Evaluación de la efectividad e impacto de los programas de vacunación a partir de la vigilancia de gripe y COVID-19 en España

Incluye: PDF de la presentación y video del seminario.Se presenta el estudio sobre la evaluación de la efectividad e impacto de los programas de vacunación de gripe y COVID-19 en España, a partir de la información recogida a través del SVGE (Sistema de Vigilancia de la gripe en España) y del SIVIRA (Sistema de Vigilancia de Infección Respiratoria Aguda), cuyos datos permiten estimar la efectividad e impacto en función de distintas variables sociosanitarias, edad y gravedad, entre otras.N

Illness Severity in Hospitalized Influenza Patients by Virus Type and Subtype, Spain, 2010-2017

We conducted a retrospective cohort study to assess the effect of influenza virus type and subtype on disease severity among hospitalized influenza patients in Spain. We analyzed the cases of 8,985 laboratory-confirmed case-patients hospitalized for severe influenza by using data from a national surveillance system for the period 2010-2017. Hospitalized patients with influenza A(H1N1)pdm09 virus were significantly younger, more frequently had class III obesity, and had a higher risk for pneumonia or acute respiratory distress syndrome than patients infected with influenza A(H3N2) or B (p<0.05). Hospitalized patients with influenza A(H1N1)pdm09 also had a higher risk for intensive care unit admission, death, or both than patients with influenza A(H3N2) or B, independent of other factors. Determining the patterns of influenza-associated severity and how they might differ by virus type and subtype can help guide planning and implementation of adequate control and preventive measures during influenza epidemics.S

Gravedad de la epidemia gripal 2017-18 en España

[ES] Siguiendo las recomendaciones de la Organización Mundial de la Salud (OMS), España ha adaptado su guía PISA (por las siglas en inglés de Pandemic Influenza Severity Assessment) para evaluar la gravedad de cualquier epidemia de gripe, estacional o pandémica, a partir de la información de vigilancia de gripe disponible. Dicha gravedad se establece en función de tres indicadores: la transmisibilidad del virus circulante, la gravedad clínica de la enfermedad que produce y su impacto en la población. En este manuscrito se aplican los indicadores y parámetros PISA utilizados en España con la información obtenida en el Sistema de Vigilancia de Gripe en España (SVGE) y del sistema de monitorización de la mortalidad diaria (MoMo y EuroMOMO), con el objetivo de evaluar la gravedad de la gripe durante la temporada 2017-18 en España. La transmisibilidad de la epidemia gripal de la temporada 2017-18 alcanzó un nivel moderado/alto para todas las edades en la semana de máxima actividad gripal (3/2018), y se caracterizó particularmente por una alta transmisibilidad en mayores de 64 años. En cuanto a la gravedad clínica, la epidemia gripal 2017-18, según el grado de admisión en UCI entre los casos graves hospitalizados confirmados de gripe (CGHCG), presentó un nivel bajo para todas las edades, adultos jóvenes y mayores de 64 años. En menores de 15 años el porcentaje de admisión en UCI alcanzó niveles altos respecto a los valores observados en temporadas previas. En términos de letalidad entre los CGHCG, se estimó que en la temporada 2017-18 se alcanzó un nivel alto de gravedad clínica en todas las edades y mayores de 64 años. En adultos jóvenes de 15-64 años la letalidad se estabilizó en un nivel bajo en el pico de la epidemia gripal y en menores de 15 años se consideró baja respecto a los valores observados en temporadas previas. En cuanto al impacto, la temporada 2017-18 presentó un impacto muy alto en términos de tasas de hospitalización de CGHCG en todas las edades, a expensas fundamentalmente de las hospitalizaciones por gripe en el grupo de mayores de 64 años. En este grupo de edad se observaron las tasas más altas de hospitalización desde la temporada 2013-14. En términos de excesos de mortalidad por todas las causas, la epidemia alcanzó un impacto alto en todas las edades, a expensas fundamentalmente de la mortalidad observada en el grupo de mayores de 64 años, siendo, en menores de 15 años y adultos jóvenes, el impacto nulo. En definitiva, la guía PISA permite la estimación de una serie de indicadores y parámetros para evaluar la gravedad de una epidemia o posible pandemia de gripe. La actividad realizada en el marco del proyecto PISA es un proceso dinámico en continua revisión, susceptible de mejora a medida que se desarrolla y aplica a las diferentes temporadas de gripe. [EN] Following World Health Organization (WHO) recommendations, Spain has adapted its PISA guide (for Pandemic Influenza Severity Assessment) to assess the severity in seasonal epidemics and pandemics, based on available influenza surveillance information. This severity is defined in terms of three indicators: the transmissibility of the circulating virus, the seriousness or clinical severity of the disease it produces and its impact on the population. In this manuscript the PISA indicators and parameters used in Spain are applied with the information obtained in the Spanish Influenza Surveillance System and the daily mortality monitoring system (MoMo and EuroMOMO), with the objective of evaluating the severity of the influenza during the 2017-18 season in Spain. The transmissibility indicator in the 2017-18 influenza season reached a moderate / high level for all ages in the peak week (week 03/2018), and was particularly high in people over 64 years. Regarding seriousness, the 2017-18 influenza epidemic, according to the cumulative percentage of ICU admissions among severe hospitalized confirmed influenza cases (SHCIC), presented a low level for all ages, young adults and those over 64 years. In children under 15, the cumulative percentage of ICU admissions reached high levels compared to the values observed in previous seasons. In terms of lethality among the SHCIC, it was estimated that the 2017-18 season presented a high level of clinical severity at all ages and over 64 years. In young adults aged 15-64, lethality stabilized at a low level at the peak of the flu epidemic. In children under 15 years, the lethality was estimated low compared to the values observed in previous seasons. Regarding the impact, the 2017-18 influenza season presented a very high impact in terms of SHCIC rates at all ages, mainly due to hospitalizations in the group over 64 years. In this age group, the highest hospitalization rates were observed this season, since the 2013-14 season. In terms of excess mortality from all causes, the epidemic reached a high impact at all ages group, mainly due to the mortality observed in the group over 64 years. In children under 15 years and young adults, the impact according to excess mortality from all causes was low. In short, the PISA guide allows the estimation of indicators and parameters to assess the severity in seasonal epidemics and possible pandemics. The activity carried out within the framework of the PISA project is a dynamic process in continuous revision, susceptible to improvement as it develops and applies to the different influenza seasons

The Impact of COVID-19 on Mortality in Spain: Monitoring Excess Mortality (MoMo) and the Surveillance of Confirmed COVID-19 Deaths

Measuring mortality has been a challenge during the COVID-19 pandemic. Here, we compared the results from the Spanish daily mortality surveillance system (MoMo) of excess mortality estimates, using a time series analysis, with those obtained for the confirmed COVID-19 deaths reported to the National Epidemiological Surveillance Network (RENAVE). The excess mortality estimated at the beginning of March 2020 was much greater than what has been observed in previous years, and clustered in a very short time. The cumulated excess mortality increased with age. In the first epidemic wave, the excess mortality estimated by MoMo was 1.5 times higher than the confirmed COVID-19 deaths reported to RENAVE, but both estimates were similar in the following pandemic waves. Estimated excess mortality and confirmed COVID-19 mortality rates were geographically distributed in a very heterogeneous way. The greatest increase in mortality that has taken place in Spain in recent years was detected early by MoMo, coinciding with the spread of the COVID-19 pandemic. MoMo is able to identify risk situations for public health in a timely manner, relying on mortality in general as an indirect indicator of various important public health problems.S

Efectividad de la vacuna COVID-19: Información para la acción en la vigilancia centinela de Infección Respiratoria Aguda Grave

Comunicación presentada en las II Jornada del Centro Nacional de Epidemiología - 2021.Se presentan resultados sobre la efectividad de la vacuna COVID-19 a partir de la información de la vigilancia centinela de Infección Respiratoria Aguda Grave. Las conclusiones del estudio son las siguientes: 1. Alta protección de las vacunas (>90%) frente a hospitalización por IRAG confirmada de COVID-19 para todas las edades, algo menor (83%) en la población de 80 y más años. 2. Las vacunas mRNA (Pfizer, Moderna) presentan la EV más alta (90%), seguidas por Janssen (79%) y AstraZeneca (73%). 3. Bajada progresiva de la EV después de cinco meses de la vacunación. 4. Alta protección frente a las variantes Alpha y Delta, aunque ligera menor EV frente a la hospitalización de IRAG con variante Delta, en comparación con Alpha

Direct and Indirect Effectiveness of mRNA Vaccination against Severe Acute Respiratory Syndrome Coronavirus 2 in Long-Term Care Facilities, Spain

We conducted a registries-based cohort study of long-term care facility residents >65 years of age offered vaccination against severe acute respiratory syndrome coronavirus 2 before March 10, 2021, in Spain. Risk for infection in vaccinated and nonvaccinated persons was compared with risk in the same persons in a period before the vaccination campaign, adjusted by daily-varying incidence and reproduction number. We selected 299,209 persons; 99.0% had >1 dose, 92.6% had 2 doses, and 99.8% of vaccines were Pfizer/BioNTech (BNT162b2). For vaccinated persons with no previous infection, vaccine effectiveness was 81.8% (95% CI 81.0%-82.7%), and 11.6 (95% CI 11.3-11.9) cases were prevented per 10,000 vaccinated/day. In those with previous infection, effectiveness was 56.8% (95% CI 47.1%-67.7%). In nonvaccinated residents with no previous infection, risk decreased by up to 81.4% (95% CI 73.3%-90.3%). Our results confirm vaccine effectiveness in this population and suggest indirect protection in nonvaccinated persons.S

Real time surveillance of COVID-19 space and time clusters during the summer 2020 in Spain

Background: On June 21st de-escalation measures and state-of-alarm ended in Spain after the COVID-19 first wave. New surveillance and control strategy was set up to detect emerging outbreaks. Aim: To detect and describe the evolution of COVID-19 clusters and cases during the 2020 summer in Spain. Methods: A near-real time surveillance system to detect active clusters of COVID-19 was developed based on Kulldorf's prospective space-time scan statistic (STSS) to detect daily emerging active clusters. Results: Analyses were performed daily during the summer 2020 (June 21st - August 31st) in Spain, showing an increase of active clusters and municipalities affected. Spread happened in the study period from a few, low-cases, regional-located clusters in June to a nationwide distribution of bigger clusters encompassing a higher average number of municipalities and total cases by end-August. Conclusion: STSS-based surveillance of COVID-19 can be of utility in a low-incidence scenario to help tackle emerging outbreaks that could potentially drive a widespread transmission. If that happens, spatial trends and disease distribution can be followed with this method. Finally, cluster aggregation in space and time, as observed in our results, could suggest the occurrence of community transmission.This research has been financed by Carlos III Health Institute (ISCIII) under the project COV20–00881.S

Effectiveness of mRNA vaccine boosters against infection with the SARS-CoV-2 omicron (B.1.1.529) variant in Spain: a nationwide cohort study

Factor de impacto: 25,71 Q1Background: The omicron (B.1.1.529) variant of SARS-CoV-2 has increased capacity to elude immunity and cause breakthrough infections. The aim of this study was to estimate the effectiveness of mRNA-based vaccine boosters (third dose) against infection with the omicron variant by age, sex, time since complete vaccination, type of primary vaccine, and type of booster. Methods: In this nationwide cohort study, we linked data from three nationwide population registries in Spain (Vaccination Registry, Laboratory Results Registry, and National Health System registry) to select community-dwelling individuals aged 40 years or older, who completed their primary vaccine schedule at least 3 months before the start of follow-up, and had not tested positive for SARS-CoV-2 since the start of the pandemic. On each day between Jan 3, and Feb 6, 2022, we matched individuals who received a booster mRNA vaccine and controls of the same sex, age group, postal code, type of vaccine, time since primary vaccination, and number of previous tests. We estimated risk of laboratory-confirmed SARS-CoV-2 infection using the Kaplan-Meier method and compared groups using risk ratios (RR) and risk differences. Vaccine effectiveness was calculated as one minus RR. Findings: Between Jan 3, and Feb 6, 2022, 3 111 159 matched pairs were included in our study. Overall, the estimated effectiveness from day 7 to 34 after a booster was 51·3% (95% CI 50·2-52·4). Estimated effectiveness was 52·5% (51·3-53·7) for an mRNA-1273 booster and 46·2% (43·5-48·7) for a BNT162b2 booster. Effectiveness was 58·6% (55·5-61·6) if primary vaccination had been with ChAdOx1 nCoV-19 (Oxford-AstraZeneca), 55·3% (52·3-58·2) with mRNA-1273 (Moderna), 49·7% (48·3-51·1) with BNT162b2 (Pfizer-BioNTech), and 48·0% (42·5-53·7) with Ad26.COV2.S (Janssen). Estimated effectiveness was 43·6% (40·0-47·1) when the booster was administered between 151 days and 180 days after complete vaccination and 52·2% (51·0-53·3) if administered more than 180 days after primary scheduled completion. Interpretation: Booster mRNA vaccine-doses were moderately effective in preventing infection with the omicron variant of SARS-CoV-2 for over a month after administration, which indicates their suitability as a strategy to limit the health effects of COVID-19 in periods of omicron variant domination. Estimated effectiveness was higher for mRNA-1273 compared with BNT162b2 and increased with time between completed primary vaccination and booster.S

Interim 2019/20 influenza vaccine effectiveness: six European studies, September 2019 to January 2020

BackgroundInfluenza A(H1N1)pdm09, A(H3N2) and B viruses were co-circulating in Europe between September 2019 and January 2020.AimTo provide interim 2019/20 influenza vaccine effectiveness (VE) estimates from six European studies, covering 10 countries and both primary care and hospital settings.MethodsAll studies used the test-negative design, although there were some differences in other study characteristics, e.g. patient selection, data sources, case definitions and included age groups. Overall and influenza (sub)type-specific VE was estimated for each study using logistic regression adjusted for potential confounders.ResultsThere were 31,537 patients recruited across the six studies, of which 5,300 (17%) were cases with 5,310 infections. Most of these (4,466; 84%) were influenza A. The VE point estimates for all ages were 29% to 61% against any influenza in the primary care setting and 35% to 60% in hospitalised older adults (aged 65 years and over). The VE point estimates against A(H1N1)pdm09 (all ages, both settings) was 48% to 75%, and against A(H3N2) ranged from -58% to 57% (primary care) and -16% to 60% (hospital). Against influenza B, VE for all ages was 62% to 83% (primary care only).ConclusionsInfluenza vaccination is of continued benefit during the ongoing 2019/20 influenza season. Robust end-of-season VE estimates and genetic virus characterisation results may help understand the variability in influenza (sub)type-specific results across studies.Funding statement: ECDC contributed to funding some of the study sites and the coordination of the EU-PC study. WHO/Europe contributed to funding the EU-H study. Epiconcept contributed to funding the EU-H study

Gravedad de la epidemia gripal 2017-18 en España

[ES] Siguiendo las recomendaciones de la Organización Mundial de la Salud (OMS), España ha adaptado su guía PISA (por las siglas en inglés de Pandemic Influenza Severity Assessment) para evaluar la gravedad de cualquier epidemia de gripe, estacional o pandémica, a partir de la información de vigilancia de gripe disponible. Dicha gravedad se establece en función de tres indicadores: la transmisibilidad del virus circulante, la gravedad clínica de la enfermedad que produce y su impacto en la población. En este manuscrito se aplican los indicadores y parámetros PISA utilizados en España con la información obtenida en el Sistema de Vigilancia de Gripe en España (SVGE) y del sistema de monitorización de la mortalidad diaria (MoMo y EuroMOMO), con el objetivo de evaluar la gravedad de la gripe durante la temporada 2017-18 en España. La transmisibilidad de la epidemia gripal de la temporada 2017-18 alcanzó un nivel moderado/ alto para todas las edades en la semana de máxima actividad gripal (3/2018), y se caracterizó particularmente por una alta transmisibilidad en mayores de 64 años. En cuanto a la gravedad clínica, la epidemia gripal 2017-18, según el grado de admisión en UCI entre los casos graves hospitalizados confirmados de gripe (CGHCG), presentó un nivel bajo para todas las edades, adultos jóvenes y mayores de 64 años. En menores de 15 años el porcentaje de admisión en UCI alcanzó niveles altos respecto a los valores observados en temporadas previas. En términos de letalidad entre los CGHCG, se estimó que en la temporada 2017-18 se alcanzó un nivel alto de gravedad clínica en todas las edades y mayores de 64 años. En adultos jóvenes de 15-64 años la letalidad se estabilizó en un nivel bajo en el pico de la epidemia gripal y en menores de 15 años se consideró baja respecto a los valores observados en temporadas previas. En cuanto al impacto, la temporada 2017-18 presentó un impacto muy alto en términos de tasas de hospitalización de CGHCG en todas las edades, a expensas fundamentalmente de las hospitalizaciones por gripe en el grupo de mayores de 64 años. En este grupo de edad se observaron las tasas más altas de hospitalización desde la temporada 2013-14. En términos de excesos de mortalidad por todas las causas, la epidemia alcanzó un impacto alto en todas las edades, a expensas fundamentalmente de la mortalidad observada en el grupo de mayores de 64 años, siendo, en menores de 15 años y adultos jóvenes, el impacto nulo.En definitiva, la guía PISA permite la estimación de una serie de indicadores y parámetros para evaluar la gravedad de una epidemia o posible pandemia de gripe. La actividad realizada en el marco del proyecto PISA es un proceso dinámico en continua revisión, susceptible de mejora a medida que se desarrolla y aplica a las diferentes temporadas de gripe. [EN] Following World Health Organization (WHO) recommendations, Spain has adapted its PISA guide (for Pandemic Influenza Severity Assessment) to assess the severity in seasonal epidemics and pandemics, based on available influenza surveillance information. This severity is defined in terms of three indicators: the transmissibility of the circulating virus, the seriousness or clinical severity of the disease it produces and its impact on the population. In this manuscript the PISA indicators and parameters used in Spain are applied with the information obtained in the Spanish Influenza Surveillance System and the daily mortality monitoring system (MoMo and EuroMOMO), with the objective of evaluating the severity of the influenza during the 2017-18 season in Spain. The transmissibility indicator in the 2017-18 influenza season reached a moderate / high level for all ages in the peak week (week 03/2018), and was particularly high in people over 64 years. Regarding seriousness, the 2017-18 influenza epidemic, according to the cumulative percentage of ICU admissions among severe hospitalized confirmed influenza cases (SHCIC), presented a low level for all ages, young adults and those over 64 years. In children under 15, the cumulative percentage of ICU admissions reached high levels compared to the values observed in previous seasons. In terms of lethality among the SHCIC, it was estimated that the 2017-18 season presented a high level of clinical severity at all ages and over 64 years. In young adults aged 15-64, lethality stabilized at a low level at the peak of the flu epidemic. In children under 15 years, the lethality was estimated low compared to the values observed in previous seasons. Regarding the impact, the 2017-18 influenza season presented a very high impact in terms of SHCIC rates at all ages, mainly due to hospitalizations in the group over 64 years. In this age group, the highest hospitalization rates were observed this season, since the 2013-14 season. In terms of excess mortality from all causes, the epidemic reached a high impact at all ages group, mainly due to the mortality observed in the group over 64 years. In children under 15 years and young adults, the impact according to excess mortality from all causes was low. In short, the PISA guide allows the estimation of indicators and parameters to assess the severity in seasonal epidemics and possible pandemics. The activity carried out within the framework of the PISA project is a dynamic process in continuous revision, susceptible to improvement as it develops and applies to the different influenza seasons.N