Interim 2017/18 influenza seasonal vaccine effectiveness: Combined results from five European studies

Between September 2017 and February 2018, influenza A(H1N1)pdm09, A(H3N2) and B viruses (mainly B/Yamagata, not included in 2017/18 trivalent vaccines) co-circulated in Europe. Interim results from five European studies indicate that, in all age groups, 2017/18 influenza vaccine effectiveness was 25 to 52% against any influenza, 55 to 68% against influenza A(H1N1)pdm09, -42 to 7% against influenza A(H3N2) and 36 to 54% against influenza B. 2017/18 influenza vaccine should be promoted where influenza still circulates

2015/16 seasonal vaccine effectiveness against hospitalisation with influenza a(H1N1)pdm09 and B among elderly people in Europe: Results from the I-MOVE+ project

We conducted a multicentre test-negative caseâ\u80\u93control study in 27 hospitals of 11 European countries to measure 2015/16 influenza vaccine effectiveness (IVE) against hospitalised influenza A(H1N1)pdm09 and B among people aged â\u89¥ 65 years. Patients swabbed within 7 days after onset of symptoms compatible with severe acute respiratory infection were included. Information on demographics, vaccination and underlying conditions was collected. Using logistic regression, we measured IVE adjusted for potential confounders. We included 355 influenza A(H1N1)pdm09 cases, 110 influenza B cases, and 1,274 controls. Adjusted IVE against influenza A(H1N1)pdm09 was 42% (95% confidence interval (CI): 22 to 57). It was 59% (95% CI: 23 to 78), 48% (95% CI: 5 to 71), 43% (95% CI: 8 to 65) and 39% (95% CI: 7 to 60) in patients with diabetes mellitus, cancer, lung and heart disease, respectively. Adjusted IVE against influenza B was 52% (95% CI: 24 to 70). It was 62% (95% CI: 5 to 85), 60% (95% CI: 18 to 80) and 36% (95% CI: -23 to 67) in patients with diabetes mellitus, lung and heart disease, respectively. 2015/16 IVE estimates against hospitalised influenza in elderly people was moderate against influenza A(H1N1)pdm09 and B, including among those with diabetes mellitus, cancer, lung or heart diseases

Surveillance van griep en andere luchtweginfecties: winter 2018/2019

Griepepidemie De griepepidemie in de winter van 2018/2019 was mild en duurde 14 weken. Dat is langer dan het gemiddelde van negen weken in de afgelopen 20 jaar, maar korter dan de lange griepepidemie van 2017/2018 (18 weken). In totaal zijn tussen oktober 2018 en mei 2019 ongeveer 400.000 mensen ziek geworden door het griepvirus. Ongeveer 165.000 mensen gingen naar de huisarts met griepachtige klachten. Minder mensen moesten vanwege complicaties van griep (meestal longontsteking) in het ziekenhuis worden opgenomen. Naar schatting waren dit er ruim 11.000, tegenover 16.000 in het griepseizoen 2017/2018. Mensen zijn vooral ziek geworden van het type A griepvirus. Tijdens de griepepidemie zijn er 2900 mensen meer overleden dan normaal is in deze periode. Effectiviteit griepvaccin In het griepseizoen 2018/2019 hadden gevaccineerden in Nederland 57 procent minder kans op griep. Dat is ongeveer hetzelfde als in vorige griepseizoenen. In Europa werkte het vaccin minder goed tegen een van de meest voorkomende griepvirussen. Internationaal wordt uitgezocht wat de reden daarvan is. De effectiviteit van het griepvaccin kan per seizoen sterk verschillen. Dat komt omdat een half jaar van tevoren wordt bepaald welke virussen in het griepvaccin komen. Dat gebeurt op basis van de virussen die het griepseizoen ervoor in de wereld het meest voorkwamen. Maar griepvirussen kunnen veranderen, of andere griepvirussen kunnen overheersen tegen de tijd dat het griepseizoen in Nederland begint. Daardoor kan van tevoren nooit precies worden voorspeld welke griepvirussen hierin omloop zullen zijn. Meldingsplichtige luchtweginfecties Sommige luchtweginfecties moeten bij de GGD worden gemeld. De GGD kan ze dan intensief volgen en als het nodig is op tijd actie ondernemen om te voorkomen dat ze zich verder verspreiden. Het aantal meldingen van legionella is in 2018 nog verder gestegen naar 584, het hoogste aantal ooit gerapporteerd. Het aantal gemelde gevallen van tuberculose (806), Q-koorts (18) en psittacose (64) bleef stabiel. Q-koorts, psittacose en legionella uiten zich meestal in de vorm van longontstekingen. Het aantal gemelde gevallen is lager dan het werkelijke aantal. Dat komt doordat vaak niet op deze ziekten wordt getest als mensen een longontsteking hebben.Influenza epidemic The influenza epidemic of the 2018/2019 winter was mild and lasted 14 weeks. That is longer than the average period of nine weeks during the last 20 years, but it is shorter than the extended influenza epidemic of 2017/2018 which lasted 18 weeks. Between October 2018 and May 2019, a total of approximately 400,000 people became ill due to the influenza virus. Approximately 165,000 people consulted their general practitioner with influenza-like symptoms. Fewer people were admitted to the hospital as a result of influenza complications (mostly pneumonia). This number was estimated to be around 11,000, compared to 16,000 during the 2017/2018 flu season. Type A influenza virus was responsible for the majority of illnesses. There were 2,900 more deaths during the influenza epidemic than would normally be expected during this period. Influenza vaccine effectiveness During the 2018/2019 flu season, the influenza vaccine in the Netherlands reduced the risk of developing flu by 57%. This is about the same effect as in the previous flu seasons. In Europe, the vaccine was less effective against one of the most common circulating influenza viruses. An international study is being carried out to determine the reason for this. The effectiveness of the influenza vaccine can differ greatly from season to season. This is because the decision on the composition of the flu vaccine is made half a year beforehand. This is based on the viruses that were most common globally during the previous flu season. However, influenza viruses can change or other influenza viruses may dominate by the time the flu season breaks out in the Netherlands. This is why it is not possible to predict exactly which influenza viruses will circulate in the Netherlands in the next season. Notifiable respiratory infections Some respiratory infections have to be reported to the Public Health Services. They can then intensively monitor such infections and, if necessary, take timely action to prevent their further spread. The number of reports of legionella increased further in 2018 and reached 584, which is the highest number ever reported. The number of reports of tuberculosis (806), Q fever (18) and psittacosis (64) remained stable. Q fever, psittacosis and legionella generally manifest themselves in the form of pneumonia. The number of cases reported is an underestimation of the actual number. This is because tests are often not carried out for these illnesses if people have pneumonia.Ministerie van VW

Repeated seasonal influenza vaccination among elderly in Europe: Effects on laboratory confirmed hospitalised influenza

In Europe, annual influenza vaccination is recommended to elderly. From 2011 to 2014 and in 2015-16, we conducted a multicentre test negative case control study in hospitals of 11 European countries to measure influenza vaccine effectiveness (IVE) against laboratory confirmed hospitalised influenza among people aged >= 65 years. We pooled four seasons data to measure IVE by past exposures to influenza vaccination. We swabbed patients admitted for clinical conditions related to influenza with onset of severe acute respiratory infection <= 7 days before admission. Cases were patients RT-PCR positive for influenza virus and controls those negative for any influenza virus. We documented seasonal vaccination status for the current season and the two previous seasons. We recruited 5295 patients over the four seasons, including 465A(H1N1)pdm09, 642A(H3N2), 278 B case-patients and 3910 controls. Among patients unvaccinated in both previous two seasons, current seasonal IVE (pooled across seasons) was 30% (95%CI: -35 to 64), 8% (95%CI: -94 to 56) and 33% (95%CI: -43 to 68) against influenza A(H1N1)pdm09, A(H3N2) and B respectively. Among patients vaccinated in both previous seasons, current seasonal IVE (pooled across seasons) was -1% (95%CI: -80 to 43), 37% (95%CI: 7-57) and 43% (95%CI: 1-68) against influenza A(H1N1)pdm09, A(H3N2) and B respectively. Our results suggest that, regardless of patients' recent vaccination history, current seasonal vaccine conferred some protection to vaccinated patients against hospitalisation with influenza A(H3N2) and B. Vaccination of patients already vaccinated in both the past two seasons did not seem to be effective against A(H1N1)pdm09. To better understand the effect of repeated vaccination, engaging in large cohort studies documenting exposures to vaccine and natural infection is needed. (C) 2017 The Author(s). Published by Elsevier Ltd

Surveillance van griep en andere luchtweginfecties: winter 2017/2018

Influenza In the winter of 2017/2018 the influenza epidemic lasted 18 weeks. This is longer than the average over the last 20 years (nine weeks). Between October 2017 and May 2018, an estimated 900,000 people had symptomatic influenza and 340,000 people consulted their general practitioner with influenza-like symptoms. Hospitals were also temporarily overstretched as many patients had to be admitted due to complications of flu (usually pneumonia); this number is estimated to have been over 16,000. Also, during the epidemic, 9,500 more people died than would normally be the case in the influenza season (October to May). Throughout the entire epidemic, people mostly became ill due to an influenza type B virus of the Yamagata lineage. This is the first time that an influenza type B virus has been dominant right from the start of the epidemic. Influenza vaccine effectiveness In the current season, vaccination prevented 44% of the vaccinated people from getting the influenza B virus. This is despite the fact that the Yamagata lineage of influenza virus type B was not included in the vaccine. Apparently, the other B virus in the vaccine provided a reasonable level of cross-protection. The long duration of the flu epidemic can therefore not be explained by a low effectiveness of the vaccine. The effectiveness of the vaccine can differ greatly from season to season. This is because the composition of the vaccine is decided upon six months in advance and is determined based on the viruses that dominated in the previous season all over the world. However, influenza viruses can change and when the influenza season breaks out in the Netherlands other viruses may dominate. This is why it is not possible to predict exactly which viruses will be dominant. Notifiable respiratory infections Some respiratory infections have to be notified to the Public Health Services in order to prevent any further spread. In 2017, there was a striking increase in the number of notifications of legionella; at 561 this was the highest number ever reported. The number of reports of tuberculosis dropped to 787. The number of reports of Q fever (23) and psittacosis (52) remained stable. Q fever, psittacosis and legionella generally manifest themselves in the form of pneumonia. The number of reported cases is an underestimation of the real number as these diseases are normally not tested for when people have pneumonia.Griep In de winter van 2017/2018 duurde de griepepidemie 18 weken. Dat is langer dan het gemiddelde van de afgelopen 20 jaar (negen weken). In totaal zijn tussen oktober 2017 en mei 2018 ongeveer 900.000 mensen ziek geworden door het griepvirus. Naar schatting bezochten 340.000 mensen de huisarts met griepachtige klachten. Daarnaast waren ziekenhuizen tijdelijk overbelast door de vele patiënten die vanwege complicaties van griep (meestal longontsteking) moesten worden opgenomen; naar schatting ruim 16.000. Ook zijn er tijdens de epidemie 9.500 meer mensen overleden dan gebruikelijk is in het griepseizoen (oktober tot mei). Tijdens de gehele epidemie zijn mensen vooral ziek geworden van het type B (Yamagata-lijn) griepvirus. Het is niet eerder voorgekomen dat een type B-griepvirus vanaf het begin van de epidemie overheerst. Effectiviteit griepvaccin In het onderzochte seizoen heeft het vaccin bij 44 procent van de mensen die zich tegen de griep hebben laten vaccineren, voorkomen dat ze griepvirus B kregen. De Yamagata-lijn van griepvirus type B zat niet in het vaccin van het afgelopen seizoen. De redelijke bescherming die het vaccin bood komt doordat er wel een ander type B in zat. De lange duur van de griepepidemie kan dan ook niet verklaard worden door de lage effectiviteit van het vaccin.De effectiviteit van het vaccin kan per seizoen sterk verschillen. Dat komt omdat de samenstelling van het griepvaccin een half jaar van tevoren wordt bepaald op basis van de virussen die het seizoen ervoor in de wereld heersten. Griepvirussen kunnen echter veranderen of andere virussen kunnen overheersen tegen de tijd dat het griepseizoen in Nederland aanbreekt. Daardoor kan van tevoren nooit precies worden voorspeld welke virussen zullen overheersen. Meldingsplichtige luchtweginfecties Sommige luchtweginfecties moeten bij de GGD worden gemeld om te voorkomen dat ze zich verder verspreiden. Opvallend in 2017 was de toename van het aantal meldingen van legionella naar 561, het hoogste aantal ooit gerapporteerd. Het aantal gemelde gevallen van tuberculose (787) is gedaald. Het aantal meldingen van Q-koorts (23) en psittacose (52) bleef stabiel. Q-koorts, psittacose en legionella ziekten uiten zich meestal in de vorm van longontstekingen. Het aantal gemelde gevallen is een onderschatting van het werkelijke aantal, omdat vaak niet op deze ziekten wordt getest als mensen een longontsteking hebben.Ministerie van VW