Dr. Fauci discusses steps toward vaccine, treatment, diagnostic development at NIAID in briefing on U.S. response to coronavirus spread where Sec. Azar leaves travel restrictions “on the table”
The U.S. Centers for Disease Control and Prevention has expanded its recommendation to avoid nonessential travel to Wuhan, China to one advising travelers to avoid nonessential travel across China, as the coronavirus first recognized in the centrally located Yangtze River city continues to spread across the country and to a growing number of international locations, including the United States. The news comes with word from China that half of the cases in China now are outside of the Hubei province where Wuhan is located, Health and Human Secretary Alex Azar said. The agency also will expand public health entry screening for the virus — provisionally called 2019-nCoV — from the five U.S. international airports announced last week, to 20 airports, CDC Director Robert Redfield said today. That expanded screening will focus on travelers from China, but include people with symptoms or other potential risk factors, the CDC’s Dr. Nancy Messonnier said, reiterating a point she has emphasized over previous briefings that the screening will serve to both identify people who may be infected, and provide information on measures to take if infected or exposed to the coronavirus.
They spoke at a briefing led by Azar on the cross-agency response to the epidemic in China, also reiterating that while the spread of the coronavirus still does not pose a public health threat in the United States, much remains unknown about the virus, including accurate data on the number of people infected so far and the potential for transmissions from people who do not show symptoms. China has reported that more than 100 of 4,500 patients diagnosed with the virus so far have died, a “high rate,” Dr. Redfield noted. He noted as well, however, that as the number of cases noticed could be skewed by their severity, the actual rate of deaths caused by the coronavirus among all of those infected may be lower. Public health experts are continuing to try to determine the speed of the spread of the virus — or the number of people that an infected person is likely to transmit the virus to. Estimates of that number have ranged from 1.5 to 3.5, he said, contrasting that to the reach of infection from measles, which can be transmitted to 12 to 18 people by one infected person.
In addition, the potential for transmission by people not experiencing or showing symptoms of the virus remains unknown, with Chinese health officials saying they have evidence demonstrating that is occurring, that they have not yet shared with CDC or international health officials, Dr. Redfield said. While answers to that question would factor in to public health policies, Dr. Anthony Fauci of the National Institute of Allergy and Infectious Diseases added, “in all the history of infectious disease outbreaks,” asymptomatic transmission has never been a driver.
While noting that information informing public health responses to the outbreak remain the most immediate concern, Dr. Fauci also outlined research underway to develop diagnostics, treatments and vaccines to stem the impacts of the outbreak. These efforts, he said, have been underway since December, when the emergence of an apparently new coronavirus was first reported in Wuhan. While the CDC quickly developed a diagnostic test based on genetic sequencing of the virus shared by China, work continues to develop a faster point-of-care test. While no treatment exists for coronavirus infection, a foundation for current research towards effective treatments for 2019-nCoV was laid during outbreaks of SARS and MERS, the most well-known and wide-spread coronavirus outbreaks until now. While research continues in laboratories, two drugs remdesevir, an antiviral drug tried but found ineffective in Ebola treatment, and Kaletra, a combination of antiretroviral medicines used for HIV treatment, are being offered on a compassionate basis in China.
With the coronavirus genetic sequencing shared by China, Fauci said, research towards a vaccine is off to a promising start with a planned preliminary trial to evaluated safety planned in the next three months. While larger trials to determine effectiveness would follow and consume additional months making it possible the current outbreak will be contained before a vaccine is available for use, work towards the vaccine is proceeding on the assumption that it will be deployed in the event of a “worst case scenario,” Dr. Fauci said.
Also, potentially in the worse case scenario category, Sec. Azar repeated during the briefing that “it is important not to take anything off the table,” including restrictions to travel. Still he voiced confidence that the current responses are sound, as the agency continues to assess the situation based on evidence.
“This is what we do,” he said, repeating, “This is our day job.”
Cooperation from Chinese officials, who, he indicated had not yet responded to requests to work with CDC experts on the ground, will be critical. He was pleased, he said to learn during the briefing of the World Health Organization’s announcement this morning that China will admit and work with international experts.
Rabita Aziz, MPH, is senior specialist in global health policy for the Infectious Diseases Society of America.