Now there's a new threat known as the Delta plus variant. It's a mutation of the predominant Delta variant, and has been detected in Santa Clara County.
RELATED: As Delta variant turns into dominant strain in California, scientists detect 'Delta plus'
The news wasn't a surprise to Stanford University School of Medicine infectious disease expert, Dr. Yvonne Maldonado.
[Ads /]
"Viruses that can adapt more readily to humans are just going to survive better," Dr. Maldonado told ABC7 News. "We just know that that's going to continue to happen as long as viruses are circulating. And the most important way that this happens is by having unvaccinated people."
"So the more unvaccinated people we have, the more likely viruses will mutate to survive better in humans," she continued.
According to Santa Clara County's COVID-19 variant dashboard, it's identified almost 50 total cases of mutated Delta variants. On Wednesday, the dashboard included 46 cases of AY.1, also known as delta plus.
RELATED: Stanford epidemiologist explains how effective the COVID-19 vaccine really is
How effective is the COVID-19 vaccine against the Delta variant? Stanford epidemiologist explains
In a statement, the county said in part:
"Cases of Delta plus exist statewide and nationwide, and there is currently not enough information on these particular variants to indicate whether they may be more concerning than the original Delta variant."
[Ads /]
Dr. Maldonado made note, "We really didn't see Delta in any real appreciable way until May of this year, and now it's become the most common variant- and we're learning even today, two months later about it. So it may take longer for us to understand really what the Delta plus is doing."
"It's possible that we can have additional variants that will be even more infectious," she told ABC7 News. "I don't know whether that's going to happen or not, because we may build up sufficient immunity in the U.S. population and hopefully globally, that we'll start to see reductions in disease."
She pointed to India as a good example. She said India saw a major surge, and now their cases are reduced by more than 90%.
RELATED: How much of California is vaccinated against COVID-19? See percentages in every county
"We don't really know why that is, but it's possible that with more infections or more immunity, the viruses tend to slow down in terms of circulation," Dr. Maldonado said. "The hope is that we can slow these variants down."
On Tuesday, Center for Strategic and International Studies (CSIS) Senior Vice President J. Stephen Morrison spoke with Dr. Anthony Fauci.
In their interview, Dr. Fauci explained the anticipation for drug resistance, and the planning needed to navigate this ever-mutating virus.
[Ads /]
"When you have variants, you've got to be ready," Dr. Fauci shared. "It isn't gonna be where you have one pathogen and one drug that's the knockout homerun drug. You always have to be ready to continue to develop alternatives that could keep up with the variants."
Dr. Maldonado told ABC7 News, "We predicted that viruses would mutate- that's what we've been saying all along. I think it's very hard for people to visualize that, but it's true. And it's happening in real time."
RELATED: These 5 Bay Area cities may be 'most at risk' for new COVID-19 infections, data shows
ABC7 News reached out to all Bay Area counties about whether they've detected delta plus within their own communities. By Wednesday night, only Napa, Solano and San Mateo counties responded.
Napa County said they have not seen any cases of Delta plus.
Solano County said it's developing the capacity to collect and report on Delta plus data in the near future.
San Mateo County said it's not sharing data about variants of concern at its local level.
CDC COVID-19 Transmission Categories by California County
Map not displaying correctly? Click here to open in a new window.
VACCINE TRACKER: How California is doing, when you can get a coronavirus vaccine
Having trouble loading the tracker above? Click here to open it in a new window.
RELATED STORIES & VIDEOS:
- Everything to know about California's reopening
- What we know about the delta variant of COVID-19 following new CDC report
- Cheat sheet: What you can and can't do after being fully vaccinated
- Can a workplace require the coronavirus vaccine? Here's what we found
- COVID-19 vaccine: Everything to know about your 2nd Pfizer or Moderna shot
- CA COVID-19 Vaccine Tracker: See your status here
- These CA counties are way ahead in vaccinations
- Map shows everywhere you can get a COVID-19 test in the Bay Area
- Data tracker: Coronavirus cases, deaths, hospitalizations in every Bay Area county
- Get the latest updates on California EDD, stimulus checks, unemployment benefits
- Coronavirus origin: Where did COVID-19 come from?
- What is a COVID-19 genetic, antigen and antibody test?
- What does COVID-19 do to your body and why does it spread so easily?
- Coronavirus Timeline: Tracking major moments of COVID-19 pandemic in San Francisco Bay Area