"We know what the virus will do. We just don't know what the humans will do," said Dr. John Wherry with UPenn.
TRENTON, New Jersey (WPVI) -- A COVID-19 surge is sweeping the nation.
Cases, deaths, and hospitalizations are on the rise, but doctors say we have all the necessary tools to fight the virus. Especially with new data showing the Pfizer booster shot is extremely effective against the new highly contagious omicron variant.
"We know what the virus will do. We just don't know what the humans will do," said Dr. John Wherry with the University of Pennsylvania.
Health experts say COVID case rates are once again on the rise.
Wherry says the continued message is for everyone to get vaccinated if they are not already, and get a booster when you're eligible.
SEE ALSO: Pfizer says booster dose of COVID vaccine offers protection against omicron variant
"The only way we are going to end this pandemic is by vaccinating as many people as possible, having as much immunity in the population to prevent ongoing spread and emergence of new variants," said Wherry.
Dr. Rachel Evans, who is the chief medical officer at Henry Jackson Health System in Trenton, New Jersey, says she is alarmed by the rise in cases in her state.
Her biggest concern is what it could mean for local hospitals.
"Any community at any time, if you get enough of a burden of COVID, it can overwhelm your hospitals, and that is when people start to die again," said Dr. Evans.
The Action News Data Journalism Team discovered Sussex, Salem and Ocean counties are among the five counties in New Jersey with the highest COVID case rates. They are also among the counties with the lowest vaccination rates.
"As long as you have unvaccinated people in your community, you will catch and spread COVID," said Dr. Evans.
From Nov. 6 to Dec. 6, New Jersey's new daily cases nearly tripled and hospitalizations have more than doubled, according to the data.
And while the new omicron variant is a concern, there is still a lot of unknowns. For now, the delta variant is still having the most impact.
Doctors blame the recent increase in cases in New Jersey and across the country on holiday gatherings and the unvaccinated. They say the reality is that COVID will be around for a while and there will likely be more variants.
Health experts say even if you are vaccinated, you still have to use caution.
"Vaccinated people can catch delta. Vaccinated people can spread delta. People often ask: so why get vaccinated? Because then you don't die from COVID," said Dr. Evans.
New Jersey will host a Boost NJ Day on Dec. 15.
Vaccination sites across the state will be urged to host walk-in booster clinics for people who qualify for a COVID booster shot.