The Use of Live Attenuated Influenza Vaccine (LAIV) in Healthcare Personnel (HCP)

Guidance From the Society for Healthcare Epidemiology of America (SHEA)

Thomas R. Talbot, MD, MPH; Hilary Babcock, MD, MPH; Deborah Cotton, MD, MPH; Lisa L. Maragakis, MD, MPH; Gregory A. Poland, MD; Edward J. Septimus, MD; Michael L. Tapper, MD; David J. Weber, MD, MPH


Infect Control Hosp Epidemiol. 2012;33(10):981-983. 

In This Article

LAIV and Viral Shedding

Shedding of attenuated vaccine virus is common in the first few days following vaccination with LAIV;[8,9] however, the quantity of attenuated virus shed in adults is 100–10,000-fold lower than the median human infectious dose required for LAIV vaccination in adults.[8] Reversion of LAIV virus to wild-type virus has never been demonstrated despite extensive testing.[10] Importantly, secondary transmission from a person who recently received the LAIV that resulted in clinically important illness has never been reported in the medical literature,[11] and to date there has been only 1 documented episode of LAIV virus transmission, which occurred in a day care attendee as part of a placebo-controlled LAIV trial.[12] The virus obtained from this subject retained LAIV attenuation, and virus could not be recovered in additional specimens collected from the subject. No additional cases of LAIV transmission have been reported to the manufacturer of the only licensed LAIV (C. Rizzo, MedImmune, personal communication, April 13, 2012).