Authored by Dr. Brian Koffman
Bottom Line:
There’s a 21% chance of chronic lymphocytic leukemia (CLL) patients getting a second COVID-19 infection within a year of the first, but it should be mild. The good news is that there were no deaths or ICU admissions with the second infection.
Who Performed the Research and Where Was it Presented:
Sara Pepe led a group of researchers from Rome, Italy, to present this research at the European Hematology Association (EHA) Annual Congress in Madrid in 2024.
Background:
Recurrent COVID-19 infections occur commonly in the general population, but there is little data on their frequency in CLL patients who may be at higher risk due to compromised immunity.
Method and Participants:
This was a retrospective study of CLL patients from a single institution in Rome, Italy, who had experienced their first COVID-19 infection between March 2020 and September 2023. Reinfection was defined as a new COVID-19 diagnosis occurring 90 days after the prior event.
Results:
- 220 patients with CLL who experienced COVID-19 infections were studied.
- 210 (95%) patients survived.
- 78 (37%) received an additional dose of the SARS-CoV2 vaccine on average 6.6 months from the first COVID-19 event
- A new COVID-19 infection was recorded in 52/210 (25%) patients after a median time of 12.2 months with a range of 7.5-18.7 months from the first event.
- No patients experienced a subsequent COVID-19 event before the Omicron wave.
- The 12-month “Second COVID-19 Free Survival probability” was 78.8%. In other words, fewer than 8 out of 10 CLL patients lived for 1 year after a first infection without getting a second one.
- Factors that increased the risk of a second infection sooner were:
- Multiple comorbidity or other illnesses besides the CLL with a hazard ratio (HR) of 2.4, meaning nearly 2½ x increased risk of a second event.
- Active treatment for CLL [HR 3.54]. That’s more than 3½ times the risk.
- TP53 aberrations [HR 1.98]
- Not surprisingly, no protection against a second infection was seen with Tixagevimab / cilgavimab (EVUSHELD) prophylaxis.
- Somewhat surprising was the fact that an additional vaccination did not reduce risk.
- At the time of the new COVID-19 event, 23 (44%) patients were on treatment (BTK inhibitors in 79%; venetoclax-based regimens in 17%).
- Comparing the first event in the 210 patients to the second infection in 52 of those patients, the second event was associated with:
- Significantly lower rate of pneumonia (8% vs. 21%)
- Significantly lower rate of hospitalization (10% vs. 25)
- Moreover, no patients who had a subsequent event required admission to the Intensive Care Unit (ICU).
- There were no deaths in the second COVID-19 case.
- There was greater use of antiviral and antibody therapies in second events as more therapies were available, and their appropriate use was better understood.
Conclusions and Discussions:
It is never wise to generalize about COVID-19 infections, but it does seem that at least for those CLL patients seen at the Hematology Unit of the Sapienza University of Rome between March 2020 and September of 2023, they had between a 1 in 4 and 1 in 5 chance of a second infection in the year following the first infection. Other illnesses (comorbidities), especially being on treatment, significantly increased that risk. There are many possible explanations beyond the direct effects of the drugs and the comorbidities causing more infections. Such patients likely require more clinic and hospital visits, which increases their risk of COVID-19 exposure. More simply, the same lifestyle and decisions about mask-wearing and other protective measures that led to their first infection also led to the second.
The good news is that the second cases were generally mild. Again, there are many possible reasons, including:
- All infections were Omicron, generally a variant that causes more upper respiratory illness rather than the more dangerous lung infections seen with the dominant strains earlier in the pandemic.
- Better treatments were available.
- Immunity from prior infections and vaccinations may have provided some protection.
How these data translate beyond Rome is not clear, but I would bet that the general experience across the globe is that there is a high risk of a second bout of COVID-19 within a year of the first, coupled with a very low risk of it being serious.
Links:
Listen to Dr. Koffman’s monologue below.
Read the full EHA abstract at REPEATED COVID-19 EVENTS IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA.
For more information on COVID-19 in CLL, see CLL Society’s resources and news on our COVID-19 homepage.
