Though COVID-19 vaccines and boosters provide strong protection against severe disease, hospitalizations, and deaths, the quickly-spreading Omicron variant remains a significant challenge. With a daily average of more than 750,000 cases in the U.S., some doubt the vaccines' effectiveness and wonder, 'Why get the booster if I can still get infected?"

But Dr. Eric Topol, founder and director of the Scripps Research Translational Institute, said people's doubts are misplaced.

"The Omicron variant provides "a 90% reduction of hospitalizations," Topol said, adding that after three months that number can drop to 80%.

That is still comparable to two doses versus the original strain, Topol said.

Third doses of Pfizer (PFE)/BioNTech's (BNTX) and Moderna (MRNA)'s shots — both mRNA vaccines — have shown strong results against Omicron. And Johnson & Johnson's (JNJ) has shown its two doses are able to hold durable protection over a long period of time.

But because the U.S. has a low booster rate, the Omicron variant is affecting more people, though overall the strain is milder compared to previous variants. It's why hospitalizations continue to strain the country's health care systems, setting new records daily, with more than 159,000 individuals in hospitals now, according to the CDC.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, recently told Yahoo Finance that ongoing protection from vaccines is why the U.S. is holding off on fourth doses for now — except for in the case of immunocompromised individuals.

Israel has already tested fourth doses, and a recent report shows it isn't providing significant protection. Fauci said the U.S. needs to understand the durability of protection from a third dose before weighing a fourth.

Topol noted that in the Israeli study it is unclear what level of protection against hospitalization and death the fourth dose provides, but that data will become available in coming weeks.

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