EU regulators caution that too many booster shots could weaken immune systems

Regulators in the European Union warned recently that receiving frequent COVID-19 booster shots could have an adverse affect on the immune system. 

According to the European Medicines Agency, receiving a booster every four months could ultimately weaken an individual's immune system. For that reason, the agency is recommending that countries space out booster campaigns and have them correspond with the onset of cold and flu season. 

The recommendation arrives as a number of countries contemplate offering residents another round of booster shots as a way to fight the Omicron variant of the virus. Individuals over 60 in Israel can now receive a second booster shot (fourth shot total). 

The head of biological health threats and vaccines strategy at the European Medicines Agency, Marco Cavaleri, said boosters are "not something that we can think should be repeated constantly."

"We need to think about how we can transition from the current pandemic setting to a more endemic setting," he said, matching the recent comments of WHO envoy Dr. David Nabarro.

The highly contagious Omicron variant has been spreading rapidly across the globe (more than 2.8 million new cases of the virus were reported Tuesday), though early evidence suggests symptoms from Omicron may be less severe than previous strains.