"More people are getting COVID-19 twice, suggesting immunity wanes quickly in some" - sciencemag.org

[Hugin]

- snip -

South Korean scientists reported the first suspected reinfections in April, but it took until 24 August before a case was officially confirmed: a 33-year-old man who was treated at a Hong Kong hospital for a mild case in March and who tested positive again at the Hong Kong airport on 15 August after returning from a trip to Spain. Since then, at least 24 other reinfections have been officially confirmed—but scientists say that is definitely an underestimate.

To count as a case of reinfection, a patient must have had a positive polymerase chain reaction (PCR) test twice with at least one symptom-free month in between. But virologist Chantal Reusken of the Dutch National Institute for Public Health and the Environment (RIVM) explains that a second test can also be positive because the patient has a residue of nonreplicating viral RNA from their original infection in their respiratory tract, because of an infection with two viruses at the same time or because they had suppressed but never fully cleared the virus. So most journals want to see two full virus sequences, from the first and second illnesses, that are sufficiently different, says Paul Moss, a hematologist at the University of Birmingham. “The bar is very high,” Moss says. “In many cases, the genetic material just isn’t there.”

Even if it is, many labs don’t have the time or money to clinch the case. As a result, the number of genetically proven reinfections is orders of magnitude lower than that of suspected reinfections. The Netherlands alone has 50 such cases, Brazil 95, Sweden 150, Mexico 285, and Qatar at least 243.

- snip -

They could become more common over the next couple of months if early cases begin to lose their immunity. Reinfections with the four coronaviruses that cause the common cold occur after an average of 12 months, a team led by virologist Lia van der Hoek at Amsterdam University Medical Center recently showed. Van der Hoek thinks COVID-19 may follow that pattern: “I think we’d better prepare for a wave of reinfections over the coming months.” That’s “bad news for those who still believe in herd immunity through natural infections,” she adds, and a worrisome sign for vaccines."

From: https://www.sciencemag.org/news/2020/11/more-people-are-getting-covid-19-twice-suggesting-immunity-wanes-quickly-some

Well, reinfection occurs with the other four coronaviruses which cause the so-called common cold. So, it's not surprising if it happens with the COVID virus also.

[C_U_L8R]

1. Our friends' kid got it twice.

Once last winter and then again right now. Tested many times along the way. Their doctors explained the same thing this article says, the antibodies/immunity fade after a few months.

[Hugin]

2. I'm terribly sorry to hear that.

The down side to this revelation is that vaccinated persons may need a booster every six months to a year. The up side is that after a few years of building an immune response boosters could be reduced in strength or become unnecessary. Also, I'm wondering if those who have recently had the COVID virus could be successfully vaccinated with a lower dose vaccine.

But, I know nothing.

Stay safe CU. I hope the kid is on the mend.

[Mike 03]

3. Kicking

Doctors and virologists very early on on "Doctor Radio" (SiriusXM) said this could well be the case because coronaviruses are like this (like colds). Then they stopped talking about it when all the vaccines went into development.

Anecdotal stories piled up, but I was hoping people were shedding dead virus particles.

Well, now that multiple infections are being confirmed scientifically, i guess we have to face this new unwelcome complication. I wonder what this means in terms of the frequency of vaccinations. Four shots a year (two and two spaced six months apart? Will that be enough? Do we need six shots a year? Two, two and two spaced four months apart? This will be fun.)

[Hugin]

4. Hey, Mike. Thanks for the thoughts.

So many unknowns.

It is getting better, though. Now there are tools and we need to figure out the best way to use them.