A cura di Giorgio Conforti, coordinatore Area Vaccini e Vaccinazioni FIMP
All’affacciarsi dell’offerta vaccinale contro la Varicella in età pediatrica, una delle obiezioni fu che si potessero verificare più casi di Zoster nella fascia di età di competenza pediatrica nell’ipotesi che la protezione immunologica data dal vaccino fosse minore rispetto a quella garantita dalla malattia contratta naturalmente. Ciò non è; anche, e soprattutto, alla luce di quanto riportato da un lavoro pubblicato su Pediatrics di luglio 2019 (vedi sotto) e relativo a uno studio di oltre 12 anni post-vaccino in una platea di osservazione di oltre 6 milioni di bambini.
Le conclusioni sono che il tasso di incidenza di zoster nei vaccinati per Varicella rispetto ai non vaccinati scese del 78% e che l’incidenza in generale dello Zoster è calato del 72%.
Quindi anche questo “dubbio” si scioglie e si può rinforzare ulteriormente la raccomandazione a vaccinare (con due dosi!)
Qui di seguito è riportato l’abstract per gli interessati.
INCIDENCE OF HERPES ZOSTER AMONG CHILDREN: 2003–2014
Sheila Weinmann, Allison L. Naleway, Padma Koppolu, Roger Baxter, Edward A. Belongia, Simon J. Hambidge, Stephanie A. Irving, Michael L. Jackson, Nicola P. Klein, Bruno Lewin, Elizabeth Liles, Mona Marin, Ning Smith, Eric Weintraub and Colleen Chun
Pediatrics July 2019, 144 (1) e20182917; DOI: https://doi.org/10.1542/peds.2018-2917
BACKGROUND AND OBJECTIVES:
After the 1996 introduction of routine varicella vaccination in the United States, most studies evaluating pediatric herpes zoster (HZ) incidence reported lower incidence over time, with varying degrees of decline. Using the combined databases of 6 integrated health care organizations, we examined HZ incidence in children over a 12-year period in the varicella vaccine era.
METHODS:
This study included children aged 0 through 17 years from 2003 through 2014. Using electronic medical records, we identified HZ cases through International Classification of Diseases, Ninth Revision diagnosis code 053. We calculated HZ incidence rates per 100 000 person years of health plan membership for all children and among children who were vaccinated versus unvaccinated. We calculated rates for the 12-year period and examined temporal trends. Among children who were vaccinated, we compared HZ rates by month and year of age at vaccination.
RESULTS:
The study included 6 372 067 children with ≥1 month of health plan membership. For the 12-year period, the crude HZ incidence rate for all subjects was 74 per 100 000 person years, and the rate among children who were vaccinated was 38 per 100 000 person years, which was 78% lower than that among children who were unvaccinated (170 per 100 000 person years; P < .0001). Overall HZ incidence declined by 72% (P < .0001) from 2003 through 2014. Annual rates in children who were vaccinated were consistently lower than in children who were unvaccinated.
CONCLUSIONS:
With this population-based study, we confirm the decline in pediatric HZ incidence and the significantly lower incidence among children who are vaccinated, reinforcing the benefit of routine varicella vaccination to prevent pediatric HZ.
