immunity and virus neutralizing capabilities will be critical to control the anticipated worsening of the SARS-CoV-2 pandemic however already emerging studies are indicating that there could be many complications and disappointments although numerous pharmaceutical and biotech companies along with certain governments are trying to conceal these news in order to either profit from the trillions of dollars now at stake in vaccines and antibody treatments and also to maintain political control.
Till now, it has been assumed that patients who were infected with SARS-CoV-2 will develop antibodies as it is the case with other coronaviruses, like MERS-CoV and SARS-CoV. However it is beginning to emerge that this is not the case and even when antibodies and T-Cells are found in these incidences, there is no full proof that they could offer protection against reinfections. This has many implications in vaccines that are under development.
In the present German research, the study team analyzed the antibody development of 77 oncology patients 26 days after positive RT-qPCR testing for SARS-CoV-2. RT-qPCR and anti-SARS-CoV2-antibody methods from BGI (MGIEasy Magnetic Beads Virus DNA/RNA Extraction Kit) and Roche (Elecsys Anti-SARS-CoV-2 immunoassay) were used, respectively, according to the manufacturers’ specifications.
Shockingly, only 6 of 77 individuals with a confirmed history of COVID-19 antibody development was detected. Despite multiple testing, the remaining patients did not show measurable antibody concentrations in subsequent tests.
These study results undermine the previous hypothesis that SARS-CoV-2 infections are regularly associated with antibody development and cast doubt on the provided immunity to COVID-19. Understanding the adaptive and humoral response to SARS-CoV-2 will play a key-roll in vaccine development and gaining further knowledge on the pathogenesis.
The study findings were published on a preprint server and have yet to be peer reviewed. https://www.researchsquare.com/article/rs-71560/v1
The new research data suggest that an infection with SARS-CoV-2 is not automatically accompanied by antibody development. After the peak of positive SARS-CoV-2 PCRs in Bavaria between April 15 and March 30, there should now be a peak phase of antibody development in those patients.
However the study results however clearly indicate that far from all patients develop antibodies, as has shown multiple testing at regular intervals. This is particularly interesting in view of the therapies administered during this period.
Most of the patients tested positive in RT-qPCR received the first negative RT-qPCR result 13 days (in median, SD 8,1) after confirmation of the positive test. The timeframe of positive PCR detection of the virus was therefore only a few days. The reason for the short time interval of positive RT-qPCR results might be a low virus load to which patients are exposed.
From patient surveys the study team presumed that the patients consistently adhered to the requirements of social distancing and may therefore only been exposed to low virus concentrations. Since the team assumes that patients with a low viral load may not be infectious, the vi
ral load determination could be used to enable selective isolation measures, which would make a decisive socioeconomic contribution.
The patient cohort of oncological patients is particularly suitable for this purpose, as they are predominantly asymptomatic SARS-CoV-2 carriers.
An additional explanation for the mild cases could be special oncological therapies that inhibit virus replication and thus have a positive effect on the course of the infection. So far it is largely unclear why many infected tumor patients remain asymptomatic or show only mild symptoms, whereas previously healthy individuals can develop a fatal infection. This illustrates the importance of determining the viral load in addition to RT- qPCR test.
Significantly the observed lower incidence of COVID-19 disease in oncology patients offers a completely new perspective on the possible underlying pathomechanisms of the disease.
However the limitations of the study are that only a small sample size of only 77 patients was used although they have been followed up over a relatively long period of time. In addition, only one test (Roche) was used to test antibody development, even though the test has a sensitivity of up to 100% and a specificity of 98% according to the manufacture´s specification.
Also the cohort consisted of only oncology patients, including immunosuppressed patients and thus represents a special cohort.
But when focused on non-hospitalized cases of COVID-19 is a strength and represent real-world data of outpatient oncology medical care.
It has to be noted that RT-qPCR only shows a test result at a certain point in time, whereas antibody tests can provide information about an infection that has occurred in the past. Moreover, it could be that antibody tests detect patients who were infected earlier, without being tested by RT-qPCR. However, further investigations are needed to determine which patients infected by SARS-CoV-2 develop antibodies and if this provides immunity. Antibody tests cannot replace the RT-qPCR but could provide further information on immunity.
According to the study team, a negative test cannot rule out an infection that has already occurred. A positive antibody development, however, indicates that the patient has been infected. Comprehensive testing of the population could provide important information on the number of infected persons.
The study team advocates that antibody tests should be widely available, but in combination with RT-qPCR, solely due to our data which demonstrates that some infected individuals do not develop antibodies
As far as the understanding goes, on how the mechanism works but determine who develops antibodies and who does not, both tests should be comprehensive. This is particularly important, as it is assumed that people who have suffered from the infection will automatically become immune.
Although the study data shows that this is not the case and that these patients could be reinfected. This could prove to be a special challenge for those countries that pursue the strategy of herd immunity. Due to the novelty of SARS-SoV-2, there are still no long-term studies on answering the question whether people who have experienced the disease are protected from new infections; therefore it is important to follow an antibody development through long-term studies to find out how long they provide immunity to COVID-19.
This also underlines the urgent need to validate the antibody detection approaches to support diagnosis, vaccine development and safety.
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