Covid vaccines cut the global death toll by 20 million in the first year after they were available, according to the first major analysis.
Lo studio, which modelled the spread of the disease in 185 countries and territories between December 2020 and December 2021, found that without Covid vaccines 31.4 million people would have died, and that 19.8 million of these deaths were avoided. The study is the first attempt to quantify the number of deaths prevented directly and indirectly as a result of Covid-19 vaccinations.
“We knew it was going to be a large number, but I did not think it would be as high as 20 million deaths during just the first year,” said Oliver Watson, of Imperial College London, who is a co-first author on the study carried out by scientists at the university.
Many more deaths could have been prevented if access to vaccines had been more equal worldwide. Quasi 600,000 additional deaths – one in five of the Covid deaths in low-income countries – could have been prevented if the World Salute Organization’s global goal of vaccinating 40% of each country’s population by the end of 2021 had been met, the research found.
“Our findings show that millions of lives have likely been saved by making vaccines available to people everywhere, regardless of their wealth,” said Watson. "Tuttavia, more could have been done.”
He said that while it remained vital to provide vaccines worldwide, particularly to high-risk individuals, in many parts of the world with low vaccine coverage there were high levels of immunity due to previous infection, meaning the opportunity to save lives had narrowed.
Since the first Covid vaccine was administered outside a clinical trial setting su 8 dicembre 2020, almost two-thirds of the world’s population have received at least one dose of a vaccine, and the Covid-19 vaccines global access initiative (Covax) has facilitated access to affordable vaccines for lower-income countries to try to reduce inequalities.
Lo studio, published in the journal Lancet Infectious Diseases, used official figures – or estimates when official data was not available – for deaths from Covid, as well as total excess deaths from each country. Excess mortality is the difference between the total number of people who died from all causes and the number of deaths expected based on past data, and in many countries these figures give the most reliable picture of Covid deaths.
These analyses were compared with a hypothetical alternative scenario in which no vaccine was administered. This means the figures capture the direct protection of vaccines for individuals and also the wider benefits to the health system, for instance the effect on mortality rates of more hospital beds being available.
The figures probably represent the upper end of how many deaths were avoided had no vaccines been available, as policies around lockdowns, ad esempio, would have been different.
Prof Azra Ghani, a chair in infectious disease epidemiology at Imperial College London, disse: “Our study demonstrates the enormous benefit that vaccines had in reducing deaths from Covid-19 globally. Whilst the intense focus on the pandemic has now shifted, it is important that we ensure the most vulnerable people in all parts of the world are protected from ongoing circulation of Covid-19 and from the other major diseases that continue to disproportionately affect the poorest.”