After discovering that about 3,900 people who received Pfizer COVID-19 vaccinations at the Kaiser Permanente Walnut Creek (Calif.) Medical Center in late 2021 may have received a slightly less than recommended dose, Kaiser announced it will offer repeat vaccinations to those potentially affected, the health system said in a statement shared with Becker's.
Hospital officials said the individuals who received vaccinations at the medical center between Oct. 25 and Dec. 10 may have received between 0.01 and 0.04 milliliters less of the recommended 0.3-milliliter dose.
Kaiser Permanente said it is contacting patients about the issue and that it immediately consulted with experts in infectious diseases and vaccine science and reviewed CDC guidelines.
"All experts agreed the difference between the recommended dose and the dose an individual may have received was not significant and not likely to reduce their protection against COVID-19. Nevertheless, Kaiser Permanente is offering to provide a repeat dose of Pfizer vaccine to any affected individual who wishes to receive it, offering special hours and locations," the health system said.
Kaiser Permanente attributed the "isolated incident" to some staff misunderstanding instructions and potentially drawing slightly less than the recommended vaccine dose.
"We took immediate steps to confirm that the issue was isolated and promptly retrained staff and validated their understanding of the correct procedure. We are continuously monitoring so this does not happen again," the health system said. "We sincerely apologize for any concern or inconvenience this may cause for those patients we are contacting."