Metformin continuation post-metabolic bariatric surgery and relapse of diabetes.

AIM: To evaluate the association of metformin continuation with relapse of diabetes after metabolic bariatric surgery (MBS) in patients with type 2 diabetes and obesity who achieved an HbA1c level of less than 6.5%. MATERIALS AND METHODS: This observational, retrospective cohort study included Clalit Health Service members aged 24 years or older with obesity and diabetes, who were treated with metformin, underwent MBS during 2005-2020 and achieved an HbA1c level of less than 6.5% up to 6 months after surgery (index date). Patients who continued metformin treatment (> 2 prescriptions filled, n = 122) after the index date were matched (1:2) on age, sex and HbA1c level at index date and compared with those who stopped treatment (no filled prescriptions, n = 244). The outcome was relapse of diabetes as measured by an HbA1c level of 6.5% or higher (yes/no). RESULTS: The two matched groups maintained a mean HbA1c level of less than 6.5% during the follow-up (mean ~ 5 years). An adjusted Cox proportional hazards model revealed no significant association of metformin continuation after MBS with relapse of diabetes (adjusted hazard ratio = 1.70, 95% confidence interval: 0.98-2.94). No significant differences were observed between the two groups in weight loss and filled prescriptions for other diabetes medications during the follow-up period. CONCLUSIONS: Among individuals living with obesity and diabetes who achieved diabetes remission post-MBS, metformin continuation was not associated with relapse of diabetes. This lack of an association indicates that metformin did not provide an additional benefit for maintaining glycaemic control or weight reduction during an average of 5 years postsurgery.

Internal medicine in the 21st century: Back to the future.

Healthcare systems face multiple challenges arising from demographic factors (population aging) and epidemiological factors (rise of chronic diseases and patients with multimorbidity) as well as threats to their financial sustainability when maintaining equitable access to medical and technological advances. Current healthcare models, based on specialized medical care, lead to fragmented care that can be harmful to the patient and is inefficient for the system due to the overuse of redundant, low-value medical acts. Internal medicine is the hospital-centered general medical specialty par excellence, providing a comprehensive and holistic vision that is centered on the patient and not on the disease. Internists should be the leading physicians in the hospital setting for complex patients with or those with an uncertain diagnosis. Internists must play a key role, as hospitalists do, in the continued care of acute patients hospitalized for medical or surgical diseases, establishing shared care models in multidisciplinary teams. Likewise, to guarantee continuity of care for chronic patients, internists must establish mechanisms for collaboration with primary care and nursing, participating in the development of new out-of-hospital care models that use the available technological resources. Internal medicine should play a leading role in graduate and postgraduate medical education to promote a holistic vision among medical students and residents in medical subspecialties.

Assessing the state of obesity care: Quality, access, guidelines, and standards.

Background: An international panel of obesity medicine experts from multiple professional organizations examined patterns of obesity care and current obesity treatment guidelines to identify areas requiring updating in response to emerging science and clinical evidence. Aims: The panel focused on multiple medical health and societal issues influencing effective treatment of obesity and identified several unmet needs in the definition, assessment, and care of obesity. Methods: The panel was held in Leesburg, Virginia in September 2019. Results: The panelists recommended addressing these unmet needs in obesity medicine through research, education, evaluation of delivery and payment of care, and updating clinical practice guidelines (CPG) to better reflect obesity's pathophysiological basis and heterogeneity, as well as the disease's health, sociocultural, and economic complications; effects on quality of life; need for standards for quantitative comparison of treatment benefits, risks, and costs; and the need to more effectively integrate obesity treatment guidelines into routine clinical practice and to facilitate more direct clinician participation to improve public understanding of obesity as a disease with a pathophysiological basis. The panel also recommended that professional organizations working to improve the care of people with obesity collaborate via a working group to develop an updated, patient-focused, comprehensive CPG establishing standards of care, addressing identified needs, and providing for routine, periodic review and updating. Conclusions: Unmet needs in the definition, assessment and treatment of obesity were identified and a blueprint to address these needs developed via a clinical practice guideline that can be utilized worldwide to respond to the increasing prevalence of obesity.

Bariatric Metabolic Surgery vs Glucagon-Like Peptide-1 Receptor Agonists and Mortality.

Importance: Evidence regarding the relative effectiveness of bariatric metabolic surgery (BMS) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) in reducing mortality and major adverse cardiovascular events (MACEs) is limited. Objective: To compare all-cause mortality and nonfatal MACEs associated with BMS vs GLP-1RAs for adults with obesity and diabetes and without known cardiovascular disease. Design, Setting, and Participants: This observational, retrospective cohort study was based on data obtained from the electronic medical records of Clalit Health Services (Clalit), the largest health care organization in Israel. The study included 6070 members aged 24 years or older, who had diabetes and obesity and no prior history of ischemic heart disease, ischemic stroke, or congestive heart failure. Patients who underwent BMS and patients who received GLP-1RAs from January 1, 2008, through December 31, 2021, were matched 1:1 by age, sex, and clinical characteristics. Follow-up ended December 31, 2022. Exposures: Initiation of BMS or GLP-1RAs. Main Outcomes and Measures: The primary outcome was all-cause mortality, assessed by multivariate Cox proportional hazards regression models. The secondary outcome was nonfatal MACEs, assessed by multivariate competing risk models. Results: The study included 3035 matched pairs of patients (total, 6070; mean [SD] age, 51.0 [9.5] years; 3938 women [64.9%]), who were followed up for a median of 6.8 years (IQR, 4.1-9.4 years). Among those with a diabetes duration of 10 years or less (2371 pairs), mortality was lower for those who underwent BMS than for those treated with GLP-1RAs (hazard ratio [HR], 0.38; 95% CI, 0.25-0.58). This association became nonsignificant when weight loss during the follow-up period was also included in the model (HR, 0.79; 95% CI, 0.43-1.48). Among patients with a duration of diabetes longer than 10 years (664 pairs), no survival advantage was demonstrated for BMS over GLP-1RA (HR, 0.65; 95% CI, 0.39-1.08). The risk for nonfatal MACEs did not differ between the treatment groups (HR, 0.74; 95% CI, 0.49-1.10 among patients with a diabetes duration of ≤10 years; HR, 1.21; 95% CI, 0.80-1.85 among patients with a diabetes duration of >10 years). Conclusions and Relevance: In this cohort study, BMS was associated with greater reduced mortality compared with first-generation GLP-1RAs among individuals with a diabetes duration of 10 years or less, mediated via greater weight loss. No differences in the risk for mortality were observed between the treatment modalities among individuals with a longer duration of diabetes, nor in the occurrence of nonfatal MACEs among all patients.

Long-term weight loss effects of semaglutide in obesity without diabetes in the SELECT trial.

In the SELECT cardiovascular outcomes trial, semaglutide showed a 20% reduction in major adverse cardiovascular events in 17,604 adults with preexisting cardiovascular disease, overweight or obesity, without diabetes. Here in this prespecified analysis, we examined effects of semaglutide on weight and anthropometric outcomes, safety and tolerability by baseline body mass index (BMI). In patients treated with semaglutide, weight loss continued over 65 weeks and was sustained for up to 4 years. At 208 weeks, semaglutide was associated with mean reduction in weight (-10.2%), waist circumference (-7.7 cm) and waist-to-height ratio (-6.9%) versus placebo (-1.5%, -1.3 cm and -1.0%, respectively; P < 0.0001 for all comparisons versus placebo). Clinically meaningful weight loss occurred in both sexes and all races, body sizes and regions. Semaglutide was associated with fewer serious adverse events. For each BMI category (<30, 30 to <35, 35 to <40 and ≥40 kg m-2) there were lower rates (events per 100 years of observation) of serious adverse events with semaglutide (43.23, 43.54, 51.07 and 47.06 for semaglutide and 50.48, 49.66, 52.73 and 60.85 for placebo). Semaglutide was associated with increased rates of trial product discontinuation. Discontinuations increased as BMI class decreased. In SELECT, at 208 weeks, semaglutide produced clinically significant weight loss and improvements in anthropometric measurements versus placebo. Weight loss was sustained over 4 years. ClinicalTrials.gov identifier: NCT03574597 .

Effectiveness of bariatric metabolic surgery versus glucagon-like peptide-1 receptor agonists for prevention of congestive heart failure.

Comparative evidence for the effects of bariatric metabolic surgery (BMS) and glucagon-like peptide-1 receptor agonists (GLP-1RA) on cardiovascular outcomes is limited. Here, in an observational, retrospective cohort study, we compared the incidence of congestive heart failure (CHF) in adults living with obesity and diabetes without history of CHF (primary CHF) treated with BMS versus GLP-1RA. The population cohort comprised members of Clalit Health Services with no prior history of ischemic heart disease, ischemic stroke or CHF. During the time period of 2008-2021, patients who underwent their first BMS were matched 1:1 with patients who initiated treatment with GLP-1RA, based on clinical characteristics. The study included 2,205 matched pairs of patients (64.5% female), followed for a median of 6.6 years and up to 12 years. Primary incidence of CHF occurred in 26 (1.2%) patients treated with BMS and in 90 patients treated with GLP-1RA (4.1%) (adjusted hazard ratio 0.43, 95% confidence interval 0.27-0.68). Further adjustment for weight reduction did not significantly diminish this association (hazard ratio adjusted for weight reduction 0.48, 95% confidence interval 0.28-0.82), indicating that the differential effect was not mediated through the relative advantage of BMS in maximal weight reduction. In this study, BMS was associated with a stronger reduction in primary incidence of CHF compared with treatment with GLP-1RA. With the increasing use of highly potent next-generation GLP-1RAs, further comparative long-term studies are warranted.

Association of Waist Circumference and Body Mass Index Deciles Ratio with All-Cause Mortality: Findings from the National Health and Nutrition Examination Survey.

Given the importance and continued interest in finding a simple, accessible, and universal measure which reflects both general and abdominal adiposity, this study tested for an association of the ratio of WC decile to BMI decile (WC-d/BMI-d) with all-cause mortality. Individuals aged 18-79 years who had participated in the National Health and Nutrition Examination Survey (NHANES) during the years 2007 to 2018 were included in the analysis. WC and BMI deciles were defined separately for males and females, while WC-d/BMI-d was calculated for each individual. The association of WC-d/BMI-d with mortality was assessed using logistic models for the total study population, and then again after stratification by sex, ethnicity, morbidity level, and BMI categories. Positive associations between WC-d/BMI-d and mortality were demonstrated for the total study population (adjusted OR = 1.545, 95%CI: 1.369-1.722) and within different sub-groups, including the population with a normal BMI level (adjusted OR = 1.32, 95%CI: 1.13-1.50). WC-d/BMI-d increased with age, with ~40 years representing a critical time point when WC-d surpasses BMI-d, with a sharper incline for males as compared to females. WC-d/BMI-d was significantly associated with all-cause mortality amongst NHANES American adults; thus, measurements of WC and its integration with BMI in this metric should be considered in clinical practice.

Metabolic Bariatric surgery in People with Obesity aged ≥65 Years.

Obesity management guidelines recommend metabolic bariatric surgery for individuals with body mass index (BMI) ≥35 kg/m2, regardless of the presence of any obesity-related comorbidity; and for individuals with BMI 30-34.9 kg/m2 with metabolic diseases. Older age is not in itself a contraindication for bariatric surgeries, which can be performed after careful selection and assessment, to decrease the risks of postoperative complications. An essential amount of data has accumulated about bariatric surgery results for persons aged ≥60 years; but data are limited though increasingly accumulating for the ≥65-year-old population. Laparoscopic Roux-en-Y-gastric bypass and sleeve gastrectomy have been the preferred bariatric procedures for older adults with obesity, as for younger patients. This review summarizes the safety and efficacy of bariatric surgery for individuals aged ≥65 years with obesity, and the efforts that have been invested to improve the perioperative and long-term consequences.

Can Consultation by a Clinical Pharmacist Prevent Morbidity and Mortality in Patients Undergoing Bariatric Surgery?

The purpose of this work was to investigate the effect of clinical pharmacist consultation on the long-term morbidity and mortality outcomes among patients undergoing bariatric surgery. In this retrospective cohort study, 165 bariatric patients at Herzliya Medical Center who were identified as complex cases and were consulted by a clinical pharmacist (2013-2019) were compared with a wider group of bariatric patients with chronic diseases who were recorded in the Israeli General Bariatric Registry during the same years. The primary outcomes were rates of surgical complications, re-hospitalizations, and death up to one year after surgery. The secondary outcome was the rate of re-hospitalizations in different time periods. The twelve (12)-month rate of re-hospitalization in the intervention group was 10.9% vs. 19.5% in the comparison group (p = 0.005); the rate of documented postoperative complications was 2.7% vs. 3.9% (p = 0.462), and mortality was null vs. 0.16%, respectively. As for the secondary outcomes, the rates of re-hospitalizations in the periods of 0-30, 31-90, 91-180, and 181-365 days after surgery were 1.8% vs. 5.3% (p = 0.046), 2.4% vs. 4.1% (p = 0.278), 3.6% vs. 4.8% (p = 0.476), and 7.3% vs. 9.9% (p = 0.256) in the intervention vs. comparison cohorts, respectively. In conclusion, this study demonstrates the importance and benefit of referring to a specialized clinical pharmacist around bariatric surgery for improving patient safety, especially in complex patients. This is the first study to look at the long-term effects of clinical pharmacist consultation on re-hospitalization and mortality among bariatric patients, and our encouraging outcomes should hopefully stimulate more studies to show the invaluable role of specialized clinical pharmacists.

Post metabolic bariatric surgery weight regain: the importance of GLP-1 levels.

Weight regain and insufficient weight loss are essential problems after metabolic bariatric surgery (MBS) in people living with obesity. Changes in the level of glucagon-like peptide-1 (GLP-1) secreted from the gut after bariatric surgery are one of the underlying mechanisms for successful initial weight loss. Studies and meta-analyses have revealed that postprandial GLP-1 levels increase after the Roux-en-Y gastric bypass and sleeve gastrectomy, but fasting GLP-1 levels do not increase significantly. Some observational studies have shown the relationship between higher postprandial GLP-1 levels and successful weight loss after bariatric surgery. There is growing evidence that GLP-1-receptor agonist (GLP-1-RA) use in patients who regained weight after bariatric surgery has resulted in significant weight loss. In this review, we aimed to summarize the changes in endogenous GLP-1 levels and their association with weight loss after MBS, describe the effects of GLP-1-RA use on weight loss after MBS, and emphasize metabolic adaptations in light of the recent literature. We hypothesized that maintaining higher basal-bolus GLP-1-RA levels may be a promising treatment choice in people with obesity who failed to lose weight after bariatric surgery.

Subcutaneous Semaglutide Use for Weight Management: Practice and Attitudes of Physicians in Israel.

BACKGROUND: In 2019, 1 mg subcutaneous semaglutide was registered for the treatment of diabetes in Israel. Recognition of its effect on weight has led to its use as a treatment for obesity. OBJECTIVES: To explore physicians' pre-therapy considerations, therapy practices, and attitudes regarding subcutaneous semaglutide for weight loss. METHODS: A 22-item questionnaire was disseminated to physicians who prescribed semaglutide 1-mg for weight loss using an authorized off-label path. RESULTS: In total, 127 physicians completed the questionnaire. As for pretreatment requirements, in the absence of diabetes, 30% requested a minimal body mass index of 30 kg/m2. Additional requirements were documented lifestyle-change effort (67%) and prior weight loss medication use (13%). Half of the physicians regarded calorie restriction, and 23% considered physical activity as necessary for weight loss while on therapy. As for dose, most physicians (78%) started with a 0.25-mg weekly injection, 57% doubled the dose monthly, and all others recommended doubling when side effects subsided. Regarding weight loss goal, 43% of the physicians set a personal goal with each patient while 26% limited the goal to 10% of initial weight. Fewer than 50% of physicians discussed treatment duration with their patients, and 52% of patients discontinued therapy in the first 3 months. The main reasons for discontinuation were price, lack of effect, and fear of long-term side effects. CONCLUSIONS: The diverse approaches regarding off-label use of semaglutide for weight reduction highlight the necessity to guide physicians and standardize treatment regimen.

Towards an adiposity-related disease framework for the diagnosis and management of obesities.

Obesity is a complex disease that relapses frequently and associates with multiple complications that comprise a worldwide health priority because of its rising prevalence and association with numerous complications, including metabolic disorders, mechanic pathologies, and cancer, among others. Noteworthy, excess adiposity is accompanied by chronic inflammation, oxidative stress, insulin resistance, and subsequent organ dysfunction. This dysfunctional adipose tissue is initially stored in the visceral depot, overflowing subsequently to produce lipotoxicity in ectopic depots like liver, heart, muscle, and pancreas, among others. People living with obesity need a diagnostic approach that considers an exhaustive pathophysiology and complications assessment. Thus, it is essential to warrant a holistic diagnosis and management that guarantees an adequate health status, and quality of life. The present review summarizes the different complications associated with obesity, at the same time, we aim to fostering a novel framework that enhances a patient-centered approach to obesity management in the precision medicine era.

Effects of Semaglutide on Albuminuria and Kidney Function in People With Overweight or Obesity With or Without Type 2 Diabetes: Exploratory Analysis From the STEP 1, 2, and 3 Trials.

OBJECTIVE: These post hoc analyses of the Semaglutide Treatment Effect in People with obesity (STEP) 1-3 trials (NCT03548935, NCT03552757, and NCT03611582) explored the effects of semaglutide (up to 2.4 mg) on kidney function. RESEARCH DESIGN AND METHODS: STEP 1-3 included adults with overweight/obesity; STEP 2 patients also had type 2 diabetes. Participants received once-weekly subcutaneous semaglutide 1.0 mg (STEP 2 only), 2.4 mg, or placebo for 68 weeks, plus lifestyle intervention (STEP 1 and 2) or intensive behavioral therapy (STEP 3). Changes in urine albumin-to-creatinine ratio (UACR) and UACR status from baseline to week 68 were assessed for STEP 2. Changes in estimated glomerular filtration rate (eGFR) were assessed from pooled STEP 1-3 data. RESULTS: In STEP 2, 1,205 (99.6% total cohort) patients had UACR data; geometric mean baseline UACR was 13.7, 12.5, and 13.2 mg/g with semaglutide 1.0 mg, 2.4 mg, and placebo, respectively. At week 68, UACR changes were -14.8% and -20.6% with semaglutide 1.0 mg and 2.4 mg, respectively, and +18.3% with placebo (between-group differences [95% CI] vs. placebo: -28.0% [-37.3, -17.3], P < 0.0001 for semaglutide 1.0 mg; -32.9% [-41.6, -23.0], P = 0.003 for semaglutide 2.4 mg). UACR status improved in greater proportions of patients with semaglutide 1.0 mg and 2.4 mg versus placebo (P = 0.0004 and P = 0.0014, respectively). In the pooled STEP 1-3 analyses, 3,379 participants had eGFR data; there was no difference between semaglutide 2.4 mg and placebo in eGFR trajectories at week 68. CONCLUSIONS: Semaglutide improved UACR in adults with overweight/obesity and type 2 diabetes. In participants with normal kidney function, semaglutide did not have an effect on eGFR decline.

Time-varying association of acute and post-acute COVID-19 with new-onset diabetes mellitus among hospitalized and non-hospitalized patients.

INTRODUCTION: Previous studies have shown disruption of glycometabolic control and new diabetes mellitus (DM) diagnosis among patients with COVID-19. It is still unclear how the association of COVID-19 and new-onset DM may be modified by disease severity or vary over time, during acute and post-acute phases. RESEARCH DESIGN AND METHODS: In this retrospective matched cohort study, 157 936 patients with COVID-19 (aged ≥25 years, diagnosis date between March 01, 2020 and August 31, 2021) were compared with individuals without COVID-19, separately for non-hospitalized, hospitalized, and severe hospitalized patients. Stratified Cox proportional hazards models, with changing baseline time (starting at the date of COVID-19 diagnosis, and at 1, 2, 3, and 4 months afterwards), were used to evaluate the occurrence of new DM in relation to COVID-19 infection in different time frames-from each landmark date until end of study. RESULTS: During mean follow-up time of 10.9 months, there were 1145 (0.72%) new diagnoses of DM compared with 1013 (0.64%) in the individuals without COVID-19 (p=0.004). Non-hospitalized patients with COVID-19 were not at higher risk of new DM neither during the acute phase nor afterward. Hospitalized patients with COVID-19 had a higher risk of developing DM, with the highest risk among severe hospitalized patients. This risk among hospitalized patients was highest in the acute phase (HR 2.47 (95% CI 1.86 to 3.29)), attenuated over time, but remained significant at 4-month landmark analysis (HR 1.60 (95% CI 1.12 to 2.29)). CONCLUSIONS: Acute and post-acute COVID-19 were associated with new DM only among hospitalized patients, with the highest risk among those hospitalized with severe disease. Those patients should be followed and monitored post-discharge for new DM. Patients who were not hospitalized did not have higher risk of new-onset DM.

European Association for the Study of Obesity Position Statement on Medical Nutrition Therapy for the Management of Overweight and Obesity in Adults Developed in Collaboration with the European Federation of the Associations of Dietitians.

INTRODUCTION: Obesity affects nearly 1 in 4 European adults increasing their risk for mortality and physical and psychological morbidity. Obesity is a chronic relapsing disease characterized by abnormal or excessive adiposity with risks to health. Medical nutrition therapy based on the latest scientific evidence should be offered to all Europeans living with obesity as part of obesity treatment interventions. METHODS: A systematic review was conducted to identify the latest evidence published in the November 2018-March 2021 period and to synthesize them in the European guidelines for medical nutrition therapy in adult obesity. RESULTS: Medical nutrition therapy should be administered by trained dietitians as part of a multidisciplinary team and should aim to achieve positive health outcomes, not solely weight changes. A diverse range of nutrition interventions are shown to be effective in the treatment of obesity and its comorbidities, and dietitians should consider all options and deliver personalized interventions. Although caloric restriction-based interventions are effective in promoting weight reduction, long-term adherence to behavioural changes may be better supported via alternative interventions based on eating patterns, food quality, and mindfulness. The Mediterranean diet, vegetarian diets, the Dietary Approaches to Stop Hypertension, portfolio diet, Nordic, and low-carbohydrate diets have all been associated with improvement in metabolic health with or without changes in body weight. In the November 2018-March 2021 period, the latest evidence published focused around intermittent fasting and meal replacements as obesity treatment options. Although the role of meal replacements is further strengthened by the new evidence, for intermittent fasting no evidence of significant advantage over and above continuous energy restriction was found. Pulses, fruit and vegetables, nuts, whole grains, and dairy foods are also important elements in the medical nutrition therapy of adult obesity. DISCUSSION: Any nutrition intervention should be based on a detailed nutritional assessment including an assessment of personal values, preferences, and social determinants of eating habits. Dietitians are expected to design interventions that are flexible and person centred. Approaches that avoid caloric restriction or detailed eating plans (non-dieting approaches) are also recommended for improvement of quality of life and body image perceptions.

Physicians' responsibility toward environmental degradation and climate change: A position paper of the European Federation of Internal Medicine.

The current data on climate change and environmental degradation are dramatic. The consequences of these changes are already having a significant impact on people's health. Physicians - as advocates of the patients, but also as citizens - have an ethical obligation to be involved in efforts to stop these changes. The European Federation of Internal Medicine (EFIM) strongly encourages the Internal Medicine societies and internists across Europe to play an active role in matters related to climate change and environmental degradation. At a national level, this includes advocating the adoption of measures that reduce greenhouse gas (GHG) emissions and environmental degradation and contributing to policy decisions related to these issues. At a hospital level and in clinical practice, supporting actions by the health sector to reduce its ecological footprint is vital. At the level of EFIM and its associated internal societies, promoting educational activities and developing a toolkit to prepare internists to better care for citizens who suffer from the consequences of climate change. In addition to advocating and implementing effective actions to reduce the ecological footprint of the health industry, recommending the introduction of these themes in scientific programs of Internal Medicine meetings and congresses and the pre- and postgraduate medical training. At a personal level, internists must be active agents in advocating sustainable practices for the environment, increasing the awareness of the community about the health risks of climate change and environmental degradation, and being role models in the adoption of environmentally friendly behaviour.

Longitudinal kinetics of RBD+ antibodies in COVID-19 recovered patients over 14 months.

We describe the longitudinal kinetics of the serological response in COVID-19 recovered patients over a period of 14 months. The antibody kinetics in a cohort of 192 recovered patients, including 66 patients for whom follow-up serum samples were obtained at two to four clinic visits, revealed that RBD-specific antibodies decayed over the 14 months following the onset of symptoms. The decay rate was associated with the robustness of the response in that antibody levels that were initially highly elevated after the onset of symptoms subsequently decayed more rapidly. An exploration of the differences in the longitudinal kinetics between recovered patients and naïve vaccinees who had received two doses of the BNT162b2 vaccine showed a significantly faster decay in the naïve vaccinees, indicating that serological memory following natural infection is more robust than that following to vaccination. Our data highlighting the differences between serological memory induced by natural infection vs. vaccination contributed to the decision-making process in Israel regarding the necessity for a third vaccination dose.