Coronavirus disease 2019 (COVID-19) vaccinations have played a vital role in reducing severe infection, morbidity, and mortality throughout the pandemic.

Nonetheless, certain patient groups still face the next risk of death as a result of COVID-19, even after receiving the first vaccination course. Moreover, the effectiveness of vaccines may decline over time.

To deal with these concerns and overcome severe outcomes, booster doses were introduced, as other infection control measures were relaxed.

In a recent study posted to the medRxiv* preprint server, researchers discover patient groups at the next risk of death as a result of COVID-19 amongst adults who received a second booster dose in England.

Study: Risk of COVID-19 death in adults who received booster COVID-19 vaccinations: national retrospective cohort study on 14.6 million people in England. Image Credit: Shutterstock.com

*Necessary notice: medRxiv publishes preliminary scientific reports that are usually not peer-reviewed and, due to this fact, shouldn’t be considered conclusive, guide clinical practice/health-related behavior, or treated as established information.

Concerning the study

The researchers utilized person-level data from the 2021 Census linked to varied health records to research the association between COVID-19 booster doses and mortality outcomes in England. The linked dataset included information on 52 million individuals, which accounted for 91.8% of the population.

The study population consisted of people between 50-100 years of age who received a COVID-19 booster dose after September 1, 2022. Booster doses were administered at the very least 84 days after their most up-to-date clinically acceptable dose, with all patients having received at the very least two vaccine doses before the booster.

The first consequence was COVID-19 death, which was identified by specific International Classification of Disease (ICD) codes on death certificates. The secondary consequence was non-COVID-19 mortality. Individuals were monitored from 14 days after the booster dose until April 11, 2023, the occurrence of death, or end of the study period.

Medical conditions were identified using primary care records from definitions utilized by the QCovid2 risk prediction model. These data were collected between March 1, 2015, and March 21, 2021. Missing census characteristics were determined by nearest-neighbor donor imputation, which is the methodology employed by the Office for National Statistics (ONS) for 2011 Census variables. Missing body mass index (BMI) data was managed by adding a “Missing” category.

Cause-specific Cox regression evaluation was conducted to find out the association between each health comorbidity and the danger of COVID-19 death, in addition to all-other-cause mortality. A model adjusted for age, sex, and calendar time was used, with additional adjustments made for ethnic group, region, BMI, and disability.

Advanced age and health conditions increase risk of COVID-19 death amongst boosted individuals

The study included 14,651,440 individuals between 50-100 years of age, with a mean age of 67.9 years. Among the many study population, 90.4% were White British individuals, and 46.9% were male.

Between September 1, 2022, to April 11, 2023, 150,075 non-COVID-19 deaths and 6,800 COVID-19 deaths were reported. The mean age was 84 years for COVID-19 deaths and 82.3 years for non-COVID-19 deaths.

Age was a big predictor, with the next risk related to increasing age. Women had a lower risk of death as in comparison with men.

Black Caribbean, Indian, and other ethnic groups had a lower risk of COVID-19 death as in comparison with the White British group. Being morbidly obese or underweight increases the danger of COVID-19 and non-COVID-19 death.  

Several health conditions were related to the next risk of COVID-19-related death, including learning disabilities or Down’s syndrome, pulmonary hypertension or fibrosis, motor neuron disease, multiple sclerosis, cancer of bone marrow and blood, myasthenia or Huntington’s disease, Parkinson’s disease, lung or oral cancer, dementia, and liver cirrhosis.

Specific conditions comparable to cancers of the blood or bone marrow, chronic kidney diseases, cystic fibrosis, pulmonary hypotension or fibrosis, systemic lupus erythematosus, and rheumatoid arthritis were also related to the next relative risk of COVID-19 death as in comparison with non-COVID-19 death.

In a supplementary evaluation not adjusted for other health conditions, the danger of COVID-19 outcomes was higher than that in a model where other conditions were considered. Notably, the danger was lower for asthma within the model adjusted for other health conditions; nevertheless, within the supplementary evaluation, the danger of death was significantly higher for people diagnosed with asthma.

Conclusions

To effectively manage COVID-19 risk, it’s crucial to prioritize probably the most vulnerable groups for booster vaccination. Based on the authors, this study was the primary to research the danger of COVID-19 and non-COVID-19 deaths in adults who received a booster dose within the autumn of 2022.

Certain patient groups had a very higher risk of COVID-19 death as in comparison with death from other causes. Thus, these groups ought to be prioritized for subsequent vaccinations, therapeutics, and progressive treatments.

Moreover, the researchers highlight the danger related to various health conditions and sociodemographic characteristics. Taken together, this information can inform policymakers and other researchers regarding key demographics of interest for future research and vaccination efforts.

*Necessary notice: medRxiv publishes preliminary scientific reports that are usually not peer-reviewed and, due to this fact, shouldn’t be considered conclusive, guide clinical practice/health-related behavior, or treated as established information.