New research from the World Health Organization suggests that the Covid-19 pandemic caused a far greater number of deaths than official figures indicate. According to the authors of the study, there would have been about 15 million more pandemic-related deaths in 2020 and 2021, most of which are caused directly by the virus. Unexpectedly, excess deaths were even higher in 2021, despite the arrival of several highly effective vaccines to prevent serious complications.
From the beginning of the pandemic, scientists were aware that officially reported deaths were underestimated. At first, testing for the virus was scarce worldwide, making it difficult to officially determine whether a person had died from the infection. While rich countries have made progress in documenting deaths over time, those with weaker health systems have continued to struggle. Not to mention the accusations leveled at some countries of intentionally underestimating deaths, providing numbers that are inconsistent with data collected elsewhere.

New WHO study, how it reached conclusions
WHO's new estimates published in Nature (I'll link them here) are among the most comprehensive ever for the first two years of the pandemic on a global scale. The "hunt" for hidden deaths was carried out by carefully calculating the deaths in excess of the "baselines" of expected mortality.
The research team led by the statistician William Msemburi, resulted in excess mortality in more than 200 countries and territories. Not an easy task, as only a minority of these countries (52%) had nationwide death data available for analysis. For other, often low-income countries, the team had to turn to local data sources or use data from other countries to estimate expected and excess mortality.
The final estimate is that the pandemic has caused an excess of 14,83 million dead in 2020 and 2021, approximately three times the official number of covid-19 deaths in the same period. The 1918 flu pandemic killed between 25 million and 50 million people, it is the only one in the last 100 years to come close to this number. Among the countries analysed, there are few with data that is almost identical, or slightly different: most have "overstepped", in some cases even a lot. In the USA, for example, the estimate is over a million more deaths than the "official" ones.

The excess number of deaths forces us to revise the balance sheet of our response to Covid
What we are finding on the shoreline after this tsunami is bleak. With 4,47 million more deaths in 2020 and 10,36 million more deaths in 2021, the questions still open are more and more. First of all: the one on the contribution of vaccines. Why were there more deaths in the year of vaccines than in the previous one? First of all, because in 2021 global lockdown policies were less stringent. Secondly, says Msemburi, it is true that many vaccines arrived in 2021, widely used in "rich" countries. They have probably helped to save many lives, avoiding even worse damage (net of the "adverse reactions" denounced by various critical voices, which should also be the subject of further investigations). However, access to these vaccines has been delayed, guilty, in many less developed parts of the world. And the emergence of new variants have caused even more serious or more easily transmissible diseases in some groups of the population.
It does not end here
Msemburi's team is still researching different types of deaths during the pandemic. In some regions, some causes of death have decreased due to indirect factors, such as reduced use of cars (with fewer road accidents). This suggests that the estimated deaths may still be low compared to reality.