First confirmed case in the US of reinfection by SARS-CoV-2

Since the emergence of the coronavirus disease (COVID-19) in December 2019, cases of reinfections have been reported worldwide. It is not yet clear whether being infected with coronavirus 2 (SARS-CoV-2), severe acute respiratory syndrome, will provide long-lasting immunity. Still, scientists hope it will be so so that vaccines can work efficiently.

Of the cases of reinfections around the world, scientists from the Nevada Institute of Personalized Medicine at the University of Nevada have reported a particular case. A 25-year-old man from Washoe County in the United States, the most affected country in the world, has more than 7.85 million cases.

Transmission electron micrograph of SARS-CoV-2 virus particles isolated from a patient. Image captured and color enhanced at NIAID’s Integrated Research Facility (IRF) at Fort Detrick, Maryland. Credit: NIAID

A case of reinfection

The patient presented to a community testing event conducted by the Washoe Country Health District on April 18 with symptoms of cough, sore throat, nausea, headache, and diarrhea that began on March 25. The patient had no history of any underlying health conditions, and during isolation, his symptoms improved. He recovered on April 27.

The patient resumed his daily activities and continued to feel well until May 28. On May 31, the patient went to an emergency center for headache, fever, dizziness, cough, nausea, and diarrhea. He was finally discharged after a chest X-ray. However, five days later, the patient became hypoxic with shortness of breath and was directed to go to the emergency department for further assistance.

Reinfection by Covid in a 25-year-old man in Nevada, confirmed by genomic sequencing of the virus; Second most serious infection @TheLancetInfDis https://t.co/nbIn5aNYJ0 pic.twitter.com/IpSkKKapNm

– Eric Topol (@EricTopol) October 12, 2020

Two positive tests

At each occurrence of his symptoms, he had nasopharyngeal swabs. He was also tested twice during follow-up. To determine whether the disease can be attributed to a single coronavirus strain, the team evaluated the sequence data using two different bioinformatics methodologies.

The first nasopharyngeal swab obtained at the community screening event in April tested positive for SARS-CoV-2 on real-time RT-PCR. The two follow-up tests were negative. When the patient’s symptoms reappeared in May, the sample tested positive for SARS-CoV-2 infection.

The second episode was worse because the patient needed continuous oxygen in the hospital. The chest radiograph results showed irregular, bilateral, and interstitial opacities suggesting viral or atypical pneumonia. Also, on June 6, the patient was tested for antibodies to SARS-CoV-2 and the results were positive, meaning that he had been infected with the virus.

Given that the patient had two episodes of symptoms consistent with COVID-19, with positive tests separated by up to 48 days, the case can be considered a reinfection.

“Our findings have implications for the role of vaccination in response to COVID-19. If we have indeed reported a case of reinfection, the initial exposure to SARS-CoV-2 might not result in a level of immunity that protects all people 100%, ”the authors wrote in the article.

“With regards to vaccination, this understanding is established, and influenza regularly shows the challenges of designing an effective vaccine,” they added.

Understanding the mechanism of infection and whether reinfection can occur is vital to developing effective vaccines. In this way, they have a better understanding of the possibility of reinfection in some patients who have already recovered from COVID-19.

The case study is published in The lancet.

Global toll

COVID-19 is wreaking havoc around the world, making it more critical that vaccines are ready as soon as possible. Some countries that have flattened the curve have reported second waves of infection.

The global number of cases has reached more than 38 million cases, with at least 1 million people dying from the SARS-CoV-2 infection. The United States reports the highest number of cases, with more than 7.85 million infections, followed by India, with at least 7.17 million confirmed cases.

Other countries that report high infections are Brazil, with more than 5.11 million cases, Russia, with more than 1.31 million cases, and Colombia with more than 924,000 cases.

With the alarming number of cases globally, the race to find an effective vaccine against COVID-19 is on, with more than 200 vaccine candidates. Currently, more than 40 are in clinical evaluation, while ten are in phase III vaccine trials.