But a new study, published Thursday in The Lancet Infectious Diseases, shows how much worse the pandemic might have been, if not for the development of safe and effective COVID vaccines.

The study estimates that vaccines prevented 14.4 million COVID deaths between Dec. 8, 2020—the date when the first COVID vaccine was administered outside a trial setting—and Dec. 8, 2021. Had those deaths occurred, COVID’s death toll would jump from 6.3 million today to almost 21 million, a threefold increase.

The number of prevented deaths is even greater if “excess deaths” are counted, notes the study. “Excess deaths” use the gap between actual and pre-pandemic mortality levels to estimate the number of COVID and COVID-related deaths that may have gone unreported. The study estimates that without vaccines, COVID’s death toll may have reached as high as 31 million, 63% of which could have been prevented by vaccines. 

Still, the study’s authors note that a poor distribution of doses hindered the potential of vaccines. The COVID-19 Vaccines Global Access initiative, or COVAX, set a target of achieving 20% coverage among its 190 participating nations by the end of 2021. The World Health Organization’s target was more aggressive, targeting 40% global coverage by the end of 2021, and 70% by mid-2022.

But 96 countries, primarily lower- and lower-middle-income countries, failed to reach the WHO’s 40% coverage target by the end of 2021. The study calculates that, if those countries were able to vaccinate enough people to reach the 40% threshold, 600,000 deaths—or about 10% of the current reported death toll—might have been prevented.

“More lives could have been saved if vaccines had been distributed more rapidly to many parts of the world and if vaccine uptake could have been strengthened worldwide,” argues the study.

To date, 12 billion doses of COVID vaccines have been administered globally, according to Bloomberg’s vaccine tracker—or about 1.53 doses per person, still below the two doses necessary to be considered “fully vaccinated.”

The COVAX initiative was launched in April 2020 with the objective to provide more equitable access to COVID vaccines to lower-income countries. As of June, COVAX has delivered about 1.5 billion doses to 146 countries.

COVAX has been plagued by shortages as countries hoarded vaccine doses for their own populations, including for booster campaigns amid last year’s Delta surge. While COVAX now says it has enough donated doses to reach a 70% vaccination coverage target, the initiative says that storing and delivering doses remains a challenge. 

Last week, the World Trade Organization agreed to allow developing countries to suspend the intellectual property protections for some COVID vaccines, allowing for local manufacturing of generic vaccines. The waiver lasts for five years, and does not yet cover COVID tests nor treatments.

Vaccine manufacturers, like Pfizer, Moderna, and China’s Sinopharm, are currently racing to develop shots that target the Omicron variant, which has proved able to evade the protection offered by earlier vaccines. On Thursday, Moderna CEO Stéphane Bancel said that an Omicron-specific version of the company’s vaccine would be available by August.