A simulation result is reported that the death toll would have quadrupled without the new corona-GIGAZINE vaccine

by Elvert Barnes

In the United States, on January 24, 2023, the number of deaths due to the new coronavirus infection (COVID-19) has passed 1.1 million.breaking new groundand has the highest number of casualties in the world. Seeing so many deaths in the United States, which developed a vaccine before the world and promoted vaccination by raising the country, there are people who wonder, “After all, vaccines were meaningless?” There may be others, but a study indicated that if there was no vaccine, the number of deaths in the United States would have quadrupled.

Two Years of COVID Vaccines Preventing Millions of Hospital Deaths | Commonwealth Fund
https://doi.org/10.26099/whsf-fp90

US COVID death toll would be 4X higher without vaccines, modeling study finds | Ars Technica
https://arstechnica.com/science/2022/12/us-covid-death-toll-would-be-4x-higher-without-vaccines-modeling-study-finds/

In the United States, more than 655 million doses of the new coronavirus vaccine have been administered since December 2020, with 80% of the population receiving at least one dose. In order to verify the effectiveness of these vaccination programs, a team led by Allison P. Galvani of the Yale Center for Modeling and Analysis of Infectious Diseases modeled and simulated the impact of the COVID-19 pandemic and vaccines.

The ‘age-stratified, pathogen-based model of COVID-19’ used by the research team included COVID-19 risk by age, US demographics, prevalence of co-morbidities, pandemic policy and associations that accounted for movement of people. parameters such as patterns, vaccine efficacy, and reduction in immunity conferred by vaccination or infection. In addition to the original Wuhan strain, five mutant types of the new coronavirus (SARS-CoV-2) were assumed: the Iota strain, the alpha strain, the gamma strain, the delta strain, and the Omicron strain.

Using this model, we ran a simulation comparing the “counterfactual scenario” of what would happen if there was no vaccine and the trajectory of the pandemic that was actually observed. Between December and November 2022, vaccination prevented 3.25 million deaths, avoiding 119.85 million infections. and 18.6 million in hospital.

Below is a graph comparing people infected with COVID-19 per 100,000 population in the United States (orange line) and the no vaccination scenario (dashed blue line).

With 798,000 COVID-19 deaths, 82 million cases, and 4.8 million hospitalizations during the same period, deaths are 4.1 times higher and infections 1.5 times higher without a vaccine, the number of hospitalized patients increased 3.8 times, and it is estimated that the required additional medical costs reached 1 trillion dollars (about 130 trillion yen).

The simulation showed that the vaccine prevented tens of millions of COVID-19 infections, which is said to be more significant than the numbers. This is because COVID-19 has risks such as “long COVID”, which has long-term effects on cognitive functions and other factors even after recovery, and deterioration of physical strength.

He pointed out that “long COVID”, where the symptoms of the new coronavirus last for a long time, is more dangerous than known-GIGAZINE

Given that multiple variations occur, the effectiveness of the vaccination program becomes more apparent. In particular, the Omicron strain has a high ability to evade immunity, and the appearance of this mutant strain caused a large increase in the number of COVID-19 cases, but the vaccine also prevented hospitalization and death of infected people. Galvani and his colleagues note that some reports that “the Omicron strain is mild” are mainly due to the protection provided by the vaccine.

Furthermore, the research team said, “The unprecedented speed of vaccine development and deployment has saved many lives, eased restrictions on COVID-19 measures to make them safer, and allowed businesses, schools and other activities to continue . has resumed. Moving forward, how to speed up booster vaccination will be the basis for avoiding serious cases and deaths in the future.”