This post is part of an occasional series on health care. Here’s the prologue to the series, which originally preceded the post below.

Here’s a fairly straightforward story from The New York Times from a few days back, reminding us of the fact that immunity from some of the COVID vaccinations is limited in time, and may well require a booster shot.

 WASHINGTON — Biden administration health officials increasingly think that vulnerable populations will need booster shots even as research continues into how long the coronavirus vaccines remain effective.

Senior officials now say they expect that people who are 65 and older or who have  compromised immune systems will most likely need a third shot from Pfizer-BioNTech or Moderna, two vaccines based on the same technology that have been used to inoculate the vast majority of Americans thus far. That is a sharp shift from just a few weeks ago, when the administration said it thought there was not enough evidence to back boosters yet.

On Thursday, a key official at the Centers for Disease Control and Prevention said  the agency is exploring options to give patients with compromised immune   systems third doses even before regulators broaden the emergency use authorization for coronavirus vaccines, a step that could come soon for the Pfizer    vaccine.

Skipping a bit:

Pfizer’s continuing global study of its clinical trial participants shows that four to six months after the second dose, the vaccine’s effectiveness against symptomatic infection drops from a high of 95 percent to 84 percent, according to the company.

As a (then) full-time hospital worker actively exposed to high concentrations of COVID, I got my second dose of the Pfizer-BioNTech shot on January 6. If the vaccine’s effectiveness definitely drops from 95% to 84% in four to six months, then I’m well past my due date for a booster. Though I’m no longer a full-time hospital worker, I’ve been waiting for twelve weeks now for the paperwork to go through on my bid to work per diem for Hunterdon Medical Center’s OR. Assuming it goes through, I’ll be back in the COVID-intensive environment I previously inhabited. And if it doesn’t go through, I intend to apply to do the same work at a different hospital. So one way or another, I intend to make my way back to hospital work, and (by implication) to re-immerse myself in COVID.