The true number of COVID cases is underestimated by 60 percent.
The number of cases of COVID-19 could be underestimated by 60%, according to a study conducted in the United States. The scientists concluded that the number of registered cases of coronavirus disease “represents only a part of the estimated total number of infections.”
The findings, published in the Proceedings of the National Academy of Sciences, are based on a study that found that the number of reported cases “represents only a fraction of the estimated total number of infections.” This is important for how many Americans need to be vaccinated to stop COVID-19 outbreaks.
The document says that in some American states in the south and Midwest, especially in Arkansas, Missouri, and Louisiana, there are outbreaks caused by infections of the “Delta” variant among unvaccinated people.
“There are a variety of data sources that we can rely on to understand the COVID-19 pandemic,” says Adrian Raftery, a professor of sociology and statistics at the University of Washington and senior author of the study.
But, according to him, “each data source has its own shortcomings, which can give a biased idea of what is actually happening. What we wanted to do was to develop a framework that corrects the shortcomings in several data sources and uses their strengths to give us an idea of the prevalence of COVID-19 in a region, state, or country as a whole.”
The study included data on deaths; the number of tests performed every day, and the proportion of positive results. It is important to note that it also included data from studies of people randomly selected to detect COVID-19 in Indiana and Ohio.
Random sample surveys provide convincing evidence of the actual prevalence of the disease since they do not rely on people undergoing tests that often do not detect asymptomatic infections.
Based on the analysis of these data, the researchers found that up to 65 million Americans could have been infected with the coronavirus. Official estimates indicate about 33 million cases. Researchers at the University of Washington estimated that 60% of all cases were missed, and only one out of every 2.3 cases was counted in Indiana and Ohio.
On Monday, the number of cases of COVID, which is led by Johns Hopkins University in Baltimore and which is often referred to by the media, was almost 34.5 million people.
Underestimation may “depend on the severity of the pandemic and the number of tests,” says Nicholas J. Irons, co-author of the study. “If you have a condition with a severe pandemic, but limited testing, the under-reporting can be very high, and you miss out on the vast majority of infections that occur,” he said. – Or you may have a situation where testing is widespread, and the pandemic is not so serious. There, the rate of under-accounting will be lower.”
The findings are important for the prospect of achieving collective immunity, the point at which outbreaks end because the virus cannot find new hosts. As of May, scientists believed that the threshold of collective immunity for COVID-19 is about 80%, and this figure has increased with the appearance of very contagious variants, such as “Delta.”
The study shows that by the spring of 2021, about 20% of the US population was infected with COVID-19.
The results show that without a mass vaccination campaign, the United States is unlikely to achieve collective immunity shortly and, consequently, will suffer from waves of outbreaks of diseases, hospitalizations, and deaths.
Even with a mass vaccination campaign in the United States, it is unlikely that collective immunity will be achieved this year or perhaps ever, due to very contagious options, low levels of vaccine acceptance in some states and because children under 12 are not eligible for vaccination.
About 56% of Americans are fully vaccinated, but these vaccinations are distributed unevenly. The northeastern states tended to use the largest proportion of vaccines, while the states in the south and Midwest used the smallest.
This uneven distribution allowed the Delta outbreak to reach unvaccinated people in Arkansas, Missouri, and Louisiana. The vaccines currently allowed in the US are very effective against variants.
Low vaccination rates, including among medical workers, in turn, sparked a nationwide debate about vaccination requirements, when hospital networks and large city governments began to introduce mandatory vaccination of workers.
Also on Monday, the American Medical Association issued a joint statement with dozens of groups of doctors and nurses, in which it called for mandatory vaccination of medical workers. In particular, elderly care workers have one of the lowest vaccination rates in the medical industry. More than 40% of them have not yet been vaccinated.