SARS-CoV-2: Booster doses of key importance for cirrhotic patients

After 2 mRNA vaccine doses against SARS-CoV-2, cirrhotic patients showed significantly reduced T-cell reactivity compared with healthy controls but this was accompanied by lower levels of serum IgG antibodies against the receptor-binding domain of the spike protein. Fortunately, the latter markedly increased after a booster vaccine compared with the second dose and even more following a natural infection.

A previously published meta-analysis showed that patients with liver cirrhosis have an elevated risk for adverse outcomes after a SARS-CoV-2 infection and have a markedly elevated COVID-19-related mortality [1]. Dr Samer Al-Dury (Sahlgrenska University Hospital, Sweden) and his team explored how well these high-risk patients are protected by vaccination [2]. They determined T cell-mediated and antibody reactivity against the spike 1 (S1) protein of SARS-CoV-2 among 48 cirrhotic patients (of variable aetiologies) and 39 healthy controls after 2 and 3 doses of an mRNA vaccine against SARS-CoV-2.

SARS-CoV-2-specific T-cell reactivity was measured by induced levels of T cell-derived interferon-gamma (IFN-γ) before and after the first and second vaccination with an mRNA vaccine. Moreover, serum IgG antibodies against the receptor-binding domain (RBD) of the spike protein were quantified by immunoassays after the first, second, and third doses of the vaccine.

T-cell reactivity against S1 was significantly reduced in cirrhotic patients compared with healthy controls after the first and second doses of the vaccine (P<0.001 for each comparison). Most (68%) patients lacked detectable S1-specific T-cell reactivity after the first vaccination compared with 19% in controls (P=0.003) and 36% remained without detectable reactivity after the second dose versus 6% in the controls (P=0.009). The lack of T-cell reactivity was mirrored by lower levels of anti-RBD-S1 IgG antibodies after the first (P<0.001) and second (P<0.05 vs controls) vaccination. Impaired T-cell reactivity in cirrhosis remained after correction for potential confounders and was particularly pronounced in patients with advanced cirrhosis. However, anti-RBD-S1 IgG levels increased significantly after the third compared with the second dose. Patients who were vaccinated and had a naturally acquired COVID-19 infection (i.e. hybrid immunity) achieved the best T-cell reactivity, with significantly higher antibody levels compared with those achieved through 3 doses of vaccination alone.

The authors emphasised that in light of immune waning with regards to COVID-19, continued vigilance as well as iterated booster vaccine doses for these vulnerable patients is likely prudent.

1. Nagarajan R, et al. Prev Chronic Dis. 2022;19:210228.
2. Al-Dury S, et al. Evaluation of the immune response against SARS-COV-2 after two and three doses of mRNA vaccination in patients with liver cirrhosis. OP106, UEG Week 2022, 8–11 October, Vienna, Austria.

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Posted on 2 December, 2022