Vaccinations may have prevented almost 20 million COVID-19 deaths worldwide

Global COVID-19 vaccine impact

Vaccinations estimated to have averted 19.8 million COVID-19 deaths worldwide in their first year, according to the latest Imperial modelling study.

In the first year of the vaccination programme, 19.8 million out of a potential 31.4 million COVID-19 deaths were prevented worldwide according to estimates based on excess deaths from 185 countries and territories. These findings were published by Imperial College London's MRC Centre for Global Infectious Disease Analysis in The Lancet Infectious Diseases.

COVID-19 Vaccine Access initiative

Since the first COVID-19 vaccine was administered outside of a clinical trial setting on 8 December 2020, almost two thirds of the world’s population has received at least one dose of a COVID-19 vaccine (66%).

If the targets set out by the WHO had been achieved, 1 in 5 lives lost due to COVID-19 in low-income countries could have been prevented. Dr Oliver Watson MRC Centre for Global Infectious Disease Analysis

The COVID-19 Vaccine Access initiative (COVAX) has facilitated access to affordable vaccines for lower income countries to try to reduce inequalities, with an initial target of giving two vaccine doses to 20% of the population in countries covered by the commitment by the end of 2021.

The World Health Organisation expanded this target by setting a global strategy to fully vaccinate 70% of the world’s population by mid-2022, with an interim target of vaccinating 40% of the population of all countries by the end of 2021.

Excess deaths

To estimate the impact of global vaccination programmes, the researchers used an established model of COVID-19 transmission using country-level data for officially recorded COVID-19 deaths occurring between 8 December 2020 and 8 December 2021 (the first year of the global vaccination programme). To account for under-reporting of deaths in countries with weaker surveillance systems, they carried out a separate analysis based on the number of excess deaths recorded above those that would have been expected during the same time period. Where official data was not available, the team used estimates of all-cause excess mortality. These analyses were compared with an alternative hypothetical scenario in which no vaccines were delivered.

The model accounted for variation in vaccination rates between countries, as well as differences in vaccine efficacy in each country based on the vaccine types known to have been predominately used in those areas. Notably, China was not included in the analysis owing to its unique position as the origin of the detected epidemic and its large influence on estimates of deaths averted stemming from its population size.

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WHO target

Despite the incredible speed of the vaccine roll-out worldwide, more than 3.5 million COVID-19 deaths have been reported since the first vaccine was administered in December 2020.

Between December 2020-December 2021, the researchers found that COVID-19 vaccination prevented an estimated 19.8 million deaths out of a total of 31.4 million potential deaths that would have occurred without vaccination, a reduction of 63%.

An additional 81,750 deaths could have been averted had the COVAX target of 20% been met by each country. Similarly, 599,300 lives could have been saved if the World Health Organisation’s target of vaccinating 40% of the population in each country with two or more doses by the end of 2021 had been met.

Equitable access

The study shows that vaccination has had a substantial impact on the trajectory of the COVID-19 pandemic. Having high vaccine coverage and access to more efficacious vaccines, higher income countries had more deaths averted per vaccine. The findings illustrate the broader impact of COVID-19 vaccination, allowing these countries with high vaccine coverage to relax interventions. 

Ensuring fair access to vaccines is crucial, but requires more than just donating vaccines. Professor Azra Ghani MRC Centre for Global Infectious Disease Analysis

Researchers highlight the importance of equitable access to vaccines, particularly in low-income regions, where substantially more lives could have been saved if the vaccination targets set out by the COVID-19 Vaccines Global Access (COVAX) Facility (20% coverage in COVAX Advance Market Commitment countries by the end of 2021) and WHO (40% coverage in each country by the end of 2021) had been reached.

Dr Oliver Watson said: “Our findings offer the most complete assessment to date of the remarkable global impact that vaccination has had on the COVID-19 pandemic. Of the almost 20 million deaths estimated to have been prevented in the first year after vaccines were introduced, almost 7.5 million deaths were prevented in countries covered by the COVID-19 Vaccine Access initiative (COVAX). This initiative was set up because it was clear early on that global vaccine equity would be the only way out of the pandemic. Our findings show that millions of lives have likely been saved by making vaccines available to people everywhere, regardless of their wealth. However, more could have been done. If the targets set out by the WHO had been achieved, we estimate that roughly 1 in 5 of the estimated lives lost due to COVID-19 in low-income countries could have been prevented.”

Professor Azra Ghani said: “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. Ensuring fair access to vaccines is crucial, but requires more than just donating vaccines. Improvements in vaccine distribution and infrastructure, as well as coordinated efforts to combat vaccine misinformation and improve vaccine demand, are needed. Only then can we ensure that everyone has the opportunity to benefit from these life-saving technologies.”