tetano
Editor, Senior Moderator
Clin Infect Dis
. 2021 Jan 5;ciaa1916.
doi: 10.1093/cid/ciaa1916. Online ahead of print.
Adjuvanted influenza vaccine and influenza outbreaks in U.S. nursing homes: Results from a pragmatic cluster-randomized clinical trial
Stefan Gravenstein[SUP] 1 2 [/SUP], Kevin W McConeghy[SUP] 2 3 [/SUP], Elie Saade[SUP] 4 5 6 [/SUP], H Edward Davidson[SUP] 7 [/SUP], David H Canaday[SUP] 4 5 6 [/SUP], Lisa Han[SUP] 7 [/SUP], James Rudolph[SUP] 1 2 3 [/SUP], Nina Joyce[SUP] 3 8 9 [/SUP], Issa J Dahabreh[SUP] 3 8 9 [/SUP], Vince Mor[SUP] 2 3 10 11 [/SUP]
Affiliations
Abstract
Background: Influenza outbreaks in nursing homes pose a threat to frail residents and occur even in vaccinated populations. We conducted a pragmatic cluster-randomized trial comparing adjuvanted trivalent influenza vaccine (aTIV) versus trivalent influenza vaccine (TIV). Here, we report an exploratory analysis to compare the effect of aTIV versus TIV on facility-reported influenza outbreaks.
Methods: Nursing homes were randomized to offer older residents either aTIV or TIV for the 2016-17 influenza season. The impact of the intent-to-treat vaccine assignment was evaluated for the total number of outbreaks reported from November-March. We collected data according to standard CDC definitions for both suspected outbreaks and those with a laboratory-confirmed case in nursing homes, and adjusted for facility-level vaccination rates and resident characteristics.
Results: Of 823 randomized nursing homes, 777 (aTIV, n=387; TIV, n=390) reported information on influenza outbreaks. The treatment groups had similar characteristics at baseline except for race/ethnicity: homes assigned to TIV had a higher percentage of African-American residents (18.0% versus 13.7%). There were 133 versus 162 facility-reported suspected influenza outbreaks in aTIV versus TIV facilities respectively, of these 115 versus 140 were laboratory confirmed. The aTIV group experienced a 17% reduction in suspected (rate ratio, RR, 0.83, 95% confidence interval, CI: 0.65, 1.05) and laboratory-confirmed influenza outbreaks (RR 0.83, 95%CI: 0.63, 1.06). Covariate adjustment increased the estimated reduction for suspected outbreaks to 21% (RR 0.79, 95%CI: 0.61, 0.99) and 22% for laboratory confirmed (RR 0.78, 95%CI: 0.60, 1.02).
Conclusions: In an exploratory analysis of a cluster-RCT we observed 17-21% fewer outbreaks with aTIV than TIV.ClinicalTrials.gov number, NCT02882100.
Keywords: adjuvanted influenza vaccine; dosage; influenza; influenza vaccines/administration & nursing homes; outbreaks.
. 2021 Jan 5;ciaa1916.
doi: 10.1093/cid/ciaa1916. Online ahead of print.
Adjuvanted influenza vaccine and influenza outbreaks in U.S. nursing homes: Results from a pragmatic cluster-randomized clinical trial
Stefan Gravenstein[SUP] 1 2 [/SUP], Kevin W McConeghy[SUP] 2 3 [/SUP], Elie Saade[SUP] 4 5 6 [/SUP], H Edward Davidson[SUP] 7 [/SUP], David H Canaday[SUP] 4 5 6 [/SUP], Lisa Han[SUP] 7 [/SUP], James Rudolph[SUP] 1 2 3 [/SUP], Nina Joyce[SUP] 3 8 9 [/SUP], Issa J Dahabreh[SUP] 3 8 9 [/SUP], Vince Mor[SUP] 2 3 10 11 [/SUP]
Affiliations
- PMID: 33400778
- DOI: 10.1093/cid/ciaa1916
Abstract
Background: Influenza outbreaks in nursing homes pose a threat to frail residents and occur even in vaccinated populations. We conducted a pragmatic cluster-randomized trial comparing adjuvanted trivalent influenza vaccine (aTIV) versus trivalent influenza vaccine (TIV). Here, we report an exploratory analysis to compare the effect of aTIV versus TIV on facility-reported influenza outbreaks.
Methods: Nursing homes were randomized to offer older residents either aTIV or TIV for the 2016-17 influenza season. The impact of the intent-to-treat vaccine assignment was evaluated for the total number of outbreaks reported from November-March. We collected data according to standard CDC definitions for both suspected outbreaks and those with a laboratory-confirmed case in nursing homes, and adjusted for facility-level vaccination rates and resident characteristics.
Results: Of 823 randomized nursing homes, 777 (aTIV, n=387; TIV, n=390) reported information on influenza outbreaks. The treatment groups had similar characteristics at baseline except for race/ethnicity: homes assigned to TIV had a higher percentage of African-American residents (18.0% versus 13.7%). There were 133 versus 162 facility-reported suspected influenza outbreaks in aTIV versus TIV facilities respectively, of these 115 versus 140 were laboratory confirmed. The aTIV group experienced a 17% reduction in suspected (rate ratio, RR, 0.83, 95% confidence interval, CI: 0.65, 1.05) and laboratory-confirmed influenza outbreaks (RR 0.83, 95%CI: 0.63, 1.06). Covariate adjustment increased the estimated reduction for suspected outbreaks to 21% (RR 0.79, 95%CI: 0.61, 0.99) and 22% for laboratory confirmed (RR 0.78, 95%CI: 0.60, 1.02).
Conclusions: In an exploratory analysis of a cluster-RCT we observed 17-21% fewer outbreaks with aTIV than TIV.ClinicalTrials.gov number, NCT02882100.
Keywords: adjuvanted influenza vaccine; dosage; influenza; influenza vaccines/administration & nursing homes; outbreaks.