This week may mark the beginning of a new phase in our Covid journey at Kendal. As I write this (August 12, 2021), I have just learned of a new positive Covid test among the residents in Westmoreland, our skilled-nursing area. It is the latest case in an outbreak here that started more than a week ago.

This new case is significant for two reasons. First, it adds to the 4 cases in Westmoreland that we just learned of yesterday, and to 6 cases among independent-living residents (also confirmed yesterday). All of these are “breakthrough” cases in fully-vaccinated people. Second, this individual tested negative a week earlier. That could either mean the earlier test was after infection but before the person had developed a detectable viral load, or it could mean the person was infected since the earlier test. Either way, it means that we can’t really say if we have our outbreak under control.

At this point, it is my understanding that there are over 50 residents in quarantine because contact-tracing efforts have shown that they were exposed to one of the positive cases. I myself was in a meeting with a person who subsequently developed symptoms and tested positive, so Jan and I are among the quarantined. We have tested negative and have not shown any symptoms. “Quarantine,” in this case, means not leaving our cottage (except to tend our flower bed), no face-to-face contacts, and our dinners are brought to us.

It’s not just Kendal. There are outbreaks occurring in other “congregate-living” settings across the country. The most detailed information about this comes from the nursing-home data collected by the Centers for Medicare & Medicaid Services (CMS). In addition to typical nursing homes, the data includes nursing facilities in retirement communities such as ours. An analysis of CMS data by National Public Radio showed a big acceleration in nursing-home Covid cases in late June through early July (the most recent data available at the time). Many of these were cases in vaccinated residents. For example, at a Masonicare skilled-nursing facility in Connecticut, there was an outbreak of 21 cases, all in fully-vaccinated residents.

These outbreaks could be a reflection of the greater infectivity of the Delta variant, which now dominates US cases.

Current status of breakthrough infections. At least some level of breakthrough infection was expected. As the New York Times recently pointed out, “The vaccines were intended to prevent hospitalization and death by producing antibodies in the blood that prevent the coronavirus from taking root in the lungs and other organs.” The vaccines are very successful at this. But they are not able to eliminate infections in the nasal passages, where the Delta virus manages to replicate in large numbers.

An article in The Intelligencer, a newsletter put out by New York magazine, does a good job of summarizing the situation with breakthrough infections. They are far higher now than they were a few months ago. A widely-cited study by the Kaiser Family Foundation, which came out in July, found that only a fraction of a percent of those who contracted Covid were fully vaccinated. But that was based on mainly pre-Delta data. Now, the rates are much higher. In Delaware, for example, 13.8% of July cases were breakthrough cases in vaccinated people.  

In the Intelligencer article, there is a lengthy interview with Dr. Michael Mina, a Covid researcher at Harvard Medical School. He is worried about the waning of immunity in older people. That decline could lead to more infections starting about 9 months after vaccination. As we reach that point, Mina believes “we will start to see outbreaks, hospitalizations, and deaths happen in nursing homes and senior living facilities amongst vaccinated people.”

Mina continues, “I can almost guarantee that our senior citizens will get boosters in the U.S. In the next two months, I think the CDC is going to recommend it — there’s no way they’re not.”

Mina thinks Covid will continue to circulate permanently, like the flu. Also like the flu, he thinks we will all end up developing some level of immunity to many different variants of Covid, until the point is reached that Covid’s repertoire of genetic variation is exhausted, a process that might take up to a couple of years. That is when Covid will be considered “under control.”

That’s certainly not an argument that it’s useless being vaccinated. Mina emphasizes that vaccines are essential to prevent serious illness. But they don’t prevent all infections; and when vaccinated individuals do become infected, the viral load in their nasal passages can be as high as in unvaccinated individuals. That means they can readily transmit the disease to others. Mina concludes: “And so if peak viral loads are not differing between the vaccinated and the unvaccinated, … I think we’re pretty much going to see unabated transmission amongst vaccinated.”

What’s happening in our area? Here at Kendal, it seems likely that we are already seeing “transmission amongst vaccinated.” It’s too soon to say whether it is occurring in other similar settings. I downloaded the latest available data from the CMS website (which is for the week ending August 1) and there is no sign of any major outbreaks in nursing facilities in neighboring parts of Pennsylvania, Delaware, or New Jersey.

But our outbreak is too new to show up in that data. Perhaps, when it does appear there (about two weeks from now) the data will show other outbreaks as well. If Mina’s predictions are correct, it’s only a matter of time.