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Journal Article Ppublish 1 citation

PubMed: 40209340 DOI: 10.1016/j.htct.2025.103824

Outcomes and vaccination patterns against COVID-19 in a cohort of sickle cell disease patients in the state of Rio de Janeiro.

Hematol Transfus Cell Ther 47(2):103824

Authors: Claudia de Alvarenga Maximo, Jorge Francisco da Cunha Pinto, Fabiana Canedo Pinto, PatrĂ­cia Brasil

Affiliations

  • Instituto Estadual de Hematologia Arthur de Siqueira Cavalcanti - HEMORIO, Rio de Janeiro, State of Rio de Janeiro, Brazil.
  • Universidade Federal do Estado do Rio de Janeiro - UNIRIO, Rio de Janeiro, State of Rio de Janeiro, Brazil.
  • Instituto Estadual de Hematologia Arthur de Siqueira Cavalcanti - HEMORIO, Rio de Janeiro, State of Rio de Janeiro, Brazil.
  • Instituto de Pesquisa ClĂ­nica Evandro Chagas - FIOCRUZ, Rio de Janeiro, State of Rio de Janeiro, Brazil.

Abstract

BACKGROUND

Patients with sickle cell disease were presumed to be at high risk for severe COVID-19 outcomes due to their compromised immunity and chronic comorbidities. This study aimed to evaluate vaccination patterns, healthcare utilization, and clinical outcomes in a cohort of sickle cell disease patients during the COVID-19 pandemic in Rio de Janeiro.

METHODS

A total of 289 over 18-year-old patients from the Epidemiology and Donor Evaluation Study (REDS-III) Brazil sickle cell disease cohort were followed between January 2021 and August 2023. Sociodemographic data, emergency department visits, hospitalizations, mortality rates, and COVID-19 vaccination status were collected. SARS-CoV-2 infection was confirmed by reverse transcription polymerase chain reaction testing for symptomatic or hospitalized patients.

RESULTS

Of the participants, 89.2% completed the primary vaccination schedule, 62.2% received the first booster, 30% the second booster, and 4.1% completed all five doses. Emergency visits increased slightly during the pandemic but were primarily due to vaso-occlusive crises. Of the 119 patients tested for SARS-CoV-2, six were positive, presenting mild symptoms with no COVID-19-related deaths. Vaccination rates in the cohort were similar to those in the general population, with Oxford/AstraZeneca and Pfizer being the most used vaccines.

DISCUSSION

The findings suggest that COVID-19 infection was not a significant trigger for vaso-occlusive crises or severe disease outcomes. High vaccination adherence likely played a key role in preventing severe COVID-19, alongside other factors such as social isolation and herd immunity. However, the overlap between symptoms of vaso-occlusive crises and COVID-19 may have caused diagnostic challenges. Importantly, the low morbidity and mortality observed emphasize the protective effect of vaccines, despite the presence of thromboplastic activity and pro-inflammatory states inherent to sickle cell disease. Addressing vaccine hesitancy remains crucial, particularly as booster doses show declining adherence.

CONCLUSION

COVID-19 had a limited clinical impact on this cohort, with no significant role in triggering vaso-occlusive crises or severe outcomes. High vaccination rates and potential environmental or biological factors may have contributed to this protective effect.

MeSH

Cells, Mortality, Vaccines, Anemia, Sickle Cell, Vaccination, Signs And Symptoms, Covid-19, Immunity, Pandemics, Infections, Vaso-Occlusive Crises