Modeling studies have shown that the COVID-19 vaccine prevented 20 million deaths worldwide in the first year of its availability.

In the first modeling study to quantify the effects of the COVID-19 vaccine globally, experts found that 19.8 million of the potential 31.4 million deaths were prevented in the first year after the vaccine was introduced. It is estimated that it was done.

In addition, studies published in Lancet infectionEstimates that an additional 599,300 lives would have been saved if the World Health Organization (WHO) goal of vaccination of 40% of each country’s population at least twice by the end of 2021 was met. .. According to the author, this study is based on data from 195 countries and regions and is the first to assess mortality avoided directly and indirectly as a result of COVID-19 vaccination.

“Our findings provide the most complete assessment of the significant global impact of vaccination on the COVID-19 pandemic to date,” lead author Dr. Oliver Watson said in a press release. I am saying. “Of the estimated 20 million deaths that were estimated to have been prevented in the first year after the introduction of the vaccine, about 7.5 million deaths were prevented in the countries covered by the COVID-19 Vaccine Access Initiative (COVAX).”

Studies show that nearly 66% of the world’s population has received at least one dose since the first COVID-19 vaccine was given outside the clinical trial setting on December 8, 2020. The COVAX program has facilitated access to affordable vaccines for low-income countries to reduce inequality. The initial goal was to give 20% of the population of the COVAX target country two doses by the end of 2021. Expanded by WHO, the goal is to fully vaccinate 70% of the world’s population by mid-2022.

Despite the speed of global vaccine deployment, more than 3.5 million COVID-19 deaths have been reported since the first vaccine was given in December 2020. Global impact, not state, state, or city.

“Vaccine access varies from country to country, making it difficult to quantify the global impact of vaccination. Gene sequence data available in many countries is very limited and which COVID-19 The same is true of understanding whether a variant is prevalent, “said the co-lead author. Press release Gregory Barnsley. “It is also not possible to directly measure how many deaths occurred without vaccination. Mathematical modeling provides a useful tool for assessing alternative scenarios that are not actually directly observable.”

To estimate the impact of global vaccination efforts, researchers have identified officially recorded COVID-19 deaths that occurred between December 8, 2020 and December 8, 2021. We used an established model of COVID-19 infection using country-level data. A fictitious scenario where the vaccine was not provided.

Based on officially recorded COVID-19 deaths, researchers found that an estimated 18.1 million deaths would have occurred during the study period if vaccination had not been distributed. Of these, the model estimates that vaccination will prevent 14.4 million deaths, a reduction of 79% worldwide.

In particular, these findings do not take into account the underreporting of COVID-19 deaths, which is common in low-income countries. To explain this, the researchers conducted a further analysis based on total mortality over the same period. They found that COVID-19 vaccination prevented an estimated 19.8 million deaths out of a total of 31.4 million deaths that could have occurred without vaccination. This is equivalent to a 63% reduction.

More than three-quarters (79%) of the avoided deaths resulted in lower mortality due to direct protection against the severe symptoms posed by vaccination. The remaining 4.3 million preventive deaths were estimated to have been prevented by indirect protection from reduced transmission of the virus in the population and reduced burden on the health system.

Researchers have also found that as the pandemic progresses, the effects of vaccines change over time in different parts of the world. In the first half of 2021, the maximum number of deaths avoided by vaccination was seen in low- and middle-income countries as a result of the significant epidemic wave seen in India when the Delta variant emerged. rice field. Since then, this trend has shifted to the greatest impact of concentrating on high-income countries in the second half of 2021 as travel and social gathering restrictions have been relaxed.

Overall, estimated per capita deaths are highest in high-income countries, reflecting the early and widespread deployment of vaccines in these regions. High- and middle-income countries had the highest number of deaths avoided, demonstrating unequal access to vaccines around the world.

Of the 83 countries included in the COVAX analysis, an estimated 7.4 million deaths were avoided from the potential 17.9 million (41%). However, it is estimated that an additional 156,900 people have died because some countries failed to meet the goal of immunizing 20% ​​of the population. Studies show that these deaths are concentrated in 31 African countries, and if the goal was achieved, 123,700 deaths could have been prevented.

Similarly, researchers estimate that failure to meet WHO’s goal of fully immunizing 40% of each country’s population by the end of 2021 contributed to an additional 599,300 deaths worldwide. I found that. Studies show that most of these deaths are in low- and middle-income countries.

“Our study shows that the vaccine has provided significant benefits in reducing COVID-19 mortality worldwide,” said Azlagani, MBE, Chairman of Infectious Disease Epidemiology at Imperial College London. FMedSci said in a press release. “The focus on pandemics has now changed, but the most vulnerable people in all parts of the world continue to affect the continuous circulation of COVID-19, and the poorest, disproportionately. It is important to ensure that you are protected from major illnesses. “

reference

Lancet infections: The COVID-19 vaccine is estimated to have prevented 20 million deaths worldwide in the first year of the vaccine program. news release. EurekAlert; June 23, 2022. Accessed on June 28, 2022. https://www.eurekalert.org/news-releases/956782