Closing COVID-19 mortality, vaccination, and evidence gaps for those with severe mental illness

In The Lancet Psychiatry, Dana Tzur Bitan and colleagues¹ present the results of the first longitudinal study assessing COVID-19 outcomes before and after vaccination in a cohort of over 25 000 people with schizophrenia and an equally large sample of matched controls in Israel. Particular strengths of this study are the impressive and well-characterised dataset, and the longitudinal design, allowing exploration of dynamic trends over the course of the first year of the COVID-19 pandemic. From a policy perspective, Israel, where all citizens aged 16 and older gained full access to SARS-CoV-2 vaccination as early as January, 2021, represents an interesting case study.

Tzur Bitan and colleagues' analysis suggests that a substantial survival gap persisted between controls and people with schizophrenia throughout the first year of the pandemic. These findings contribute to the growing body of evidence showing severe mental illness, and psychotic disorders in particular, represent a significant and independent risk factor for COVID-19-associated mortality.2, 3 The first reports of increased mortality among people with mental disorders emerged in September, 2020, about halfway through the follow-up period of this study, but these new insights apparently did not translate to specific action or better outcomes for these patients. In fact, the mortality gap was found to be larger in the second half of the follow-up window (HR 2·72 late phase vs 2·15 early phase). Hospital admission rates associated with COVID-19 of people with schizophrenia were also found to be increased in Israel. This finding has been replicated in other studies, although more equivocally, possibly reflecting country differences in health-care organisation and patients' access to care.²

Tzur Bitan and colleagues also found a small but significant vaccination gap between controls and people with schizophrenia, confirming earlier preprint findings that patients with schizophrenia are not being vaccinated at the same rate, despite early universal access (in Israel) or priority status (in the UK).⁴ In March, 2021, 2 months after its entire adult population became eligible for vaccination, the proportion of fully vaccinated individuals in Israel was 2·2% lower among people with schizophrenia.¹ Although this finding might seem only a limited and overall acceptable lag, significantly higher prevalences of important comorbid conditions in the cohort with schizophrenia, such as obesity (32·5% vs 22·3%), smoking (51·6% vs 39·3%), diabetes (20·7% vs 13·6%), hyperlipidaemia (47·5% vs 38·5%), and chronic obstructive pulmonary disease (4·6% vs 2·0%), warranted a superior vaccination rate in this group.⁵ According to Israel's national vaccination strategy, people with these comorbidities would have been granted priority access to SARS-CoV-2 vaccination before January, 2021. Metabolic comorbidities did predict vaccination status among the patients with schizophrenia included in this study, but this did not lead to an overall higher vaccination proportion among patients with schizophrenia versus controls. It is possible that the predictive effect of the metabolic comorbidities was confounded by these patients' status of more chronic disease and being an inpatient or living in a collective setting, but this hypothesis could not be explored. The immediate implication of this finding is that only granting priority access to patients with severe mental illness in national vaccination strategies does not solve the problem. Even before the first vaccination was administered, policy makers were warned about the decreased likelihood of receipt of other preventive vaccines and the need for targeted interventions to maximise vaccination uptake among these patients.⁶ Being eligible for vaccination—with priority or not—is clearly not good enough.⁷

Finally, Tzur Bitan and colleagues' work provides the first preliminary evidence that vaccination offers adequate protection against severe COVID-19 illness in people with schizophrenia, despite concerns about immunological disturbances and suboptimal serological vaccine responses;⁸ a reason for hope, which at the same time compels increased efforts. The current findings warn us that even a fully accessible health-care system cannot counteract mortality and vaccination gaps. Coordinated and appropriate interventions are needed to prevent avoidable deaths among patients with severe mental illness. Where policy makers have failed these patients, it now becomes mental health professionals' duty, in close collaboration with community stakeholders, families and carers, to continue the advocacy efforts, to reach out in any way possible, and to remove any and all barriers that stand in the way of vaccination of people with severe mental illness.9, 10

Unfortunately, scientific evidence on vaccine hesitancy and the attitudes of people with schizophrenia towards vaccination is a knowledge gap. Although Tzur Bitan and colleagues' study provides a first attempt to characterise determinants of vaccine uptake among patients with schizophrenia, no study to date has stratified patients' COVID-19 outcomes or vaccination rates by their clinical psychiatric status or involvement with psychiatric care. The potential effect of psychiatric care on the pandemic outcomes of these patients thus remains a blind spot. The organisation of care for patients with psychotic disorders is notoriously complex and heterogeneous. Consequently, the pandemic offers a unique opportunity to study the individual (eg, clinical predictors of at-risk groups), mental health-care (eg, treatment setting), and macro-organisational (eg, country health-care system) determinants of COVID-19 outcomes and vaccine uptake among patients with mental disorders. I consider this a priority in the research agenda of mental health-care researchers worldwide. Evidence is the prerequisite for effective action, during and after the COVID-19 pandemic.

I declare no competing interests.