ABSTRACT
Third dose COVID-19 vaccines are being deployed widely but their efficacy has not been assessed adequately in vulnerable elderly people who exhibit suboptimal responses after primary series vaccination. We studied spike-specific immune responses in 341 staff and residents in long-term care facilities (LTCF) who received an mRNA vaccine following dual primary series vaccination with BNT162b2 or ChAdOx1. Third dose vaccination strongly increased antibody responses with preferential enhancement in older people and was required to elicit neutralisation of Omicron. Cellular immune responses were also enhanced with strong cross-reactive recognition of Omicron. However, antibody titres fell 21-78% within 100 days post vaccine and 27% of participants developed a breakthrough Omicron infection. These findings reveal strong immunogenicity of a 3rd vaccine in one of the most vulnerable population groups and endorse an approach for widespread delivery across this population. Ongoing assessment will be required to determine the stability of immune protection.
Subject(s)
COVID-19ABSTRACT
BackgroundPatients with kidney failure requiring kidney replacement therapy (KRT) are at high risk of complications and death following SARS-CoV-2 infection with variable antibody responses to vaccination reported. We investigated the effects of COVID-19 vaccination on incidence of infection, hospitalization and death of COVID-19 infection. MethodsStudy design was an observational data linkage cohort study. Multiple healthcare datasets were linked to ascertain all SARS-CoV-2 testing, vaccination, hospitalization, and mortality data for all patients treated with KRT in Scotland, from the start of the pandemic over a period of 20 months. Descriptive statistics, survival analyses and vaccine effectiveness were calculated. ResultsAs of 19th September 2021, 93% (n=5281) of the established KRT population in Scotland had received two doses of an approved SARS-CoV-2 vaccine. Over the study period, there were 814 cases of SARS-CoV-2 infection (15.1% of the KRT population). Vaccine effectiveness against infection and hospitalization was 33% (95% CI 0-52) and 38% (95% CI 0-57) respectively. 9.2% of fully vaccinated individuals died within 28 days of a SARS-CoV-2 positive PCR test (7% dialysis patients and 10% kidney transplant recipients). This compares to <0.1% of the vaccinated Scottish population being admitted to hospital or dying death due to COVID19 during that period. ConclusionsThese data demonstrate a primary vaccine course of two doses has limited impact on COVID-19 infection and its complications in patients treated with KRT. Adjunctive strategies to reduce risk of both COVID-19 infection and its complications in this population are urgently required.
Subject(s)
COVID-19 , Death , Renal InsufficiencyABSTRACT
Not all patients with cancer, in particular those with hematogic malignancies, develop functional immunity against SARS-CoV-2 variants of concern (VOC) following COVID-19 vaccines. Durability of vaccine-induced immunity after two doses and the impact of a third dose were evaluated in CAPTURE (NCT03226886), a longitudinal prospective cohort study of vaccine responses in patients with cancer. In evaluating 316 patients, at a median of 111 days following two doses of either BNT16b2 or ChadOX, we observed a time-dependant decline in neutralising antibody titres (NAbT) in a proportion of patients, where NAbTs became undetectable against Delta and Beta in 17% and 15% of patients, respectively. Vaccine-induced T cell responses declined in 44% of patients. Patients with breakthrough infections following two vaccines doses were characterised by absent/low NAbT to Delta prior to infection. Administration of the third vaccine dose boosted NAb responses against VOC in the majority of patients with cancer, especially those with solid cancer. In patients with hematologic malignancies who had undetectable NAbT against Delta after two vaccine doses, 54% did not develop NAb against both Beta and Delta following the third dose. Third vaccine dose boosted T cell responses were boosted in patients with both solid and hematologic malignancies. These results provide critical information on vaccine responses in patients with cancer, especially against VOCs and support widespread access to a third COVID-19 vaccination in this patient group.