eprintid: 3770 rev_number: 6 eprint_status: archive userid: 69 dir: disk0/00/00/37/70 datestamp: 2017-09-04 13:40:21 lastmod: 2017-09-04 13:40:21 status_changed: 2017-09-04 13:40:21 type: article metadata_visibility: show creators_name: Betta, Monica creators_name: Laurino, Marco creators_name: Pugliese, Andrea creators_name: Guzzetta, Giorgio creators_name: Landi, Alberto creators_name: Manfredi, Piero creators_id: monica.betta@imtlucca.it creators_id: creators_id: creators_id: creators_id: creators_id: title: Perspectives on optimal control of varicella and herpes zoster by mass routine varicella vaccination ispublished: pub subjects: QH301 subjects: R1 divisions: CSA full_text_status: none abstract: Herpes zoster arises from reactivation of the varicella–zoster virus (VZV), causing varicella in children. As reactivation occurs when cell-mediated immunity (CMI) declines, and there is evidence that re-exposure to VZV boosts CMI, mass varicella immunization might increase the zoster burden, at least for some decades. Fear of this natural zoster boom is the main reason for the paralysis of varicella immunization in Europe. We apply optimal control to a realistically parametrized age-structured model for VZV transmission and reactivation to investigate whether feasible varicella immunization paths that are optimal in controlling both varicella and zoster exist. We analyse the optimality system numerically focusing on the role of the cost functional, of the relative zoster–varicella cost and of the planning horizon length. We show that optimal programmes will mostly be unfeasible for public health owing to their complex temporal profiles. This complexity is the consequence of the intrinsically antagonistic nature of varicella immunization programmes when aiming to control both varicella and zoster. However, we show that gradually increasing—hence feasible—vaccination schedules can perform better than routine programmes with constant vaccine uptake. Finally, we show the optimal profiles of feasible programmes targeting mitigation of the post-immunization natural zoster boom with priority. date: 2016 date_type: published publication: Proceedings of the Royal Society B: Biological Sciences volume: 283 number: 1826 pagerange: 20160054 id_number: doi:10.1098/rspb.2016.0054 refereed: TRUE issn: 0962-8452 official_url: http://doi.org/10.1098/rspb.2016.0054 citation: Betta, Monica and Laurino, Marco and Pugliese, Andrea and Guzzetta, Giorgio and Landi, Alberto and Manfredi, Piero Perspectives on optimal control of varicella and herpes zoster by mass routine varicella vaccination. Proceedings of the Royal Society B: Biological Sciences, 283 (1826). p. 20160054. ISSN 0962-8452 (2016)