By Selina Wellbelove – 15 Nov 2021
Vaccinated patients with blood cancers experiencing breakthrough COVID-19 infections remain at high risk for severe or critical disease and death, new research shows.
Furthermore, it was found that patients with lymphomas were more at risk than those with other haematological malignancies.
The study, led by Dr Livio Pagano, from the Università Cattolica del Sacro Cuore in Rome, Italy, is the first to report data on the incidence of breakthrough COVID-19 infection in blood cancer patients.
The research team looked at data from EPICOVIDEHA, an international open web-based registry for patients with haematological malignancies infected with SARS-CoV-2.
The findings, outlined in a letter to Blood, show that out of 3,801 total cases in the registry there were 113 reports of SARS-CoV-2 infection post-vaccination in people with blood cancers, with more than three-quarters occurring in those who had received two doses of vaccine.
Within the breakthrough group, 79 (60%) had a severe or critical infection, and 75 (66%) were admitted to hospital. Of those hospitalised, 16 (21%) were admitted into an intensive care unit, of which 10 required mechanical ventilation.
After a follow-up of 30 days post COVID-19 diagnosis, 14 patients had died (12% of the infected patients), with the virus listed as the main or secondary cause of death for all but one of the patients. Interestingly, the researchers said they found no statistical difference in terms of mortality between partially or fully vaccinated patients (15% vs 12%) and between patients achieving a serological response to vaccine vs non responders (13% vs 16%).
“Importantly, the overall mortality observed in our patients, although lower than in the pre-vaccination period (around 31%), remained high (12.4%),” the authors wrote. “This percentage, on one hand, remains quite worrying for haematologists, but on the other hand should be interpreted as a significant achievement following the spread of vaccination programs around the world.”
The authors also found that COVID-19 vaccine response was also linked the type of blood cancer; more than 80% of patients with breakthrough infection had underlying lymphoproliferative malignancies, such as chronic lymphoid leukaemia, non-Hodgkin’s lymphoma, acute lymphoblastic leukaemia, Hodgkin’s lymphoma, and multiple myeloma. On the other hand, people with myeloproliferative disorders were the least likely to develop COVID-19 post vaccination.
“Unfortunately, people with lymphomas are more likely to have suppressed immune systems and to develop infections, and it is no different for COVID-19,” Dr Pagano noted. “In future studies we will look at the efficacy of additional vaccine doses to understand if they can reduce infection in our patients, especially those with lymphoproliferative disorders.”
The authors stressed that their observations are preliminary and based on limited data. Nevertheless, “the key message is that we must make a great effort to vaccinate as many people as we can,” said Dr Pagano. “We can’t only vaccinate our patients with haematologic malignancies; it is also important to vaccinate their caregivers so we can form a barrier of protection around them, because their own immunity from the vaccine is not enough.”