Data from the Centers for Disease Control and Prevention (CDC) reveal that boosters lose part of their effectiveness after four months.
Two studies published on the CDC website on Saturday examined vaccine effectiveness (VE) relative to preventing COVID-19-related emergency department and urgent care (ED/UC) visits.
Urgent care refers to admittance into the intensive care unit and if conditions worsen, the need for a ventilator.
The data from the studies include records of over 240,000 hospitalizations or urgent care visits from 10 states from August 26, 2021 to January 22, 2022.
After the first two months following a booster, VE was at about 91% at preventing ED/UC. After four months, VE drops to 66% at preventing ED and 78% at preventing UC.
The two studies “reinforce the importance of further consideration of additional doses to sustain or improve protection against COVID-19–associated ED/UC encounters and COVID-19 hospitalizations.”
In other words, the CDC requires further research to determine if a fourth dose should be recommended.