When Did COVID-19 Really Hit the US?

COVID-19 may have arrived in the US earlier than health officials thought

(RxWiki News) COVID-19 might have arrived in the United States earlier than we realized.

That's the key finding of a new study from researchers at the National Institutes of Health (NIH). This study tested blood samples collected before the pandemic hit in full force to see if they contained COVID-19 antibodies.

Antibodies to COVID-19 in the blood suggest that the person had been exposed to the COVID-19 virus. The body's immune system produces antibodies when it is exposed to pathogens in an effort to fight off the invading virus or bacteria.

“Antibody testing of blood samples helps us better understand the spread of SARS-CoV-2 in the U.S. in the early days of the U.S. epidemic, when testing was restricted and public health officials could not see that the virus had already spread outside of recognized initial points of entry,” said lead study author Dr. Keri N. Althoff, of the Johns Hopkins Bloomberg School of Public Health, in a press release.

The study authors looked for antibodies in more than 24,000 stored blood samples from all 50 states. In nine of those samples, these researchers detected COVID-19 antibodies.

The blood samples that showed COVID-19 antibodies came from people who were nowhere near New York City and Seattle. Health officials believed that these cities were major points of entry for the virus in the US, but this finding suggests this may not be true.

The positive samples came from Illinois, Massachusetts, Mississippi, Pennsylvania and Wisconsin. In most cases, the samples were collected before the first reported cases in each state, suggesting that cases were circulating well before state officials knew about them.

Some of the positive samples were collected as early as Jan. 7, 2020, the study authors noted.

US health officials strongly recommend getting the COVID-19 vaccine and continuing to maintain pandemic precautions until you are fully vaccinated. Speak with your health care provider if you have any questions or concerns about COVID-19 or the available vaccines.

This research was published in the journal Clinical Infectious Diseases.

The NIH and National Cancer Institute funded this study. Information about potential conflicts of interest was not available at the time of publication.

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Review Date: 
June 23, 2021