In an effort to halt the projected wave of illnesses and hospitalizations this fall, the U.S. authorized the first significant modification to the Covid-19 vaccinations this week. However, it’s unclear how much protein the new booster shots will provide.  Without any information from clinical trials testing the modified doses in humans, the Food and Drug Administration and the Centers for Disease Control and Prevention approved the injections. 

The new boosters, which are approved for use in persons 12 and older, target the immune evasive and highly contagious omicron BA.5 subvariant that has been responsible for a spate of breakthrough infections this summer. 

The vaccinations also target the virus’s initial strain, which first appeared in Wuhan, China, in 2019. In order to guarantee that the new boosters would go into effect in time for the fall, the nation’s top health  officials moved quickly this summer. They fear that in winter, when people spend more time indoors, Omicron will take advantage of the warning efficacy of the older vaccines and trigger another wave of hospitalizations.

According to Heather Scobie, a CDC epidemiologist, as Omicron has continued to mutate into more and more transmissible sub variants that avoid the protection of the original vaccines, deaths and hospitalizations have increased. The new boosters are intended to re-establish the high levels of protection that immunizations displayed in early 2021, according to Dr. Peter Marks, director of the FDA unit that oversees vaccine reviews. 

However, Marks admitted that the federal government’s specialties simply do not yet know whether the boosters will achieve the demanding standards set by those doses.