Should we be concerned that there was a COVID outbreak among vaccinated people in a Kentucky nursing home? – Hot air

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Outbreaks shouldn’t happen among the vaccinated, right? Last week, the CDC told us it had found only 5,800 confirmed cases of COVID out of 66 million people who had been vaccinated, a percentage of .008 percent. If that percentage applies universally, there should be no infections in a nursing home of a few dozen people. At most, there should be one purely fluky.

Viewed through that lens, yes, an outbreak of any kind among every vaccinated cohort is of concern, as it strongly suggests that there are many more undetected “breakthrough infections” among vaccinated people than the CDC knows. In the case of the Kentucky nursing home, in addition to a group of vaccinated residents, they had a group of unvaccinated residents and staff, so they went ahead and tested everyone. See, they found a lot of asymptomatic infections among those who got vaccinated.

So maybe the “true” infection rate among the vaccinees is more than 0.8 percent instead of 0.008. Maybe it’s even higher and the CDC is still in the dark.

On the other hand, virologists are celebrating the nursing home’s data as it proves that the vaccines provide strong protection even when the conditions for a truly devastating outbreak are all in place. The case involved an elderly population living close together in the midst of an outbreak that infected dozens – and to top it all off, the virus infecting them was found to have several mutations known to make it more dangerous than the standard coronavirus. A year ago, such a situation would have cut a trail through the house. As it is now, in this case only one vaccinated resident died. Most of them didn’t even have symptoms.

The outbreak involved a variant of the virus with multiple mutations in the spike protein, the kind that makes the vaccines less effective. Vaccinated residents and health workers at the Kentucky facility were less likely to be infected than those who were not vaccinated, and they were much less likely to develop symptoms. The study estimated that the vaccine, identified as Pfizer-BioNTech, showed an effectiveness of 66 percent for residents and 75.9 percent for workers, and was 86 percent to 87 percent effective at protecting against symptomatic disease.

In the Kentucky outbreak, the virus variant is not listed among the CDCs considered to be of concern or interesting variants. However, the study authors note, the variant has several important mutations: D614G, which shows evidence of increased transmissibility; E484K in the receptor binding domain of the spike protein, also seen in B.1.351, the variant first recognized in South Africa, and P.1. from Brazil; and W152L, which could reduce the effectiveness of neutralizing antibodies.

Raw figures: 75 of the 83 inhabitants were vaccinated. All eight non-vaccinated were infected during the outbreak, compared to only 18 vaccinated. So with an unpleasant variation at work in a group of elderly and sick people, the vaccines still prevented infection in more than two-thirds of the elderly and prevented symptoms in more than 85 percent of the entire group. Of the eight unvaccinated residents who were infected, two died, but of the 18 who became infected despite vaccination, only one did. A public health professor was amazed that the vaccines held up just as well as in a group with a weaker immune system fighting a variant with an impending mutation:

According to the Times, more data came out of Chicago nursing homes today. Of the 78 institutions, there were 627 infections among residents and staff – but only 22 among vaccinated people and two-thirds of them were asymptomatic. Yet another “breakthrough infection” study at Rockefeller University looked at 417 school employees who had been fully vaccinated to see how many were infected. Answer: Two, at a rate of 0.5 percent. That’s 60 times higher than the 0.008 percent rate the CDC revealed last week, but still very small. And it should go without saying that the number of “breakthrough infections” can be higher or lower within different age groups. Among a group of vaccinated elderly whose immune systems are no longer what it used to be, even after being prepped by Pfizer and Moderna, the percentage is perhaps one percent or higher. Among a group of healthy young adults who have been vaxed, this may even be less than .008 percent.

Regardless, the percentage experiencing symptoms within both groups will be much less than the number of infections, and the percentage needing hospital care will be even lower.

On the other hand, Patterico has a point here. If more vaccinated people become infected than we know, more vaccinated people can transmit the virus than we suspect:

I threw the .008 percent figure to experts like Fauci for the past week when they recommend vaccinated people stay out of restaurants until the community spread is lower. I still think advice is too cautious as the number of “breakthrough infections” remains extremely low by any standard (as Fauci himself acknowledges). But those infections seem to be more common than the one in 11,000 ratio implied by the CDC’s data, given the results from Rockefeller U and the Kentucky nursing home. How much more often? * Shrug * But you can understand why vaccinated older people in particular continue to take basic precautions when they are indoors and around large groups of strangers, at least until we get a little closer to the immunity of the herd. For example, a one in 100 chance of infection is significantly different from one in 11,000.

I leave you with this, a reminder that herd immunity is not only real, it is also spectacular.

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