COVID-19, Harvard Gazette: “Protection against reinfection: COVID patients may be protected for up to four months”
2012-08-31: SARS-COV-2 IGG QUAL Neg
A negative test result means that SARS-CoV-2 specific antibodies were not detected in the specimen above the limit of detection... This test was performed using Diasorin Liaison XL methodology which is designed to detect IgG antibodies to the spike protein of SARS-CoV-2. COVID-19 lab tests are currently reviewed by the FDA under Emergency Use Authorization (EUA).
I had my COVID-19 IgG antibody test about 4.5 months after my 2.5 week April health episode. My working theory has been that my ongoing EBV/Hashimoto’s problem might have been triggered by CV19. The findings below cast doubt on that theory. However, a single small study is never something to rely on, and the work doesn’t go beyond 4 months.
If “protection against reinfection” is not immunity, then I don’t know what it is. Maybe someone fact-check the fact-checkers at Twitter and their ilk.
Protection against reinfection: COVID patients may be protected for up to four months
People who survive serious COVID-19 infections have long-lasting immune responses against the virus, according to a new study led by researchers at Harvard-affiliated Massachusetts General Hospital (MGH).
The study, published in Science Immunology, offers hope that people infected with the virus will develop lasting protection against reinfection. The study also demonstrates that measuring antibodies can be an accurate tool for tracking the spread of the virus in the community.
...The researchers found that levels of an antibody called immunoglobulin G (IgG) remained elevated in infected patients for four months and were associated with the presence of protective neutralizing antibodies, which also demonstrated little decrease in activity over time.
“That means that people are very likely protected for that period of time,” said Charles. “We showed that key antibody responses to COVID-19 do persist.”
They also found that measuring IgG was highly accurate in identifying infected patients who had symptoms for at least 14 days...
In another finding, Charles and her colleagues showed that people infected with SARS-CoV-2 had immunoglobulin A (IgA) and immunoglobulin M (IgM) responses that were relatively short-lived, declining to low levels within about two and a half months or less, on average.
“We can say now that if a patient has IgA and IgM responses, they were likely infected with the virus within the last two months,” said Charles.
Peter K writes:
Antibody testing just has many limitations, and the fact that your body actively filters them out as part of its daily cleanup isn’t helping them to register on tests.
Since you’re an athlete, and I’m assuming still riding at least one bike, you’re helping the process of filtering them out. So it’s no surprise to me that you tested negative.
As an anecdote, my sister developed Covid toes, which is an indisputable sign she had antibodies in her system. Yet, 2-3 months later, negative antibody test.
Another example would be me, as a celiac. As long as I’m not ingesting gluten or any of its components, negative antibody test. Even if I start ingesting them, it won’t show sufficiently for a diagnosis. If I ingest moderately and exercise heavily, still insufficient, even though I have clear symptoms. It’s only after prolonged exposure and buildup in the body that antigens will show sufficiently. It’s just the nature of the tests, you have to be sick enough for long enough for it to show in the results.
WIND: I was in exceptionally strong condition prior to my 2.5-week April episode (having come off strong fitness from two double centuries in March as well as being fully acclimatized to high altitude). I've long felt that my body in such condition just deals with stuff aggressively—I hardly ever get sick, and my body seems to eliminate toxins and drugs quickly.
It took me 3-4 weeks after that to get my fitness up to acceptable levels again (for me), and I was seemingly OK on and off, but any hard physical effort seemed to wipe my out like it never had before, such as my ascent of White Mountain Peak. Normally I’d recover from that relatively moderate effort (see hard core) in a day or so, but I could hardly walk 1/4 mile on level ground without feeling exhausted. It took a full week to feel semi normal, which is not to say strong. Whatever hit me has had a lasting impact even here in mid-October eg EBV and Hashimoto’s Thyroiditis.