Virus model sees deaths doubling by end of year
The Institute for Health Metrics and Evaluation at the University of Washington projects that under the most likely scenario, 410,451 people in the United States will die of covid-19 by Jan. 1 — more than doubling the current toll.
The best-case scenario is 288,381 deaths and worstcase is 620,029, the institute’s model forecasts.
The global death toll could triple by year’s end, with an additional 1.9 million deaths, according to a new forecast from the institute.
The estimate reinforces warnings by many experts that cooler, drier weather and increased time spent indoors could boost viral transmission in the Northern Hemisphere this fall and winter — something typically seen with other respiratory viruses.
The institute’s forecasts were influential earlier in the pandemic in guiding policies developed by the White House coronavirus task force, but they have been criticized by some experts as projecting further into the future than can be done reliably.
The U.S. death toll from covid-19, the disease caused by the coronavirus, now stands at more than 187,000, according to a tally kept by Johns Hopkins University.
The scenarios pivot on human behavior and public policy. The best-case scenario would result from
near-universal mask-wearing and the maintenance of social distancing and government mandates limiting the size of indoor gatherings. The worstcase scenario assumes that people and their communities stop taking precautions.
“It’s easy given the summer lull to think the epidemic is going away,” Christopher Murray, director of the institute, said Friday on a conference call. But there are “bleak times ahead in the Northern Hemisphere winter, and unfortunately we are not collectively doing everything we can to learn from the last five months.”
TRYING TO SEE LONG-RANGE
In recent weeks, the daily numbers of U.S. infections and deaths have gradually tapered, following an early-summer surge driven largely by community transmission in the Sun Belt. But experts warn that viral infections typically spike in the weeks after school resumes and when colder, drier weather can help viruses stay viable longer and spread more easily.
One key insight in recent months is that the coronavirus has a much harder time transmitting outdoors. But as temperatures drop, people will spend more time inside.
Few models forecast as far into the future as the University of Washington’s institute does. Many do not project further than four to six weeks.
“Beyond that, it’s all conjecture and guesswork because there are so many factors we just can’t predict and factors about transmission that truthfully scientists don’t understand very well yet,” said Jeffrey Shaman, an infectious-disease expert who leads the modeling team at Columbia University. “What happens the next few months really depends on what we do as a society the next few weeks.”
Murray defended the longer-range projections, however, saying they are intended to help government leaders and the public make decisions now to avoid the worst-case scenario.
The new forecasts represent the institute’s first attempt to model the global spread of the virus and show the daily death toll peaking in mid-December at about 30,000, a more than fivefold increase from the current daily fatality numbers.
The specific timing of the second wave matters less, he said, than the fact that it is likely to happen and that many deaths could be avoided if precautions are taken now. The institute projects that with rigid adherence to social distancing and mask-wearing, 770,000 lives could be saved globally by year’s end.
One of the most useful tools for public health officials following different projections has been ensemble models — an aggregation of several of the country’s leading models to make a more reliable forecast. One of the most heavily used ensemble models — assembled by Nicholas Reich, a biostatistician at the University of Massachusetts — shows deaths declining slightly but maintaining a fairly high rate of more than 5,000 a week for the next four weeks, with a likely total of 205,093 before the end of September.
FEWER PEOPLE STAYING HOME
The recent declines in cases and deaths appear to be prompting a relaxation in behavior that could quickly drive those numbers back up. One model that takes into account the extent of social distancing, using cellphone data, forecasts the daily number of deaths increasing over the course of this month from roughly 1,000 deaths a day to almost 2,000 by the end of September.
“We’ve been seeing mobility increase the last few weeks,” said Lauren Ancel Meyers of the University of Texas at Austin, who developed the model that factors in mobility.
In Texas, for example, mobility data shows more people staying home in June when hospitalizations were going up at alarming rates. But since August, that mobility has accelerated.
“One of the challenges is as soon as things look good in the community, it’s tempting to say the virus is gone,” Meyers said. “What we really should be thinking is: How did we get to this better place? By being cautious and vigilant. And instead of relaxing, we should focus on the things that worked.”
About 910,000 people globally are known to have died of the virus, according to the University of Washington institute — a tally higher than the 865,000 used by the World Health Organization. But most experts agree the true death toll is probably higher, with many people dying at home or without having been tested for the virus.
The “most likely” scenario produced by the institute is for 2.8 million global deaths by the end of December. The best-case scenario would be about 2 million, and the worst-case about 4 million.
VACCINE ENTERS HUMAN TRIALS
Meanwhile, Sanofi and Glaxo-Smith-Kline, two of the world’s biggest vaccine makers, began testing their experimental covid-19 shot in the first patients Thursday and aim to start late-stage trials before year’s end.
The drugmakers started human studies at 11 sites across the U.S. The trial — which compresses the early and middle stages of clinical tests — will assess 440 healthy patients in two age groups: 18 to 49, and over 50. Sanofi and Glaxo aim to have results by December, allowing the final stage to begin.
Though the pair are just now starting human trials, a number of vaccine front-runners may deliver interim data from their late-stage studies as early as this month.
There are more than 175 covid-19 vaccines in development, according to the World Health Organization, and 33 in human trials. A handful have ambitions to secure emergency-use authorizations in the fall.
“I’m not concerned that we’re a few months behind some of the other vaccine candidates,” said John Shiver, senior vice president of global vaccine research and development. Sanofi’s expertise in conducting trials and “experience with very similar viruses” will allow it to gain back time on its peers, he said, and ultimately, multiple shots will be needed.
“They showed very, very high levels of neutralizing antibodies in monkeys that are comparable to levels in humans who recovered from the covid-19 infection,” Shiver said of the pre-clinical studies, which are to be published in medical journals later this year. That data gave Sanofi confidence as it moves to the next stage, he said.
As Sanofi turns its attention to the next phase trial enrollment, it’s focused on recruiting a diverse cohort that reflects different geographies, races, ethnicities, genders and ages.
“Older people, unfortunately, people like me over the age of 50, tend not to respond as well to vaccines,” Shiver said. Sanofi is targeting the enrollment of 140 people over age 50 to identify a vaccine formulation that’s best suited for them, he said. The Sanofi-Glaxo vaccine is likely to require a two-dose regimen.
Covid-19 vaccine clinical trials have thus far relied on test pools with largely white participants, though Shiver said Sanofi will focus on recruiting “tremendous diversity” in the 30,000-person phase 3 trial it aims to start in December. It will take place in multiple countries, and particularly where covid cases continue to rise. Sanofi is currently consulting with epidemiologists on how to design the trial.
The Trump administration’s “Operation Warp Speed” effort is providing as much as $2.1 billion to Sanofi and Glaxo to fast-track its shot. If successful with a regulatory approval in the first half of 2021, the companies plan to make 1 billion doses next year.
“That’s all feasible if the pandemic continues in the way that it’s been proceeding so far this year,” Shiver said. “I expect cases are going to accumulate later this year when our phase 3 trial starts.”
RUSSIAN VACCINE UNDER REVIEW
Meanwhile, Russia’s covid-19 vaccine induced an antibody response in all participants in early trials and found no serious adverse effects, according to the first peer-reviewed data on studies of the controversial project.
The vaccine also produced a response in T-cells, a type of white blood cell that helps the immune system destroy infection, according to preliminary results from phase 1 and 2 trials published Friday in the Lancet medical journal. Russian officials had made broadly similar claims about the shot before review by outside experts.
Russia has been seeking to gain international credibility after health officials elsewhere criticized the country’s regulatory approval of the vaccine last month, before it had gone through wider phase 3 trials. Russian President Vladimir Putin hailed Sputnik V, named after the Soviet Union’s 1957 launch of the world’s first satellite into space, as the first vaccine globally to receive clearance.
The trials, which took place in two Russian hospitals and involved 76 healthy adults ages 18 to 60, used a two-part vaccine with two different human adenoviruses — pathogens linked to the common cold — to transport the antigen into the body. All participants were given the vaccine, with no control group — one of several limitations to the trials that were cited in the report.
The investigators took convalescent plasma from 4,817 people who had recovered from mild or moderate covid-19 to compare post-vaccination immunity with natural immunity. Antibody responses were higher in those vaccinated, according to the data.
WHO VOWS CAUTION
In London, the head of the WHO said the U.N. health agency will not recommend any covid-19 vaccine before it is proved safe and effective, even as Russia and China have started using their experimental vaccines before large studies have finished and other countries have proposed streamlining authorization procedures.
China has reportedly begun inoculating some highrisk groups with one of its experimental vaccines, while the large studies to prove its efficacy and safety are ongoing. In July, the head of China’s Center for Disease Control and Prevention announced that he had received the shot, although he did not specify whether that was done as part of a clinical trial.
At a news briefing Friday, U.N. head Tedros Adhanom Ghebreyesus said vaccines have been used successfully for decades, and credited them with eradicating smallpox and bringing polio to the brink of being eliminated.
“I would like to assure the public that WHO will not endorse a vaccine that’s not effective and safe,” Tedros said. He said newly developed vaccines helped end the recent Ebola outbreak in Congo, noting that stopping the deadly virus was complicated by the dozens of armed groups operating in the region.
Tedros appealed to people opposed to vaccination to do their own research.
“The anti-vaccine movement, they can build narratives to fight against vaccines, but the track record of vaccines tells its own story and people should not be confused,” he said, appealing to parents in particular. “They can have a look for themselves on how the world actually used vaccines to reduce under-5 mortality to save children.”