Are some COVID-19 vaccines better than others regarding the short-term side effects?

Controlling the pandemic is primarily achieved through vaccination against COVID-19. Although various COVID-19 vaccines are used worldwide, little is known about their safety and side effects. As a result, the objectives of this research are to identify the shortterm side effects of the different COVID-19 vaccines used in Iraq. Furthermore, exploring the association between experienced side effects and the brand of vaccine received. The current study evaluated the shortterm side effects of Pfizer, Sinopharm and AstraZeneca vaccines among healthcare workers in Iraq. The study used a questionnaire that consisted of dedicated sections to collect demographic data, the brand of COVID-19 vaccine received, the short-term side effects, and the willingness to receive a third booster dose. Regarding the post-vaccination side effects, the studied COVID-19 vaccines showed a comparable range of side effects, such as headaches, fever, muscle pain, joint pain, malaise, tenderness, redness, as well as pain at the site of vaccination. However, the Pfizer vaccine showed a higher incidence of pain and tenderness at the site of injection and fever compared to AstraZeneca and Sinopharm, respectively. On the other hand, the Sinopharm vaccine was associated with a higher occurrence of headaches, muscle pain, joint pain, and malaise in comparison to the Pfizer and AstraZeneca vaccines, respectively. In summary, the short-term side effects of the three vaccines were comparable; however, the AstraZeneca vaccine was associated with a lower risk of side effects.

Long COVID-six months of prospective follow-up of changes in symptom profiles of non-hospitalised children and young people after SARS-CoV-2 testing: A national matched cohort study (The CLoCk) study.

BACKGROUND: Little is known about the prevalence and natural trajectory of post-COVID symptoms in young people, despite very high numbers of young people having acute COVID. To date, there has been no prospective follow-up to establish the pattern of symptoms over a 6-month time period. METHODS: A non-hospitalised, national sample of 3,395 (1,737 SARS-COV-2 Negative;1,658 SARS-COV-2 Positive at baseline) children and young people (CYP) aged 11-17 completed questionnaires 3 and 6 months after PCR-confirmed SARS-CoV-2 infection between January and March 2021 and were compared with age, sex and geographically-matched test-negative CYP. RESULTS: Three months after a positive SARS-CoV-2 PCR test, 11 of the 21 most common symptoms reported by >10% of CYP had reduced. There was a further decline at 6 months. By 3 and 6 months the prevalence of chills, fever, myalgia, cough and sore throat of CYP who tested positive for SARS-CoV-2 reduced from 10-25% at testing to <3%. The prevalence of loss of smell declined from 21% to 5% at 3 months and 4% at 6 months. Prevalence of shortness of breath and tiredness also declined, but at a lower rate. Among test-negatives, the same common symptoms and trends were observed at lower prevalence's. Importantly, in some instances (shortness of breath, tiredness) the overall prevalence of specific individual symptoms at 3 and 6 months was higher than at PCR-testing because these symptoms were reported in new cohorts of CYP who had not reported the specific individual symptom previously. CONCLUSIONS: In CYP, the prevalence of specific symptoms reported at time of PCR-testing declined with time. Similar patterns were observed among test-positives and test-negatives and new symptoms were reported six months post-test for both groups suggesting that symptoms are unlikely to exclusively be a specific consequence of SARS-COV-2 infection. Many CYP experienced unwanted symptoms that warrant investigation and potential intervention.

[Myalgic Encephalitis/Chronic Fatigue Syndrome: Diagnostic and Therapeutic Approach and Biological Research].

Myalgic encephalitis/chronic fatigue syndrome, an intractable disease characterized by profound fatigue, sleep disturbance, cognitive impairment, and orthostatic intolerance, among other features, often occurs after infectious episodes. Patients experience various types of chronic pain; however, post-exertional malaise is the most significant feature, which requires pacing. In this article, I summarize the current diagnostic and therapeutic approaches and describe recent biological research in this domain.

Long COVID active case detection initiative among COVID-19 patients in Port Dickson, Malaysia: a retrospective study on the positive outcomes, the proportion of patients with long COVID and its associated factors.

Background: Long COVID is new or ongoing symptoms at four weeks or more after the start of acute COVID-19. However, the prevalence and factors associated with long COVID are largely unknown in Malaysia. We aim to determine the proportion and factors associated with long COVID among COVID-19 patients in Port Dickson, Malaysia. The positive outcomes of our long COVID active detection initiative were also described. Methods: This was a retrospective analysis of long COVID data collected by the Port Dickson District Health Office between 1 September 2021 to 31 October 2021. Monitoring long COVID symptoms was our quality improvement initiative to safeguard residents' health in the district. The study population was patients previously diagnosed with COVID-19 who resided in Port Dickson. The inclusion criteria were adults aged 18 years and above and were in the fifth week (day 29 to 35) post-COVID-19 diagnosis during the data collection period. We called all consecutive eligible patients to inquire regarding long COVID symptoms. Long COVID was defined as new or ongoing symptoms lasting more than 28 days from the date of positive SARS-CoV-2 by polymerase chain reaction test. Binary multivariate logistic regression was conducted to determine factors associated with long COVID. Results: Among 452 patients, they were predominantly male (54.2%), Malays (68.8%) and aged 18-29 years (58.6%). A total of 27.4% (95% CI [23.4-31.8]) of patients experienced long COVID symptoms and were referred to government clinics. The most frequent long COVID symptoms experienced were fatigue (54.0%), cough (20.2%), muscle pain (18.5%), headache (17.7%) and sleep disturbance (16.1%). Females, patients with underlying cardiovascular disease, asthma and chronic obstructive airway disease, those who received symptomatic care, and patients with myalgia and headaches at COVID-19 diagnosis were more likely to have long COVID. Three patients with suspected severe mental health problems were referred to the district psychologist, and ten patients with no/incomplete vaccination were referred for vaccination. Conclusion: Long COVID is highly prevalent among COVID-19 patients in Port Dickson, Malaysia. Long-term surveillance and management of long COVID, especially among the high-risk groups, are needed as we transition to living with COVID-19.

Muscular strength, mobility in daily life and mental wellbeing among older adult Inuit in Greenland. The Greenland population health survey 2018.

The purpose was to analyse the association of muscular strength, muscle pain and reduced mobility in daily life with mental wellbeing among older Inuit men and women in Greenland. Data (N = 846) was collected as part of a countrywide cross-sectional health survey in 2018. Hand grip strength and 30-seconds chair stand test were measured according to established protocols. Mobility in daily life was assessed by five questions about the ability to perform specific activities of daily living. Mental wellbeing was assessed by questions about self-rated health, life satisfaction and Goldberg's General Health Questionnaire. In binary multivariate logistic regression models adjusted for age and social position, muscular strength (OR 0.87-0.94) and muscle pain (OR 1.53-1.79) were associated with reduced mobility. In fully adjusted models, muscle pain (OR 0.68-0.83) and reduced mobility (OR 0.51-0.55) but were associated with mental wellbeing. Chair stand score was associated with life satisfaction (OR 1.05). With an increasingly sedentary lifestyle, increasing prevalence of obesity and increasing life expectancy the health consequences of musculoskeletal dysfunction are expected to grow. Prevention and clinical handling of poor mental health among older adults need to consider reduced muscle strength, muscle pain and reduced mobility as important determinants.

Effect of Massage Therapy with Lime (Citrus Aurantifolia) Essential Oil on the Recovery of Delayed Onset of Muscle Soreness in Athletes.

Background: Physical exercise is a systematic exercise to increase muscle strength achieve goals such as improving the athlete's physical and preventing injury. Athletes must do is massage therapy to prevent muscle fatigue and pain due to physical exercise or during competition. The increase of lactic acid levels affects the maximum working ability of muscle fibers, decreases physical performance, and is fatigue in which the onset of pain. Lime essential oil as a topical oil contains high ester substances that have pharmacological effects such as natural analgesic effects to relieve pain. Objective: The purpose of this study was to determine the effect of massage therapy with lime essential oil as a topical oil on the recovery of delayed-onset muscle soreness (DOMS) in athletes. Methods: The participants are boxing athletes, 30 men, 20-22 years old, and non-smokers. Participants were divided into three groups. The exercise group (E) was doing exercises and was not given massage therapy; the exercise massage (EM) group, namely, doing exercises and being massaged with ordinary lotion as a topical oil; and the EM lime (EMC) group did exercises and was given a massage with lime essential oil as the topical oil. Results: The results showed that there was a significant difference in the average levels of lactic acid (p = 0.000) and the athlete's pain intensity (p = 0.000) in the three groups, namely, the exercise group (E), the exercise and massage group (EM), and the exercise and massage with lime essential oil (EMC). Conclusion: This study finds that lime essential oil used as topical massage therapy oil is better for accelerating the DOMS.

[Immune checkpoint inhibitor-induced eosinophilic fasciitis: a case report and literature review].

A 58-year-old male patient with angioimmunoblastic T-cell lymphoma developed a rash and skin tightness on the face, limbs, and trunk together with joint stiffness and dysfunction after 6 months of treatment with the programmed cell death protein-1 inhibitor camrelizumab. Laboratory tests revealed progressive eosinophilia over 6 months, with the eosinophil count increasing from 0.07×109/L to 3.3×109/L. Magnetic resonance imaging showed thickened skin of both forearms, while T2-weighted imaging showed markedly increased signal intensity within the myofascia. Skin biopsy of the right forearm showed thickened and fibrosed fascia and infiltration of inflammatory cells, including lymphocytes, plasma cells, and eosinophils. The patient was diagnosed with immune checkpoint inhibitor (ICI)-induced eosinophilic fasciitis (EF). After beginning treatment with methylprednisolone (40 mg daily), methotrexate (10 mg/week), and baricitinib (4 mg daily), his symptoms of skin tightness and joint dysfunction significantly improved within 1 month, and his peripheral blood eosinophil count decreased to 0.17×109/L. ICI-induced EF is a rare immune-related adverse reaction. To date, only 20 cases have been reported in published foreign literature, and their clinical characteristics are summarized here. The time from ICI treatment to EF was 12 (8,15) months, and the main clinical manifestations included skin involvement (n=19), joint dysfunction (n=11), myalgia/muscle weakness (n=9), and peripheral eosinophilia (n=16). After treatment, the clinical symptoms of EF improved in 17 patients, and eosinophil counts returned to normal after 3 (1,8) months. EF is a dysfunctional adverse response to ICI therapy. Tumor patients undergoing immunotherapy should be monitored for symptoms of EF. Early treatment is essential for preventing complications.

Influence of Cluster Sets on Mechanical and Perceptual Variables in Adolescent Athletes.

Cluster sets (CS) are effective in maintaining performance and reducing perceived effort compared to traditional sets (TRD). However, little is known about these effects on adolescent athletes. The purpose of this study was to compare the effect of CS on the performance of mechanical and perceptual variables in young athletes. Eleven subjects [4 boys (age = 15.5 ± 0.8 years; body mass = 54.3 ± 7.0 kg; body height = 1.67 ± 0.04 m; Back Squat 1RM/body mass: 1.62 ± 0.19 kg; years from peak height velocity [PHV]: 0.94 ± 0.50) and 7 girls (age = 17.2 ± 1.4 years; body mass = 54.7 ± 6.3 kg; body height = 1.63 ± 0.08 m; Back Squat 1RM/body mass: 1.22 ± 0.16 kg; years from PHV: 3.33 ± 1.00)] participated in a randomized crossover design with one traditional (TRD: 3 × 8, no intra-set and 225 s interest rest) and two clusters (CS1: 3 × 2 × 4, one 30 s intra-set and 180 s inter-set rest; and CS2: 3 × 4 × 2, three 30 s intra-set and 90 s inter-set rest) protocols. The subjects were assessed for a Back Squat 1RM for the first meet, then performed the three protocols on three different days, with at least 48 h between them. During experimental sessions, a back squat exercise was performed, and mean propulsive velocity (MPV), power (MPP), and force (MPF) were collected to analyze performance between protocols, together with measures of countermovement jump (CMJ) and perceptual responses through Rating of Perceived Exertion for each set (RPE-Set) and the overall session (S-RPE), and Muscle Soreness (DOMS). The results showed that velocity and power decline (MVD and MPD) were favorable for CS2 (MVD: -5.61 ± 14.84%; MPD: -5.63 ± 14.91%) against TRD (MVD: -21.10 ± 11.88%; MPD: -20.98 ± 11.85%) (p < 0.01) and CS1 (MVD: -21.44 ± 12.13%; MPD: -21.50 ± 12.20%) (p < 0.05). For RPE-Set, the scores were smaller for CS2 (RPE8: 3.23 ± 0.61; RPE16: 4.32 ± 1.42; RPE24: 4.46 ± 1.51) compared to TRD (RPE8: 4.73 ± 1.33; RPE16: 5.46 ± 1.62; RPE24: 6.23 ± 1.97) (p = 0.008), as well as for Session RPE (CS2: 4.32 ± 1.59; TRD: 5.68 ± 1.75) (p = 0.015). There were no changes for jump height (CMJ: p = 0.985), and the difference between time points in CMJ (ΔCMJ: p = 0.213) and muscle soreness (DOMS: p = 0.437) were identified. Our findings suggest that using CS with a greater number of intra-set rests is more efficient even with the total rest interval equalized, presenting lower decreases in mechanical performance and lower perceptual effort responses.

[Recommendations of diagnosis and treatment of giant cell arteritis and polymyalgia rheumatic in China].

Polymyalgia rheumatica (PMR) is a syndrome characterized by pain and morning stiffness in the neck and shoulder and pelvic girdles, as well as raised acute-phase reactants, with or without systemic symptoms, such as fever. Giant cell arteritis (GCA) is a systemic vasculitis of unclear etiology that involves systemic arteries, principally affecting medium- and large-sized arteries with skipped, segmental alterations and granulomatous vasculitis seen on histopathology. In China, epidemiological data describing GCA are still limited; thus, the prevalence might be underestimated. The involvement of vessels in GCA can cause irreversible visual impairment or loss and stroke, which are serious complications. PMR is three times more prevalent than GCA, and other specific diseases should be excluded before the diagnosis is established. PMR symptoms can be present in 40%-60% of patients with GCA. Conversely, GCA can develop in 15% of patients with PMR. Chinese Rheumatology Association, based on the clinical diagnosis and treatment guidelines in 2005, utilizing the experience and guidelines of diagnosis and treatment at home and abroad, formulated this specification to standardize the diagnosis and treatment of GCA and PMR and improve the patient's prognosis.

Assessment of Exercise Capacity of Individuals with Long COVID: A Cross-sectional Study.

BACKGROUND: Clinical investigations of long-term effects of coronavirus disease 2019 (COVID-19) are rarely translated to objective findings. OBJECTIVES: To assess the functional capacity of individuals reported on deconditioning that hampered their return to their pre-COVID routine. METHODS: Assessment included the 6-minute walk test (6MWT) and the 30-second sit-to-stand test (30-STST). We compared the expected and observed scores using the Wilcoxon signed-rank test. Predictors of test scores were identified using linear regression models. RESULTS: We included 49 individuals, of whom 38 (77.6%) were recovering from mild COVID-19. Twenty-seven (55.1%) individuals had a 6MWT score lower than 80% of expected. The average 6MWT scores were 129.5 ± 121.2 meters and 12.2 ± 5.0 repeats lower than expected scores, respectively (P < 0.001 for both). The 6MWT score was 107.3 meters lower for individuals with severe COVID-19 (P = 0.013) and rose by 2.7 meters per each 1% increase in the diffusing capacity of carbon monoxide (P = 0.007). The 30-STST score was 3.0 repeats lower for individuals who reported moderate to severe myalgia (P = 0.038). CONCLUSIONS: Individuals with long COVID who report on deconditioning exhibit significantly decreased physical capacity, even following mild acute illness. Risk factors include severe COVID-19 and impaired diffusing capacity or myalgia during recovery.

Vascular endothelial growth factor-A is involved in intramuscular carrageenan-induced cutaneous mechanical hyperalgesia through the vascular endothelial growth factor-A receptor 1 and transient receptor potential vanilloid 1 pathways.

OBJECTIVES: Vascular endothelial growth factor-A (VEGF-A) plays a leading role in angiogenesis and pain hypersensitivity in cancer and chronic pain. It is not only induced by ischemic conditions but is also highly correlated with proalgesic cytokines, both of which are prominent in inflammatory muscle pain. However, the molecular basis of the involvement of VEGF-A in muscle pain remains unknown. METHODS: In the present study, we performed behavioral and pharmacological analyses to determine the possible involvement of VEGF-A in the development of inflammatory muscle pain and the associated signal transduction pathway. RESULTS: Unilateral intramuscular injection of carrageenan, a classical model of inflammatory muscle pain, increased VEGF-A gene expression in the tissues surrounding the injection site. Intramuscular administration of recombinant VEGF-A165 on the same side induced cutaneous mechanical hyperalgesia during the acute and subacute phases. The application of a specific VEGFR1 antibody on the same side significantly reduced the mechanical hyperalgesia induced by carrageenan or VEGF-A165 injection, whereas both a VEGFR2-neutralizing antibody and a VEGFR2 antagonist showed limited effects. Local preinjection of capsazepine, a transient receptor potential vanilloid 1 (TRPV1) antagonist, also inhibited VEGF-A165-induced hyperalgesia. Finally, intramuscular VEGF-A165-induced mechanical hyperalgesia was not found in TRPV1 knockout mice during the subacute phase. CONCLUSIONS: These findings suggest that inflammatory stimuli increase interstitial VEGF-A165, which in turn induces cutaneous mechanical pain via the VEGFR1-mediated TRPV1 nociceptive pathway during inflammatory muscle pain. VEGFR1 could be a novel therapeutic target for inflammation-induced muscle pain.

Dietary Effects on Pain Symptoms in Patients with Fibromyalgia Syndrome: Systematic Review and Future Directions.

Fibromyalgia syndrome (FMS) is recognized for its difficulty to diagnose and its subjective symptomatology. There is neither a known cure nor a recommended therapeutic diet to aid in the multidisciplinary treatment. We conducted a systematic review to investigate if diets can improve pain symptoms of fibromyalgia. Through the PubMed search in March 2022, 126 abstracts were identified. We included both intervention and observational studies of diets and pain symptoms among patients with FMS. After screening titles, abstracts, and full-texts, 12 studies, including 11 intervention and one observational study, were selected. These studies included 546 participants and investigated plant-based diets (n = 3), anti-inflammatory diets (n = 1), gluten-free diets (n = 2), and elimination/restrictive diets (n = 6). These studies assessed pain symptoms through visual analogue scale for pain, fibromyalgia impact questionnaire/revised fibromyalgia impact questionnaire, tender point count, pain pressure threshold, and/or total myalgic score. Nine studies, including all three plant-based diet studies, reported statistically significant beneficial effects of their respective diets on pain symptom measurements. Given the small sample size and short intervention duration of the included studies, limited evidence currently exists to recommend any specific diet to patients with FMS. Further research is warranted to clarify specific diets to recommend and explore their potential mechanisms.

Pain inhibition-the unintended benefit of electrically elicited muscle strengthening contractions.

BACKGROUND: Neuromuscular electrical stimulation (NMES) is effective in muscle strengthening after orthopedic injury particularly when muscle activation failure is present, but the associated pain can be a barrier. Pain itself can produce a pain inhibitory response called Conditioned Pain Modulation (CPM). CPM is often used in research studies to assess the state of the pain processing system. However, the inhibitory response of CPM could make NMES more tolerable to patients and could improve functional outcomes in people with pain. This study compares the pain-inhibitory effect of NMES compared to volitional contractions and noxious electrical stimulation (NxES). METHODS: Healthy participants, 18-30 years of age experienced 3 conditions: 10 NMES contractions, 10 bursts of NxES on the patella, and 10 volitional contractions on the right knee. Pressure pain thresholds (PPT) were measured before and after each condition in both knees and the middle finger. Pain was reported on an 11-point VAS. Repeated measures ANOVAs with 2 factors: site and time were performed for each condition followed by post-hoc paired t-tests, with Bonferroni correction. RESULTS: Pain ratings were higher in the NxES condition compared to NMES (p = .000). No differences in PPTs prior to each condition were observed but PPTs were significantly higher in the right and left knees after the NMES contractions (p = .000, p = .013, respectively) and after the NxES (p = .006, P-.006, respectively). Pain during NMES and NxES did not correlate with pain inhibition (p > .05). Self-reported pain sensitivity correlated with pain during NxES. CONCLUSION: NxES and NMES produced higher PPTs in both knees but not in the finger, suggesting that the mechanisms responsible for the reduction in pain are located in the spinal cord and local tissues. Pain reduction was elicited during the NxES and NMES conditions regardless of the self-reported pain ratings. When NMES is used for muscle strengthening significant pain reduction can also occur, which is an unintended benefit of the intervention that could improve functional outcomes in patients.

Relationships between training load, peak height velocity, muscle soreness and fatigue status in elite-level young soccer players: a competition season study.

BACKGROUND: This study aimed to compare training load parameters, delayed onset muscle soreness (DOMS), and fatigue status between season periods (1st and 2nd halves) in U14 soccer players and to analyze the relationships between training load parameters based on season periods (1st and 2nd halves) with peak height velocity (PHV), DOMS, and fatigue status in under-14 (U14) young elite soccer players. Additionally, it was intended to analyze if fatigue, DOMS and PHV could explain training load parameters across the season. METHODS: Twenty U14 players that competed in the national league participated in this study. The players were monitored during the whole season (26 weeks), and evaluations were carried out at the end of the in-season. Anthropometric and body composition parameters and the maturity offset of each player were utilized to compute each player's age at PHV. Players reported their levels of DOMS and fatigue status using Hooper index questionnaires. The internal load was monitored using the rating of perceived exertion (RPE). Acute weekly internal load (AW), chronic weekly internal load (CW), acute: chronic workload ratio (ACWR), training monotony (TM), and training strain (TS) were also obtained. RESULTS: The main results showed that TM was higher in the 2nd half, while CW, AW and DOMS were higher in the 1st half of the season. Moreover, the main correlations showed a positive correlation between PHV and TS (2nd half of the season) and between fatigue and TM (1st half of the season). CONCLUSION: In conclusion, variations in well-being status and PHV cannot explain the variations in internal training loads in elite U14 soccer players. In addition, internal training load indices during the first half of the competitive season can promote a fundamental base for progression loads during the second period of the competitive season.

Effects of Different Recovery Modalities on Delayed Onset Muscle Soreness, Recovery Perceptions, and Performance Following a Bout of High-Intensity Functional Training.

The purpose of this study was to investigate the effects of the foam rolling technique and static stretching on perceptual and neuromuscular parameters following a bout of high-intensity functional training (HIFT), which consisted of 100 pull-ups, 100 push-ups, 100 sit-ups, and 100 air squats (Angie benchmark) in recreationally trained men (n = 39). Following baseline measurements (Feeling Scale, Visual Analogue Scale, Total Quality Recovery, Sit-and-Reach, Countermovement Jump, and Change-of-Direction t-test), the volunteers performed a single bout of HIFT. At the end of the session, participants were randomly assigned to one of three distinct groups: control (CONT), foam rolling (FR), or static stretching (SS). At the 24 h time-point, a second experimental session was conducted to obtain the post-test values. The level of significance was set at p < 0.05. Regarding power performance, none of the three groups reached pretest levels at 24 h point of the intervention. However, the CONT group still showed a greater magnitude of effect at the 24 h time-point (ES = 0.51, p ≥ 0.05). Flexibility presented the same recovery pattern as power performance (post × 24 h CONT = ES = 0.28, FR = ES = 0.21, SS = ES = 0.19). At 24 h, all groups presented an impaired performance in the COD t-test (CONT = ES = 0.24, FR = ES = 0.65, SS = ES = 0.56 p ≥ 0.05). The FR protocol resulted in superior recovery perceptions (pre × 24 h TQR = ES = 0.32 p ≥ 0.05). The results of the present study indicate that the use of FR and SS exercises may not be indicated when aiming to restore neuromuscular performance following a single bout of HIFT. The use of the FR technique during the cooldown phase of a HIFT session may be helpful in improving an individual's perception of recovery.

Epidemiological Predictors of Positive SARS-CoV-2 Polymerase Chain Reaction Test in Three Cohorts: Hospitalized Patients, Healthcare Workers, and Military Population, Serbia, 2020.

(1) Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its resulting coronavirus disease 2019 (COVID-19) has caused a fast-moving pandemic. Diagnostic testing, aimed to identify patients infected with SARS-CoV-2, plays a key role in controlling the COVID-19 pandemic in different populations. (2) Methods: This retrospective cohort study aimed to investigate predictors associated with positive polymerase chain reaction (PCR) SARS-CoV-2 test results in hospitalized patients, healthcare workers (HCWs), and military personnel (MP) during 2020, before the widespread availability of COVID-19 vaccines. Persons with a positive test result were compared with persons with a negative test result in three cohorts during the study period. (3) Results: A total of 6912 respondents were tested, and 1334 (19.3%) of them had positive PCR SARS-CoV-2 test results. Contact with a known COVID-19 case within 14 days (p < 0.001; OR: 1.48; 95% CI: 1.25-1.76), fever (p < 0.001; OR: 3.66; 95% CI: 3.04-4.41), cough (p < 0.001; OR: 1.91; 95% CI: 1.59-2.30), headache (p = 0.028; OR: 1.24; 95% CI: 1.02-1.50), and myalgia/arthralgia (p < 0.001; OR: 1.99; 95% CI: 1.65-2.42) were independently associated with positive PCR SARS-CoV-2 test results in the cohort of MP. Furthermore, fever (p < 0.001; OR: 2.75; 95% CI: 1.83-4.13), cough (p < 0.001; OR: 2.04; 95% CI: 1.32-3.13), headache (p = 0.008; OR: 1.76; 95% CI: 1.15-2.68), and myalgia/arthralgia (p = 0.039; OR: 1.58; 95% CI: 1.02-2.45) were independently associated with positive PCR SARS-CoV-2 test results in the cohort of HCWs. Moreover, independent predictors of positive PCR SARS-CoV-2 test results in hospitalized patients were contact with a known COVID-19 case within 14 days (p < 0.001; OR: 2.56; 95% CI: 1.71-3.83), fever (p < 0.001; OR: 1.89; 95% CI: 1.38-2.59), pneumonia (p = 0.041; OR: 1.45; 95% CI: 1.01-2.09), and neurological diseases (p = 0.009; OR: 0.375; 95% CI: 0.18-0.78). (4) Conclusions: According to data gathered from cohorts of hospitalized patients, HCWs, and MP, before the widespread availability of COVID-19 vaccines in Serbia, we can conclude that predictors of positive PCR SARS-CoV-2 test results in MP and HCWs were similar. Accurate estimates of COVID-19 in different population groups are important for health authorities.