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1.
Eur J Clin Invest ; 52(6): e13782, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1949146

ABSTRACT

There are no widely accepted, quantitative definitions for the end of a pandemic such as COVID-19. The end of the pandemic due to a new virus and the transition to endemicity may be defined based on a high proportion of the global population having some immunity from natural infection or vaccination. Other considerations include diminished death toll, diminished pressure on health systems, reduced actual and perceived personal risk, removal of restrictive measures and diminished public attention. A threshold of 70% of the global population having being vaccinated or infected was probably already reached in the second half of 2021. Endemicity may still show major spikes of infections and seasonality, but typically less clinical burden, although some locations are still hit more than others. Death toll and ICU occupancy figures are also consistent with a transition to endemicity by end 2021/early 2022. Personal risk of the vast majority of the global population was already very small by end 2021, but perceived risk may still be grossly overestimated. Restrictive measures of high stringency have persisted in many countries by early 2022. The gargantuan attention in news media, social media and even scientific circles should be tempered. Public health officials need to declare the end of the pandemic. Mid- and long-term consequences of epidemic waves and of adopted measures on health, society, economy, civilization and democracy may perpetuate a pandemic legacy long after the pandemic itself has ended.


Subject(s)
COVID-19 , Social Media , COVID-19/epidemiology , Humans , Pandemics/prevention & control , Public Health , SARS-CoV-2
2.
Proc Natl Acad Sci U S A ; 119(28): e2204074119, 2022 Jul 12.
Article in English | MEDLINE | ID: covidwho-1937499

ABSTRACT

Massive scientific productivity accompanied the COVID-19 pandemic. We evaluated the citation impact of COVID-19 publications relative to all scientific work published in 2020 to 2021 and assessed the impact on scientist citation profiles. Using Scopus data until August 1, 2021, COVID-19 items accounted for 4% of papers published, 20% of citations received to papers published in 2020 to 2021, and >30% of citations received in 36 of the 174 disciplines of science (up to 79.3% in general and internal medicine). Across science, 98 of the 100 most-cited papers published in 2020 to 2021 were related to COVID-19; 110 scientists received ≥10,000 citations for COVID-19 work, but none received ≥10,000 citations for non-COVID-19 work published in 2020 to 2021. For many scientists, citations to their COVID-19 work already accounted for more than half of their total career citation count. Overall, these data show a strong covidization of research citations across science, with major impact on shaping the citation elite.


Subject(s)
COVID-19 , Pandemics , Periodicals as Topic , Humans , Periodicals as Topic/trends
3.
Lancet Reg Health Eur ; 20: 100453, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-1914783

ABSTRACT

Background: Data on the rate and severity of SARS-CoV-2 reinfections in real-world settings are scarce and the effects of vaccine boosters on reinfection risk are unknown. Methods: In a population-level observational study, registered SARS-CoV-2 laboratory-confirmed Vojvodina residents, between March 6, 2020 and October 31, 2021, were followed for reinfection ≥90 days after primary infection. Data were censored at the end of follow-up (January 31, 2022) or death. The reinfection risk was visualized with Kaplan-Meier plots. To examine the protective effect of vaccination, the subset of individuals with primary infection in 2020 (March 6-December 31) were matched (1:2) with controls without reinfection. Findings: Until January 31, 2022, 13,792 reinfections were recorded among 251,104 COVID-19 primary infections (5.49%). Most reinfections (86.77%, 11,967/13,792) were recorded in January 2022. Reinfections were mostly mild (99.17%, 13,678/13,792). Hospitalizations were uncommon [1.08% (149/13,792) vs. 3.66% (505/13,792) in primary infection] and COVID-19 deaths were very rare (20/13,792, case fatality rate 0.15%). The overall incidence rate of reinfections was 5.99 (95% CI 5.89-6.09) per 1000 person-months. The reinfection risk was estimated as 0.76% at six months, 1.36% at nine months, 4.96% at 12 months, 16.68% at 15 months, and 18.86% at 18 months. Unvaccinated (OR=1.23; 95%CI=1.14-1.33), incompletely (OR=1.33; 95%CI=1.08-1.64) or completely vaccinated (OR=1.50; 95%CI=1.37-1.63), were modestly more likely to be reinfected compared with recipients of a third (booster) vaccine dose. Interpretation: SARS-CoV-2 reinfections were uncommon until the end of 2021 but became common with the advent of Omicron. Very few reinfections were severe. Boosters may modestly reduce reinfection risk. Funding: No specific funding was obtained for this study.

4.
Environ Res ; 213: 113754, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-1907008

ABSTRACT

Different modeling approaches can be used to calculate excess deaths for the COVID-19 pandemic period. We compared 6 calculations of excess deaths (4 previously published [3 without age-adjustment] and two new ones that we performed with and without age-adjustment) for 2020-2021. With each approach, we calculated excess deaths metrics and the ratio R of excess deaths over recorded COVID-19 deaths. The main analysis focused on 33 high-income countries with weekly deaths in the Human Mortality Database (HMD at mortality.org) and reliable death registration. Secondary analyses compared calculations for other countries, whenever available. Across the 33 high-income countries, excess deaths were 2.0-2.8 million without age-adjustment, and 1.6-2.1 million with age-adjustment with large differences across countries. In our analyses after age-adjustment, 8 of 33 countries had no overall excess deaths; there was a death deficit in children; and 0.478 million (29.7%) of the excess deaths were in people <65 years old. In countries like France, Germany, Italy, and Spain excess death estimates differed 2 to 4-fold between highest and lowest figures. The R values' range exceeded 0.3 in all 33 countries. In 16 of 33 countries, the range of R exceeded 1. In 25 of 33 countries some calculations suggest R > 1 (excess deaths exceeding COVID-19 deaths) while others suggest R < 1 (excess deaths smaller than COVID-19 deaths). Inferred data from 4 evaluations for 42 countries and from 3 evaluations for another 98 countries are very tenuous. Estimates of excess deaths are analysis-dependent and age-adjustment is important to consider. Excess deaths may be lower than previously calculated.


Subject(s)
COVID-19 , Mortality , Pandemics , Aged , Child , Databases, Factual , Humans , Income , Spain
5.
Environ Res ; 211: 113038, 2022 08.
Article in English | MEDLINE | ID: covidwho-1906998

ABSTRACT

There are important questions surrounding the potential contribution of outdoor and indoor air quality in the transmission of SARS-CoV-2 and perpetuation of COVID-19 epidemic waves. Environmental health may be a critical component of COVID-19 prevention. The public health community and health agencies should consider the evolving evidence in their recommendations and statements, and work to issue occupational guidelines. Evidence coming from the current epidemiological and experimental research is expected to add knowledge about virus diffusion, COVID-19 severity in most polluted areas, inter-personal distance requirements and need for wearing face masks in indoor or outdoor environments. The COVID-19 pandemic has highlighted the need for maintaining particulate matter concentrations at low levels for multiple health-related reasons, which may also include the spread of SARS-CoV-2. Indoor environments represent even a more crucial challenge to cope with, as it is easier for the SARS-COV2 to spread, remain vital and infect other subjects in closed spaces in the presence of already infected asymptomatic or mildly symptomatic people. The potential merits of preventive measures, such as CO2 monitoring associated with natural or controlled mechanical ventilation and air purification, for schools, indoor public places (restaurants, offices, hotels, museums, theatres/cinemas etc.) and transportations need to be carefully considered. Hospital settings and nursing/retirement homes as well as emergency rooms, infectious diseases divisions and ambulances represent higher risk indoor environments and may require additional monitoring and specific decontamination strategies based on mechanical ventilation or air purification.


Subject(s)
Air Pollution, Indoor , COVID-19 , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Pandemics/prevention & control , Particulate Matter , RNA, Viral , SARS-CoV-2
6.
Microbiol Spectr ; : e0092622, 2022 Jun 14.
Article in English | MEDLINE | ID: covidwho-1891748

ABSTRACT

SARS-CoV-2 Omicron variants contain many mutations in its spike receptor-binding domain, the target of all authorized monoclonal antibodies (MAbs). Determining the extent to which Omicron variants reduced MAb susceptibility is critical to preventing and treating COVID-19. We systematically reviewed PubMed and three preprint servers, last updated 11 April 2022, for the in vitro activity of authorized MAbs against the Omicron variants. Fifty-one studies were eligible, including 50 containing Omicron BA.1 susceptibility data and 17 containing Omicron BA.2 susceptibility data. The first two authorized MAb combinations, bamlanivimab/etesevimab and casirivimab/imdevimab, were largely inactive against the Omicron BA.1 and BA.2 variants. In 34 studies, sotrovimab displayed a median 4.0-fold (interquartile range [IQR]: 2.6 to 6.9) reduction in activity against Omicron BA.1, and in 12 studies, it displayed a median 17-fold (IQR: 13 to 30) reduction in activity against Omicron BA.2. In 15 studies, the combination cilgavimab/tixagevimab displayed a median 86-fold (IQR: 27 to 151) reduction in activity against Omicron BA.1, and in six studies, it displayed a median 5.4-fold (IQR: 3.7 to 6.9) reduction in activity against Omicron BA.2. In eight studies against Omicron BA.1 and six studies against Omicron BA.2, bebtelovimab displayed no reduction in activity. Disparate results between assays were common. For authorized MAbs, 51/268 (19.0%) results for wild-type control variants and 78/348 (22.4%) results for Omicron BA.1 and BA.2 variants were more than 4-fold below or 4-fold above the median result for that MAb. Highly disparate results between published assays indicate a need for improved MAb susceptibility test standardization or interassay calibration. IMPORTANCE Monoclonal antibodies (MAbs) targeting the SARS-CoV-2 spike protein are among the most effective measures for preventing and treating COVID-19. However, SARS-CoV-2 Omicron variants contain many mutations in their spike receptor-binding domains, the target of all authorized MAbs. Therefore, determining the extent to which Omicron variants reduced MAb susceptibility is critical to preventing and treating COVID-19. We identified 51 studies that reported the in vitro susceptibility of the two main Omicron variants BA.1 and BA.2 to therapeutic MAbs in advanced clinical development, including eight authorized individual MAbs and three authorized MAb combinations. We estimated the degree to which different MAbs displayed reduced activity against Omicron variants. The marked loss of activity of many MAbs against Omicron variants underscores the importance of developing MAbs that target conserved regions of spike. Highly disparate results between assays indicate the need for improved MAb susceptibility test standardization.

7.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336875

ABSTRACT

ABSTRACT Different modeling approaches can be used to calculate excess deaths for the COVID-19 pandemic period. We compared 6 calculations of excess deaths (4 previously published and two new ones that we performed with and without age-adjustment) for 2020-2021. With each approach, we calculated excess deaths metrics and the ratio R of excess deaths over recorded COVID-19 deaths. The main analysis focused on 33 high-income countries with weekly deaths in the Human Mortality Database (HMD at mortality.org) and reliable death registration. Secondary analyses compared calculations for other countries, whenever available. Across the 33 high-income countries, excess deaths were 2.0-2.8 million without age-adjustment, and 1.6-2.1 million with age-adjustment with large differences across countries. In our analyses after age-adjustment, 8 of 33 countries had no overall excess deaths;there was a death deficit in children;and 0.478 million (29.7%) of the excess deaths were in people <65 years old. In countries like France, Germany, Italy, and Spain excess death estimates differed 2 to 4-fold between highest and lowest figures. The R values’ range exceeded 0.3 in all 33 countries. In 16 of 33 countries, the range of R exceeded 1. In 25 of 33 countries some calculations suggest R>1 (excess deaths exceeding COVID-19 deaths) while others suggest R<1 (excess deaths smaller than COVID-19 deaths). Inferred data from 4 evaluations for 42 countries and from 3 evaluations for another 98 countries are very tenuous Estimates of excess deaths are analysis-dependent and age-adjustment is important to consider. Excess deaths may be lower than previously calculated. SIGNIFICANCE STATEMENT Excess deaths are a key metric for assessing the impact of a pandemic. They reflect the composite impact of deaths from infection, from indirect pandemic effects, and from the measures taken. Different modeling approaches can be used to calculate excess deaths for the COVID-19 pandemic. Here, we compare four previous calculations of excess deaths and two new ones that we performed with and without adjusting for changing age structure in the estimation. Proper age-adjustment results in substantial reduction in estimates of excess deaths for 2020-2021. While results from different calculation methods are correlated, the absolute differences in estimated excess deaths are very high in most countries. Extrapolations to countries without reliable death registration is extremely tenuous.

8.
J Clin Epidemiol ; 148: 1-9, 2022 Apr 06.
Article in English | MEDLINE | ID: covidwho-1773456

ABSTRACT

OBJECTIVES: To evaluate for coronavirus disease 2019 treatments without benefits in subsequent large randomized controlled trials (RCTs) how many of their most-cited clinical studies had declared favorable results. STUDY DESIGN AND SETTING: Scopus searches (December 23, 2021) identified articles on lopinavir-ritonavir, hydroxychloroquine, azithromycin, remdesivir, convalescent plasma, colchicine, or interferon (index interventions) that represented clinical trials and had >150 citations. Their conclusions were correlated with study design features. The 10 most recent citations for the most-cited article on each index intervention were examined on whether they were critical to the highly cited study. Altmetric scores were also obtained. RESULTS: Forty eligible articles of clinical studies had received >150 citations. Twenty of forty (50%) had favorable conclusions and four were equivocal. Highly cited articles with favorable conclusions were rarely RCTs (3/20), although those without favorable conclusions were mostly RCTs (15/20, P = 0.0003). Only one RCT with favorable conclusions had >160 patients. Citation counts correlated strongly with Altmetric scores, especially news items. Only nine (15%) of 60 recent citations to the most highly cited studies with favorable or equivocal conclusions were critical. CONCLUSION: Many clinical studies with favorable conclusions for largely ineffective coronavirus disease 2019 treatments are uncritically heavily cited and disseminated. Early observational studies and small randomized trials may cause spurious claims of effectiveness that get perpetuated.

9.
BMJ Evid Based Med ; 2022 Mar 25.
Article in English | MEDLINE | ID: covidwho-1765116

ABSTRACT

Non-randomised studies assessing COVID-19 vaccine effectiveness need to consider multiple factors that may generate spurious estimates due to bias or genuinely modify effectiveness. These include pre-existing immunity, vaccination misclassification, exposure differences, testing, disease risk factor confounding, hospital admission decision, treatment use differences, and death attribution. It is useful to separate whether the impact of each factor admission decision, treatment use differences, and death attribution. Steps and measures to consider for improving vaccine effectiveness estimation include registration of studies and of analysis plans; sharing of raw data and code; background collection of reliable information; blinded assessment of outcomes, e.g. death causes; using maximal/best information in properly-matched studies, multivariable analyses, propensity analyses, and other models; performing randomised trials, whenever possible, for suitable questions, e.g. booster doses or comparative effectiveness of different vaccination strategies; living meta-analyses of vaccine effectiveness; better communication with both relative and absolute metrics of risk reduction and presentation of uncertainty; and avoidance of exaggeration in communicating results to the general public.

10.
Eur J Epidemiol ; 37(3): 235-249, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1750758

ABSTRACT

This mixed design synthesis aimed to estimate the infection fatality rate (IFR) of Coronavirus Disease 2019 (COVID-19) in community-dwelling elderly populations and other age groups from seroprevalence studies. Protocol: https://osf.io/47cgb . Eligible were seroprevalence studies done in 2020 and identified by any of four existing systematic reviews; with ≥ 500 participants aged ≥ 70 years; presenting seroprevalence in elderly people; aimed to generate samples reflecting the general population; and whose location had available data on cumulative COVID-19 deaths in elderly (primary cutoff ≥ 70 years; ≥ 65 or ≥ 60 also eligible). We extracted the most fully adjusted (if unavailable, unadjusted) seroprevalence estimates; age- and residence-stratified cumulative COVID-19 deaths (until 1 week after the seroprevalence sampling midpoint) from official reports; and population statistics, to calculate IFRs adjusted for test performance. Sample size-weighted IFRs were estimated for countries with multiple estimates. Thirteen seroprevalence surveys representing 11 high-income countries were included in the main analysis. Median IFR in community-dwelling elderly and elderly overall was 2.9% (range 1.8-9.7%) and 4.5% (range 2.5-16.7%) without accounting for seroreversion (2.2% and 4.0%, respectively, accounting for 5% monthly seroreversion). Multiple sensitivity analyses yielded similar results. IFR was higher with larger proportions of people > 85 years. The IFR of COVID-19 in community-dwelling elderly is lower than previously reported.


Subject(s)
COVID-19 , Aged , Humans , Independent Living , SARS-CoV-2 , Seroepidemiologic Studies
11.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-330334

ABSTRACT

SARS-CoV-2 Omicron variants contain many mutations in its spike receptor binding domain, the target of all authorized monoclonal antibodies (mAbs). Determining the extent to which Omicron variants reduced mAb susceptibility is critical to preventing and treating COVID-19. We systematically reviewed PubMed and three preprint servers, last updated February 22, 2022, of the in vitro activity of authorized mAbs against the Omicron variants. Thirty-three studies were eligible including 33 containing Omicron BA.1 susceptibility data and five that also contained Omicron BA.2 susceptibility data. The first two authorized mAb combinations, bamlanivimab/etesevimab and casirivimab/imdevimab, were inactive against the Omicron BA.1 and BA.2 variants. In 24 studies, sotrovimab (third authorized mAb) displayed a median 4.1-fold (IQR: 2.4-7.6) reduced activity against Omicron BA.1 and, in four studies, a median 26-fold (IQR:16-35) reduced activity against Omicron BA.2. In 18 studies, cilgavimab and tixagevimab independently displayed median reductions in activity of >300-fold against Omicron BA.1, while in ten studies, the cilgavimab/tixagevimab combination (fourth authorized mAb preparation) displayed a median 63-fold (IQR: 26-145) reduced activity against Omicron BA.1. In two studies, cilgavimab was approximately 100-fold more susceptible to BA.2 than to BA.1. In two studies, bebtelovimab, the most recently authorized mAb, was fully active against both the Omicron variants. Disparate results between assays were common as evidenced by a median 42-fold range (IQR: 25-625) in IC50 between assays for the eight authorized individual mAbs and three authorized mAb combinations. Highly disparate results between published assays indicates a need for improved mAb susceptibility test standardization or inter-assay calibration.

12.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-330067

ABSTRACT

Importance The case fatality rate of SARS-CoV-2 has been high among residents of long-term care (LTC) facilities. It is important to know if the excess mortality persists beyond the acute infection. Objective To evaluate whether SARS-CoV-2 is associated with higher mortality after the first month from documented infection. Design We extended the follow-up period of a previous, retrospective cohort study based on the Swedish Senior Alert register. LTC residents infected with SARS-CoV-2 were matched to uninfected controls using time-dependent propensity scores on age, sex, body mass index, health status, comorbidities, and prescription medication use. In a sensitivity analysis, residents were also matched on geographical region and time of Senior Alert registration. Setting LTC facilities in Sweden. Participants 3731 LTC residents with SARS-CoV-2 and 3731 controls (n=3604 in each group in the sensitivity analysis). Exposure SARS-CoV-2 infection, documented in the SmiNet register (until September 15, 2020). Main Outcome All-cause mortality over 8 months (until October 24, 2020). Results The median age was 87 years, and 65% were women. Excess mortality was highest 5 days after documented infection (hazard ratio 19.1;95% confidence interval [CI], 14.6-24.8), after which excess mortality decreased rapidly. After the second month, the mortality rate became lower in infected residents than in controls. Median survival of uninfected controls was 577 days (1.6 years), which is much lower than national life expectancy in Sweden at age 87 (5.05 years in men, 6.07 years in women). During days 61-210 of follow-up, the hazard ratio for death was 0.41 (95% CI, 0.34-0.50) in the main analysis and 0.76 (95% CI, 0.62-0.93) in the sensitivity analysis. Conclusions and Relevance No excess mortality was observed in LTC residents who survived the acute SARS-CoV-2 infection (the first month). The life expectancy of uninfected residents was much lower than that of the general population of the same age and sex. This difference should be taken into account in calculations of years of life lost among LTC residents. Key points Question Does SARS-CoV-2 increase mortality in residents of long-term care (LTC) facilities beyond the first month (that is, beyond the acute infection)? Findings In a matched cohort study, we found that excess mortality was high during the first month but then decreased sharply. After the second month, the mortality rate became lower in infected residents than in uninfected controls. Meaning No excess mortality was observed in LTC residents who survived the acute SARS-CoV-2 infection.

13.
SSRN;
Preprint in English | SSRN | ID: ppcovidwho-326055

ABSTRACT

Vaccine effectiveness for COVID-19 is typically estimated for different outcomes that often are hierarchical in severity (e.g. any documented infection, symptomatic infection, hospitalization, death) and which may be subsets of each other. Conditional effectiveness for a more severe outcome conditional on a less severe outcome is the protection offered against the severe outcome (e.g. death) among those who have already sustained the less severe outcome (e.g. documented infection). The concept applies also to the protection offered not only by vaccines but also by previous infection. Formulas and a nomogram are provided here for calculating conditional effectiveness. Illustrative examples are presented from recent vaccine effectiveness studies, including situations where effectiveness for different outcomes changed at different pace over time. E(death ;documented infection) is the percent decrease in the case fatality rate (CFR) and E(death ;infection) is the percent decrease in the infection fatality rate (IFR). One can thus calculate the evolving CFR and IFR in a population as more people become vaccinated and/or infected. Conditional effectiveness depends on many factors including availability and use of better treatment options, lethality of predominant viral strains, background immunity, increased exposure of disproportionately low risk people (due to fewer precautions or/and more active epidemic waves) and more aggressive testing of asymptomatic people. Conditional effectiveness should be used for better personalized communication of the benefits of vaccination, considering also IFR and epidemic activity. Patients, physicians, and policy makers would benefit to know this information for shared decision making.

14.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-313224

ABSTRACT

The COVID-19 crisis led to a flurry of clinical trials activity. The COVID-Evidence database shows 2,814 COVID-19 randomized trials registered as of February 16, 2021. Most were small (only 18% have a planned sample size >500) and the rare completed ones have not provided published results promptly (only 283 trial publications as of 2/2021). Small randomized trials and observational, non-randomized analyses have not had a successful track record and have generated misleading expectations. Different large trials on the same intervention have generally been far more efficient in producing timely and consistent evidence. The rapid generation of evidence and accelerated dissemination of results have led to new challenges for systematic reviews and meta-analyses (e.g. rapid, living, and scoping reviews). Pressure to regulatory agencies has also mounted with massive emergency authorizations, but some of them have had to be revoked. Pandemic circumstances have disrupted the way trials are conducted;therefore, new methods have been developed and adopted more widely to facilitate recruitment, consent, and overall trial conduct. Based on the COVID-19 experience and its challenges, planning of several large, efficient trials, and wider use of adaptive designs may change the future of clinical research. Pragmatism, integration in clinical care, efficient administration, promotion of collaborative structures, and enhanced integration of existing data and facilities may be several of the legacies of COVID-19 on future randomized trials.

15.
Environ Res ; 209: 112911, 2022 06.
Article in English | MEDLINE | ID: covidwho-1670484

ABSTRACT

Seroprevalence surveys suggest that more than a third and possibly more than half of the global population has been infected with SARS-CoV-2 by early 2022. As large numbers of people continue to be infected, the efficacy and duration of natural immunity in terms of protection against SARS-CoV-2 reinfections and severe disease is of crucial significance for the future. This narrative review provides an overview on epidemiological studies addressing this issue. National surveys covering 2020-2021 documented that a previous SARS-CoV-2 infection is associated with a significantly reduced risk of reinfections with efficacy lasting for at least one year and only relatively moderate waning immunity. Importantly, natural immunity showed roughly similar effect sizes regarding protection against reinfection across different SARS-CoV-2 variants, with the exception of the Omicron variant for which data are just emerging before final conclusions can be drawn. Risk of hospitalizations and deaths was also reduced in SARS-CoV-2 reinfections versus primary infections. Observational studies indicate that natural immunity may offer equal or greater protection against SARS-CoV-2 infections compared to individuals receiving two doses of an mRNA vaccine, but data are not fully consistent. The combination of a previous SARS-CoV-2 infection and a respective vaccination, termed hybrid immunity, seems to confer the greatest protection against SARS-CoV-2 infections, but several knowledge gaps remain regarding this issue. Natural immunity should be considered for public health policy regarding SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/prevention & control , Humans , Reinfection/epidemiology , Seroepidemiologic Studies , Vaccines, Synthetic
16.
J Neurosurg Anesthesiol ; 34(1): 107-112, 2022 Jan 01.
Article in English | MEDLINE | ID: covidwho-1555674

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic incited a global clinical trial research agenda of unprecedented speed and high volume. This expedited research activity in a time of crisis produced both successes and failures that offer valuable learning opportunities for the scientific community to consider. Successes include the implementation of large adaptive and pragmatic trials as well as burgeoning efforts toward rapid data synthesis and open science principles. Conversely, notable failures include: (1) inadequate study design and execution; (2) data reversal, fraud, and retraction; and (3) research duplication and waste. Other challenges that became highlighted were the need to find unbiased designs for investigating complex, nonpharmaceutical interventions and the use of routinely collected data for outcomes assessment. This article discusses these issues juxtaposing the COVID-19 trials experience against trials in anesthesiology and other fields. These lessons may serve as a positive catalyst for transforming future clinical trial research.


Subject(s)
COVID-19 , Humans , Pandemics , Randomized Controlled Trials as Topic , SARS-CoV-2
18.
Environ Res ; 204(Pt C): 112342, 2022 03.
Article in English | MEDLINE | ID: covidwho-1499856

ABSTRACT

OBJECTIVES: Most countries initially deployed COVID-19 vaccines preferentially in elderly populations. We aimed to evaluate whether population-level vaccine effectiveness is heralded by an increase in the relative proportion of deaths among non-elderly populations that were less covered by vaccination programs. ELIGIBLE DATA: We collected data from 40 countries on age-stratified COVID-19 deaths during the vaccination period (1/14/2021-5/31/2021) and two control periods (entire pre-vaccination period and excluding the first wave). MAIN OUTCOME MEASURES: We meta-analyzed the proportion of deaths in different age groups in vaccination versus control periods in (1) countries with low vaccination rates; (2) countries with age-independent vaccination policies; and (3) countries with standard age-dependent vaccination policies. RESULTS: Countries that prioritized vaccination among older people saw an increasing share of deaths among 0-69 year old people in the vaccination versus the two control periods (summary proportion ratio 1.32 [95 CI% 1.24-1.41] and 1.35 [95 CI% 1.26-1.44)]. No such change was seen on average in countries with age-independent vaccination policies (1.05 [95 CI% 0.78-1.41 and 0.97 [95 CI% 0.95-1.00], respectively) and limited vaccination (0.93 [95 CI% 0.85-1.01] and 0.95 [95 CI% 0.87-1.03], respectively). Proportion ratios were associated with the difference of vaccination rates in elderly versus non-elderly people. No significant changes occurred in the share of deaths in age 0-49 among all 0-69 deaths in the vaccination versus pre-vaccination periods. CONCLUSIONS: The substantial shift in the age distribution of COVID-19 deaths in countries that rapidly implemented vaccination predominantly among elderly provides evidence for the population level-effectiveness of COVID-19 vaccination and a favorable evolution of the pandemic towards endemicity with fewer elderly deaths.


Subject(s)
COVID-19 Vaccines , COVID-19 , Adolescent , Adult , Age Distribution , Aged , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Middle Aged , SARS-CoV-2 , Vaccination , Young Adult
19.
Eur J Clin Invest ; 51(11): e13678, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1501400

ABSTRACT

Strategies for the use of COVID-19 vaccines in children and young adults (in particular university students) are hotly debated and important to optimize. As of late August 2021, recommendations on the use of these vaccines in children vary across different countries. Recommendations are more uniform for vaccines in young adults, but vaccination uptake in this age group shows a large range across countries. Mandates for vaccination of university students are a particularly debated topic with many campuses endorsing mandates in the USA in contrast to European countries, at least as of August 2021. The commentary discusses the potential indirect impact of vaccination of youth on the COVID-19 burden of disease for other age groups and societal functioning at large, estimates of direct impact on reducing fatalities and nonlethal COVID-19-related events in youth, estimates of potential lethal and nonlethal adverse events from vaccines and differential considerations that may exist in the USA, European countries and nonhigh-income countries. Decision-making for deploying COVID-19 vaccines in young people is subject to residual uncertainty on the future course of the pandemic and potential evolution towards endemicity. Rational recommendations would also benefit from better understanding of the clinical and sociodemographic features of COVID-19 risk in young populations and from dissecting the role of re-infections and durability of natural vs. vaccine-induced immunity.


Subject(s)
COVID-19 Vaccines/therapeutic use , COVID-19/prevention & control , Organizational Policy , Practice Guidelines as Topic , Students , Universities , Adolescent , Age Distribution , COVID-19/epidemiology , Child , Humans , Risk Assessment , SARS-CoV-2 , Young Adult
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