included children born in the state of Michigan between April 1, 1995, and January 1, 2014. A total of 1,022 children with sickle cell disease were matched to 3,725 children without SCD using age, sex, race, and zip code.

Results showed that by 36 months, substantially higher percentages of children with sickle cell disease had completed the pneumococcal conjugate vaccine series (68.8 percent) than children without SCD (45.2 percent) and 59 percent of children with SCD had received a meningococcal vaccine.

Compared to children without the condition, kids with SCD were more likely to have up-to-date pneumococcal status at ages 5 months, 7 months, and 16 months; however, a large proportion of children with SCD were still missing vaccination targets.

Of those who received a full seven-valent pneumococcal conjugate vaccine series, 29.1 percent had not received a 13-valent pneumococcal vaccine dose. Similarly, 21.8 percent had not received a pneumococcal polysaccharide vaccine.

Even though the recommended pneumococcal and meningococcal vaccination schedules have become increasingly complex in recent years, not considering them puts these children at higher risk of meningococcal and invasive pneumococcal disease because they lack normal spleen function.

According to the lead author of the study, Abram L. Wagner, PhD, the Centers for Disease Control and Prevention’s (CDC) advisory committee on immunization practices (ACIP), the child vaccination schedule specifically includes recommendations for these two vaccines in children with sickle cell disease.

In February 2010, ACIP recommended that all children receive the 13-valent pneumococcal conjugate vaccine (PCV13), replacing the seven-valent pneumococcal conjugate vaccine (PCV7).

In addition, ACIP also recommended that children with SCD receive two doses of the 23-valent polysaccharide vaccine (PPV23) starting at age 2. These children should also receive a PCV13 dose before turning 18 years old, even if they received the PCV7 vaccine before.

“By directly including SCD status in a child’s immunization record, an immunization information system could use a specialized algorithm to indicate to healthcare providers which vaccines should be given to a patient with SCD, which may differ from a typical patient,” the authors wrote.

“Educational campaigns targeted to parents of these children and their providers could also help advance the importance of vaccination, particularly as more vaccines enter the market, many of which may be highly recommended for children with SCD,” they added.

The authors highlight the complexity of ACIP recommendations, however. On average, ACIP released seven different recommendations per year between 2006 and 2015, which could have had a significant impact on these findings.

“Although providers have a responsibility to educate themselves on how best to protect children with high-risk conditions, these figures speak to the need for MCIR, the state’s immunization information system, to provide additional information on children, such as those who have sickle cell disease, who have special vaccination recommendations,” they added.