The New York Times reports:

Over the last few months, a steady drumbeat of headlines has highlighted the astounding real-world effectiveness of the Covid-19 vaccines, especially the mRNA vaccines made by Pfizer-BioNTech and Moderna. The vaccines, study after study has shown, are more than 90 percent effective at preventing the worst outcomes, including hospitalization and death.

But alongside this good news have been rare reports of severe Covid in people who had been fully vaccinated.

On June 3, for instance, Napa County announced that a fully vaccinated woman, who was more than a month past her second Moderna shot, had died after being hospitalized with Covid. The woman, who was over 65 and had underlying medical conditions, had tested positive for the Alpha variant, which was first identified in Britain.

Although these cases are tragic, they are uncommon — and not unexpected.

“I’m very sad that she had a sufficiently severe illness that it actually led to her death,” said Dr. William Schaffner, medical director of the National Foundation for Infectious Diseases and a vaccine expert at Vanderbilt University. But, he noted, “we expected to have the occasional breakthrough infection.”

Such cases should not dissuade people from getting vaccinated, scientists said. “There is not a vaccine in history that has ever been 100 percent effective,” said Dr. Paul Offit, the director of the Vaccine Education Center at Children’s Hospital of Philadelphia. “This is your best chance of avoiding severe, critical disease. But as is true of everything in medicine, it’s not perfect.” [Continue reading…]