Skip to main content
. Author manuscript; available in PMC: 2018 Feb 10.
Published in final edited form as: N Engl J Med. 2017 Aug 10;377(6):534–543. doi: 10.1056/NEJMoa1700153

Figure 4. Adjusted Estimates of Influenza Vaccine Effectiveness, Stratified According to Receipt of Vaccines for the Current Season (2015–2016) and Previous Season (2014–2015).

Figure 4

In each subgroup, the number of case patients is the number of participants with the specified vaccination history who tested positive for the relevant influenza virus subtype or lineage; the total number in each subgroup is the number of participants with the specified vaccination history who tested negative for influenza or tested positive for the specified subtype or lineage. Vaccine effectiveness was calculated as (1 – OR) × 100, in which OR is the odds ratio for testing positive for influenza virus among participants who were vaccinated in the season or seasons of interest versus participants who received no vaccination in either season (the reference group). Horizontal bars indicate 95% confidence intervals.