Clinical Outcomes of SARS-CoV-2 Breakthrough Infections in Liver Transplant Recipients during the Omicron Wave

Effectiveness and evolution of anti-SARS-CoV-2 spike protein titers after three doses of COVID-19 vaccination in people with HIV

BACKGROUND

Real-world vaccine effectiveness following the third dose of vaccination against SARS-CoV-2 remains less investigated among people with HIV (PWH).

METHODS

PWH receiving the third dose of BNT162b2 and mRNA-1273 (either 50- or 100-μg) were enrolled. Participants were followed for 180 days until the fourth dose of COVID-19 vaccination, SARS-CoV-2 infection, seroconversion of anti-nucleocapsid IgG, death, or loss to follow-up. Anti-spike IgG was determined every 1-3 months.

RESULTS

Of 1427 participants undergoing the third-dose COVID-19 vaccination, 632 (44.3%) received 100-μg mRNA-1273, 467 (32.8%) 50-μg mRNA-1273, and 328 (23.0%) BNT162b2 vaccine and the respective rate of SARS-CoV-2 infection or seroconversion of anti-nucleocapsid IgG was 246.1, 280.8 and 245.2 per 1000 person-months of follow-up (log-rank test, p = 0.28). Factors associated with achieving anti-S IgG titers >1047 BAU/mL included CD4 count <200 cells/mm3 (adjusted odds ratio [aOR], 0.11; 95% CI, 0.04-0.31), plasma HIV RNA >200 copies/mL (aOR, 0.27; 95% CI, 0.09-0.80), having achieved anti-spike IgG >141 BAU/mL within 3 months after primary vaccination (aOR, 3.69; 95% CI, 2.68-5.07), receiving BNT162b2 vaccine as the third dose (aOR, 0.20; 95% CI, 0.10-0.41; reference, 100-μg mRNA-1273), and having previously received two doses of mRNA vaccine in primary vaccination (aOR, 2.46; 95% CI, 1,75-3.45; reference, no exposure to mRNA vaccine).

CONCLUSIONS

PWH receiving different types of the third dose of COVID-19 vaccine showed similar vaccine effectiveness against SARS-CoV-2 infection. An additional dose with 100-μg mRNA-1273 could generate a higher antibody response than with 50-μg mRNA-1273 and BNT162b2 vaccine.

Efficacy and safety of COVID-19 vaccination in solid organ transplant recipients: a systematic review and network meta-analysis

The impact of COVID-19 vaccination on clinical outcomes in solid organ transplant (SOT) recipients remains unclear. This systematic review and network meta-analysis (NMA) sought to assess the efficacy and safety of COVID-19 vaccination in SOT recipients. We searched six databases from inception to March 1st, 2024 for randomized controlled trials (RCTs) and observational studies evaluating different COVID-19 vaccination strategies in SOT recipients. Based on patient-important outcomes, we performed frequentist random-effects pairwise meta-analyses and NMAs, separating RCTs and non-randomized evidence, and used the GRADE approach to assess our certainty in the evidence. We included 6 RCTs (N=814) and 43 observational studies (N=125,199). Overall, the there is a paucity of randomized evidence evaluating COVID-19 vaccines in SOT recipients. The non-randomized evidence evaluating COVID-19 vaccination strategies patient-important outcomes, including COVID-19 infection, mortality, hospitalization, ICU admission, and rejection, demonstrated low to very low certainty due to the included studies' risk of bias. Throughout the COVID-19 pandemic, clinicians and SOT recipients worked with minimal, very low-quality evidence in relation to COVID-19 vaccines in this population. In the instance of future public health emergencies, clinicians and researchers should collaborate closely with patient partners to ensure there is sufficient evidence in the transplant population on patient-important outcomes.

Proceedings of the 28th Annual Congress of the International Liver Transplantation Society

The 2023 Joint International Congress of the International Liver Transplantation Society (ILTS), the European Liver and Intestine Transplant Association (ELITA), and the Liver Intensive Care Group of Europe (LICAGE) held in Rotterdam, the Netherlands, marked a significant recovery milestone for the liver transplant community after COVID-19. With 1159 participants and a surge in abstract submissions, the event focused on "Liver Disorders and Transplantation: Innovations and Evolving Indications." This conference report provides a comprehensive overview of the key themes discussed during the event, encompassing Hepatology, Anesthesia and Critical Care, Acute Liver Failure, Infectious Disease, Immunosuppression, Pediatric Liver Transplantation, Living Donor Liver Transplantation, Transplant Oncology, Surgical Approaches, and Machine Perfusion. The congress provided a platform for extensive discussions on a wide range of topics, reflecting the continuous advancements and collaborative efforts within the liver transplant community.

High vaccination coverage and infection rate result in a robust SARS-CoV-2-specific immunity in the majority of liver cirrhosis and transplant patients: A single-center cross-sectional study

BACKGROUND

In the third year of the SARS-CoV-2 pandemic, little is known about the vaccine- and infection-induced immune response in liver transplant recipients (LTR) and liver cirrhosis patients (LCP).

OBJECTIVE

This cross-sectional study assessed the vaccination coverage, infection rate, and the resulting humoral and cellular SARS-CoV-2-specific immune responses in a cohort of LTR and LCP at the University Medical Center Hamburg-Eppendorf, Germany between March and May 2023.

METHODS

Clinical and laboratory data from 244 consecutive patients (160 LTR and 84 LCP) were collected via chart review and a patient survey. Immune responses were determined via standard spike(S)- and nucleocapsid-protein serology and a spike-specific Interferon-gamma release assay (IGRA).

RESULTS

On average, LTR and LCP were vaccinated 3.7 and 3.3 times, respectively and 59.4% of patients received ≥4 vaccinations. Altogether, 68.1% (109/160) of LTR and 70.2% (59/84) of LCP experienced a SARS-CoV-2 infection. Most infections occurred during the Omicron wave in 2022 after an average of 3.0 vaccinations. Overall, the hospitalization rate was low (<6%) in both groups. An average of 4.3 antigen contacts by vaccination and/or infection resulted in a seroconversion rate of 98.4%. However, 17.5% (28/160) of LTR and 8.3% (7/84) of LCP demonstrated only low anti-S titers (<1000 AU/ml), and 24.6% (16/65) of LTR and 20.4% (10/59) of LCP had negative or low IGRA responses. Patients with hybrid immunity (vaccination plus infection) elicited significantly higher anti-S titers compared with uninfected patients with the same number of spike antigen contacts. A total of 22.2% of patients refused additional booster vaccinations.

CONCLUSION

By spring 2023, high vaccination coverage and infection rate have resulted in a robust, mostly hybrid, humoral and cellular immune response in most LTR and LCP. However, booster vaccinations with vaccines covering new variants seem advisable, especially in patients with low immune responses and risk factors for severe disease.

Clinical characteristics and outcomes of liver transplant recipients infected by Omicron during the opening up of the dynamic zero-coronavirus disease policy in China: A prospective, observational study

We analyzed the characteristics, risk factors, outcomes, and post-coronavirus disease 2019 (COVID-19) symptoms in liver transplant recipients in China's late 2022 COVID-19 wave. Recipients with COVID-19 were enrolled from December 1, 2022, to January 31, 2023, and followed up until May 31, 2023. Baseline and characteristic data were collected. A total of 930 recipients were included, with a vaccination rate (non-mRNA) of 40.0%. Among 726 (78.1%) recipients with COVID-19, 641 (88.3%) patients were treated at home, 81 (11.2%) patients required hospitalization in general wards, 4 (0.6%) patients required intensive care, and 1 (0.1%) patient died because of COVID-19. Severe acute respiratory syndrome coronavirus 2 infection was related to close contact with confirmed cases (P < .001) and the condition of end-stage kidney disease (P < .046). Older age, male sex, less vaccination, and hypertension were independent risk factors for hospitalization. Fatigue (36.9%) was the most common symptom post-COVID-19, followed by memory loss (35.7%) and sleep disturbance (23.9%). Two doses of vaccines had a protective effect against these post-COVID-19 symptoms (P < .05). During this Omicron outbreak, liver transplant recipients were susceptible to COVID-19, with frequent hospitalization but low mortality. Two doses of non-mRNA COVID-19 vaccines could protect against liver transplant recipient hospitalization and post-COVID-19 symptoms.

Third dose of BNT162b2 improves immune response in liver transplant recipients to ancestral strain but not Omicron BA.1 and XBB

Vaccine immunogenicity in transplant recipients can be impacted by the immunosuppressive (IS) regimens they receive. While BNT162b2 vaccination has been shown to induce an immune response in liver transplant recipients (LTRs), it remains unclear how different IS regimens may affect vaccine immunogenicity after a third BNT162b2 dose in LTRs, which is especially important given the emergence of the Omicron sublineages of SARS-CoV-2. A total of 95 LTRs receiving single and multiple IS regimens were recruited and offered three doses of BNT162b2 during the study period. Blood samples were collected on days 0, 90, and 180 after the first BNT162b2 dose. At each time point, levels of anti-spike antibodies, their neutralizing activity, and specific memory B and T cell responses were assessed. LTRs receiving single IS regimens showed an absence of poor immunogenicity, while LTRs receiving multiple IS regimens showed lower levels of spike-specific antibodies and immunological memory compared to vaccinated healthy controls after two doses of BNT162b2. With a third dose of BNT162b2, spike-specific humoral, memory B, and T cell responses in LTR significantly improved against the ancestral strain of SARS-CoV-2 and were comparable to those seen in healthy controls who received only two doses of BNT162b2. However, LTRs receiving multiple IS regimens still showed poor antibody responses against Omicron sublineages BA.1 and XBB. A third dose of BNT162b2 may be beneficial in boosting antibody, memory B, and T cell responses in LTRs receiving multiple IS regimens, especially against the ancestral Wuhan strain of SARS-CoV-2. However, due to the continued vulnerability of LTRs to presently circulating Omicron variants, antiviral treatments such as medications need to be considered to prevent severe COVID-19 in these individuals.