According to a new study, at least twice as many people in the US have developed antibodies to the new coronavirus as official numbers suggest.
Researchers looked at the results of tests that determine if someone is infected and if their body has produced immune cells that can protect them from re-infection.
Results, which were analyzed until September 30 last year, showed that 6.6 percent of people have antibodies against the virus.
That’s more than double the 2.1 percent of Americans with then-confirmed cases of COVID-19.
The team at Clinical Reference Laboratory Inc., based in Lenexa, Kansas, says this means that by the end of the summer of 2020, nearly 16 million people will be infected, rather than the official 7.1 million.
It also means that the number of confirmed cases in the US could actually be around 60 million instead of the confirmed 29.4 million – but it still indicates that only 18 percent of the people are infected, which is far from the immunity of the herd of ice.
A new study looked at 61,910 participants who tested for coronavirus antibodies by September 30, 2020, and 6.6% tested positive. Pictured: Healthcare worker draws blood from sheriff in Los Angeles County during antibody test in Pico Rivera, California, February 2021
New York had the highest percentage of positive antibody tests with 14.4% and Alaska had the lowest percentage with 0% (above). Researchers say their findings suggest that by September 30, 15.9 million people were infected with COVID-19 rather than the 7.1 million confirmed cases
Antibody tests, known as a serology test, are looking for antibodies against the new coronavirus.
Blood is collected through a vein and can only be analyzed in a certified laboratory. Looks like someone was once exposed and is now immune.
Some tests identify the IgG antibody, a protein that the body produces in the late stages of infection and that can last for months and possibly years after a person has recovered.
Others detect the antibody, IgM, which is made by the body a few days after infection.
Health officials say the test could help scientists understand how widespread the virus is, how many people come in contact with the virus and do not get sick, and how long patients remain immune after recovering.
For the study, published in JAMA Network Open, the team looked at 61,910pparticipants tested for antibodies to the virus known as SARS-CoV-2 until September 30, 2020.
The test used by Roche Diagnostics had a reported sensitivity and specificity rate of 99.5 percent and 99.8 percent, respectively.
Sensitivity is how often people who have been infected in the past correctly determine and specifically how those identify those who have never been infected.
Of the patients, 4 094 tested positive for antibodies.
Among demographic groups, antibodies were found to have slightly more women than men at 6.9 percent versus 6.4 percent.
In addition, these older than 70 years the lowest rate was 2.8 percent and younger than 30 years had the highest rate at 9.8 percent.
Researchers also looked at the number of people who tested positive for antibodies based on condition.
New York had the highest rate with 14.4 percent, which is not surprising since the country at the time had the highest number of infections.
Louisiana, Nevada, Florida and Mississippi rounded out the top five.
Alaska had the lowest percentage, zero percent, but only 85 people were tested for antibodies. The other four states with the lowest rates were Maine Oregon, Hawaii and New Mexico.
Based on the findings, the team believes that there was 15.9 million asymptomatic or undiagnosed COVID-19 infections in the US from 30 September 2020.
That is more than double the then 7.1 million confirmed infections, based on data from Johns Hopkins University.
It also means that the actual number of cases in the US could actually be closer to 60 million rather than the 29.4 million confirmed.
“Our estimate implies more than twice the number of infections as cases reported to Centers for Disease Control and Prevention, indicating a more widespread pandemic,” the authors write.
‘The findings of this cross-sectional study suggest that the total number of SARS-CoV-2 infections in the US, based on a sample from an otherwise healthy population, may be significantly higher than estimated based on reporting on public health. ‘
