Cases Of Reinfection Research Articles

1978. Vaccine effect on household transmission of omicron and delta SARS-CoV-2 variants in South Korea

Abstract Background We aimed to evaluate household secondary attack rate (SAR) of SARS-CoV-2 variants, omicron and delta, based on index case and contact vaccination status, and antibody level effect of vaccinated index cases on household transmission. Methods A prospective study of 92 index cases and 197 quarantined household contacts was performed. Tests for SARS-CoV-2 variant type and antibody level were conducted in index cases, and results of PCR tests (during the quarantine period) were collected from contacts. Association of antibody levels in vaccinated index cases and SAR was evaluated by multivariate regression analysis. To evaluate the association between antibody levels in vaccinated index cases and household transmission, the probability of transmission was calculated using the logistic regression model. We refit the model for the probability of transmission using the variables that could affect the household transmission (meal with index, contact with index case ≥5/day, respiratory symptoms and immunocompromised status of index patients, and vaccination status of contacts). For this analysis, only vaccinated index cases who tested antibody levels within 7 days of symptom onset or diagnosis, whichever was earlier, were included. Figure 1. Study flow chart A total of 187 SARS-CoV-2 patients were recruited for this study. Of those, 155 patients and 262 of their household members were eligible for inclusion. After excluding unknown primary and reinfection cases, 77 household contacts of 41 index cases with delta variant infection and 120 household contacts of 51 index cases with omicron variant infection were included. Figure 2.The link between index cases and household contacts based on their vaccination status The link between index cases and household contacts according to their vaccination status is shown in Figure. A total of 40, 27, and 10 contacts were linked with 20 unvaccinated index cases, 14 booster-unvaccinated index cases, and 7 booster-vaccinated index cases with delta variant infection, respectively. Among the contacts of index cases with omicron variant infection, 20, 65, and 35 contacts were exposed to 7 unvaccinated, 25 booster-unvaccinated, and 9 booster-vaccinated index cases, respectively. Results SAR was higher in households exposed to omicron variant than those exposed to delta variant. SAR was 35% and 23% for unvaccinated and vaccinated delta variant exposed contacts, respectively. SAR was 44% and 41% for unvaccinated and vaccinated omicron exposed contacts, respectively. Booster dose immunisation of contacts or vaccination of index cases reduced SAR of vaccinated omicron variant exposed contacts. In a model with adjustment, anti-receptor binding domain antibody levels in vaccinated index cases were inversely correlated with household transmission of both delta and omicron variants. Neutralising antibody levels had a similar relationship. When we performed sensitivity analyses using 3 day and 5 day thresholds for the period of antibody test, the results did not differ from the main analyses. Table 1.The secondary attack rate among household contacts of index cases with delta and omicron variant infections according to vaccination status of contactsSAR, secondary attack rate; CI, confidence interval*P-value was calculated using the Fisher’s Exact Test.Table 2.The secondary attack rate according to vaccination status of household contacts linked to that of index casesSAR, secondary attack rate; CI, confidence intervalFigure 3.The association of antibody levels in vaccinated index cases and household transmission. In a model with adjustment for factors that could affect the household transmission, the estimated probabilities of SARS-CoV-2 infection among 132 contacts according to the level of anti-RBD antibodies (A) and neutralising antibodies (B) of 62 index cases. Serum samples for antibody tests were collected within 7 days of symptom onset or diagnosis, whichever was earlier, in vaccinated index cases. Shaded areas indicate 95% confidence intervals. RBD, receptor-binding domain Conclusion Despite of decreased vaccine effectiveness on the transmission of the omicron variant in households, we suggest that enhancing the immunity of all household members through vaccination may help mitigate the current pandemic. Disclosures All Authors: No reported disclosures.

1876. COVID-19 Reinfection and Disease Severity in the New York City Health + Hospitals System

Abstract Background Though reinfection with SARS-CoV-2 is well documented, there remains uncertainty about the potential for more severe symptoms with reinfections compared to index infections. Methods Patients who received SARS-CoV-2 PCR testing between March 1, 2020 and March 1, 2021 at New York City Health and Hospitals (NYC H+H) facilities and had two positive tests > =90 days apart were included in the analysis. Clinical and demographic data were extracted from the electronic medical record. Manual chart review was done to confirm symptomatology, assess COVID-19 related hospital admissions, and determine WHO disease severity. Patients were then classified as unlikely reinfection, possible reinfection, or probable reinfection based on symptomatology, PCR and antibody testing, and lack of alternative diagnoses. Patients were classified as “unable to be assessed” if symptomatology could not be assessed for both episodes of PCR positivity. Figure 1:Flow chart of selection process for study inclusionFigure 2:Reinfection Classification Results During our study timeframe, 1,255,584 unique patients received at least one SARS-CoV-2 PCR test, 265 of whom had two positive tests > =90 days apart. We categorized 20 patients as unable to be assessed, 28 as unlikely reinfection (1 persistent PCR positivity, 27 unlikely true infection at index or second PCR-positive episode), and 217 as possible or probable reinfection. Of the 217, at their index episode 79 had an asymptomatic infection (36.4%) and 17 were severe or critical (7.8%). At their second episode, 162 patients had an asymptomatic infection (74.7%), and 5 were severe or critical (2.3%). Only 24 patients with possible/probable reinfection had a more severe COVID reinfection than index infection, and 20 of the 24 had asymptomatic index infections. Three patients were hospitalized at both episodes, and two deaths possibly attributable to COVID-19 reinfection were noted in this cohort. Figure 3:Change in WHO disease severity classification from index to second infection among probable/possible reinfection cases (n=217) Red indicates increase in disease severity from index to reinfection (n=24), blue indicates decrease in disease severity from index to reinfection (n=100), white indicates no change (n=74) and gray indicates unable to assess disease severity at index or second infection (n=19). Conclusion COVID-19 reinfection was rare in a high incidence setting among patients tested at NYC H+H facilities. Disease severity was generally milder in reinfection, although severe and critical disease occurred in a small number of patients. These findings from earlier in the pandemic (presumably wild-type and alpha variant) provide data for comparison in understanding how reinfection is evolving with newer variants. Disclosures Carlos Salama, MD, Genentech: Advisor/Consultant Gabriel Cohen, MD, Daybreak Health: Advisor/Consultant|Daybreak Health: Board Member|Daybreak Health: Ownership Interest.

1527. Use of a SARS-CoV-2 Strand-specific Assay to detect Relapse or Ongoing Infection at a Tertiary Care Center, California 2020–2022

Abstract Background Determining if a patient with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains infectious can be challenging in patients with severe disease or those profoundly immunosuppressed. We use an assay that detects minus-strand RNA as a surrogate for actively replicating SARS-CoV-2. Here, we describe a cohort of patients who had strand-assay reversion: a detectable minus strand-specific assay after having had an undetectable value which may signify relapse of infection or reinfection. Methods We used a 2-step rRT-PCR specific to the minus strand of the SARS-CoV-2 envelope gene. The strand-specific assay is used to evaluate for infectivity in asymptomatic patients with a positive screening admission or pre-procedural test or in cases when ongoing infection was suspected (critical illness or profound immunosuppression). We collected minus strand-specific assays performed at Stanford Healthcare during August 2020–April 2022. We describe basic demographics and clinical characteristics for patients who reverted from undetectable to detectable using the minus strand-specific assay. Results A total of 2,505 strand-specific tests were collected from August 2020–April 2022 from 2,064 patients. A total of 292 (14%) had two or more strand-specific tests. Of them, 19 (7%) had an undetected minus strand-specific assay followed by a subsequent detectable value. Of them, seven (37%) had a minus strand-specific CT value of < 33. Most were male (n=4), median age was 54 (range: 8–62). All were profoundly immunosuppressed: Four had hematologic malignancies and three were post transplantation (kidney, lung, bone marrow). Median time from onset of symptoms or first positive test to reversion was 41 days (range:27–159). Median time from undetectable to detectable minus strand specific test was 26 days (range:4–34). All cases were considered relapses or ongoing infection rather than a new infection. Conclusion Among patients with SARS-CoV-2 infection and consecutive strand-specific testing, a small proportion reverted from negative to positive. Most were profoundly immunosuppressed. The strand-specific assay can be an important tool in the evaluation of suspected cases of relapse or reinfection. Disclosures Aruna Subramanian, MD, Gilead Sciences: Grant/Research Support|Regeneron, Inc: Grant/Research Support.

Risk of SARS-CoV-2 reinfection: a systematic review and meta-analysis

This meta-analysis aims to synthesize global evidence on the risk of reinfection among people previously infected with SARS-CoV-2. We systematically searched PubMed, Scopus, Embase and Web of Science as of April 5, 2021. We conducted: (1) meta-analysis of cohort studies containing data sufficient for calculating the incidence rate of SARS-CoV-2 reinfection; (2) systematic review of case reports with confirmed SARS-CoV-2 reinfection cases. The reinfection incidence was pooled by zero-inflated beta distribution. The hazard ratio (HR) between reinfection incidence among previously infected individuals and new infection incidence among infection-naïve individuals was calculated using random-effects models. Of 906 records retrieved and reviewed, 11 studies and 11 case reports were included in the meta-analysis and the systematic review, respectively. The pooled SARS-CoV-2 reinfection incidence rate was 0.70 (standard deviation [SD] 0.33) per 10,000 person-days. The incidence of reinfection was lower than the incidence of new infection (HR = 0.12, 95% confidence interval 0.09–0.17). Our meta-analysis of studies conducted prior to the emergency of the more transmissible Omicron variant showed that people with a prior SARS-CoV-2 infection could be re-infected, and they have a lower risk of infection than those without prior infection. Continuing reviews are needed as the reinfection risk may change due to the rapid evolution of SARS-CoV-2 variants.

Evidence of SARS-CoV-2 reinfection: analysis of 35,000 subjects and overview of systematic reviews.

BackgroundReinfection by SARS-CoV-2 is a rare but possible event. We evaluated the prevalence of reinfections in the Province of Modena and performed an overview of systematic reviews to summarize the current knowledge. MethodsWe applied big data analysis and retrospectively analysed the results of oro- or naso-pharyngeal swab results tested for molecular research of viral RNA of SARS-CoV-2 between 1 January 2021 and 30 June 2021 at a single center. We selected individuals with samples sequence of positive, negative and then positive results. Between first and second positive result we considered a time interval of 90 days to be sure of a reinfection. We also performed a search for and evaluation of systematic reviews reporting SARS-CoV-2 reinfection rates. Main information was collected and the methodological quality of each review was assessed, according to A Measurement Tool to Assess systematic Reviews (AMSTAR).ResultsInitial positive results were revealed in more than 35,000 (20%) subjects; most (28%) were aged 30–49 years old. Reinfection was reported in 1,258 (3.5%); most (33%) were aged 30–49 years old. Reinfection rates according to vaccinated or non-vaccinated subjects were 0.6% vs 1.1% (p < 0.0001). Nine systematic reviews were identified and confirmed that SARS-CoV-2 reinfection rate is a rare event. AMSTAR revealed very low-moderate levels of quality among selected systematic reviews.ConclusionsThere is a real, albeit rare risk of SARS-CoV-2 reinfection. Big data analysis enabled accurate estimates of the reinfection rates. Nevertheless, a standardized approach to identify and report reinfection cases should be developed.

Genetic pattern of the COVID-19 course and reinfection

A new coronavirus infection (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) broke out at the end of 2019 in Wuhan (China). The disease has become a global pandemic and claimed more than 6 million lives after spreading rapidly around the world. Issues related to the complicated course of COVID-19 mechanisms continue to be the subject of active study. It is known that morbidity and mortality increase dramatically with increasing age and concomitant diseases, including obesity, diabetes, cancer, and cardiovascular diseases. Although most infected people recover, even young and otherwise healthy patients can get sick with this disease. In this regard, an urgent task is to search for specific genetic factors that can explain the predisposition of people to infection and the development of a severe COVID-19 form. Human genetic determinants can provide the scientific basis for disease prediction and the development of personalized therapies to counteract the epidemic. In addition, cases of repeated infection with SARS-CoV-2 are increasingly being registered, which occurs 16 months after initial infection on average and depends on the virus genome structure. Studies conducted on sequencing viral genomes have shown that some patients were re-infected with the same strain of coronavirus, while others were different. This, in turn, causes researchers concerns about the effectiveness of immunity after infection and vaccine reliability. The genetic characteristics of a person and a virus commonly determine the tendency for reinfection. It is difficult to determine the true COVID-19 reinfection prevalence, which is explained by the low detectability of asymptomatic reinfection and the fact that many patients with a mild course of the disease were not tested at an early stage of the pandemic. Therefore, the true prevalence of reinfection with COVID-19 does not reflect the current reality. There are many more cases of reinfection than are described in the literature. In this regard, the true contribution of a virus genetic features to reinfection of COVID-19 can be determined only after population studies, and when developing immunization programs against a COVID-19, it is necessary to take into account the prevalence of reinfection in the population.

Cryopreserved human heart valve allografts: a ten-year single centre experience.

This study provides an overview of tissue banking activities at the Croatian Cardiovascular Tissue Bank (CTB) during past ten years and presents the outcomes of cryopreserved heart valve allografts (CHAs) use in different patient groups. From June 2011 until December 2021, 75 heart donations were referred to CTB: 41 recipient of heart transplant (RHT), 32 donors after brain death (DBD) and 2 donors after circulatory death (DCD) donations. Processing resulted in 103 valves of which 65 met quality requirements for clinical use. Overall tissue discard rate was 37%. The most frequent reasons for discard were inadequate morphology (12%) in RHT donations and microbiological contamination (19%) in DBD donations. Altogether, 38 CHAs were transplanted to 36 patients. Recipients were divided in three groups; infective endocarditis (IE), non-infectious heart disease and congenital heart disease group. In the IE group, the 30-day, 1-year and 3-year survival was 71%, 53% and 47%, respectively. Freedom from re-operation due to all graft-related causes was 76% and due to structural valve deterioration 88%. There were no cases of graft reinfection. In the congenital heart disease group CHAs were predominantly (94%) used for right ventricular outflow tract reconstruction and 88% of patients recovered without graft-related complications. At present, the number of demands for CHAs at CTB considerably outweighs their availability.

Milder outcomes of SARS-CoV-2 genetically confirmed reinfections compared to primary infections with the delta variant: A retrospective case-control study.

BackgroundSARS-CoV-2 infection does not confer long immunity. However, studies suggest that prior infection is associated with lower risk of reinfection and milder outcomes of recurrent infections. The aims of this retrospective observational case-control study were to describe the clinical and molecular characteristics of genetically confirmed Delta reinfection cases and to assess the potential protective role of preceding infection on the severity of reinfection.MethodsWe used next generation sequencing (NGS) to explore if cases with two positive real time RT-PCR tests > 90 days apart were infected with a different SARS-CoV-2 variant. Cases with confirmed reinfection between August 1st and October 31st, 2021 (the Delta wave) in Slovenia were matched 1:4 by age, sex and timeframe (week of positive test) with individuals with primary infection. Sociodemographic and epidemiologic data, vaccination status, and data on hospitalization and outcome of infection were retrieved from several centralized and standardized national databases. Additional epidemiologic surveys were performed on a limited number of cases and controls.ResultsWe identified 628 cases of genetically confirmed reinfection during the study period and matched them with 2,512 control subjects with Delta primary infection. Primary infections in individuals with reinfection were mainly caused by B.1.258.17 (51.1%), followed by B.1.1.7 (15.1%) and reinfection was detected on average 271 days after primary infection (range 101–477 days). Our results show a substantially lower probability of hospitalization in cases with reinfection compared with controls (OR: 0.21, p = 0.017), but no significant difference was observed in intensive care unit admission and deaths. We observed a significantly lower proportion of vaccinated individuals among cases compared to controls (4.5% vs. 28.2%), suggesting that hybrid immunity leads to lower probability of reinfection. Detailed analysis of the temporal distribution of variants, responsible for reinfections, showed no significant differences in reinfection potential.ConclusionReinfection with the SARS-CoV-2 Delta variant resulted in fewer hospitalizations compared to the primary Delta infection, suggesting that primary infection may, to some extent, produce at least short lasting protective immunity. This study provides additional insight into the reinfection dynamics that may allow appropriate public health measures to be taken in subsequent waves of the COVID-19 pandemic.

SARS-CoV-2 reinfections with BA.1 (Omicron) variant among fully vaccinated individuals in northeastern Brazil.

BackgroundThe first case of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in Rio Grande do Norte, northeastern Brazil, was diagnosed on March 12, 2020; thereafter, multiple surges of infection occurred, similar to what was seen elsewhere. These surges were mostly due to SARS-CoV-2 mutations leading to emergence of variants of concern (VoC). The introduction of new VoCs in a population previously exposed to SARS-CoV-2 or after vaccination has been a challenge to understanding the kinetics of the protective immune response against this virus. The aim of this study was to investigate the outbreak of SARS-CoV-2 reinfections observed in mid-January 2022 in Rio Grande do Norte state, Brazil. It describes the clinical and genomic characteristics of nine cases of reinfection that occurred coincident with the introduction of the omicron variant.Methodology/Principal findingsOf a total of 172,965 individuals with upper respiratory symptoms tested for SARS-CoV-2, between March 2020 through mid-February 2022, 58,097 tested positive. Of those, 444 had documented a second SARS-CoV-2 infection and nine reinfection cases were selected for sequencing. Genomic analysis revealed that virus lineages diverged between primary infections and the reinfections, with the latter caused by the Omicron (BA.1) variant among individuals fully vaccinated against SARS-CoV-2.Conclusions/SignificanceOur findings suggest that the Omicron variant is able to evade both natural and vaccine-induced immunity, since all nine cases had prior natural infection and, in addition, were fully vaccinated, emphasizing the need to develop effective blocking vaccines.

Pan-coronavirus fusion inhibitors to combat COVID-19 and other emerging coronavirus infectious diseases.

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the causative agent of the currently ongoing coronavirus disease 2019 (COVID‐19) pandemic, has posed a serious threat to global public health. Recently, several SARS‐CoV‐2 variants of concern (VOCs) have emerged and caused numerous cases of reinfection in convalescent COVID‐19 patients, as well as breakthrough infections in vaccinated individuals. This calls for the development of broad‐spectrum antiviral drugs to combat SARS‐CoV‐2 and its VOCs. Pan‐coronavirus fusion inhibitors, targeting the conserved heptad repeat 1 (HR1) in spike protein S2 subunit, can broadly and potently inhibit infection of SARS‐CoV‐2 and its variants, as well as other human coronaviruses. In this review, we summarized the most recent development of pan‐coronavirus fusion inhibitors, such as EK1, EK1C4, and EKL1C, and highlighted their potential application in combating current COVID‐19 infection and reinfection, as well as future emerging coronavirus infectious diseases.

Reporting of COVID-19 Reinfection and Potential Role of Immunosuppressant/Immunomodulating Agents: A Cross-Sectional Observational Analysis Based on a Spontaneous Reporting Database.

BackgroundThe enduring presence of COVID-19 and subsequent increasing incidence of COVID-19 reinfection has prompted evaluation of associated risk factors, particularly the role of immunosuppression.ObjectiveThe objective of this study was to characterize cases indicative of COVID-19 reinfection with respect to their reported use of immunosuppressant/immunomodulating agents.MethodsThis cross-sectional observational study leveraged the Pfizer global safety database (SDB) containing adverse event data collected in association with use of Pfizer products between 1 October 2019, and 30 June 2022. Selected Medical Dictionary for Drug Regulatory Activities (MedDRA®) Preferred Terms were used to identify COVID-19 cases; the search was further refined to comprise cases that subsequently reported events potentially indicative of COVID-19 reinfection.ResultsOf the cumulative total of 218,242 COVID-19 cases reported into the SDB, 4590 cases (2.1%) involving potential COVID-19 reinfection were identified. Of these 4590 cases of potential Covid-19 reinfection, a total of 134 cases reported COVID-19 specifically during treatment with pharmaceutical products, of which approximately 16% (21/134) of cases reported use of immunosuppressant/immunomodulating agents. Likewise, in the overall dataset (213,652 cases; excluding the 4590 cases involving potential COVID-19 recurrence), the percentage of reported immunosuppressant/immunomodulating agents was low (12%). In applying similar parameters to a dataset that excludes COVID-19 vaccine cases, 18% of cases reported use of immunosuppressant/immunomodulating agents (similar to the aforementioned 16% of cases reported from the overall total dataset that was inclusive of vaccine cases).ConclusionThis pharmacovigilance study provides a characterization of cases indicative of COVID-19 reinfection with respect to reported use of immunosuppressant/immunomodulating agents. The observations generated from this cross-sectional observational analysis may prompt further research into the role of immunosuppression in COVID-19 reinfection, in an effort to better inform clinical practice and patient management.

Significant Rise in SARS-CoV-2 Reinfection Rate in Vaccinated Hospital Workers during the Omicron Wave: A Prospective Cohort Study.

Relatively low SARS-CoV-2 reinfection rates have been reported in vaccinated individuals, but updates considering the Omicron variant are lacking. The objective of the study was to provide a current estimate of the SARS-CoV-2 reinfection rate in a highly immunized population. A prospective cohort of Mexican hospital workers was followed (March 2020-February 2022). Reinfection was defined as the occurrence of two or more episodes of COVID-19 separated by a period of ≥ 90 days without symptoms. The reinfection rate was calculated as the number of reinfection episodes per 100,000 persons per day. A total of 3732 medical consultations were provided to 2700 workers, of whom 1388 (51.4%) were confirmed COVID-19 cases. A total of 73 reinfection cases were identified, of whom 71 (97.3%) had completed their primary vaccination series and 22 (30.1%) had had a booster dose before the second episode. The overall reinfection rate was 23.1 per 100,000 persons per day (as compared to a rate of 1.9 per 100,000 persons per day before the Omicron wave). The SARS-CoV-2 reinfection rate rose significantly during the Omicron wave despite a high primary vaccination coverage rate. Almost one-third of reinfected workers had a vaccine booster ≥ 14 days before the last COVID-19 episode.

Occurrence of SARS-CoV-2 reinfections at regular intervals in Ecuador.

SARS-CoV-2 reinfection is defined as a new infection with a different virus variant in an individual who has already recovered from a previous episode of COVID-19. The first case of reinfection in the world was described in August 2020, since then, reinfections have increased over time and their incidence has fluctuated with specific SARS-CoV-2 variant waves. Initially, reinfections were estimated to represent less than 1% of total COVID-19 infections. With the advent of the Omicron variant, reinfections became more frequent, representing up to 10% of cases (based on data from developed countries). The frequency of reinfections in Latin America has been scarcely reported. The current study shows that in Ecuador, the frequency of reinfections has increased 10-fold following the introduction of Omicron, after 22 months of surveillance in a single center of COVID-19 diagnostics. Suspected reinfections were identified retrospectively from a database of RT-qPCR-positive patients. Cases were confirmed by sequencing viral genomes from the first and second infections using the ONT MinION platform. Monthly surveillance showed that the main incidence peaks of reinfections were reached within four to five months, coinciding with the increase of COVID-19 cases in the country, suggesting that the emergence of reinfections is related to higher exposure to the virus during outbreaks. This study performed the longest monitoring of SARS-CoV-2 reinfections, showing an occurrence at regular intervals of 4-5 months and confirming a greater propensity of Omicron to cause reinfections.

Antibody correlates of protection from SARS-CoV-2 reinfection prior to vaccination: A nested case-control within the SIREN study

ObjectivesTo investigate serological differences between SARS-CoV-2 reinfection cases and contemporary controls, to identify antibody correlates of protection against reinfection.MethodsWe performed a case-control study, comparing reinfection cases with singly infected individuals pre-vaccination, matched by gender, age, region and timing of first infection. Serum samples were tested for anti-SARS-CoV-2 spike (anti-S), anti-SARS-CoV-2 nucleocapsid (anti-N), live virus microneutralisation (LV-N) and pseudovirus microneutralisation (PV-N). Results were analysed using fixed effect linear regression and fitted into conditional logistic regression models.ResultsWe identified 23 cases and 92 controls. First infections occurred before November 2020; reinfections occurred before February 2021, pre-vaccination. Anti-S levels, LV-N and PV-N titres were significantly lower among cases; no difference was found for anti-N levels. Increasing anti-S levels were associated with reduced risk of reinfection (OR 0·63, CI 0·47-0·85), but no association for anti-N levels (OR 0·88, CI 0·73-1·05). Titres >40 were correlated with protection against reinfection for LV-N Wuhan (OR 0·02, CI 0·001–0·31) and LV-N Alpha (OR 0·07, CI 0·009–0·62). For PV-N, titres >100 were associated with protection against Wuhan (OR 0·14, CI 0·03–0·64) and Alpha (0·06, CI 0·008–0·40).ConclusionsBefore vaccination, protection against SARS-CoV-2 reinfection was directly correlated with anti-S levels, PV-N and LV-N titres, but not with anti-N levels. Detectable LV-N titres were sufficient for protection, whilst PV-N titres >100 were required for a protective effect.Trial registration numberISRCTN11041050

Diagnostic significance of lactate dehydrogenase in measles virus reinfection cases.

Lactate dehydrogenase (LDH) levels in measles virus (MeV) reinfection cases for the diagnosis of measles have not been extensively studied. Thus, we evaluated the significance of serum LDH in the immune response of patients with MeV reinfection in comparison with those of patients with primary infection. Among 70 patients who tested positive for MeV-RNA, 42 with high MeV-specific IgG avidity (HA) were suspected as cases of reinfection and 28 with low MeV-specific IgG (LA) were suspected as cases of primary infection. The viral loads in the HA group were also lower than those in the LA group (P < 0.001). The titers of MeV-specific IgM and IgG in the HA group were significantly lower and higher, respectively, than those in the LA group (P < 0.001). The total LDH and LDH isozyme levels were elevated in the LA group compared with those in the HA group (P < 0.001). Through receiver operating characteristic curve analyses, we determined that the area under the curve of total LDH level was 0.87 (95% CI 0.74-1.00) and that the discriminatory accuracy was high for total LDH and all isozymes. By stepwise binary logistic regression analysis considering MeV-specific IgG avidity, we developed a model using IgG, IgM, and total LDH as explanatory variables, which was optimal for distinguishing the LA and HA groups (adjusted R2 = 0.773, P < 0.001). Thus, the serum LDH level in addition to IgM and IgG may be useful parameters for differentiating MeV reinfection from primary infection.

Characteristics of a case-series of COVID-19 reinfection and its trend from 2020 to June 2022 in a general medicine office in Toledo, Spain

Background: Longitudinal data on SARS-CoV-2 re-infection are scarce. Objectives: 1) Characterize COVID-19 reinfection cases clinically and epidemiologically; 2) Determine whether the risk of SARS-CoV-2 reinfection has altered over time in the context of the development of beta, delta, and omicron variants.Methods: From March 1, 2020 to July 1, 2022, an observational, longitudinal, and prospective investigation of Covid-19 re-infections was done in a general medical practice in Toledo, Spain.Results: There were 43 cases in total, including 45 reinfections (2 cases presented 2 reinfections). The average period between first infection and reinfection was 346 days (range: 95-813 days). The average age was 41 years (range: 17-70 years). 5% were over the age of 65. 56% were female. 14% belonged to an ethnic minority. 82% of reinfections occurred among individuals who had been vaccinated (19%, 28%, and 35% in those who had received one dose, two doses, and a booster, respectively). They were symptomatic in 96% of the cases. All cases of reinfection were minor, with nonspecific symptoms (discomfort, asthenia, myalgia, fever, arthralgia) predominating (39%). Chronic illnesses were present in 60% of reinfection cases, with the Genitourinary (19%), Endocrine (17%), and Respiratory (16%) systems predominately. Reinfections have been steadily growing since 2020, with 67% occurring in 2022.Conclusion: We discovered evidence of a continual increase in the incidence of reinfections in Toledo, Spain, primarily beginning in January 2022, which is temporally congruent with the introduction of the omicron variety, indicating its improved ability to infect previously infected persons.

SARS-Cov-2: From Indian to Omicron New Variants: Descriptive Minireview

A new type of coronavirus called BA.5 is causing a stir because it is more evolved than other Omicron variants. However, BA.5 strategically circumvents the accumulated defenses against previous versions of the virus. All this means that cases of reinfection are on the rise, including among newly vaccinated and infected people. The most common symptoms of the original Omicron strain include runny nose, sneezing and sore throat. Headache, muscle aches, coughing, sneezing, high temperature, pressure in the ears and face, and loss of taste and smell, especially in vaccinated persons. Diarrhea and anorexia are likely linked to Covid-19, but the two lists of symptoms are nearly identical. , now seems to be lurking everywhere and infecting everyone, whether they already have a vaccine, have booster shots, or have a recent bout of COVID-19. “If you have BA.1, you are not adequately protected against BA.4/5”.The purpose of this short descriptive review in General Is to To shed light on the occurrence and implications of various mutations in SARS-CoV-2 to date.

Analysis of COVID-19 Incidence and Severity Among Adults Vaccinated With 2-Dose mRNA COVID-19 or Inactivated SARS-CoV-2 Vaccines With and Without Boosters in Singapore

Assessing booster effectiveness of COVID-19 mRNA vaccine and inactivated SARS-CoV-2 vaccine over longer time intervals and in response to any further SARS-CoV-2 variants is crucial in determining optimal COVID-19 vaccination strategies. To determine levels of protection against severe COVID-19 and confirmed SARS-CoV-2 infection by types and combinations of vaccine boosters in Singapore during the Omicron wave. This cohort study included Singapore residents aged 30 years or more vaccinated with either at least 2 doses of mRNA COVID-19 vaccines (ie, Pfizer-BioNTech BNT162b2 or Moderna mRNA-1273) or inactivated SARS-CoV-2 vaccines (Sinovac CoronaVac or Sinopharm BBIBP-CorV) as of March 10, 2022. Individuals with a known SARS-CoV-2 infection prior to December 27, 2021, an infection on or before the date of their second vaccine dose, or with reinfection cases were excluded. Two or 3 doses of Pfizer-BioNTech BNT162b2, Moderna mRNA-1273, Sinovac CoronaVac, or Sinopharm BBIBP-CorV. Notified infections from December 27, 2021, to March 10, 2022, adjusted for age, sex, race, housing status, and calendar days. Estimated booster effectiveness, defined as the relative incidence-rate reduction of severe disease (supplemental oxygen, intensive care, or death) or confirmed infection following 3-dose vaccination compared with 5 months after second mRNA dose, was determined using binomial regression. Among 2 441 581 eligible individuals (1 279 047 [52.4%] women, 846 110 (34.7%) aged 60 years and older), there were 319 943 (13.1%) confirmed SARS-CoV-2 infections, of which 1513 (0.4%) were severe COVID-19 cases. mRNA booster effectiveness against confirmed infection 15 to 60 days after boosting was estimated to range from 31.7% to 41.3% for the 4 boosting combinations (homologous BNT162b2, homologous mRNA-1273, 2-dose BNT162b2/mRNA-1273 booster, and 2-dose mRNA-1273/BNT162b2 booster). Five months and more after boosting, estimated booster effectiveness against confirmed infection waned, ranging from -2.8% to 14.6%. Against severe COVID-19, estimated mRNA booster effectiveness was 87.4% (95% CI, 83.3%-90.5%) 15 to 60 days after boosting and 87.2% (95% CI, 84.2%-89.7%) 5 to 6 months after boosting, with no significant difference comparing vaccine combinations. Booster effectiveness against severe COVID-19 15 days to 330 days after 3-dose inactivated COVID-19 vaccination, regardless of combination, was estimated to be 69.6% (95% CI, 48.7%-81.9%). Booster mRNA vaccine protection against severe COVID-19 was estimated to be durable over 6 months. Three-dose inactivated SARS-CoV-2 vaccination provided greater protection than 2-dose but weaker protection compared with 3-dose mRNA.

Burden of sexually transmitted infections from acute HIV infection among women in South Africa: Evidence from a prospective cohort study

PurposeHIV and other sexually transmitted infections (STIs) often co-occur. However, less evidence exists on the long-term STI dynamics among persons living with HIV in sub-Saharan Africa to inform interventions. We investigated the incidence, prevalence and factors associated with STIs, starting from acute HIV infection in a cohort of South African women. MethodsThe CAPRISA002 study enrolled women with acute HIV infection and performed STI testing and treatment 1-2 times annually from 2004-2020. We estimated STI incidence, re-infection, and prevalence trends before and after antiretroviral treatment (ART). We fitted Cox regression models to identify factors associated with STIs. ResultsWe followed up 235 women (median age = 25 years, IQR 22-29) for 7.5 years (IQR 5.7-10.8). New STI and re-infection cases per 100 person-years (PYs) were 5.1 and 9.5 for Neisseria gonorrhoeae (NG), 7.4 and 14.7 for Chlamydia trachomatis (CT), 8.0 and 26.6 for Trichomonas vaginalis (TV), 7.7 and 16.7 for Mycoplasma genitalium (MG) and 25.2 and 37.3 for any STI. STI incidence, was associated with HIV log10 viral load (AHR = 1.24, 95% CI 1.06-1.44), active syphilis (AHR = 16.55, 95% CI 7.49-36.55), a positive HSV-2 PCR (AHR = 1.54, 95% CI 1.01-2.35), bacterial vaginosis (AHR = 1.48, 95% CI 1.01-2.18), recent regular sexual partners at enrolment (one vs none: AHR = 2.62, 95% CI 1.41-4.87; two plus vs none: AHR = 3.68, 95% CI 1.79-7.59) and age (5-year fold: AHR = 0.80, 95% CI 0.70-0.92). ConclusionThe persistent STI/HIV co-infection burden among South African women highlights that early HIV diagnosis and ART initiation needs to be combined with better STI care for women and their partners to prevent HIV and STI transmission.

Epidemiological assessment of SARS-CoV-2 reinfection

ObjectivesSARS-CoV-2 vaccination has been shown to reduce infection severity; however, the reinfection frequency among unvaccinated, partially vaccinated, and fully vaccinated individuals remains unclear. This study aims to elucidate the rates of and factors associated with such occurrences. MethodsThis retrospective epidemiological report included 1362 COVID-19 reinfection cases in Bahrain between April 2020 and July 2021. We analyzed differences in disease severity and reinfection characteristics among various vaccination statuses: fully vaccinated, interrupted vaccination, one-dose vaccination, postreinfection vaccination, and unvaccinated. ResultsReinfection cases increased from zero per month in April-June 2020 to a sharp peak of 579 in May 2021. A significantly larger proportion of reinfected individuals were male (60.3%, P <0.0001). Reinfection episodes were highest among those 30-39 years of age (29.7%). The fewest reinfection episodes occurred at 3-6 months after the first infection (20.6%) and most occurred ≥9 months after the initial infection (46.4%). Most individuals were asymptomatic during both episodes (35.7%). Reinfection disease severity was mild, with vaccinated patients less likely to have symptomatic reinfection (odds ratio 0.71, P = 0.004). Only 6.6% of reinfected patients required hospitalization. One death was recorded; the patient belonged to the unvaccinated group. ConclusionVaccine-induced immunity and previous infection with or without vaccination were effective in reducing reinfection disease severity.