Currently available vaccines for COVID-19 are very effective in preventing hospitalizations and deaths. However, there have been reports of COVID-19-related deaths in fully vaccinated individuals. Thus, it is essential to characterize these post-vaccination COVID-19 deaths to inform public health strategy and vaccination policy.
Researchers from the UK used EAVE II, an individual-level, national surveillance system, to determine the frequency of COVID-19-related fatalities among fully vaccinated individuals and to define the clinical and demographic characteristics of COVID-19 deaths in fully vaccinated individuals since the beginning of the COVID-19 vaccination program in Scotland.
They also performed survival analyses to identify the predictors for death among fully vaccinated individuals who were severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive. COVID-19-related fatalities in fully vaccinated individuals were defined as death in individuals who tested positive for SARS-CoV-2 using RT-PCR at any time after 14 days of receiving the second dose of BNT162b2 (Pfizer–BioNTech) or ChAdOx1 nCoV-19 (AZD1222; Oxford–AstraZeneca) vaccines and subsequently died with COVID-19 as either an underlying or a contributory cause of death on their death certificate.
Of the 3,273,336 fully vaccinated individuals (73.6% of the eligible population) in Scotland by August 18, 2021, a total of 1,205,642 individuals received 2 doses of BNT162b2 and 2,026,198 individuals received 2 doses of ChAdOx1 nCoV-19. Since there were no deaths among 41,496 individuals who had received two doses of the mRNA-1273 (Moderna) vaccine during the study duration, they were not further included in this analysis.
Deaths in Elderly Population
A total of 236 deaths were recorded in fully vaccinated people, which is 0.007% of all fully vaccinated individuals; 47 (0.004%) of the individuals had received the BNT162b2 vaccine and had a median age of 74.0 years, and 188 (0·009%) of the individuals had received the ChAdOx1 nCoV-19 vaccine and had a median age of 80.0 years. One death was reported in an individual who had received the first dose of ChAdOx1 nCoV-19 vaccine and a second dose of the BNT162b2 vaccine.
COVID-19 was the underlying cause of death in 195 (82.6%) individuals and a contributing cause of mortality in 41 (17.4%) individuals. In the vaccine-eligible Scottish population aged 65–79 years, the death rate per 10,000 person-years was 4.2 in fully vaccinated individuals and 64.8 among unvaccinated individuals.
This difference in death rate was most prominent in the elderly population above 80 years of age and was 14.0 deaths per 10,000 person-years in fully vaccinated individuals versus 420.1 deaths per 10,000 person-years among unvaccinated individuals. However, this difference in death rate was diminished in younger individuals in the 18–64 years age group with 0.8 deaths per 10,000 person-years among fully vaccinated versus 3.1 deaths per 10 000 person-years in unvaccinated individuals.
While the median age at death was 79.5 years, 146 (61.8%) deaths occurred in men. Also, 63 (34.2%) individuals tested positive for COVID-19 before hospital admission, and 184 (78.0%) individuals were hospitalized before death. Since 101 (54.9%) individuals tested positive for COVID -19 on or after hospitalization, it is clear that they did not seek or receive medical attention for COVID-19 before being hospitalized. A total of 41 individuals were admitted to an ICU or high-dependency unit after testing positive for SARS-CoV-2 and before death.
The most common causes of death that were not COVID-19-related were chronic heart or kidney disease, diabetes, atrial fibrillation, and chronic obstructive pulmonary disease. Viral sequencing data available for 106 deaths showed that five individuals died with the alpha variant of concern, and 101 individuals who died had the delta VOC. Sequencing data were not available for the remaining 130 deaths.
To summarize, COVID-19-related deaths were very rare in individuals fully vaccinated with BNT162b2 or ChAdOx1 nCoV-19 vaccines. Most deaths in fully vaccinated individuals were in those aged 75 years or above and those who had multiple comorbidities, which is similar to the risk profile for death in unvaccinated individuals or those who have received a single dose of the COVID-19 vaccine. Thus, the results show that being fully vaccinated does not entirely eliminate the risk of COVID-19-related death, suggesting the significance of non-pharmaceutical interventions and continued caution, especially in the case of older adults with comorbidities.