*Arpita Bhattacharyya1, *Anirban
Das1,6, Sonal Dalvi-Mitra1, Gaurav
Goel3, Sanjay Bhattacharya3, Shampa
Chowdhury4, Vaskar Saha1,2,5
* Contributed equally to this work.
Department of Paediatric Haematology and Oncology, Tata Medical Center,
Kolkata, India 1; Tata Translational Research Centre,
Tata Medical Center, Kolkata, India 2; Department of
Microbiology; Tata Medical Center, Kolkata, India 3;
St. Jude India Cancer Care Centres, Kolkata, India 4;
Division of Cancer Sciences, Faculty of Biology, Medicine and Health,
University of Manchester, Manchester, United Kingdom5. Hospital for Sick Children, Toronto,
Canada6.
Correspondence to: Arpita Bhattacharyya, Department of
Paediatric Haematology and Oncology, Tata Medical Center, 14 main
Arterial Road, Newtown, Kolkata 700160, India.
Telephone: +91 9831311289
Email:
arpita.bhattacharyya@tmckolkata.com
Word count: 500
Short running title: Varicella vaccination of caregivers
Keywords: Varicella, immunisation, caregivers, outbreak, children,
cancer
Varicella-zoster (VZV) causes serious complications in immunocompromised
children with cancer, including need for mechanical ventilation,
secondary infections, and death1,2. In low-middle
income countries (LMIC), anti-VZV immunization is infrequent for
children and non-existent for adults3. Therefore the
source of this highly contagious infection is often a family member or
caregiver. Use of the live-attenuated vaccine in immunocompromised
children has risks of vaccine-induced infection and therefore limited
acceptance4. Post-exposure prophylaxis (PEP) using
anti-VZV immunoglobulin (V-ZIG) and/or treatment with acyclovir can
limit complications5. However, the cost of V-ZIG is
prohibitive in LMIC. Treatment for VZV mandates interruptions in cancer
therapy, potentially impacting outcome6.
An accepted strategy to reduce treatment-abandonment and fever
neutropenia deaths in LMIC, both of which can be related to prolonged
travel times7,8, is to provide free accommodation in
the vicinity of treatment centers for children with cancer and their
families. However this may present with its own unique challenges. We
describe our novel experience in managing and preventing VZV outbreaks
in such a residential facility.
The 1st outbreak (November 2014–January 2015) in our
facility involved 5 children, 3 parents and 3 staff-members, the index
case being one of the parents. All 5 children were admitted and treated
with intravenous acyclovir; one needed assisted ventilation.
Twenty-two/28 (79%) children residing at the facility were
sero-negative and received PEP with oral acyclovir (20mg/kg 4-times
daily for 21-days). The 2nd-outbreak (November
2015–February 2016) involved 5 children, 3 parents and 1 staff, the
latter being the index case. Ten/15 (67%) of resident children were
seronegative and given acyclovir PEP; still breakthrough infections
developed in 7/10 children. Though there was no mortality, affected
families had to temporarily return to their homes, impacting
cancer-treatment of their wards.
A screening-cum-immunization programme was initiated in March 2017.
Consent was obtained. All caregivers, children, and staff arriving at
the facility were counselled, information materials were shared, and
they were initiated on clinical surveillance for signs and symptoms for
3-weeks post-arrival. Serological screening for all adult caregivers was
performed within a week of arrival by testing for presence of VZV
immunoglobulin-G (Vidas, Biomeriuex, France). Seronegative individuals
were offered 2-doses (0.5 ml) of VZV vaccine (Variped Lyophilised
Vaccine, Merck Sharp & Dohme, USA), 4-8 weeks apart. Females were
offered pregnancy-testing prior to vaccination.
Between March 2017-November 2019, 357 caregivers were screened. Among
123 (34%) seronegative adults, 117 (95%) received 2-doses, 3 (2.4%)
received 1-dose, 2 refused, and 1 caregiver was detected to have
clinical VZV on post-arrival surveillance and was promptly isolated. No
major adverse effects were noted in those vaccinated, except for
transient rash in 2/120 (1.6%). Over this 32-month period, only 4 cases
of VZV were detected among recently-arrived children by active
surveillance (1 in 2018; 3 in 2019), allowing rapid intervention and
preventing outbreaks.
Our experience suggests that a caregiver screening and sero-surveillance
directed vaccination program can be a safe and effective intervention
for limiting VZV outbreaks and can be adopted in similar housing
facilities for paediatric cancer patients in LMIC.