Prevention of Antigenically Drifted Influenza by Inactivated and Live Attenuated Vaccines

Abstract

In the 2004-2005 season, in which most circulating viruses were dissimilar to those included in the vaccine, the inactivated vaccine was efficacious in preventing laboratory-confirmed symptomatic illnesses from influenza in healthy adults. The live attenuated vaccine also prevented influenza illnesses but was less efficacious. (ClinicalTrials.gov number, NCT00133523.)

Novel Bivalent Viral-Vectored Vaccines Induce Potent Humoral and Cellular Immune Responses Conferring Protection against Stringent Influenza A Virus Challenge

“…For the past 70 years vaccination has been the mainstay healthcare strategy against influenza infection (4)(5)(6). However traditional inactivated influenza vaccines (IIVs) confer strain-specific protection and do not typically induce the broad-spectrum immunity needed in the face of a newly emergent IAV (7)(8)(9). The possible threat of a pandemic outbreak has therefore catalysed the development of broadly protective IAV vaccines.…”

Comparison of the trivalent live attenuated vs. inactivated influenza vaccines among U.S. military service members

“…However, Nichol et al found LAIV to be statistically significantly effective at preventing severe febrile illnesses and febrile upper respiratory tract illnesses compared to placebo [8]. Another randomized, placebo-controlled trial by Ohmit et al, found a higher absolute efficacy for TIV for culture or real-time PCR positive influenza (75% and 16%) compared to LAIV (48% and 8%) for both the 2004-2005 and 2005-2006 influenza seasons among adults, but with overlapping confidence intervals [5,7]. TIV has also been reported by Bridges et al to be 86% efficacious against laboratory confirmed influenza when compared to placebo [9].…”

“…A limited number of studies, mostly randomized trials or experimental challenge studies, have been conducted among adults. Although both vaccines have been shown to have absolute effectiveness against influenza-like illness in adults, studies directly comparing LAIV to TIV found mixed results on which vaccine had superior efficacy in the prevention of culture-confirmed influenza [5][6][7][8][9].…”

Benefits of influenza vaccination during pregnancy for pregnant women

“…4 Efficacy of inactivated influenza vaccine among adults has been demonstrated in several randomized placebo-controlled trials with the outcome of laboratory-confirmed influenza. [5][6][7][8][9][10][11][12] A recent meta-analysis reported a pooled vaccine efficacy of 59% (95% confidence interval, 51-67%) for the trivalent inactivated influenza vaccine among adults aged 18-64 years. 13 Among studies that enrolled participants with similar age distributions to those of pregnant women, demonstrated vaccine efficacy ranged from 54% to 89%.…”

“…Over 3 influenza seasons, inactivated influenza vaccine efficacy ranged from 54% to 77%. [9][10][11] Although the efficacy and effectiveness of influenza vaccination in preventing influenza infection and illness has been demonstrated in nonpregnant, healthy adults, the immune response to vaccination might be different in pregnant women for several reasons. During pregnancy, immune alterations that allow the mother to tolerate fetal tissue of paternal origin occur.…”