Tag: covid vaccine

Impact of COVID-19 vaccination on symptoms and immune phenotypes in vaccine-naïve individuals with Long COVID

Abstract:

Background Long COVID contributes to the global burden of disease. Proposed root cause hypotheses include the persistence of SARS-CoV-2 viral reservoir, autoimmunity, and reactivation of latent herpesviruses. Patients have reported various changes in Long COVID symptoms after COVID-19 vaccinations, leaving uncertainty about whether vaccine-induced immune responses may alleviate or worsen disease pathology.

Methods In this prospective study, we evaluated changes in symptoms and immune responses after COVID-19 vaccination in 16 vaccine-naïve individuals with Long COVID. Surveys were administered before vaccination and then at 2, 6, and 12 weeks after receiving the first vaccine dose of the primary series. Simultaneously, SARS-CoV-2-reactive TCR enrichment, SARS-CoV-2-specific antibody responses, antibody responses to other viral and self-antigens, and circulating cytokines were quantified before vaccination and at 6 and 12 weeks after vaccination.

Results Self-report at 12 weeks post-vaccination indicated 10 out of 16 participants had improved health, 3 had no change, 1 had worse health, and 2 reported marginal changes. Significant elevation in SARS-CoV-2-specific TCRs and Spike protein-specific IgG were observed 6 and 12 weeks after vaccination. No changes in reactivities were observed against herpes viruses and self-antigens. Within this dataset, higher baseline sIL-6R was associated with symptom improvement, and the two top features associated with non-improvement were high IFN-β and CNTF, among soluble analytes.

Conclusions Our study showed that in this small sample, vaccination improved the health or resulted in no change to the health of most participants, though few experienced worsening. Vaccination was associated with increased SARS-CoV-2 Spike protein-specific IgG and T cell expansion in most individuals with Long COVID. Symptom improvement was observed in those with baseline elevated sIL-6R, while elevated interferon and neuropeptide levels were associated with a lack of improvement.

Plain language summary The impact of the COVID-19 vaccine on vaccine-naïve individuals suffering from Long COVID is uncertain. This study assessed the experience and immune signatures of 16 unvaccinated participants with Long COVID. A total of 10 participants had improved health status after vaccination, and one person reported only worsening health. As expected, vaccination increased immune cells and antibodies against the viral spike protein. Immune signatures may prove to be predictors of health status after vaccination. However, given the small number of participants, these initial findings need further validation.

Source: Connor B Grady, Bornali Bhattacharjee, Julio Silva, Jillian Jaycox, Lik Wee Lee, Valter Silva Monteiro, Mitsuaki Sawano, Daisy Massey, César Caraballo, Jeff R. Gehlhausen, Alexandra Tabachnikova, Tianyang Mao, Carolina Lucas, Mario A. Peña-Hernandez, Lan Xu, Tiffany J. Tzeng, Takehiro Takahashi, Jeph Herrin, Diana Berrent Güthe, Athena Akrami, Gina Assaf, Hannah Davis, Karen Harris, Lisa McCorkell, Wade L Schulz, Daniel Grffin, Hannah Wei, Aaron M Ring, Leying Guan, Charles Dela Cruz, Akiko Iwasaki, Harlan M Krumholz. Impact of COVID-19 vaccination on symptoms and immune phenotypes in vaccine-naïve individuals with Long COVID. medRxiv 2024.01.11.24300929; doi: https://doi.org/10.1101/2024.01.11.24300929. https://www.medrxiv.org/content/10.1101/2024.01.11.24300929v1.full-text (Full text)

Characteristics of long COVID and the impact of COVID-19 vaccination on long COVID 2 years following COVID-19 infection: prospective cohort study

Abstract:

This prospective cohort study aimed to identify characteristics of long COVID and any potential mitigating effects of COVID-19 vaccinations in patients 24 months following COVID-19 infection. Adult patients diagnosed with COVID-19 between February 17, 2020, and March 24, 2020, were scheduled to visit the study hospital four times (6, 12, 18, and 24 months after infection) to assess their symptoms, quality of life, and mental health. Among the 235 patients, 121 (51.5%) completed the study visits. Of these, 59.5% were female, with a median age of 52 years. Mild to moderate disease severity were identified in 101 (83.4%) patients.

A total of 75 participants (62.0%) were still experiencing long COVID symptoms 24 months after acute infection. Fatigue, amnesia, difficulty concentrating, and insomnia were the most common symptoms. The frequency of neuropsychiatric symptoms did not differ based on vaccination status or the number of doses received. Quality of life improved over time for the participants, but 32.2% of respondents still reported anxiety/depression at the end of the study. Overall, our cohort demonstrates that long COVID can persist up to 24 months after COVID-19 infection, affecting mental health and quality of life.

Source: Kim, Y., Bae, S., Chang, HH. et al. Characteristics of long COVID and the impact of COVID-19 vaccination on long COVID 2 years following COVID-19 infection: prospective cohort study. Sci Rep 14, 854 (2024). https://doi.org/10.1038/s41598-023-50024-4 https://www.nature.com/articles/s41598-023-50024-4 (Full text)

The effectiveness of COVID-19 vaccines to prevent long COVID symptoms: staggered cohort study of data from the UK, Spain, and Estonia

Summary:

Background: Although vaccines have proved effective to prevent severe COVID-19, their effect on preventing long-term symptoms is not yet fully understood. We aimed to evaluate the overall effect of vaccination to prevent long COVID symptoms and assess comparative effectiveness of the most used vaccines (ChAdOx1 and BNT162b2).

Methods: We conducted a staggered cohort study using primary care records from the UK (Clinical Practice Research Datalink [CPRD] GOLD and AURUM), Catalonia, Spain (Information System for Research in Primary Care [SIDIAP]), and national health insurance claims from Estonia (CORIVA database). All adults who were registered for at least 180 days as of Jan 4, 2021 (the UK), Feb 20, 2021 (Spain), and Jan 28, 2021 (Estonia) comprised the source population. Vaccination status was used as a time-varying exposure, staggered by vaccine rollout period. Vaccinated people were further classified by vaccine brand according to their first dose received. The primary outcome definition of long COVID was defined as having at least one of 25 WHO-listed symptoms between 90 and 365 days after the date of a PCR-positive test or clinical diagnosis of COVID-19, with no history of that symptom 180 days before SARS-Cov-2 infection. Propensity score overlap weighting was applied separately for each cohort to minimise confounding. Sub-distribution hazard ratios (sHRs) were calculated to estimate vaccine effectiveness against long COVID, and empirically calibrated using negative control outcomes. Random effects meta-analyses across staggered cohorts were conducted to pool overall effect estimates.

Findings: A total of 1 618 395 (CPRD GOLD), 5 729 800 (CPRD AURUM), 2 744 821 (SIDIAP), and 77 603 (CORIVA) vaccinated people and 1 640 371 (CPRD GOLD), 5 860 564 (CPRD AURUM), 2 588 518 (SIDIAP), and 302 267 (CORIVA) unvaccinated people were included. Compared with unvaccinated people, overall HRs for long COVID symptoms in people vaccinated with a first dose of any COVID-19 vaccine were 0·54 (95% CI 0·44–0·67) in CPRD GOLD, 0·48 (0·34–0·68) in CPRD AURUM, 0·71 (0·55–0·91) in SIDIAP, and 0·59 (0·40–0·87) in CORIVA. A slightly stronger preventative effect was seen for the first dose of BNT162b2 than for ChAdOx1 (sHR 0·85 [0·60–1·20] in CPRD GOLD and 0·84 [0·74–0·94] in CPRD AURUM).

Interpretation: Vaccination against COVID-19 consistently reduced the risk of long COVID symptoms, which highlights the importance of vaccination to prevent persistent COVID-19 symptoms, particularly in adults.

Source: Martí Català, Núria Mercadé-Besora, Raivo Kolde,Nhung T H Trinh,Elena Roel,Edward Burn, Trishna Rathod-Mistry, Kristin Kostka, Wai Yi Man, Antonella Delmestri, Hedvig M E Nordeng, Anneli Uusküla, Talita Duarte-Salles, Daniel Prieto-Alhambra, Annika M Jödicke. The effectiveness of COVID-19 vaccines to prevent long COVID symptoms: staggered cohort study of data from the UK, Spain, and Estonia. The Lancet Respiratory Medicine. Published:January 11, 2024 ,DOI: https://doi.org/10.1016/S2213-2600(23)00414-9  https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(23)00414-9/fulltext (Full text)

Mechanisms of long COVID: An updated review

Abstract:

The coronavirus disease 2019 (COVID-19) pandemic has been ongoing for more than 3 years, with an enormous impact on global health and economies. In some patients, symptoms and signs may remain after recovery from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which cannot be explained by an alternate diagnosis; this condition has been defined as long COVID.

Long COVID may exist in patients with both mild and severe disease and is prevalent after infection with different SARS-CoV-2 variants. The most common symptoms include fatigue, dyspnea, and other symptoms involving multiple organs. Vaccination results in lower rates of long COVID. To date, the mechanisms of long COVID remain unclear. In this narrative review, we summarized the clinical presentations and current evidence regarding the pathogenesis of long COVID.

Source: Yan Liu, Xiaoying Gu, Haibo Li, Hui Zhang, Jiuyang Xu. Mechanisms of long COVID: An updated review. Chinese Medical Journal Pulmonary and Critical Care Medicine, Volume 1, Issue 4, December 2023, Pages 231-240. https://www.sciencedirect.com/science/article/pii/S2772558823000580 (Full text)

COVID-19 mRNA Vaccination Reduces the Occurrence of Post-COVID Conditions in U.S. Children Aged 5-17 Years Following Omicron SARS-CoV-2 Infection, July 2021-September 2022

Abstract:

Background An estimated 1-3% of children with SARS-CoV-2 infection will develop Post-COVID Conditions (PCC). This study evaluates mRNA COVID-19 vaccine impact on likelihood of PCC in children.
Methods A multi-site cohort of children enrolled 7/21/2021-9/1/2022 underwent weekly SARS-CoV-2 screening tests and were surveyed via self- or parental report 12/1/2022-5/31/2023 regarding PCC (defined as ≥1 new or on-going symptoms lasting ≥ 1 month after infection). Multivariable logistic regression was performed to estimate the occurrence of PCC by vaccination status among children aged 5–17 years whose first PCR-confirmed SARS-CoV-2 infection occurred in-study with Omicron variant, who completed the survey >60 days from infection, and who were vaccine age-eligible at time of infection per ACIP recommendations. Vaccination status was categorized as vaccinated (at least primary series completed >14 days before infection) and unvaccinated (no vaccine doses before infection). Vaccination status was verified through vaccine registry and/or medical records.
Results Of 622 participants surveyed, 5% (n=28) had PCC (Table 1) and 67% (n=474) were vaccinated (Table 2). Surveys were completed a median (IQR) of 203.7 days (119.0–293.0) after infection. Children with non-Hispanic Black race/ethnicity and good/fair/poor self-rated baseline health were more likely to report PCC. Children aged 12-18 years, Non-Hispanic Asian and White children, those reporting symptomatic SARS-CoV-2 infection, and those with excellent/very good self-rated baseline health were more likely to report vaccination When comparing children with and without PCC symptoms, COVID-19 mRNA vaccination was associated with a decreased likelihood of >1 PCC symptom (aOR 0.66, 95% CI 0.43-0.99), >2 PCC symptoms (aOR 0.52, 95% 0.32-0.83), and respiratory PCC symptoms (aOR 0.53, 95% CI 0.33-0.87) (Table 3).
Conclusion In this study, mRNA COVID-19 vaccination appeared to be protective against PCC in children following Omicron SARS-CoV-2 infection. The adjusted ORs correspond to an estimated 34%, 48%, and 47% reduced likelihood of >1, >2, and respiratory PCC symptoms among vaccinated children, respectively. These findings support COVID-19 vaccination for children and may encourage increased pediatric vaccine uptake.
Source: Anna R Yousaf, Josephine Mak, Lisa Gwynn, Robin Bloodworth, Ramona Rai, Zuha Jeddy, Lindsay B LeClair, Laura Edwards, Lauren E W Olsho, Gabriella Newes-Adeyi, Alexandra F Dalton, Manjusha Gaglani, Sarang K Yoon, Kurt Hegmann, Katherine Ellingson, Leora R Feldstein, Angela P Campbell, Amadea Britton, Sharon Saydah, 1935. COVID-19 mRNA Vaccination Reduces the Occurrence of Post-COVID Conditions in U.S. Children Aged 5-17 Years Following Omicron SARS-CoV-2 Infection, July 2021-September 2022, Open Forum Infectious Diseases, Volume 10, Issue Supplement_2, December 2023, ofad500.2466, https://doi.org/10.1093/ofid/ofad500.2466 https://academic.oup.com/ofid/article/10/Supplement_2/ofad500.2466/7448254 (Full text available as PDF file)

A synbiotic preparation (SIM01) for post-acute COVID-19 syndrome in Hong Kong (RECOVERY): a randomised, double-blind, placebo-controlled trial

Abstract:

Background: Post-acute COVID-19 syndrome (PACS) affects over 65 million individuals worldwide but treatment options are scarce. We aimed to assess a synbiotic preparation (SIM01) for the alleviation of PACS symptoms.

Methods: In this randomised, double-blind, placebo-controlled trial at a tertiary referral centre in Hong Kong, patients with PACS according to the US Centers for Disease Control and Prevention criteria were randomly assigned (1:1) by random permuted blocks to receive SIM01 (10 billion colony-forming units in sachets twice daily) or placebo orally for 6 months. Inclusion criterion was the presence of at least one of 14 PACS symptoms for 4 weeks or more after confirmed SARS-CoV-2 infection, including fatigue, memory loss, difficulty in concentration, insomnia, mood disturbance, hair loss, shortness of breath, coughing, inability to exercise, chest pain, muscle pain, joint pain, gastrointestinal upset, or general unwellness. Individuals were excluded if they were immunocompromised, were pregnant or breastfeeding, were unable to receive oral fluids, or if they had received gastrointestinal surgery in the 30 days before randomisation. Participants, care providers, and investigators were masked to group assignment. The primary outcome was alleviation of PACS symptoms by 6 months, assessed by an interviewer-administered 14-item questionnaire in the intention-to-treat population. Forward stepwise multivariable logistical regression was performed to identify predictors of symptom alleviation. The trial is registered with ClinicalTrials.gov, NCT04950803.

Findings: Between June 25, 2021, and Aug 12, 2022, 463 patients were randomly assigned to receive SIM01 (n=232) or placebo (n=231). At 6 months, significantly higher proportions of the SIM01 group had alleviation of fatigue (OR 2·273, 95% CI 1·520-3·397, p=0·0001), memory loss (1·967, 1·271-3·044, p=0·0024), difficulty in concentration (2·644, 1·687-4·143, p<0·0001), gastrointestinal upset (1·995, 1·304-3·051, p=0·0014), and general unwellness (2·360, 1·428-3·900, p=0·0008) compared with the placebo group. Adverse event rates were similar between groups during treatment (SIM01 22 [10%] of 232 vs placebo 25 [11%] of 231; p=0·63). Treatment with SIM01, infection with omicron variants, vaccination before COVID-19, and mild acute COVID-19, were predictors of symptom alleviation (p<0·0036).

Interpretation: Treatment with SIM01 alleviates multiple symptoms of PACS. Our findings have implications on the management of PACS through gut microbiome modulation. Further studies are warranted to explore the beneficial effects of SIM01 in other chronic or post-infection conditions.

Source: Lau RI, Su Q, Lau ISF, Ching JYL, Wong MCS, Lau LHS, Tun HM, Mok CKP, Chau SWH, Tse YK, Cheung CP, Li MKT, Yeung GTY, Cheong PK, Chan FKL, Ng SC. A synbiotic preparation (SIM01) for post-acute COVID-19 syndrome in Hong Kong (RECOVERY): a randomised, double-blind, placebo-controlled trial. Lancet Infect Dis. 2023 Dec 7:S1473-3099(23)00685-0. doi: 10.1016/S1473-3099(23)00685-0. Epub ahead of print. PMID: 38071990. https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(23)00685-0/fulltext (Full text)

Chronic Fatigue and Dysautonomia following COVID-19 Vaccination Is Distinguished from Normal Vaccination Response by Altered Blood Markers

Abstract:

SARS-CoV-2 mRNA vaccination can entail chronic fatigue/dysautonomia tentatively termed post-acute COVID-19 vaccination syndrome (PACVS). We explored receptor autoantibodies and interleukin-6 (IL-6) as somatic correlates of PACVS. Blood markers determined before and six months after first-time SARS-CoV-2 vaccination of healthy controls (N = 89; 71 females; mean/median age: 39/49 years) were compared with corresponding values of PACVS-affected persons (N = 191; 159 females; mean/median age: 40/39 years) exhibiting chronic fatigue/dysautonomia (≥three symptoms for ≥five months after the last SARS-CoV-2 mRNA vaccination) not due to SARS-CoV-2 infection and/or confounding diseases/medications.

Normal vaccination response encompassed decreases in 11 receptor antibodies (by 25-50%, p < 0.0001), increases in two receptor antibodies (by 15-25%, p < 0.0001) and normal IL-6. In PACVS, serological vaccination-response appeared significantly (p < 0.0001) altered, allowing discrimination from normal post-vaccination state (sensitivity = 90%, p < 0.0001) by increased Angiotensin II type 1 receptor antibodies (cut-off ≤ 10.7 U/mL, ROC-AUC = 0.824 ± 0.027), decreased alpha-2B adrenergic receptor antibodies (cut-off ≥ 25.2 U/mL, ROC-AUC = 0.828 ± 0.025) and increased IL-6 (cut-off ≤ 2.3 pg/mL, ROC-AUC = 0.850 ± 0.022). PACVS is thus indicated as a somatic syndrome delineated/detectable by diagnostic blood markers.

Source: Semmler A, Mundorf AK, Kuechler AS, Schulze-Bosse K, Heidecke H, Schulze-Forster K, Schott M, Uhrberg M, Weinhold S, Lackner KJ, Pawlitzki M, Meuth SG, Boege F, Ruhrländer J. Chronic Fatigue and Dysautonomia following COVID-19 Vaccination Is Distinguished from Normal Vaccination Response by Altered Blood Markers. Vaccines (Basel). 2023 Oct 26;11(11):1642. doi: 10.3390/vaccines11111642. PMID: 38005974. https://www.mdpi.com/2076-393X/11/11/1642 (Full text)

Post-Vaccination Syndrome: A Descriptive Analysis of Reported Symptoms and Patient Experiences After Covid-19 Immunization

Abstract:

Introduction: A chronic post-vaccination syndrome (PVS) after covid-19 vaccination has been reported but has yet to be well characterized.

Methods: We included 241 individuals aged 18 and older who self-reported PVS after covid-19 vaccination and who joined the online Yale Listen to Immune, Symptom and Treatment Experiences Now (LISTEN) Study from May 2022 to July 2023. We summarized their demographics, health status, symptoms, treatments tried, and overall experience.

Results: The median age of participants was 46 years (interquartile range [IQR]: 38 to 56), with 192 (80%) identifying as female, 209 (87%) as non-Hispanic White, and 211 (88%) from the United States. Among these participants with PVS, 127 (55%) had received the BNT162b2 [Pfizer-BioNTech] vaccine, and 86 (37%) received the mRNA-1273 [Moderna] vaccine. The median time from the day of index vaccination to symptom onset was three days (IQR: 1 day to 8 days). The time from vaccination to symptom survey completion was 595 days (IQR: 417 to 661 days). The median Euro-QoL visual analogue scale score was 50 (IQR: 39 to 70). The five most common symptoms were exercise intolerance (71%), excessive fatigue (69%), numbness (63%), brain fog (63%), and neuropathy (63%). In the week before survey completion, participants reported feeling unease (93%), fearfulness (82%), and overwhelmed by worries (81%), as well as feelings of helplessness (80%), anxiety (76%), depression (76%), hopelessness (72%), and worthlessness (49%) at least once. Participants reported a median of 20 (IQR: 13 to 30) interventions to treat their condition.

Conclusions: In this study, individuals who reported PVS after covid-19 vaccination had low health status, high symptom burden, and high psychosocial stress despite trying many treatments. There is a need for continued investigation to understand and treat this condition.

Source: Harlan M Krumholz, Yilun Wu, Mitsuaki Sawano, Rishi Shah, Tianna Zhou, Adith S Arun, Pavan Khosla, Shayaan Kaleem, Anushree Vashist, Bornali Bhattacharjee, Qinglan Ding, Yuan Lu, Cesar Caraballo, Frederick Warner, Chenxi Huang, Jeph Herrin, David Putrino, Danice Hertz, Brianne Dressen, Akiko Iwasaki. Post-Vaccination Syndrome: A Descriptive Analysis of Reported Symptoms and Patient Experiences After Covid-19 Immunization. medRxiv 2023.11.09.23298266; doi: https://doi.org/10.1101/2023.11.09.23298266 https://www.medrxiv.org/content/10.1101/2023.11.09.23298266v1 (Full text available as PDF file)

The long-term health outcomes, pathophysiological mechanisms and multidisciplinary management of long COVID

Abstract:

There have been hundreds of millions of cases of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the growing population of recovered patients, it is crucial to understand the long-term consequences of the disease and management strategies.

Although COVID-19 was initially considered an acute respiratory illness, recent evidence suggests that manifestations including but not limited to those of the cardiovascular, respiratory, neuropsychiatric, gastrointestinal, reproductive, and musculoskeletal systems may persist long after the acute phase. These persistent manifestations, also referred to as long COVID, could impact all patients with COVID-19 across the full spectrum of illness severity.

Herein, we comprehensively review the current literature on long COVID, highlighting its epidemiological understanding, the impact of vaccinations, organ-specific sequelae, pathophysiological mechanisms, and multidisciplinary management strategies. In addition, the impact of psychological and psychosomatic factors is also underscored.

Despite these crucial findings on long COVID, the current diagnostic and therapeutic strategies based on previous experience and pilot studies remain inadequate, and well-designed clinical trials should be prioritized to validate existing hypotheses. Thus, we propose the primary challenges concerning biological knowledge gaps and efficient remedies as well as discuss the corresponding recommendations.

Source: Li, J., Zhou, Y., Ma, J. et al. The long-term health outcomes, pathophysiological mechanisms and multidisciplinary management of long COVID. Sig Transduct Target Ther 8, 416 (2023). https://doi.org/10.1038/s41392-023-01640-z https://www.nature.com/articles/s41392-023-01640-z (Full text)

SARS-CoV-2 spike antigen-specific B cell and antibody responses in pre-vaccination period COVID-19 convalescent males and females with or without post-covid condition

Abstract:

Background: Following SARS-CoV-2 infection a significant proportion of convalescent individuals develop the post-COVID condition (PCC) that is characterized by wide spectrum of symptoms encompassing various organs. Even though the underlying pathophysiology of PCC is not known, detection of viral transcripts and antigens in tissues other than lungs raise the possibility that PCC may be a consequence of aberrant immune response to the viral antigens. To test this hypothesis, we evaluated B cell and antibody responses to the SARS-CoV-2 antigens in PCC patients who experienced mild COVID-19 disease during the pre-vaccination period of COVID-19 pandemic.

Methods: The study subjects included unvaccinated male and female subjects who developed PCC or not (No-PCC) after clearing RT-PCR confirmed mild COVID-19 infection. SARS-CoV-2 D614G and omicron RBD specific B cell subsets in peripheral circulation were assessed by flow cytometry. IgG, IgG3 and IgA antibody titers toward RBD, spike and nucleocapsid antigens in the plasma were evaluated by ELISA.

Results: The frequency of the B cells specific to D614G-RBD were comparable in convalescent groups with and without PCC in both males and females. Notably, in females with PCC, the anti-D614G RBD specific double negative (IgD–CD27–) B cells showed significant correlation with the number of symptoms at acute of infection. Anti-spike antibody responses were also higher at 3 months post-infection in females who developed PCC, but not in the male PCC group. On the other hand, the male PCC group also showed consistently high anti-RBD IgG responses compared to all other groups.

Conclusions: The antibody responses to the spike protein, but not the anti-RBD B cell responses diverge between convalescent males and females who develop PCC. Our findings also suggest that sex-related factors may also be involved in the development of PCC via modulating antibody responses to the SARS-CoV-2 antigens.

Source: Limoges MA, Quenum AJI, Chowdhury MMH, Rexhepi F, Namvarpour M, Akbari SA, Rioux-Perreault C, Nandi M, Lucier JF, Lemaire-Paquette S, Premkumar L, Durocher Y, Cantin A, Lévesque S, Dionne IJ, Menendez A, Ilangumaran S, Allard-Chamard H, Piché A, Ramanathan S. SARS-CoV-2 spike antigen-specific B cell and antibody responses in pre-vaccination period COVID-19 convalescent males and females with or without post-covid condition. Front Immunol. 2023 Sep 21;14:1223936. doi: 10.3389/fimmu.2023.1223936. PMID: 37809081; PMCID: PMC10551145. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10551145/ (Full text)