AMMI Canada /CPHA Co-developed Accredited Learning Activity December 3, 2014 Dat Tran, MD, MSc Staff Physician, Division of Infectious Diseases The Hospital for Sick Children Two Bs? Or not Two Bs?Examining Quadrivalent Influenza Vaccines Epidemiology of influenza and burden of influenza B

Faculty/Presenter Disclosure Faculty: Dr. Dat Tran Relationships with commercial interests: – Grants/Research Support: -Novartis Vaccines via CPS -GSK via CPS -Hoffman La Roche -Sanofi Pasteur via Clinical Trials Research Center/Canadian Center for Vaccinology – Other: Employee of The Hospital for Sick Children

Mitigating Potential Bias The planning committee has deemed there to be no potential for bias or conflict of interest in relation to the speaker(s) declaration(s) and the workshop content. All speakers were independently selected by the Education Planning committee. No speakers have received an honorarium for this session.

Outline Background Epidemiology of influenza Burden of influenza B Conclusions Outline Background Epidemiology of influenza Burden of influenza B Conclusions

An influenza virus Outline Background Epidemiology of influenza Burden of influenza B Conclusions

Influenza infection Outline Background Epidemiology of influenza Burden of influenza B Conclusions

3 types of influenza viruses Influenza A Found in many animals (ducks, chickens, pigs, whales, horses, seals) Wild birds = natural hosts Responsible for all pandemics Influenza B Circulates widely only in humans Influenza C Causes mild infection in humans Does not cause epidemics Outline Background Epidemiology of influenza Burden of influenza B Conclusions

Antigenic drift and shift Drift Gradual change due to point mutations in H & N Occurs in both A and B viruses Localized or worldwide spread Shift Occurs through reassortment of genes Sudden change Occurs only in influenza A viruses Worldwide spread (pandemic) Outline Background Epidemiology of influenza Burden of influenza B Conclusions

Influenza affects millions of people each year in Canada Outline Background Epidemiology of influenza Burden of influenza B Conclusions Deaths (~4000) Hospitalizations (up to 20,000) Physician visits (I&P excess rates of /100K) Work-days lost (1.5 million; 10-12% of all absence from work) Infections (10-20% of population or million) ACS NACI Statement on Seasonal Influenza Vaccine for ; Menec et al, CJPH 2003

Laboratory-confirmed influenza cases in Canada by type and season Outline Background Epidemiology of influenza Burden of influenza B Conclusions ACS NACI Statement on Seasonal Influenza Vaccine for

Laboratory-confirmed influenza B cases by age group & season Outline Background Epidemiology of influenza Burden of influenza B Conclusions ACS NACI Statement on Seasonal Influenza Vaccine for % 40.2% 1.4% 16.6% 39.4% 12.8% 42.5% 39.7% 0.1% 14.6% 53.1% 16.1%

Incidence of influenza B in Ontario by age group and season Outline Background Epidemiology of influenza Burden of influenza B Conclusions * season only includes cases reported up to the end of Week 28 (July 12, 2014). Note: Counts from are underreported and should be interpreted with caution due to modified reporting during the pandemic. Source: (Case data) Ontario Ministry of Health and Long-Term Care, integrated Public Health Information System (iPHIS) database, extracted by Public Health Ontario [2014/07/15]; (Population data) Population Estimates , Ontario Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, date extracted [2014/07/02]. Slide courtesy of Public Health Ontario

Institutional outbreaks of influenza in Ontario by type and season Outline Background Epidemiology of influenza Burden of influenza B Conclusions Slide courtesy of Public Health Ontario *Note: season only includes outbreaks reported up to the end of Week 28 (July 12, 2014). Outbreaks with a missing date of onset were excluded. Source: Ontario Ministry of Health and Long-Term Care, integrated Public Health Information System (iPHIS) database, data extracted [2007/11/16]; data extracted [2008/09/25]; data extracted [2009/09/08]; data extracted [2010/09/09]; data extracted by Public Health Ontario [2011/09/07]; data extracted by Public Health Ontario [2012/11/06] data extracted by Public Health Ontario [2014/05/06] data extracted by Public Health Ontario [2014/07/17].

Circulating B lineage vs WHO recommended B lineage Outline Background Epidemiology of influenza Burden of influenza B Conclusions ACS NACI Statement on Seasonal Influenza Vaccine for %40.2%1.4%16.6%39.4%12.8%42.5%39.7%0.1%14.6%53.1%16.1% RVDSS:

Circulating B lineage vs WHO recommended B lineage Outline Background Epidemiology of influenza Burden of influenza B Conclusions ACS NACI Statement on Seasonal Influenza Vaccine for %40.2%1.4%16.6%39.4%12.8%42.5%39.7%0.1%14.6%53.1%16.1% RVDSS: IMPACT: 30.7% 38.1% 15.3% 36.9% 46.9% 0% 32.8% 58.3% 29.6%

Circulating B lineage vs WHO recommended B lineage Outline Background Epidemiology of influenza Burden of influenza B Conclusions ACS NACI Statement on Seasonal Influenza Vaccine for %40.2%1.4%16.6%39.4%12.8%42.5%39.7%0.1%14.6%53.1%16.1% RVDSS: IMPACT: 30.7% 38.1% 15.3% 36.9% 46.9% 0% 32.8% 58.3% 29.6% CNISP/SOS: 9.3% 54.1% 7.7%

Characteristics of influenza B versus A in hospitalized individuals Outline Background Epidemiology of influenza Burden of influenza B Conclusions Influenza BInfluenza A Hospitalization (IMPACT) Matched B seasons Mismatched B seasons 36.3% (15.3 – 58.3) 28.5% (29.6 – 32.8) 40.6% (5.3 – 58.3) 63.7% (41.7 – 84.7) 71.5% (67.2 – 70.4) 59.4% (41.7 – 84.7) Hospitalization (SOS) Matched B seasons Mismatched B seasons 7.7 – 54.1% 7.7 – 9.3% 54.1% 45.9 – 92.3% 90.7 – 92.3% 45.9% Age group (P/T) 0 – 4 5 – – – – 64 ≥ % 7.2% 0.6% 6.2% 18.3% 57.1% 16.9% 3.6% 1.1% 16.8% 30.6% 27.2% ICU admission (IMPACT)13.8%13.9% Mortality (P/T)7.1%6.0% ACS NACI Statement on Seasonal Influenza Vaccine for ; FluWatch

Characteristics of influenza B versus A in hospitalized adults by type/subtype: SOS (2011/12) Outline Background Epidemiology of influenza Burden of influenza B Conclusions Slide courtesy of PCIRN SOS Network VariableInfluenza A n = 161 Influenza B n = 299 A/H1N1 n=99 A/H3N2 n=61 B/Vic n=89 B/Yam n=204 Age mean (SD)55 (17.4)71.2 (20)61.5 (21)73.6 (17.1) 16-49y37 (37.4%)10 (16.4%)25 (28.1%)23 (11.3%) 50-64y27 (27.3%)5 (8.2%)18 (20.2%)36 (17.7%) 65-75y23 (23%)12 (19.7%)20 (22.5%)29 (14.2%) > 75y12 (12%)34 (55%)26 (29.2%)116 (56.9%) Male48 (48.5%)28 (45.9%)34 (38.2%)94 (46.1%) Admit from LTCF010 (16.4%)10 (11.4)76 (37.3)

Outcomes of influenza B versus A in hospitalized adults by type/subtype: SOS (2011/12) Outline Background Epidemiology of influenza Burden of influenza B Conclusions Slide courtesy of PCIRN SOS Network VariableInfluenza A n = 161 Influenza B n = 299 A/H1N1 n=99 A/H3N2 n=61 B/Vic n=89 B/Yam n=204 Mean LOS (SD)10.0 (10.4)10.4 (11.9) 9.3 (9.1)11.0 (12.4)11.3 (13.2)10.1 (11.4) Admit to ICU22 (13.7%)30 (10.0%) 15 (15.2%)7 (11.5%)12 (13.5%)18 (8.8%) 30d mortality10 (6.2%)23 (7.7%) 3 (3.0%)7 (11.5%)*3 (3.4%)20 (9.8%)*

Conclusions Outline Background Epidemiology of influenza Burden of influenza B Conclusions Influenza is a major cause of morbidity and mortality, and has an impact on social and economic well-being In 5 of last 12 non-pandemic influenza seasons, influenza B has accounted for ≥ 25% of all cases Circulating and vaccine strains differed in 3 seasons Co-circulation of both B lineages occurred in 4 th season Burden of influenza B (relative to A) is, on average, greater when circulating and vaccine strains do not match A heavy influenza B season can occur even when circulating and vaccine strains match

Conclusions Outline Background Epidemiology of influenza Burden of influenza B Conclusions Compared influenza A, a greater proportion of hospitalized influenza B cases occurs in Children aged 5 to 14 years Adults aged ≥ 65 years Among individuals hospitalized with influenza, severity of influenza B is comparable to that of influenza A Given the contribution of influenza B to the incidence and serious outcomes related to influenza, use QIV may offer benefits over TIV in supporting the goal of the Canadian influenza immunization program