Day 538: Breaking Through

The New York Times addresses vaccine breakthrough cases:

An outbreak in Provincetown, Mass., illustrates how quickly a cluster can grow, given the right conditions. During its famed Fourth of July celebrations, the small town hosted more than 60,000 unmasked revelers, dancing and mingling in crowded bars and house parties.

The crowds this year were much larger than usual, said Adam Hunt, 55, an advertising executive who has lived in Provincetown part time for about 20 years. But the bars and clubs didn’t open until they were allowed to, Mr. Hunt noted: “We thought we were doing the right thing. We thought we were OK.”

Mr. Hunt did not become infected with the virus, but several of his vaccinated friends who had flown in from places as far as Hawaii and Alabama tested positive after their return. In all, the cluster has grown to at least 256 cases — including 66 visitors from other states — about two-thirds in vaccinated people.

“I did not expect that people who were vaccinated would be becoming positive at the rate that they were,” said Steve Katsurinis, chair of the Provincetown Board of Health. Provincetown has moved swiftly to contain the outbreak, reinstating a mask advisory and stepping up testing. It is conducting 250 tests a day, compared with about eight a day before July 1, Mr. Katsurinis said.

Health officials should also help the public understand that vaccines are doing what they are supposed to — preventing people from getting seriously ill, said Kristen Panthagani, a geneticist at Baylor College of Medicine who runs a blog explaining complex scientific concepts.

“Vaccine efficacy isn’t 100 percent — it never is,” she said. “We shouldn’t expect Covid vaccines to be perfect, either. That’s too high an expectation.”

Delta is doing a number on Israelis, who have determined that the Pfizer vaccine is now only 39% effective at preventing infection, though it continues to prevent 91% of serious illnesses and 88% of hospitalizations. Yes, those numbers are backwards; the article does not explain why 3% of cases are hospitalized for non-serious COVID.

Pfizer is due to finish long-term safety testing in May of 2023, not long after Moderna does. By then, we may even have an experimental vaccine against the common coronavirus.

In the US the CDC is holding firm on its no-mask guidance. While the delta variant has been shown to be big in Texas, our troubles are not all delta: Illinois reports more than six times as many gamma variant cases as delta variant ones.

Here in Massachusetts, cases are creeping back up and rose an entire thirteenth of a percentage point today, with cases averaging about 500 a day this week.