The CDC believes at this time that symptoms may appear in as few as 2 days or as long as 14 days after exposure to the virus. This is based on what has been seen with the MERS virus (CDC, 2020j).
Treatment for COVID-19
There is no specific antiviral treatment recommended for COVID-19 and no vaccine or specific treatment for the infection is available. Patients should receive supportive care to help relieve symptoms. For severe cases, treatment should include care to support vital organ functions (CDC, 2020j).
Although supportive care is currently the only way to treat COVID-19, according to a CNN report, “several big biotech companies are hoping they can treat the symptoms with existing antiviral medications.” An experimental drug called remdesivir, used to treat the Ebola virus, is being tried in China to “see if the medication can combat the symptoms of coronavirus.” According to the U.S. biotech company Gilead, which makes the antiviral, remdesivir has “demonstrated some success in treating [animals exhibiting] MERS and SARS, two viruses similar to the Wuhan coronavirus” (CNN, 2020b).
The New York Times reported on February 7, 2020, that remdesivir was recently used to treat a Washington State COVID-19 patient who had suddenly worsened. The day after the medication was given, the patient’s symptoms reportedly improved. China is currently undertaking two clinical trials of remdesivir in association with Gilead (NY Times, 2020a).
On April 17, 2020, the National Institutes of Health reported that early treatment with remdesivir significantly reduced clinical disease and damage to the lungs of rhesus macaques infected with SARS-CoV-2, the coronavirus that causes COVID-19. The study was designed to follow dosing and treatment procedures used for hospitalized COVID-19 patients being administered remdesivir in a large, multi-center, clinical trial led by NIH’s National Institute of Allergy and Infectious Diseases (NIAID).
Researchers reported that twelve hours after the initial treatment, the scientists examined all animals and found the six treated animals in significantly better health than the untreated group, a trend that continued during the seven-day study. They report that one of the six treated animals showed mild breathing difficulty, whereas all six of the untreated animals showed rapid and difficult breathing. The amount of virus found in the lungs was significantly lower in the treatment group compared to the untreated group, and SARS-CoV-2 caused less damage to the lungs in treated animals than in untreated animals. From: https://www.nih.gov/news-events/news-releases/antiviral-remdesivir-prevents-disease-progression-monkeys-covid-19.
On May 22, 2020, NIAID published the results of a randomized, controlled trial that involved 1,063 participants from 10 countries hospitalized adults with COVID-19 with evidence of lower respiratory tract involvement. Investigators found that remdesivir was most beneficial for hospitalized patients with severe disease who required supplemental oxygen. Findings about benefits in other patient subgroups were less conclusive in this preliminary analysis (NIAID, 2020).
Samples of the COVID-19 virus are arriving at laboratories in the United States and around the world and scientists are studying the virus to find ways to treat it, develop a vaccine, and ultimately stop it.
On July 27, 2020, NIAID announced that a Phase 3 clinical trial designed to evaluate if an investigational vaccine can prevent symptomatic coronavirus disease 2019 (COVID-19) in adults has begun. The vaccine, known as mRNA-1273, was co-developed by the Cambridge, Massachusetts-based biotechnology company Moderna, Inc., and the National Institute of Allergy and Infectious Diseases. The trial, which will be conducted at U.S. clinical research sites, is expected to enroll approximately 30,000 adult volunteers who do not have COVID-19.
NIAID scientists developed the stabilized SARS-CoV-2 "spike" immunogen* (S-2P). The spike protein on the surface of SARS-CoV-2 facilitates entry into a cell. Moderna’s mRNA-1273 uses the mRNA (messenger RNA) delivery platform to encode for an S-2P immunogen. The investigational vaccine directs the body’s cells to express the spike protein to elicit a broad immune response. A Phase 1 clinical trial found the candidate vaccine to be safe, generally well-tolerated and able to induce antibodies with high levels of virus-neutralizing activity. Moderna initiated Phase 2 testing of the vaccine in May 2020.
*An immunogen is a specific type of antigen that is able to elicit an immune response.
Vaccines are the best way to stop the spread of COVID-19 and other infectious diseases, but traditionally they take years to develop and test. It took 20 months after the SARS outbreak to develop a vaccine, and by then the virus had died out. It took just 6 months to develop a Zika vaccine in 2015. Scientists are hopeful that this time they can build on previous knowledge to develop a vaccine rapidly (NY Times, 2020b).
Although vaccines can be developed much more quickly than in the past, they still must undergo rigorous testing to be proven safe and effective. "It will take at least a year to a year and a half to have a vaccine we can use," said National Institute of Allergy and Infectious Diseases (NIAID) director Anthony Fauci.
There are currently no Food and Drug Administration-approved drugs for the treatment of COVID-19, although remdesivir, an investigational antiviral drug, is available through an FDA emergency use authorization. Definitive clinical trial data are needed to identify safe and effective treatments for COVID-19. Such data are beginning to emerge (NIAID, 2020 Jun 16).
NIH recommends against using the following drugs to treat COVID-19 except in a clinical trial: (1) the combination of hydroxychloroquine plus azithromycin, because of the potential for toxicities, (2) Lopinavir/ritonavir or other HIV protease inhibitors, because of unfavorable pharmacodynamics and because clinical trials have not demonstrated a clinical benefit in patients with COVID-19 (NIAID, 2020 Jun 16).
The Cruise Ship Diamond Princess
On January 20, 2020, an 80-year-old man from Hong Kong boarded the cruise ship Diamond Princess when it docked in Yokohama, Japan. He disembarked in Hong Kong on January 25. Six days later he tested positive for COVID-19.
On the following February 4, ten passengers on the Diamond Princess were diagnosed with the virus and 3750 passengers and crew were quarantined aboard the ship when it returned to Yokohama harbor.
Passengers who became ill with COVID-19 were evacuated to local hospitals but the rest remained on board. At the end of the 14-day quarantine, the number of confirmed coronavirus cases exploded from 10 to 630. By the time the quarantine was over, the Diamond Princess had the greatest number of COVID-19 cases outside of China (McFall-Johnson, 2020).
According to Kentaro Iwata, an infectious diseases professor at Kobe University in Japan who visited the ship, he was “shocked” by the lack of infection control measures. “It was completely chaotic,” he said. He reported that he saw “passengers, crew members and medical professionals walking around the ship without wearing protective clothing” (ABC News, 2020).
Later, on February 17, American citizens who had been on the cruise ship were flown back to the United States. A charter flight carrying 177 American evacuees flew to Travis Air Force Base near Fairfield, California. Another plane with 151 people on board flew to Joint Base San Antonio-Lackland in San Antonio, Texas.
Although passengers had been told that anyone who was infected would remain in Japan, it was discovered before takeoff that around 14 of them had tested positive for the virus. The State Department made the decision (against CDC recommendations) to isolate the infected passengers on the same plane carrying the uninfected passengers and fly them home (Seattle Times, 2020).
Upon arrival at the military bases in the US, passengers were taken to several locations for another 2-week quarantine and those who were ill were taken to hospitals for care.