Reinfection

 

                                   Reinfection

Some info on re-infection, optimistic.

For months now, people have been watching closely to see if it’s possible to get re-infected with the coronavirus. It’s taken a while for the signal-to-noise to get better, but by now there’s no doubt that the answer is yes, it’s possible. We’ve just had the first of these in the US, a man in Nevada who was infected twice six weeks apart, with the second round being worse than the first. And in the Netherlands, the first fatality from a reinfection has been reported. All this sounds immediately like bad news, but I’m going to break out the same advice I was handing out yesterday: don’t panic.

Why not? Because from everything we can see, re-infection is a very rare event. The confirmed examples worldwide could possibly be counted on your fingers (depending on whose count you believe) out of at least 38 million total cases. Looking at the Netherlands case, this was an 89-year-old patient with Waldenström’s macroglobulinemia, a type of leukemia that affects two different varieties of B-cells. She was being treated with chemotherapy to impair. B-cell production, and was thus immune compromised, and the second infection occurred two days after her latest round of treatment.

in each of these cases, the unfortunate patients involved were infected by different variants of the coronavirus than they had the first time around. That’s pretty much what you have to show to be sure that it’s a real re-infection – otherwise you’d always wonder if the virus had just never really been cleared the first time. The first-round versus the second-round sequences show some real differences – not gigantic ones, but real. Second, these two second-round viruses were different from each other as well, so it’s not like some particular new supervirus is stomping around re-infecting people around the world. Third, in neither of these reports was it the widely publicized D614G strain coming back around the second time. That mutation really doesn’t figure into either of these cases at all, so watch out for anyone who’s mixing those stories together.

Fourth – and here’s where we start digging into some details – note that the mutations in both of these new re-infection cases have nothing to do with the Spike protein. There’s no change in the Spike in the Nevada sequences (they both had D614G), and the changes in the Netherlands sequences are conserved ones that don’t lead to changes in the protein in that region. Antibodies don’t care about genetic sequences; they respond to the eventual proteins that are displayed, and from what I can see, the Spike proteins of all of these strains are identical.

That’s important for several reasons. For one, the vaccines under development are all raising antibodies and T-cells to the Spike region. That was identified early on as the most promising antigen, building on the work during the SARS and MERS outbreaks. Note also this new paper, a thorough look at the various antibody fractions in patients who have recovered from coronavirus infection. The authors find that Spike-targeting neutralizing antibodies persist out to the limits of their study (five to seven months) while antibodies to the nucleocapsid region (N), which are also raised in most people by infection, disappear more quickly.

--From an article by Lowe

So, reinfection occurs. It is rare. It involves a mutation of the organism, not a reestablishment of the original organism and the areas of the organism being targeted by the current research does not mutate so the proposed therapies should still work.