People with blood cancers are at higher risk of becoming infected with severe and life-threatening Covid-19 than healthy people. Published in the magazine «
Blood», research suggests that vaccines do not always provide optimal protection to vaccinated people.
The study is the first to offer information on the cases of Covid-19 produced in people with hematological cancer who had been vaccinated and offers preliminary findings on the incidence of breakthrough infection in this vulnerable population.
The data of this work comes from the registry, EPICOVIDEHA, in which Spanish hospitals have intervened, which compiles reports of patients with blood cancers who developed Covid-19 infection. As of August 31, 2021, of the 4,000 total cases on the registry, there were 113 reported cases of Covid-19 after vaccination, and more than three out of four of these breakthrough cases occurred in vaccinated people who had received one dose of one dose vaccines like AstraZeneca and two doses of two dose mRNA vaccines like Moderna or Pfizer.
About 23% had been partially vaccinated, receiving only one dose of an mRNA vaccine, when they became infected with Covid-19.
Research shows that after a 30-day follow-up after Covid-19 diagnosis, 14 (12.4%) patients died and Covid-19 was considered the cause of death for all but one of these individuals.
The study researchers emphasize that although the death rate in patients with Covid-19 cases is high, it is much lower than before the vaccines were available.
Previous studies using registry data reported that during the lead-up to pandemic vaccination, people with blood cancers and Covid-19 had death rates ranging from 30% to 50% (depending on type underlying blood cancer).
“Before vaccination, many of the patients with hematological malignancies with Covid died,” says study author Livio Pagano, from the
Catholic University of the Sacred Heart (Italy).
«With these preliminary data, we show that vaccination not able to fully protect, but surely has an important role in reducing mortality from Covid-19 in people with blood cancers, “he adds.
The study has also seen that the level of response to the Covid-19 vaccine was associated with the type of blood cancer.
Thus, for example, people with disorders myeloproliferative (red blood cell and platelet disorders) were the least likely to develop Covid-19 after vaccination, while those with lymphoproliferative disorders (disorders of the lymphocytes, the white blood cells of the immune system) were the most likely.
Of the 113 COVID-19 cases, 80% occurred in people with lymphoproliferative conditions such as chronic lymphocytic leukemia, non-Hodgkin’s lymphoma, Hodgkin’s lymphoma, and multiple myeloma.
“Unfortunately, lymphoma patients are more likely to have a weakened immune system and develop infections, such as Covid-19,” says Pagano. «In future studies, we will analyze the efficacy of booster doses to understand if they can reduce infection in our patients, especially those with disorders linfoproliferativos».
Approximately 70% of the patients in this study received an mRNA vaccine – Modern or Pfizer – and the remainder either the AstraZeneca vector-based vaccine or the inactivated Sinovac vaccine. There were no significant differences in the prevention of Covid-19 between these two groups.