Breakthrough COVID-19 infections severe in blood cancer patients

While getting vaxxed remains the best protection against severe COVID-19, severe breakthrough infections are still possible, particularly in patients with haematological malignancies, a registry-based study has shown.

Of 113 patients with haematological malignancies who contracted COVID-19 after partial or complete vaccination, 79 had developed severe or critical disease. Seventy-five required hospitalization.

Among those hospitalized, 16 were admitted to the intensive care unit, 10 of whom required mechanical ventilation. Fourteen had died within 30 days of contracting the disease. All but one death was due to COVID-19.

“This suggests that patients with blood cancer have suboptimal protection against COVID-19 despite receiving the vaccine jabs,” said study author Dr Livio Pagano from the Catholic University of Sacred Heart and Fondazione Policlinico Universitario Agostino Gemelli in Rome, Italy.

Dangerous combination

Pagano and his team sought to investigate the epidemiology, risk factors, and mortality rates using data from the  EPICOVIDEHA registry, which tracks patients with blood cancers who contract COVID-19. [Blood 2021;doi:10.1182/blood.2021014124]

Over 60 percent of the patients were male, and 86 percent were older than 50 years. More than 80 percent had underlying lymphoproliferative malignancies (chronic lymphoid leukaemia, non-Hodgkin lymphoma, acute lymphoblastic leukaemia, Hodgkin’s lymphoma, and multiple myeloma).

Sixty-eight percent of the patients received active treatment for underlying haematological malignancy at the time of COVID-19 or within the previous  3 months. Following recommendations for vaccination, majority of them received an mRNA vaccine (BioNTech/Pfizer, 69.9 percent), Moderna, 17.7 percent), whereas 12.4 percent received a vector-based vaccine (AstraZeneca Oxford, 10) or an inactivated vaccine (Sinovac CoronaVac, 4).

Eighty-seven patients were fully vaccinated whereas 26 got only one shot. The median time from the last dose of vaccine and COVID-19 diagnosis was 64 days.

In fully vaccinated patients, COVID-19 was diagnosed more than 2 weeks after the second vaccine dose. There was no statistical difference in terms of mortality between partially or fully vaccinated patients. Age was the lone factor independently related to the risk of death.

Mortality after COVID-19 jabs

“Compared with a survey we carried out in the pre-vaccination period, there was a reduction in the mortality rate,” said Pagano. “The substantial reduction in deaths occurred after COVID-19 vaccines became widely available.”

Better knowledge of COVID-19 infection and the availability of more effective therapeutics, including monoclonal antibodies, were among the reasons he cited for the reduction in deaths.

“Before the advent of vaccines, there was a large number of patients with acute myeloid leukaemia who incurred infection, and the mortality rate among these patients was over 40 percent,” Pagano shared. “Preliminary data from our study showed that the mortality rate has decreased.”

Importantly,  although overall mortality was lower than in the pre-vaccination period (~31 percent), it remained high at 12.4 percent). “This is still worrying for haematologists but should be interpreted as a significant achievement following global vaccination programmes,” he added.

An obligation rather than an option

“Vaccination in blood cancer patients is not an option but a moral obligation,” said Pagano. “COVID-19 is no different than other infections. It has increased likelihood to infect people with lymphomas, who are more likely to have suppressed immune systems.”

Additionally, the finding highlights the importance of giving boosters to this immunocompromised population.