Coronavirus Latest: Experts Concerned As Reinfections Occurring In Shorter Intervals, Also New Study Shows Antibodies In Infected Diminish In About 60 Days

Coronavirus Latest: Contrary to all the hyped up news about potential drug candidates discoveries, latest research revelations about the virus pathogenesis, about advances in monoclonal antibody therapies and about COVID-19 vaccines that are in expected to be available before the end of the year thanks to the White House intervention, the COVID-19 pandemic is far from going to be over as the ever evolving SARS-CoV-2 coronavirus still has lots of surprises in store for us and we have yet witness the full magnitude of its destructibility against the human host body. We have only just perhaps seen and understanding just a minor fraction of what it can do to the human body as part of the long term health complications for those who survived the initial stages of infection.


 
While researchers strive to develop viable and effective antivirals and vaccines to counter the growing COVID-19 crisis, there is growing uncertainty about how long and how durable the immunity induced by SARS-CoV-2 coronavirus is.
 
In a new concerning development, researchers from Fort Belvoir Community Hospital-Virginia, the Naval Medical Research Center-Maryland, the Uniformed Services University-Maryland and Johns Hopkins University report of a yet another new documented case of reinfection of a young male but in this case within a time of interval of only 51 days from the recovery of his first infection. Furthermore as in other reported emerging cases and a growing trend, in the second infection, the symptoms and conditions were far more worst off.
 
The case study was published in the journal: Clinical Infectious Disease https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1436/5908892
 
Initial reports of a patient who had recovered from COVID-19 but again tested positive for the virus was the starting point for much discussion and research on whether the infection indeed induced lasting immunity against re-infection, like many other viral illnesses. Another area of concern was whether re-infection if it happened, could lead to severe COVID-19 just like the original infection.
 
In April 2020, about 50 patients in South Korea were reported to have tested positive after having been declared to have recovered and discharged home. Initially, it was felt that they were cases of reactivation. A second hypothesis was that the test kits had produced false-positive results by picking up viral remnants rather than whole infectious virions. Neither was ever concluded.
 
Then in August 2020, however, an irrefutable documented case of re-infection occurred, when a Hong Kong man tested positive some four and a half months from the first infection. This episode was remarkable in that the re-infection was less severe, producing none of the COVID-19 symptoms. The reinfecting strain was different from the original strain, confirming that this was no reactivation.
 
Then another case report from Nevada suggested that all re-infections need not follow this pattern, with the patient developing more severe symptoms the second time around. This time, too, the second infection occurred with another strain than that whic h caused the first infection.
 
There is also a hypothesis floating around that is more alarming concerning the possibility that the virus inside the patient’s body could mutate to a new strain, which would mark a fourfold jump in the known rate of viral mutation if confirmed.
 
Numerous other cases of documented reinfections have since emerged all over globally including numerous India, Italy, Brazil and China.
 
Although only a handful of true re-infections have been reported worldwide, this does raise many questions about whether all patients develop neutralizing antibodies, and if so, how long do they last? How does this impact the prospects of universal COVID-19 vaccination? How often can re-infections be expected to occur? And do re-infected asymptomatic patients continue to shed the virus, thus serving as unsuspected reservoirs of infection?
 
Many other scientists researchers have pointed out that with the known seasonal coronaviruses, re-infections naturally occur quite commonly, typically at about a year, indicating transient protective immunity.
 
In this case study of re-infection that occurred less than 90 days (51 days) of the original SARS-CoV-2 infection is the shortest duration of interval between infections ever documented.
 
The male patient was in the military medical corps, a 42-year-old who developed cough, fever, and muscle aches at the end of the third week of March 2020. He reported workplace exposure to the virus, and a reverse transcriptase-polymerase chain reaction (RT PCR) was negative. The illness resolved by the tenth day, and his health was excellent, as before infection, for the next 51 days.
 
However at this point, he again developed fever, dyspnea and gut symptoms after having been exposed to a case of COVID-19 in his household. The symptoms were noticeably worse than those of the first infection. Radiologic signs were positive for pulmonary infiltration, as was the RT PCR test for SARS-CoV-2. The serum sample obtained from him a week after the onset of the second episode showed the presence of IgG antibodies to the viral spike protein.
 
The study team attempted to culture the virus unsuccessfully, but RNA sequencing was done, generating a SARS-CoV-2 genome. The genome sequence from the first infection was built using some fragments of viral RNA amounting to just over 4,000 base pairs, with the rest being sequenced from the second illness.
 
Detailed phylogenetic analysis showed this virus had the lineage B.1.26, and it encoded the D614G spike protein mutation associated with increased infectivity.
 
However when the two sequences were compared, the researchers discovered multiple potential variations, of which at least one was associated with a high confidence level.
 
The study team point out that this patient was a young male with robust immunological function, but with a more severe clinical course in the second infection. This raises the question of whether this could have been due to antibody-dependent enhancement (ADE), a phenomenon in which non-neutralizing antibodies help a different strain of the virus to infect host cells rather than hinder viral infection. This was seen with the earlier SARS and MERS outbreaks.
 
It was also suggested that other possible reasons for the re-infection include exposure to a more pathogenic strain or a higher dose of the virus during the second exposure within the household. And since both strains were non-identical, this means that immunologists need to identify conserved viral antigens, which do not undergo significant mutation, to develop a vaccine against COVID-19.
 
The team concludes, “The clinical, epidemiological, and sequencing data of this case suggest early re-infection with SARS-CoV-2, only 51 days after resolution of initial infection. This will add to the knowledge base about the possibility of re-infection with this virus, and reinforce the need for surveillance, especially of healthcare workers who are not only more likely to be exposed to the virus but may be involved in its transmission in healthcare settings, as well.”
 
In yet another concerning study conducted by researchers from the Centers for Disease Control and Prevention-Atlanta, and the Vanderbilt University Medical Center, the study team alarmingly discovered changes in antibodies to SARS-CoV-2 over 60 days among 600 infected healthcare personnel in Nashville, Tennessee.
 
The study findings were published in the JAMA journal. https://jamanetwork.com/journals/jama/fullarticle/2770928
 
The study team stated that in view of the reports of declines in immunoglobulin antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among patients with symptomatic or asymptomatic infections, the team examined the duration of antibody response to SARS-CoV-2 infection among health care personnel, who may be at particular risk if antibody levels decline.
 
Among 600 eligible health care personnel, the first 249 volunteers (64.5% female; 91.6% White; median age, 33 years; range, 21-70 years) provided serum samples at baseline; of these, 230 (92%) returned for a second blood draw.
 
Detailed analysis revealed that over 60 days, health care personnel had reduction in anti–SARS-CoV-2 antibodies to the spike protein, which have correlated with neutralizing antibodies, with 58% of seropositive individuals becoming seronegative.
 
Interestingly as the decline in the signal-to-threshold ratio was consistent irrespective of the baseline ratio and there was a higher proportion of asymptomatic participants becoming seronegative, the interpretation as a true decline over a 2-month period rather than an artifact of assay performance is supported. 
 
The study team said if replicated, these research results suggest that cross-sectional seroprevalence studies to evaluate population immunity may underestimate rates of prior infections because antibodies may only be transiently detectable following infection.
 
Furthermore, the window after recovering from SARS-CoV-2 infection when people could donate serum that has sufficiently high antibody levels may be limited.
 
The team commented that the implications for health care personnel with antibodies assigned to care for infected patients depend on whether decline in these antibodies increases risk of reinfection and disease, which remains unknown, especially given the lack of data on memory B-cell and T-cell responses.  Limitations of this study include its single-center setting, small sample size, convenience sampling, and lack of information on timing of infection to evaluate antibody kinetics.
 
With all these new findings the big question is are vaccine developers really sure of what they are doing or were they merely in a fast rush and interest for monetary gains that they jumped to fast into vaccine developments and trials without getting all the proper studies done and procuring the relevant data. There is growing consensus that the vaccines that are already being used in China, Russia and those in phase 3 trials will likely not help in curtailing the growing pandemic rather there could be the high possibility they could backfire and cause more problems.
 
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