במחקר שהוצג בכנס המכון לחקר מדיניות בריאות המתקיים השבוע בירושליים דווח על פערים של עד פי 4 בשיעור ההתחסנות בישראל של ילדים נגד וריצלה בשכבה סוציואקונומית נמוכה בהשוואה לילדים בשכבה סוציואקונומית גבוהה. החיסון הזה כידוע אינו כלול בתכנית החיסונים ונדרש תשלום עבור ביצועו. המחקר מצא גם פער של כ-19% בתחלואה הקשורה לחיסון, שהייתה כצפוי גבוהה יותר בשכבות החלשות יותר שבהן שיעורי החיסון היו נמוכים יותר.

לפניכם האבסטרקט המקורי של העבודה שהוצגה בכנס:

THE OUTCOMES OF VARICELLA VACCINE ADOPTION IN THE POPULATION UNDER PRIVATE PURCHASE POLICY

Natalie Gavrielov-Yusim1, Erez Battat2, Lily Neumann1, Ran Balicer1,2

1Dept. of Epidemiology and Biostatistcs, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel; 2Clalit Research Institute and Health Policy Planning Department, Chief Physician Office, Clalit Health Services, Israel.

Background: Introduction of novel vaccinations as voluntary privately-purchased medical options has been long criticized as a potential source of public health inequity. Hitherto the main problem of this policy was considered the under-immunization in lower socioeconomic status (SES). However, so far the effect of SES was not demonstrated in the context of other potential vaccination-limiting factors. Moreover, the epidemiological outcomes of such policy have not been properly investigated for most privately-purchased vaccines.

Study Question: Which factors, beyond SES, have affected the adoption of privately-purchased varicella vaccine in Israel and how did varicella disease rates change due to disproportionate immunization?

Methods: Disease and vaccination rates were calculated in a random sample of 300,000 members of Clalit Health Services. Factors associated with under-immunization were analyzed in a subset of 110,902 children that included equal numbers of vaccinated and unvaccinated age-matched participants.  

Results: By the end of 9-year-long private purchase period, vaccination rates in high SES were 4-times higher than in low SES. Vaccine under-utilization was associated with Arab/Bedouin ethnicity, rural residence, place of childs and parents birth, SES, and birth order. Ethnicity and high birth order were the strongest independent risk factors for under-immunization, strongly surpassing SES.

We detected an 18.6%-gap between age-adjusted disease rates in high and low SES, which did not exist in the beginning of private-purchase period. That is, at the end of private immunization, low SES had the leading morbidity rates and high SES had the lowest disease rate.

Conclusions: Private purchase causes unequal immunization, with lowest rates among ethnic minorities, large sibships, immigrants, and low SES. Accordingly, the disease burden is disproportionate and reflects health inequity.

Health policy implications: Private-purchase periods, which in times of austerity are often practiced to introduce novel vaccines, must be short-termed, with close monitoring of resulting inequities in public health.