Can mild COVID-19 infection represent the entire Clinical Spectrum of COVID-19?

Autoantibodies to interferon alpha, nuclear antigens, cardiolipin, and beta 2 glycoprotein 1 in a Ugandan cohort and their relation to SARS-CoV-2 infection

OBJECTIVE

Autoantibodies (AAbs) to interferon alpha, nuclear antigens, cardiolipin, and beta 2 glycoprotein 1, have been associated with COVID-19 severity. Despite relatively low COVID-19 morbidity and mortality in East and Central Africa, AAb prevalence in these populations remain understudied.

METHODS

We evaluated AAb seroprevalence in 155 Ugandans, aged 40-50, using paired samples collected before and after the onset of the COVID-19 pandemic. Among these, 117 had serological evidence of SARS-CoV-2 infection, and 38 did not. To assess the effect of SARS-CoV-2 infection on AAb prevalence, we: 1) longitudinally compared AAb prevalence before and after evidence of infection, and 2) cross-sectionally compared AAb prevalence between those with and without infection evidence at both timepoints. Associations between AAbs and health characteristics were also explored.

RESULTS

There was no difference in AAb prevalence between individuals with and without evidence of infection, nor any longitudinal change after evidence of infection. However, we observed a higher-than-expected prevalence anti-beta 2 glycoprotein 1. Additionally, anti-cardiolipin was significantly associated with reported hypertension.

CONCLUSIONS

Our findings contribute to the limited literature on AAb prevalence in East Africa and suggest that SARS-CoV-2 does not induce these AAbs.

Hybrid and vaccination immunity against severe COVID-19 in the post-pandemic era-a retrospective cohort study

OBJECTIVES

As COVID-19 has transitioned to an endemic disease, there is a need for evidence-based effective strategies to mitigate its public health impacts. This study aims to evaluate the protection offered by vaccination and hybrid immunity, particularly among the elderly, against severe disease by considering their immunological history and individual characteristics.

METHODS

In a retrospective cohort study, data from the Israeli Ministry of Health (May 2022-April 2024) were analysed, including 1.2 million individuals aged 60 years and older who received at least three COVID-19 vaccine doses. Participants were categorized into two groups: those with hybrid immunity and those with vaccination and without documented previous infection. Poisson regression models, adjusted for age, sex, wave period, and time since the last immunological event, were used to estimate the risk of severe COVID-19.

RESULTS

Individuals without documented previous infection are 14.4 (95% CI, 13.2-15.7) times more at risk compared with those with hybrid immunity. Those aged 70-80 and 80+ are 3.7 (95% CI, 3.0-4.5) and 11.3 (95% CI, 9.3-13.7) times more at risk, respectively, than those aged 60-64. Males are at 1.6 (95% CI, 1.5-1.7) times higher risk than females. There is a substantial decrease over time in severe cases. Waning immunity is observed in the 3-6 months cohort, which is 1.8 (95% CI, 1.5-2.2) times more likely to develop severe disease than the 0-3 months cohort. No further waning immunity was observed after that.

DISCUSSION

At this post-pandemic stage, individuals with hybrid immunity had a significantly lower risk of severe disease. These findings support the prioritization of protection strategies for individuals without hybrid immunity and suggest that protection remains durable for at least one year.