The latest COVID-19 variant of concern, omicron, first reported to the World Health Organization from South Africa last week -- and now detected throughout the U.S. -- continues to worry many Americans with still much unknown about the virus.
Health authorities continue to urge calm as scientists across the globe search for answers.
"Right now, we're really in a state of knowledge acquisition," said Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Massachusetts. "We really need to know more. We need to know how pathogenic it is. We need to know how transmissible it is and we need to know whether or not it evades antibody responses induced by the vaccines."
Experts caution that answers to those questions may not come for months.
"What's going to happen is our band of confidence is going to narrow over time as opposed to saying in this amount of time we will have an answer. And that's what we have to recognize," said John Brownstein, epidemiologist and chief innovation officer at Boston Children's Hospital. "We just need to have some patience," Brownstein added.
When will we know about omicron transmission?
Researchers, however, expect to have estimates for transmissibility "probably ahead of some of the other questions that we have," said Brownstein.
In a press conference Wednesday, WHO COVID technical lead, Dr. Maria Van Kerkhove, said there is some suggestion omicron may be more transmissible but it's too early to say definitively. "We expect to have more information on transmission within days, not necessarily weeks," Van Kerkhove said.
"Based on the data collected through surveillance, we have a rough estimation of the proportion of infections that relate to omicron where you can start to make basic estimates of transmissibility very quickly," said Brownstein.
During the White House COVID-19 briefing on Friday, Dr. Anthony Fauci, the White House's chief medical adviser, said as more omicron cases are detected, the Centers for Disease Control and Prevention would be able to model how the new variant will spread, similar to how quickly CDC predicted the delta variant would spread from the initial 3% to 4% of cases to nearly all cases.
"We really don't know what's going to happen, how well it is going to compete or not compete with delta, but we will know as more cases occur and what the doubling time of the relative percentage of omicron versus delta will be," Fauci said.
When will we know how effective current COVID-19 vaccines are on omicron?
The Food and Drug Administration said in a statement on Tuesday it is working "as quickly as possible" to evaluate the potential impact of omicron on current treatments, vaccines and tests and said it expects to have answers in the next few weeks.
If a modification to current vaccines is necessary, vaccine manufacturers say they are prepared to make those modifications quickly.
In a statement on Sunday, Pfizer and BioNTech said they have been monitoring the effectiveness of their vaccine against emerging variants and if a "vaccine-escape variant emerges" they expect to be able to make a "tailor-made vaccine against that variant in approximately 100 days, subject to regulatory approval."
Matt Barrows, Moderna's senior director of manufacturing told ABC News that the company has the capacity to produce an omicron-specific booster vaccine within a month if it becomes necessary. He said experiments testing the efficacy of their current vaccine against omicron are ongoing and will take at least two to three weeks.
“Although we haven't proven it yet, there's every reason to believe that if you get vaccinated and boosted that you would have at least some degree of cross protection, very likely against severe disease, even against the Omicron variant,” said Fauci.
When will we know if omicron causes more serious illness?
Learning if this version of the virus is deadlier could take many months, experts say.
"We don't even know if omicron will have the ability to overtake delta and we're dealing with a delta surge right now. There's a lot of ifs and a lot of open questions," said Brownstein.
Currently, the delta variant is driving nearly all cases across the U.S., with 99.9% of cases in the country from the delta variant.
Health officials are encouraged by the mild symptoms the omicron cases are experiencing so far. According to health officials, the man who tested positive for omicron in Minnesota is fully vaccinated and had been boosted in early November. The woman identified in Colorado is also reported to be experiencing only mild symptoms and was fully vaccinated, however not boosted.
Early cases identified in South Africa have also reported no severe disease according to local officials. "Right now it does not look like there's a big signal of a high degree of severity, but it's too early to tell," said Fauci, in an interview with CNN.
As of today, there are more than 400 confirmed cases of Omicron in over 30 countries across the globe, including in the US. As scientists work on getting more answers, experts are urging to not wait and get vaccinated or boosted if eligible.
"As it stands now with the information we have, you do the best with the information you have in front of you and that information says that you get an incredible advantage by getting that booster," said Brownstein.
Barouch said that the only way to stop new variants is to vaccinate people across the globe.
On Friday, the White House announced that it's shipping out 11 million more vaccines worldwide in an effort to increase vaccination around the world. The U.S. has shipped 291 million doses so far and President Joe Biden announced plans Thursday to provide 200 million more doses worldwide in the next 3 months.
"Currently, sub-Saharan Africa has less than a seven percent vaccination rate. And so it's not a surprise that new variants are emerging in that part of the world," Barouch said. "The only way to stop these variants is to have a widespread vaccination campaign that really reaches all four corners of the planet."
Esra Demirel, M.D., is an OB-GYN resident physician at Northwell Health-North Shore University Hospital & LIJ Medical Center and is a contributor to the ABC News Medical Unit.
ABC News' Sony Salzman contributed to this report.