Xiaoli Zhou

Bio: Xiaoli Zhou is an academic researcher. The author has contributed to research in topics: Antibody & Convalescence. The author has an hindex of 1, co-authored 2 publications receiving 4 citations.

Case Report: A Re-Positive Case of SARS-CoV-2 Associated With Glaucoma.

Abstract: The current pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has already become a global threat to the human population. Infection with SARS-CoV-2 leads to a wide spectrum of clinical manifestations. Ocular abnormalities have been reported in association with COVID-19, but the nature of the impairments was not specified. Here, we report a case of a female patient diagnosed with glaucoma on re-hospitalization for ocular complications two months after being discharged from the hospital upon recovery from COVID-19. Meanwhile, the patient was found re-positive for SARS-CoV-2 in the upper respiratory tract. The infection was also diagnosed in the aqueous humor through immunostaining with antibodies against the N protein and S protein of SARS-CoV-2. Considering the eye is an immune-privileged site, we speculate that SARS-CoV-2 survived in the eye and resulted in the patient testing re-positive for SARS-CoV-2.

Antibody Responses in COVID-19: A Review.

Abstract: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread worldwide as a severe pandemic. Although its seroprevalence is highly variable among territories, it has been reported at around 10%, but higher in health workers. Evidence regarding cross-neutralizing response between SARS-CoV and SARS-CoV-2 is still controversial. However, other previous coronaviruses may interfere with SARS-CoV-2 infection, since they are phylogenetically related and share the same target receptor. Further, the seroconversion of IgM and IgG occurs at around 12 days post onset of symptoms and most patients have neutralizing titers on days 14-20, with great titer variability. Neutralizing antibodies correlate positively with age, male sex, and severity of the disease. Moreover, the use of convalescent plasma has shown controversial results in terms of safety and efficacy, and due to the variable immune response among individuals, measuring antibody titers before transfusion is mostly required. Similarly, cellular immunity seems to be crucial in the resolution of the infection, as SARS-CoV-2-specific CD4+ and CD8+ T cells circulate to some extent in recovered patients. Of note, the duration of the antibody response has not been well established yet.

SARS-CoV-2 antibodies remain detectable 12 months after infection and antibody magnitude is associated with age and COVID-19 severity

Abstract: ImportanceThe persistence of SARS-CoV-2 antibodies may be a predictive correlate of protection for both natural infections and vaccinations. Identifying predictors of robust antibody responses is important to evaluate the risk of re-infection / vaccine failure and may be translatable to vaccine effectiveness. ObjectiveTo 1) determine the durability of anti-SARS-CoV-2 IgG and neutralizing antibodies in subjects who experienced mild and moderate to severe COVID-19, and 2) to evaluate the correlation of age and IgG responses to both endemic human seasonal coronaviruses (HCoVs) and SARS-CoV-2 according to infection outcome. DesignLongitudinal serum samples were collected from PCR-confirmed SARS-CoV-2 positive participants (U.S. active duty service members, dependents and military retirees, including a range of ages and demographics) who sought medical treatment at seven U.S. military hospitals from March 2020 to March 2021 and enrolled in a prospective observational cohort study. ResultsWe observed SARS-CoV-2 seropositivity in 100% of inpatients followed for six months (58/58) to one year (8/8), while we observed seroreversion in 5% (9/192) of outpatients six to ten months after symptom onset, and 18% (2/11) of outpatients followed for one year. Both outpatient and inpatient anti-SARS-CoV-2 binding-IgG responses had a half-life (T1/2) of >1000 days post-symptom onset. The magnitude of neutralizing antibodies (geometric mean titer, inpatients: 378 [246-580, 95% CI] versus outpatients: 83 [59-116, 95% CI]) and durability (inpatients: 65 [43-98, 95% CI] versus outpatients: 33 [26-40, 95% CI]) were associated with COVID-19 severity. Older age was a positive correlate with both higher IgG binding and neutralizing antibody levels when controlling for COVID-19 hospitalization status. We found no significant relationships between HCoV antibody responses and COVID-19 clinical outcomes, or the development of SARS-CoV-2 neutralizing antibodies. Conclusions and RelevanceThis study demonstrates that humoral responses to SARS-CoV-2 infection are robust on longer time-scales, including those arising from milder infections. However, the magnitude and durability of the antibody response after natural infection was lower and more variable in younger participants who did not require hospitalization for COVID-19. These findings support vaccination against SARS-CoV-2 in all suitable populations including those individuals that have recovered from natural infection.

A review on the induction of host immunity by the current COVID-19 vaccines and a brief non-pharmaceutical intervention to mitigate the pandemic

Abstract: To mitigate the current COVID-19 pandemic by the severe acute respiratory coronavirus 2 (SARS-CoV-2), designing of repurposed antiviral drugs and the development of vaccines using different platforms have been the most significant work by the scientists around the world since the beginning of 2020.While positive results are being noticed with the currently used vaccines, the emerging variants of SARS-CoV-2 as well as the second wave of COVID-19 pandemic put the global public health in the deadliest health issue. Present review attempted to focus on the development of the current COVID-19 situation in the light of knowledge gathered from the recently published literature. An important facet regarding the COVID-19 severity is the avoidance of host immunity by the SARS-CoV-2 and its variants. Indeed, the genetic similarities between SARS-CoV-2, SARS-CoV-1 and the Middle East respiratory syndrome coronavirus (MERS-CoV) showed the viral escape strategies of the protective host immunity which appeared as the major problem for the effective vaccine development.Present review discussed the prescribed platforms of vaccine development and pondered on the cellular and humoral immune responses by vaccines; and apart from vaccination approaches, non-pharmaceutical intervention approaches have also been pondered based on modeling rules.

A review on the induction of host immunity by the current COVID-19 vaccines and a brief non-pharmaceutical intervention to mitigate the pandemic

Abstract: To mitigate the current COVID-19 pandemic by the severe acute respiratory coronavirus 2 (SARS-CoV-2), designing of repurposed antiviral drugs and the development of vaccines using different platforms have been the most significant work by the scientists around the world since the beginning of 2020.While positive results are being noticed with the currently used vaccines, the emerging variants of SARS-CoV-2 as well as the second wave of COVID-19 pandemic put the global public health in the deadliest health issue. Present review attempted to focus on the development of the current COVID-19 situation in the light of knowledge gathered from the recently published literature. An important facet regarding the COVID-19 severity is the avoidance of host immunity by the SARS-CoV-2 and its variants. Indeed, the genetic similarities between SARS-CoV-2, SARS-CoV-1 and the Middle East respiratory syndrome coronavirus (MERS-CoV) showed the viral escape strategies of the protective host immunity which appeared as the major problem for the effective vaccine development.Present review discussed the prescribed platforms of vaccine development and pondered on the cellular and humoral immune responses by vaccines; and apart from vaccination approaches, non-pharmaceutical intervention approaches have also been pondered based on modeling rules.