People with COVID-19 are now less likely to have severe or fatal outcomes from COVID-19 disease compared to the early stages of the pandemic, an international study has shown.

COVID-19 case fatality rates dropped from 35% to 11% and hospitalisation rates fell from 85% to 55% for patients with CLL between the early and later stages of the pandemic, according to findings published in Blood journal.

Investigators from 45 treatment centres globally compared COVID-19 outcomes for 254 CLL patients diagnosed prior to May 2020 with those of 120 patients diagnosed with COVID-19 between May 2020 and February 2021.

Patients in the later cohort of COVID-19 infections appeared to have less severe disease course compared to the early cohort, as evidenced by lower rates of ICU admission (15% vs 32%) and lower case fatality rates for those requiring ventilation (25% vs 44%).

In the later cohort, only 20% of BTKi-treated patients had this therapy paused or discontinued compared to 76% in the early cohort.

The study investigators noted that treatments such as remdesivir and convalescent plasma were associated with better outcomes in terms of fatality (Hazard ratios of 0.48 and 0.50 respectively). Dexamathasone treatment was associated with a higher mortality rate, but this result may have been due confounding because corticosteroids were being reserved for patients with more severe disease, the researchers said.

They noted that previous reports had suggested that patients with CLL may not be able to consistently mount anti-SARS-CoV-2 antibodies following infection, and there had been reports of inadequate response to COVID-19 vaccines in people with CLL. However until now there had been few studies of the impact of recent developments in COVID-19 treatments in the CLL population.

“Reassuringly, the overall trend in case fatality rates for CLL patients mirrors improved OS observed for patients with COVID-19 in the general population,” they wrote.

However they added that “these data highlight opportunities for further investigation into optimal management of COVID-19, immune response following infection, and effective vaccination strategy for CLL patients.”