Estimated number of lives directly saved by COVID-19 vaccination programs in the WHO European Region, December 2020 to March 2023 (preprint)

BackgroundBy March 2023, 54 countries, areas and territories (thereafter "CAT") reported over 2.2 million coronavirus disease 2019 (COVID-19) deaths to the World Health Organization (WHO) Regional Office for Europe (1). Here, we estimate how many lives were directly saved by vaccinating adults in the Region, from December 2020 through March 2023. MethodsWe estimated the number of lives directly saved by age-group, vaccine dose and circulating Variant of Concern (VOC) period, both regionally and nationally, using weekly data on COVID-19 mortality and COVID-19 vaccine uptake reported by 34 CAT, and vaccine effectiveness (VE) data from the literature. We calculated the percentage reduction in the number of expected and reported deaths. FindingsWe found that vaccines reduced deaths by 57% overall (CAT range: 15% to 75%), representing [~]1.4 million lives saved in those aged [≥]25 years (range: 0.7 million to 2.6 million): 96% of lives saved were aged [≥]60 years and 52% were aged [≥]80 years; first boosters saved 51%, and 67% were saved during the Omicron period. InterpretationOver nearly 2.5 years, most lives saved by COVID-19 vaccinationwere in older adults by first booster dose and during the Omicron period, reinforcing the importance of up-to-date vaccination among these most at-risk individuals. Further modelling work should evaluate indirect effects of vaccination and public health and social measures. FundingThis work was supported by a US Centers for Disease Control cooperative agreement (Grant number 6 NU511P000936-02-020), who had no role in data analysis or interpretation. DisclaimerThe authors affiliated with the World Health Organization (WHO) are alone responsible for the views expressed in this publication and they do not necessarily represent the decisions or policies of the WHO. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSSince first identified in late 2019, COVID-19 has caused disproportionately high mortality rates in older adults. With the rapid development and licensing of novel COVID-19 vaccines, immunization campaigns across the WHO European Region started in late 2020 and early 2021, initially targeting the most vulnerable and exposed populations, including older adults, people with comorbidities and healthcare professionals. Several studies have estimated the number of lives saved by COVID-19 vaccination, both at national and multi-country level in the earlier stages of the pandemic. However, only one multi-country study has assessed the number of lives saved beyond the first year of the pandemic, particularly when the Omicron variant of concern (VOC) circulated, a period when vaccination coverage was high in many countries, areas and territories (CAT), but COVID-19 transmission was at its highest. Added value of this studyHere we quantified the impact of COVID-19 vaccination in adults by age-group, vaccine dose and period of circulation of VOC, across diverse settings, using real world data reported by 34 CAT in the WHO European Region for the period December 2020 to April 2023. We estimated that COVID-19 vaccination programs were associated with a 57% reduction (CAT range: 15% to 75%) in the number of deaths among the [≥]25 years old, representing over 1.5 million lives saved (range: 0.7 million to 2.6 million) in 34 European CAT during the first 2.5 years following vaccine introduction. The first booster savedthe most lives (721,122 / 1,408,967, (57%) of all lives saved). The [≥]60 years old age group accounted for 96% of the total lives saved (1,349,617 / 1,408,967) whereas the [≥]80 years old age group represented 52% of the total lives saved (728,858 / 1,408,967 lives saved) and 67% of all lives were saved during the Omicron period (942,571 / 1,408,967). Implications of all the available evidenceOur results reinforce the importance of up-to-date COVID-19 vaccination, particularly among older age-groups. Communication campaigns supporting COVID-19 vaccination should stress the value of COVID-19 vaccination in saving lives to ensure vulnerable groups are up-to-date with vaccination ahead of periods of potential increased transmission.

Real-world effectiveness of molnupiravir and nirmatrelvir/ritonavir among COVID-19 community, highly vaccinated patients with high risk for severe disease: Evidence that both antivirals reduce the risk for disease progression and death (preprint)

Besides the significant benefits of vaccination against COVID-19, the risk of severe disease and death from COVID-19 among highly vulnerable populations remains of concern. Implementation of oral antiviral treatment has shown significant benefits for outpatients with high risk for severe disease, however, their effectiveness remains to be evaluated in real-life settings and in the presence of new Omicron subvariants. We aimed to investigate the effectiveness of molnupiravir and nirmatrelvir/ritonavir using a retrospective cohort design with outcomes hospital admission and death from COVID-19, in Greece. The effectiveness of each drug was estimated through a comparison of the antiviral's recipients with an age-matched control group of non-recipients, adjusted for age, previous SARS-CoV-2 infection, vaccination status, and vaccination recency. Our analysis showed that molnupiravir significantly reduced the risk for hospitalization (OR = 0.40, p < 0.001) and death from COVID-19 (OR = 0.31, p < 0.001), with the effect being more intense among elderly patients (>=75 years old). The effectiveness was higher among those with full adherence. Nirmatrelvir/ritonavir was found also to significantly reduce the risk of hospital admission (OR = 0.31, p < 0.001) and death (OR = 0.28, p < 0.001) and, similarly to molnupiravir, effectiveness was stronger among elderly patients and those with the highest levels of adherence. Analysis of the relative effectiveness of nirmatrelvir/ritonavir versus molnupiravir suggested that nirmatrelvir/ritonavir was associated with a reduced risk for hospital admission (OR = 0.58, p < 0.001) compared to molnupiravir, adjusted for age, previous SARS-CoV-2 infection, vaccination status, and co-morbidities. Our real-world study provides evidence about the reduced risk of hospitalization and death in highly vaccinated patients with a high risk for severe disease in Greece. These findings highlight that although the hospitalization and mortality risk has been reduced mainly due to vaccination and the emergence of Omicron variants, antivirals provide significant additional benefits in highly vulnerable patients and therefore their use is documented and strongly indicated.

Impact of COVID-19 Pandemic on Refugees, Migrants and Asylum Seekers Living in Camps and Reception and Identification Centers in Greece in the Pre-Vaccination Period, February 2020 to May 2021. Summary of Epidemiological Findings (preprint)

Background: Protection of refugees, migrants, and asylum seekers living in open hosting camps (HCs) and reception and identification centers (RICs) has been a priority since the beginning of the COVID-19 pandemic. We present the epidemiological data of COVID-19 infection in HCs/RICs in Greece from February 2020 to May 2021, before the initiation of the onsite vaccinations. Methods: : Case confirmation was performed by rapid antigenic test and/or RT-PCR. Data were retrieved from the National COVID-19 registry. The notification rate by type of accommodation facility, by sex and ethnicity and the mean age of cases, were calculated for HCs, RICs and general population. Data on clinical manifestations, and disease severity (admissions to intensive care unit (ICU) / case fatality rate) were analysed. Results: : Of the 397,497 recorded domestic COVID-19 infection cases, 2,609 (0.7%) regarded HCs/RICs; of them 1,566 (60%) were identified in 27 HCs and 1,043 (40%) in six RICs. The notification rate was 542 and 380 cases per 10,000 population in HCs/RICs and the general population, respectively (p-value<0.001).Up to February 2021 the occurrence of cases in HCs/RICs did not follow the occurrence of cases in the general population. After March 2021 the course of the outbreak in HCs/RICs and the general population was similar.The median age of cases in HCs/RICs and the general population was 27 (range:0-81) and 44 (range:0-106), respectively (p<0.001). Twenty-four different ethnicities were reported among migrant cases; 51% were from Afghanistan, 13% from Syria, 6% from Kongo and 5% from Somalia.Overall, 48% and 80% of cases, respectively in HCs/RICs and the general population were symptomatic (p<0.001). Five (0.2%) cases in HCs/RICs were admitted to the ICU compared to 10,426 cases (3.0%) in the general population (p-value <0.001). Case fatality rate was 3% in the general population and 0.08% in HCs/RICs (p-value <0.001). Conclusion: Recorded COVID-19 infections were less severe in migrants living at HCs/RICs than the general population, however, the number of identified cases was high and measures for the prevention of transmission should be strengthened.

Awareness, knowledge and trust in the Greek authorities towards COVID-19 pandemic: results from the Epirus Health Study cohort (preprint)

BackgroundTo assess the level of knowledge and trust in the policy decisions taken regarding the coronavirus disease (COVID-19) pandemic among Epirus Health Study (EHS) participants. MethodsThe EHS is an ongoing and deeply-phenotyped prospective cohort study that has recruited 667 participants in northwest Greece until August 31st, 2020. Level of knowledge on coronavirus (SARS-CoV-2) transmission and COVID-19 severity was labeled as poor, moderate or good. Variables assessing knowledge and beliefs towards the pandemic were summarized overall and by gender, age group (25-39, 40-49, 50-59, [≥]60 years) and period of report (before the lifting of lockdown measures in Greece: March 30th to May 3rd, and two post-lockdown time periods: May 4th to June 31st, July 1st to August 31st). An exposure-wide association analysis was conducted to evaluate the associations between 153 explanatory variables and participants knowledge. Correction for multiple comparisons was applied using a false discovery rate (FDR) threshold of 5%. ResultsA total of 563 participants (49 years mean age; 60% women) had available information on the standard EHS questionnaire, the clinical and biochemical measurements, and the COVID-19-related questionnaire. Percentages of poor, moderate and good knowledge status regarding COVID-19 were 4.5%, 10.0% and 85.6%, respectively. The majority of participants showed absolute or moderate trust in the Greek health authorities for the management of the epidemic (90.1%), as well as in the Greek Government (84.7%) and the official national sources of information (87.4%). Trust in the authorities was weaker in younger participants and those who joined the study after the lifting of lockdown measures (p-value[≤]0.001). None of the factors examined was associated with participants level of knowledge after correction for multiple testing. ConclusionsHigh level of knowledge about the COVID-19 pandemic and trust in the Greek authorities was observed, possibly due to the plethora of good quality publicly available information and the timely management of the pandemic at its early stages in Greece. Information campaigns for the COVID-19 pandemic should be encouraged even after the lifting of lockdown measures to increase public awareness.