A new Tel Aviv University study highlights the evidence-based positive impact that the routine pneumococcal conjugate vaccination (PCV) has had on childhood community-acquired bacteremia and antibiotic resistance patterns in Israeli children.
The research was led by Prof. Galia Grisaru-Soen of TAU’s Sackler Faculty of Medicine, head of the Pediatric Infectious Diseases Unit at Tel Aviv Medical Center, and conducted in collaboration with Dr. Yael Berger and Dr. Diana Averbuch of Hadassah Hebrew University Medical Center. The findings were published on December 2, 2018, in Acta Paediatrica.
The study concluded that hospitalizations as the direct result of Streptococcus pneumoniae dipped by a staggering 62% following the Israeli Ministry of Health’s decision to add a nationwide PCV to its national immunization program in July 2009.
Streptococcus pneumoniae can cause many types of illnesses, including pneumonia (infection of the lungs), ear infections, sinus infections, meningitis (infection of the covering around the brain and spinal cord), and bacteremia (blood stream infection). The nasopharyngeal carriage rate of Streptococcus pneumoniae in children is about 21% in industrialized countries. Transmission occurs from person to person via respiratory droplet contact. Viral upper respiratory tract infections, including influenza, can predispose people to pneumococcal infection and transmission. Pneumococcal infections are most prevalent during winter months.
“Our take-home message to all the parents out there is that vaccines work,” says Prof. Grisaru-Soen. “Introducing PCV [Prevnar®] into the national immunization program made a huge difference. We saw community-acquired bacteremia, pneumonia, and focal infections all decrease. If we continue to administer the vaccine, incidents of community-acquired bacteremia will likewise decrease.”
Prof. Grisaru-Soen and colleagues analyzed the medical records of hundreds of patients with childhood community-acquired bacteremia under 18 years of age across three children’s hospitals in Tel Aviv and Jerusalem from 2007 to 2015. According to the study, there were 511,904 emergency department visits and 125,922 children were hospitalized during 2007-2015 in these three hospitals.
The researchers then broke these numbers down, assessing hospitalizations that occurred before July 2009 (the pre-vaccine period) and after (the post-vaccine period). “Hospitalizations as a result of all community-acquired bacterial infections decreased by 22% in the post-vaccine period compared to the pre-vaccine period,” Prof. Grisaru-Soen says. “The proportion of pediatric admissions to the emergency department specifically due to Streptococcus pneumoniae decreased from 86.4 to 32.8 per 100,000 admissions after PCV, which was a relative risk reduction of 62%. These figures are comparable to those in the United States in the post-vaccination period.”
The U.S. Food and Drug Administration (FDA) licensed the first pneumococcal conjugate vaccine (PCV7) in the United States in 2000, providing protection against infections caused by seven other strains of Streptococcus pneumoniae through four incremental doses administered at the ages of 2, 4, 6 and 12 months. In 2010, the FDA licensed PCV13, providing protection against infections caused by six more strains.
In Israel, PCV7 was introduced in the national vaccination program in 2009 and PCV13 in 2010. The vaccine is administered in three doses at the ages of 2, 4 and 12 months.
According to Prof. Grisaru-Soen, another major advantage of the vaccine has been the reduction of certain antibiotic-resistant pneumococcal infections. “There are now far fewer antibiotic-resistant pneumococcal infections caused by the bacterial strains included in the vaccine,” Prof. Grisaru-Soen says. “The second generation of Prevnar® covers six more strains, so the ones that were not included in the new vaccine are now more prevalent in society. We will soon need another new generation of this vaccine.”
Prof. Grisaru-Soen is now researching the influence of vaccines introduced in past decade on pediatric hospital admissions.
“If you decide not to vaccinate your children, you’re not only harming them, you’re harming other kids as well,” Prof. Grisaru-Soen says. “Being a part of society means also taking responsibility for the health and welfare of other children who for medical reasons may not be able to be vaccinated.”