The COVID-19 pandemic brought an unprecedented and devastating scenario as millions of families lost their loved ones to the deadly virus.

Based on latest data, the viral infection was the leading cause of death among people between 45 and 54 years old in the United States. This was during the period between January and October 2021.

Between March 2020 and October 2021, COVID-19 was the third leading cause of death in the country, accounting for one in eight deaths, or roughly 350,000 deaths documented within the period.

The figures were presented in a study published Tuesday in JAMA Internal Medicine. For the study, the researchers at the National Cancer Institute analyzed the national death certificate data.

For the March-December 2020 period, COVID-19 was the fourth leading cause of death in the 45 to 54 age group. Meanwhile, the viral infection was the fifth leading cause of death among people between 35 and 44 during the same period.

But during the January-October 2021 period, researchers noticed that the number of deaths in the two age groups significantly increased. In the 45 to 54 group, COVID-19 became the first leading cause of death. In the 35 to 44 group, it became the second leading cause of death.

In 2020, COVID-19 was the second leading cause of death in people aged 85 and above. It dropped to third in 2021 due to the targeted vaccination efforts in this age group, as per the National Institutes of Health.

The researchers indicated that the data did not include the deaths recorded during the omicron wave that started in late 2021.

Since October 2021, around 300,000 more people in the U.S. have died from the novel coronavirus, according to Ars Technica.

Heart disease remained the leading cause of death overall, followed by cancer. Both causes of death accounted for a total of 1.29 million fatalities during the 20-month period.

Based on collected data, the fourth and fifth leading causes of death in Americans were accidents and stroke.

The researchers acknowledged that their study was limited by potential misclassification of the cause of death and incomplete death data on death certificates.