NEW YORK: In the pandemic's early phases, most deaths were among older adults, but in 2021, deaths in younger persons increased while deaths in older persons decreased, a new study has found.
The increase in "years of life lost" was due to a shift toward younger people dying of Covid-19 during the first two years of the pandemic, according to the study by two investigators from Brigham and Women's Hospital in the US.
Earlier in the pandemic, age and pre-existing conditions played a major role in developing public health advice.
But by early 2021, the Covid-19 landscape had shifted completely and vaccines became available, treatments advanced and people's behaviours changed.
While 2020 Covid death rates were high among older adults, those older adults exhibited a relatively higher vaccination rate and adhered more strictly to nonpharmaceutical interventions throughout 2021.
Such systemic and behavioural changes in response to Covid-19 impacted mortality rates and determined what ages, in what years, were higher risk.
"There were a lot of changes between the first and second years of the Covid-19 pandemic, " said corresponding author Mark Czeisler in the study published in Annals of Internal Medicine.
Between March 2020 and October 2021, COVID-19 maintained a spot as one of the top-five causes of death for US adults.
Its specific rank within that top-five, however, changed based on age, demonstrating a greater proportion of young people prematurely dying from COVID-19 in 2021.
Researchers quantified this downward age-shift in COVID-19 deaths, using 'Years of Life Lost' (YLL) rather than mortality.
Using these resources, the team calculated per cent of Covid-19 deaths and YLL per death.
Despite 20.8-per cent fewer Covid deaths in 2021 versus 2020, YLL increased 7.4-per cent.
"A shift in Covid-19 mortality to relatively younger people in the second pandemic year contributed to markedly increased premature mortality from this increasingly preventable death, " said Czeisler.
"Understanding the factors that contribute to this age shift is critical as we continue developing our knowledge of the COVID-19 pandemic, " the researchers noted.