A 25-year old man in Nevada is the first person in the United States to get diagnosed with a COVID-19 reinfection, and the results are not good. The details were published in The Lancet Infectious Diseases yesterday. Scientists compared the genetic codes of the virus to determine that it was two distinct infections. Globally there have been 22 cases of reinfection documented.
“The implications of reinfections could be relevant for vaccine development and application,” the authors of the study concluded.
- March 25 – He began to experience symtoms, including cough, headache sore throat, nausea and diarrhea.
- April 18 – His first positive test.
- April 27 – Symptoms resolve.
- May 26 – He has his second negative test.
- May 28 – He begins experiencing a cough, headache, nausea and diarrhea, as well as a fever and dizziness.
- June 5 – He tests positive again. His symptoms worsen with difficulty breathing and his blood oxygen levels are lower than normal.
The patient has since recovered. He is reported to have experienced a more severe case of the virus with his second illness, which required him to be hospitalized for breathing difficulty.
That he experienced a more serious illness was disappointing news for scientists and doctors who thought there was the possibility that if an individual did get infected twice, they might experience a less severe case the second time. The rationale for that line of thought was the first episode would teach the body how to fight the virus.
Potential Reasons for Increased Severity
The Nevada patient may have been exposed to a higher dose of the virus the second time. An alternative explanation is the first response from his immune system could have caused the second infection to be worse. This phenomenon is seen with some other viruses. This man did not have any pre-existing conditions and was otherwise healthy.
Implications for Herd Immunity
There has been speculation on how long it would take to acquire herd immunity for COVID-19. That is when enough of the population has become immune to a disease, either by getting the disease or from receiving a vaccine. The result is a significant reduction in the spread of the disease.
The realization that an infection does not necessarily provide immunity makes the search for an effective and safe vaccine even more critical.
In light of the high rate of asymptomatic cases of COVID-19, it is possible that the actual numbers of patients who experience multiple bouts of the virus is higher. The takeaway from this new development is that people need to continue to exercise caution even if they have been previously diagnosed with COVID-19. They need to wear masks and practice social distancing.
COVID 19 Reinfection in US — Sources
The Lancet Infectious Diseases – Genomic evidence for reinfection with SARS- CoV-2: a case study