As COVID-19 has loomed over the world like a dark cloud, scientists have been frantically working on vaccines that will bring this nightmare to an end, and each vaccine announcement has brought about new moments of hope. History has shown us that pandemics have a time limit and an end-of-life cycle, and as more of the population is vaccinated as well as develops antibodies from having the virus, we desperately want to return to some state of “normal.” However, viruses have survived throughout the millennia due to their ability to mutate and with mutations comes the potential for reinfection. Although instances of reinfection are currently small, the importance of testing is showing that they are happening and the number may be under reported.
What Is Reinfection?
We look to organizations such as the CDC (Center for Disease Control) for guidance and answers on the pandemic. But if you go to the CDC page for reinfection information, you will find very little that can be of any help:“In general, reinfection means a person was infected (got sick) once, recovered, and then later became infected again. Based on what we know from similar viruses, some reinfections are expected.”Learning about how reinfection occurs requires research into some of the world’s scientific studies. Those that are looking into the topic know that this condition is considered to be rare and that since those that have COVID-19 symptoms a second time don’t assume that it is the virus, they will more than often simply disregard it and don’t even both getting tested. Without testing results that confirms reinfection, there is no logical way to gauge exactly how many people are reinfected.As with so much having to do with this virus, science is continually learning the progressive stages and changes. Those patients that did suspect that they were reinfected with COVID-19 and did get tested have given the medical community some data. To be considered as reinfected, a patient’s test must be positive for PCR (polymerase chain reaction) twice and have had a minimum of one symptom-free month in between the testing. However, as a side note, due to the residue of non-replicating viral RNA residue, a patient can test positive a second time and not necessarily be reinfected. This is because the original infection may still remain in their respiratory tract due to infection with two viruses simultaneously or because the virus was suppressed but never fully cleared. Scientists are requiring proof of two full virus sequences that show sufficient differences from the first and second illness.
Scientists Sharing the Information
As you can see, the data requirement is not only more in-depth, but it has high requirements to see exact genetic material to be defined as a reinfection. With so much focus on COVID-19 testing, labs are stretched to the limit to accommodate the existing number of test cases. Most labs around the globe don’t have the budgets or the time to do the kind of detailed testing to offer reinfection results. As of this writing, there have been 50 cases of reinfection reported in The Netherlands, 95 in Brazil, 150 in Sweden, 285 in Mexico, and 243 in Qatar. Scientists are speculating that in the next months there may be more reported cases of reinfection due to some patients losing their immunity. This concept is based on the fact that the four coronaviruses that cause the common cold have reinfection at an average of 12 months. Amsterdam University Medical Center team led by Lia van derk Hoek, virologist, indicated that the COVID-19 virus may follow the same type of behavior: “I think we’d better prepare for a wave of reinfections over the coming months….it is “bad news for those who still believe in herd immunity through natural infections.” It’s also a time to be concerned regarding vaccines.
Reinfection Symptoms Less or More Severe?
Until more cases are examined, the jury will still be out on this question. In some situations such as a Hong Kong patient, the symptoms of the second infection were milder than the first one. In other cases, such as one in Rio de Janeiro, the experience was just as bad as the first infection. One study at Seattle’s Swedish Medical Center indicate that mutations of the virus could cause it to be more pathogenic or that they may cause the virus to evade immunity. Thus far, many of the reinfections reported run the gamut of combination symptoms. There is also the possibility that a secondary infection could have the kind of results that occurs in dengue fever where the reinfection causes an immune system misfiring and actually helps the dengue viruses of another serotype enter the cells so that it not only causes more severe symptoms but can sometimes also be fatal. Some in the medical community are being a bit more optimistic. Studies in general show that antibodies may lessen in months following infection but sometimes they persist. The most important neutralizing antibodies as well as the memory T cells and B cells appear to have stability over at least six months. This condition would prevent most people from getting higher levels of severity of the virus. There is a report that is shining a bit of light on data from patients that have had the most serious COVID-19 symptoms. These individuals may have the strongest responses to coronaviruses by triggering high antibody levels that have lasted as long as two years and SARS T cell responses that have been detected for even longer time periods. Some disease experts are indicating that they expect that a majority of reinfections will be asymptomatic and may be a method to train and boost the immune system on an ongoing basis. The global scientific community continues to learn about the COVID-19 virus and to maintain this ever-changing condition, we must have more data which is derived from ongoing testing.