Major Update 2: Antibody Response and Risk for Reinfection After SARS-CoV-2 Infection-Final Update of a Living, Rapid Review.

BACKGROUND: The durability of the antibody response after SARS-CoV-2 infection and the role of antibodies in protection against reinfection are unclear. PURPOSE: To synthesize evidence on the SARS-CoV-2 antibody response and reinfection risk with a focus on gaps identified in our prior reports. DATA SOURCES: MEDLINE (Ovid), EMBASE, CINAHL, World Health Organization Research Database, and reference lists from 16 December 2021 through 8 July 2022, with surveillance through 22 August 2022. STUDY SELECTION: English-language, cohort studies evaluating IgG antibody duration at least 12 months after SARS-CoV-2 infection, the antibody response among immunocompromised adults, predictors of nonseroconversion, and reinfection risk. DATA EXTRACTION: Two investigators sequentially extracted study data and rated quality. DATA SYNTHESIS: Most adults had IgG antibodies after SARS-CoV-2 infection at time points greater than 12 months (low strength of evidence [SoE]). Although most immunocompromised adults develop antibodies, the overall proportion with antibodies is lower compared with immunocompetent adults (moderate SoE for organ transplant patients and low SoE for patients with cancer or HIV). Prior infection provided substantial, sustained protection against symptomatic reinfection with the Delta variant (high SoE) and reduced the risk for severe disease due to Omicron variants (moderate SoE). Prior infection was less protective against reinfection with Omicron overall (moderate SoE), but protection from earlier variants waned rapidly (low SoE). LIMITATION: Single review for abstract screening and sequential review for study selection, data abstraction, and quality assessment. CONCLUSION: Evidence for a sustained antibody response to SARS-CoV-2 infection is considerable for both Delta and Omicron variants. Prior infection protected against reinfection with both variants, but, for Omicron, protection was weaker and waned rapidly. This information may have limited clinical applicability as new variants emerge. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality. (PROSPERO: CRD42020207098).

Complexity and Challenges of the Clinical Diagnosis and Management of Long COVID.

Importance: There is increasing recognition of the long-term health effects of SARS-CoV-2 infection (sometimes called long COVID). However, little is yet known about the clinical diagnosis and management of long COVID within health systems. Objective: To describe dominant themes pertaining to the clinical diagnosis and management of long COVID in the electronic health records (EHRs) of patients with a diagnostic code for this condition (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] code U09.9). Design, Setting, and Participants: This qualitative analysis used data from EHRs of a national random sample of 200 patients receiving care in the Department of Veterans Affairs (VA) with documentation of a positive result on a polymerase chain reaction (PCR) test for SARS-CoV-2 between February 27, 2020, and December 31, 2021, and an ICD-10 diagnostic code for long COVID between October 1, 2021, when the code was implemented, and March 1, 2022. Data were analyzed from February 5 to May 31, 2022. Main Outcomes and Measures: A text word search and qualitative analysis of patients' VA-wide EHRs was performed to identify dominant themes pertaining to the clinical diagnosis and management of long COVID. Results: In this qualitative analysis of documentation in the VA-wide EHR, the mean (SD) age of the 200 sampled patients at the time of their first positive PCR test result for SARS-CoV-2 in VA records was 60 (14.5) years. The sample included 173 (86.5%) men; 45 individuals (22.5%) were identified as Black and 136 individuals (68.0%) were identified as White. In qualitative analysis of documentation pertaining to long COVID in patients' EHRs 2 dominant themes were identified: (1) clinical uncertainty, in that it was often unclear whether particular symptoms could be attributed to long COVID, given the medical complexity and functional limitations of many patients and absence of specific markers for this condition, which could lead to ongoing monitoring, diagnostic testing, and specialist referral; and (2) care fragmentation, describing how post-COVID-19 care processes were often siloed from and poorly coordinated with other aspects of care and could be burdensome to patients. Conclusions and Relevance: This qualitative study of documentation in the VA EHR highlights the complexity of diagnosing long COVID in clinical settings and the challenges of caring for patients who have or are suspected of having this condition.

Risk for Reinfection After SARS-CoV-2: A Living, Rapid Review for American College of Physicians Practice Points on the Role of the Antibody Response in Conferring Immunity Following SARS-CoV-2 Infection.

BACKGROUND: The strength and duration of immunity from infection with SARS-CoV-2 are important for public health planning and clinical practice. PURPOSE: To synthesize evidence on protection against reinfection after SARS-CoV-2 infection. DATA SOURCES: MEDLINE (Ovid), the World Health Organization global literature database, ClinicalTrials.gov, COVID19reviews.org, and reference lists. STUDY SELECTION: Longitudinal studies that compared the risk for reinfection after SARS-CoV-2 infection versus infection risk in individuals with no prior infection. DATA EXTRACTION: Two investigators sequentially extracted study data and rated quality. DATA SYNTHESIS: Across 18 eligible studies, reinfection risk ranged from 0% to 2.2%. In persons with recent SARS-CoV-2 infection compared with unvaccinated, previously uninfected individuals, 80% to 98% of symptomatic infections with wild-type or Alpha variants were prevented (high strength of evidence). In the meta-analysis, previous infection reduced risk for reinfection by 87% (95% CI, 84% to 90%), equaling 4.3 fewer infections per 100 persons in both the general population (risk difference, -0.043 [CI, -0.071 to -0.015]) and health care workers (risk difference, -0.043 [CI, -0.069 to -0.016]), and 26.6 fewer infections per 100 persons in care facilities (risk difference, -0.266 [CI, -0.449 to -0.083]). Protection remained above 80% for at least 7 months, but no study followed patients after the emergence of the Delta or Omicron variant. Results for the elderly were conflicting. LIMITATION: Methods to ascertain and diagnose infections varied. CONCLUSION: Before the emergence of the Delta and Omicron variants, persons with recent infection had strong protection against symptomatic reinfections for 7 months compared with unvaccinated, previously uninfected individuals. Protection in immunocompromised persons, racial and ethnic subgroups, and asymptomatic index case patients is unclear. The durability of protection in the setting of the Delta and Omicron variants is unknown. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality. (PROSPERO: CRD42020207098).

Antibody Response After SARS-CoV-2 Infection and Implications for Immunity : A Rapid Living Review.

BACKGROUND: The clinical significance of the antibody response after SARS-CoV-2 infection remains unclear. PURPOSE: To synthesize evidence on the prevalence, levels, and durability of detectable antibodies after SARS-CoV-2 infection and whether antibodies to SARS-CoV-2 confer natural immunity. DATA SOURCES: MEDLINE (Ovid), Embase, CINAHL, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, World Health Organization global literature database, and Covid19reviews.org from 1 January through 15 December 2020, limited to peer-reviewed publications available in English. STUDY SELECTION: Primary studies characterizing the prevalence, levels, and duration of antibodies in adults with SARS-CoV-2 infection confirmed by reverse transcriptase polymerase chain reaction (RT-PCR); reinfection incidence; and unintended consequences of antibody testing. DATA EXTRACTION: Two investigators sequentially extracted study data and rated quality. DATA SYNTHESIS: Moderate-strength evidence suggests that most adults develop detectable levels of IgM and IgG antibodies after infection with SARS-CoV-2 and that IgG levels peak approximately 25 days after symptom onset and may remain detectable for at least 120 days. Moderate-strength evidence suggests that IgM levels peak at approximately 20 days and then decline. Low-strength evidence suggests that most adults generate neutralizing antibodies, which may persist for several months like IgG. Low-strength evidence also suggests that older age, greater disease severity, and presence of symptoms may be associated with higher antibody levels. Some adults do not develop antibodies after SARS-CoV-2 infection for reasons that are unclear. LIMITATIONS: Most studies were small and had methodological limitations; studies used immunoassays of variable accuracy. CONCLUSION: Most adults with SARS-CoV-2 infection confirmed by RT-PCR develop antibodies. Levels of IgM peak early in the disease course and then decline, whereas IgG peaks later and may remain detectable for at least 120 days. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality. (PROSPERO: CRD42020207098).