Background: Individuals with schizophrenia have an increased risk of severe COVID-19 outcomes, nonetheless, no previous study has provided a year-long account of this risk, or assessed postvaccination trends in this population. This study assessed temporal trends in COVID-19 hospitalisation and mortality among people with schizophrenia during the first year of the pandemic, the predictors for COVID-19 vaccination, postvaccination infection, admission to hospital, and mortality. Methods: In this longitudinal cohort study, people with schizophrenia (n=25 539) and controls (n=25 539) were assessed for COVID-19 outcomes before and after vaccination, up to April 30, 2021. Cox proportional hazard regression models and Kaplan-Meier analyses were done to assess longitudinal trends. The study used the databases of Clalit Health Services, the largest health-care organisation in Israel. Findings: The sample included 51 078 participants, of which 31 141 (61·0%) male and 19 937 (39·0%) female participants, with a mean age of 51·94 years (SD 15·62). Most of the sample was from the general Jewish population (75·9%), followed by the Arab (19·1%) and Jewish Ultraorthodox population (5·1%). Overall of 51 078 individuals, 356 (0·7%) people had been hospitalised, 133 (0·3%) had died, and a total of 27 400 (53·6%) had been vaccinated. People with schizophrenia showed a higher risk for COVID-19 hospitalisation (HR 4·81, 95% CI 3·57–6·48, p<0·0001) and mortality (HR 2·52, 95% CI 1·64–3·85, p<0·0001), and showed a sharper decline in survival as time progressed. The control group showed a sharper incline in probability to vaccinate (log-rank=309·88, p<0·0001). Medical comorbidity of diabetes, hypertension, obesity, or ischaemic heart disease played a significant role in predicting vaccination rates in the schizophrenia group (all p<0·0001), but not in the control group. Hospitalisation and mortality disparities remained higher among people with schizophrenia who had not been vaccinated in comparison to controls (incidence rate difference of 6·2 and 3·2, respectively) but substantially declined in fully vaccinated groups (incidence rate difference of 1·1 and −0·9, respectively). Interpretation: People with schizophrenia have higher hospitalisation and mortality risk, yet have lower rates of vaccination than in the general population. Disparities in COVID-19 severe outcomes can be substantially reduced by national vaccination plans aimed at actively reaching out to people with schizophrenia. Funding: No funding.