A pedestrian walks past a bar established in 1933 after Los Angeles County officials closed it for the second time following a spike in COVID-19 cases in Los Angeles on August 10. Photo by Jim Ruymen/UPI
Travelers walk through the entrance at San Francisco International Airport wearing full body plastic suits, face masks and goggles to protect against COVID-19 in San Francisco on August 10. Photo by John Angelillo/UPI
A beautician cuts a woman's hair August 5 outside Wonder Cuts on El Camino Real in Sunnyvale, Calif. Photo by Terry Schmitt/UPI
A priest celebrates mass August 5 outside St. Joseph of Cupertino in Cupertino, Calif. Photo by Terry Schmitt/UPI
Residents inch their way into the Dodger Stadium parking lot, where a new COVID-19 testing site was opened in Los Angeles on May 26. Photo by Jim Ruymen/UPI
In announcing the center, Los Angeles Mayor Eric Garcetti said health officials would be testing as many as 6,000 people a day at the new location, where he said he was tested. City officials say it will accommodate three times more people than any other testing site in Los Angeles County. Photo by Jim Ruymen/UPI
People stroll and bike along the beach in Half Moon Bay, Calif., on May 25. Memorial Day brought out crowds to enjoy summer weather along the coast. Photo by Terry Schmitt/UPI
Protesters hold a "Freedom Rally" calling to "open California" on the steps of City Hall in Los Angeles on May 24. Photo by Jim Ruymen/UPI
Officials have said the lockdowns are needed to reduce the spread of the coronavirus in Los Angeles. Photo by Jim Ruymen/UPI
Groups hang out in pre-drawn circles in Delores Park in San Francisco on May 23. Photo by Terry Schmitt/UPI
Warm weather and a holiday weekend brought out thousands to practice their own brands of social distancing. Photo by Terry Schmitt/UPI
Medical professionals administer rapid pinprick COVID-19 antibody testing to food service and custodial staff from the Culver City Unified School District at the Wende Museum in Culver City, Calif., on May 23. Photo by Jim Ruymen/UPI
A car passenger undergoes a rapid pinprick COVID-19 test. Photo by Jim Ruymen/UPI
Tom Bradley International Terminal is empty as the coronavirus outbreak has brought passenger traffic at Los Angeles International Airport to a near halt. Photo by Jim Ruymen/UPI
Striking McDonald's workers hold a motor march and protest of the company's "failed response" to the pandemic in Monterey Park, Calif., on May 20. Photo by Jim Ruymen/UPI
A small group of employees picket outside the Providence St. Joseph Medical Center in Burbank, Calif., on May 19. The picketers say management is putting their health and safety at risk because of lax protocols around the treatment of COVID-19 patients, a lack of personal protective equipment and short staffing. Photo by Jim Ruymen/UPI
Two young scooter riders pause on the Embarcadero in San Francisco on May 17. Photo by Terry Schmitt/UPI
A car hop brings an order to a customer at Mel's Drive In in San Francisco. The chain restaurant, featured in the movie "American Graffiti," has reverted to taking orders and delivering take-out food to waiting cars. Photo by Terry Schmitt/UPI
A homeless encampment has set up a U.S. 101 underpass in Los Angeles on May 17. A federal judge issued a preliminary order on May 15 requiring that thousands of homeless people living in encampments under Los Angeles freeway overpasses and underpasses, and near entrance and exit ramps, be relocated for health and safety reasons. Photo by Jim Ruymen/UPI
Beachgoers with face masks walk past police officers upon arriving the Venice Beach boardwalk on May 15. Photo by Jim Ruymen/UPI
Volunteers unload milk as residents of the Pico/Union and MacArthur Park areas line up for food distribution hosted by the Los Angeles County Federation of Labor in Los Angeles on May 9. Photo by Jim Ruymen/UPI
In celebration of Mother's Day, the Los Angeles County Federation of Labor and other organizations hosts a food distribution for residents impacted by the COVID-19 crisis at Jordan High School in Long Beach, Calif., on May 9. Photo by Jim Ruymen/UPI
Shoppers make their selections at one of the many wholesalers allowed to open in the downtown Los Angeles Flower District on May 8. Photo by Jim Ruymen/UPI
Workers from the Department of Public Works paint boxes on Fulton Street in the Civic Center of San Francisco on May 7. The city is attempting to place a socially disstanced tent camp for the homeless in view of City Hall. Photo by Terry Schmitt/UPI
People line up to receive food from the San Francisco-Marin Food Bank in San Francisco on May 7. Photo by Terry Schmitt/UPI
Neighbors gather for a socially distanced hangout on 21st Street in San Francisco on May 3. Photo by Terry Schmitt/UPI
Volunteers distribute food during a Virtual Drive-Thru and Walk-Up Giveaway sponsored by United Hands Multi-Purpose Center to help feed thousands of South L.A. residents during the COVID-19 pandemic in Compton, California on Saturday, May 2, 2020. The U.S. Department of Agriculture has announced a plan to purchase more food from struggling farmers and distribute it to food banks -- some $470 million this time. The purchases, announced this week, will come in addition to the $3 billion the USDA pledged to buy farm products as part of the Coronavirus Food Assistance Program that was announced April 17. File Photo by Jim Ruymen/UPI
Demonstrators rally for reopening the state at the Capitol in Sacramento, Calif., on May 1. Photo by Terry Schmitt/UPI
California Highway Patrol officers tussle with demonstrators at the Capitol in Sacramento. Photo by Terry Schmitt/UPI
Beachgoers seek relief from the heat where thousands converged on California beaches to take advantage of the cooler temperatures and to get a break from weeks of isolation at home in Huntington Beach, Calif., on April 30. Photo by Jim Ruymen/UPI
A man expresses his displeasure with the governor as he rides his bike in Huntington Beach, Calif. Photo by Jim Ruymen/UPI
A masked beachgoer watches surfers in Capitola, Calif. on April 28. Photo by Terry Schmitt/UPI
Farmworkers harvest romaine lettuce in Salinas, Calif. on April 28. Agricultural workers remain on the job providing produce during the pandemic. Photo by Terry Schmitt/UPI
Masked shoppers head out for fresh produce at the Farmer's Market in San Francisco on April 25. Photo by Terry Schmitt/UPI
San Francisco firefighters hose down an area where a sick man had been sitting in Washington Square Park in San Francisco on April 23. Photo by Terry Schmitt/UPI
A woman administers a COVID-19 testing kit at a Los Angeles Fire Department pop-up testing station, where workers in hazmat suits handed out testing swabs to the homeless from behind a protective window on April 21. Photo by Jim Ruymen/UPI
Illustrated by local artist Hijack, this mural depicts two soldiers fending off the coronavirus wearing hazmat suits with a feather duster, Windex, hand sanitizer, toilet paper and a vacuum bearing a "No COVID-19" symbol in Los Angeles on April 19. Photo by Jim Ruymen/UPI
Registered nurses at University of California Irvine Medical Center hold a candlelight vigil at their shift change to describe conditions and the need for more N95 masks, respirators and protective gear required to safely treat coronavirus patients on April 20. Photo by Jim Ruymen/UPI
Visitors sit at Delores Park in San Francisco on April 19. San Francisco Mayor London Breed has mandated that face masks be worn outside the home to protect against coronavirus. Photo by Terry Schmitt/UPI
Businesses are boarded up along Geary Boulevard in San Francisco on April 19. Photo by Terry Schmitt/UPI
A homeless encampment next to the main library sits in view of City Hall in San Francisco on April 19. Photo by Terry Schmitt/UPI
Hundreds of passengers form a line to check in and board a China Southern Airlines flight to China on April 19 in Los Angeles. Passengers at the front of the line arrived at 5:30 a.m., with many others standing in line since 8 a.m. to ensure they would have a seat before the plane was full. Photo by Jim Ruymen/UPI
People line up to receive bags of food from the San Francisco-Marin Food Bank in the parking lot of the Cow Palace in Daly City, Calif., on April 17. Photo by Terry Schmitt/UPI
President Donald Trump unveiled a program to assist U.S. farmers and ranchers to channel their products to food banks. Photo by Terry Schmitt/UPI
Protesters from Housing is a Human Right gather near the vacant 22-story Sunset Gordon tower in Los Angeles, demanding that the building be repurposed as housing for the homeless on April 17. Photo by Jim Ruymen/UPI
Los Angeles County Federation of Labor members stage a drive-through mobile food pantry to help feed thousands of South L.A. residents at the Baldwin Hills Crenshaw mall in Los Angeles. Photo by Jim Ruymen/UPI
The drive-through pantry effort is expected to feed over 10,000 people. Photo by Jim Ruymen/UPI
Two men wait to cross the street in front of a boarded-up Pottery Barn in Pasadena, Calif., on April 16. Photo by Jim Ruymen/UPI
Postal workers return to the Hollywood Station Post Office after completing their shift in Los Angeles. The U.S. Postal Service warned Congress this week that it will completely "run out of cash" in the next several months without immediate action from the White House and Congress. Photo by Jim Ruymen/UPI
A mural urges residents to stay home as a couple wearing masks kiss while taking a selfie on La Brea Avenue in Los Angeles on April 11. Photo by Jim Ruymen/UPI
A masked pedestrian crosses an empty Powell Street in San Francisco on April 11. Photo by Terry Schmitt/UPI
Shoppers, mostly masked, stand far apart to buy produce at a farmer's market on Alemany Boulevard in San Francisco on April 11. Photo by Terry Schmitt/UPI
A homeless man sits with his belongings wearing a mask in Los Angeles on April 10. Photo by Jim Ruymen/UPI
A patient is moved out of Gateway Care & Rehabillition Center, a skilled nursing facility in Hayward, Calif., on April 9. Photo by Terry Schmitt/UPI
Parishioners utilize the option of a drive-through communion to kick off Holy Week at Godspeak Calvary Chapel in Thousand Oaks, Calif., on April 5. Photo by Jim Ruymen/UPI
A drug store sells face masks after the FDA allows imports from China amid shortages in Los Angeles on April 2. Photo by Jim Ruymen/UPI
Sailors assigned to the hospital ship USNS Mercy treat a patient from Los Angeles medical facilities on March 29. The ship deployed in support of the nation's COVID-19 response efforts, and will serve as a referral hospital for non-COVID-19 patients currently admitted to shore-based hospitals. Photo by MC2 Erwin Jacob Miciano/U.S. Navy
Nurses at UCLA hold a candlelight vigil to show solidarity and support for nurses across the nation and to demand stronger leadership from the federal government in protecting healthcare workers and their patients at the Ronald Reagan Medical Center in Los Angeles on March 30. Photo by Jim Ruymen/UPI
A COVID-19 quarantine for the homeless operates in a cluster of RVs at Dockweiler State Beach in Los Angeles on March 29. Photo by Jim Ruymen/UPI
Medical and fire department personnel distribute self-testing coronavirus kits to residents who made appointments in a parking lot adjacent to Dodger Stadium in Los Angeles on March 28. Photo by Jim Ruymen/UPI
Tourists take pictures on Twin Peaks in San Francisco on March 26. Photo by Terry Schmitt/UPI
Beachgoers walk along Zuma Beach in Los Angeles on March 23. Los Angeles Mayor Eric Garcetti closed sports and recreation at city parks and closed parking at city beaches after seeing too many people in close proximity packing beaches, trails and parks. Photo by Jim Ruymen/UPI
A patient has his temperature checked by a Hayward emergency medical technician at a triage station for coronavirus in Hayward, Calif., on March 23. Photo by Peter DaSilva/UPI
Hayward emergency medical technicians check members of the public for coronavirus symptoms at a drive-up triage station in Hayward, Calif. Photo by Peter DaSilva/UPI
A couple wait to be checked by Hayward emergency medical technicians for symptoms and high temperature. Photo by Peter DaSilva/UPI
Shoppers at farmer's market on Alemany Street practice social distancing while waiting in line for produce in San Francisco on March 21. Photo by Terry Schmitt/UPI
A chain-link fence surrounds the Fairfield Inn, a hotel reserved by the state to be used as a quarantine facility for COVID-19 patients, in San Carlos, Calif., on March 12. Photo by Peter DaSilva/UPI
Medical personnel help passengers from the Grand Princess cruise ship board a chartered airplane at Oakland International Airport on March 11. The passengers were quarantined on the ship before being allowed to depart. Photo by Peter DaSilva/UPI
A woman walks on the usually bustling Stanford University campus in Palo Alto, Calif., on March 10. Photo by Terry Schmitt/UPI
The cruise ship Grand Princess sails under the Golden Gate Bridge entering San Francisco Bay on March 9. Photo by Terry Schmitt/UPI
May 18 (UPI) -- U.S. biotechnology firm Moderna announced Monday that early test results for a possible coronavirus vaccine are positive and indicate a "potential to prevent" COVID-19.
Moderna said first results of a stage-one clinical trial show its vaccine candidate "mRNA-1273" succeeded in producing antibodies to attack the SARS-CoV-2 coronavirus in all 45 test subjects, in quantities "of the magnitude caused by natural infection."
The trial, which is being done in a partnership with the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, has been underway for weeks and is one of many worldwide that could ultimately produce a COVID-19 vaccine.
Moderna said its vaccine candidate was found to produce antibody levels in participants on levels similar or better than convalescent plasma and has proven "generally safe and well tolerated."
"These interim Phase 1 data, while early, demonstrate that vaccination with mRNA-1273 elicits an immune response," Moderna Chief Medical Officer Tal Zaks said in a statement.
"[The vaccine] provided full protection against viral replication in the lungs in a mouse challenge model."
Zaks said the stage-one results, combined with those of a pre-clinical study, substantiate Moderna's belief that mRNA-1273 has the potential to "prevent COVID-19 disease" and advance plans to "select a dose for pivotal trials."
"The Moderna team continues to focus on moving as fast as safely possible to start our pivotal Phase 3 study in July and, if successful, file a [biologics license application]," added Moderna CEO Stéphane Bancel. "We are investing to scale up manufacturing so we can maximize the number of doses we can produce to help protect as many people as we can."
U.S. regulators cleared mRNA-1273 for a second phase earlier this month, and Zaks said it will begin "shortly."
Earlier this month, U.S. pharmaceutical giant Pfizer said it has started testing a vaccine candidate on human subjects in the United States. Other possible vaccines in the clinical stage are also being developed elsewhere in the United States, as well as China and Britain.