The coronavirus is spreading uncontrollably in the United States, overwhelming health systems and killing more than 1,100 Americans a day. But there is a small ray of hope: it is speeding up testing of vaccines that could eventually end the pandemic.
The rise of the virus has already allowed Pfizer and Moderna to speed up testing of their vaccines, which appear to be very effective in preventing Covid-19.
And if, as seems inevitable, the virus continues to proliferate – it‘s spreading faster than ever in the United States and some other countries – it is likely to speed up evaluations of promising vaccine candidates from other pharmaceutical companies.
“We are currently seeing something apocalyptic playing in terms of the level of transmission in the country,” said Dr Peter Hotez, vaccine specialist at the National School of Tropical Medicine at Baylor College of Medicine. “Unfortunately, this pandemic is still raging and this offers many opportunities to examine the effectiveness of vaccines.”
Over the past week, on average more than 155,000 new cases of Covid-19 have been confirmed every day in the United States. More than 166,000 were reported on Monday.
In late-stage vaccine trials, the sooner participants get sick, the faster drug developers get enough data to know whether their vaccines are working.
Researchers determine the effectiveness of a vaccine by comparing the rate at which volunteers who receive a placebo get sick versus the rate of those who receive a vaccine. If the vaccine provides strong protection, the number of people who get the placebo and get sick will far exceed the number of people vaccinated who get sick.
The trials are designed so that once a certain number of participants contract Covid-19, an independent panel of experts conduct a preliminary review of the data. (Other factors, such as how long it has been since participants were vaccinated, may also factor in this time.) The trial ends after a certain number of cases – around 150 to 170 – have accumulated . This number is chosen to ensure that the results have sufficient statistical power to tell how well the vaccine is working.
Moderna announced Monday that an initial analysis had revealed that its vaccine was 94.5% effective. The company had planned to only need 53 cases of Covid-19 for its trial before experts took a first look at the data. But the nationwide spike in infections helped Moderna surpass that figure: the results were based on 95 sick participants.
The same phenomenon has helped Pfizer, which announced last week that an initial analysis found its vaccine to be over 90% effective. By the time the Pfizer data was analyzed, 94 participants had contracted Covid-19, nearly three times the number the company had originally planned to trigger a first look to assess the vaccine’s effectiveness.
The relatively large number of sick people in the trials – coupled with the apparent effectiveness of the vaccines – could help build public confidence.
“It will be hard enough to get people to take this vaccine as is,” said Geoffrey Porges, analyst for investment bank SVB Leerink. “So the more confidence you can have, by having higher statistical power, by having more events, then that should go somewhere.”
In the weeks and months to come, the worsening pandemic could yield results of other closely watched trials, such as one for a vaccine developed by Johnson & Johnson and another by AstraZeneca and the University of Oxford, available earlier and with greater statistical power.
The rapidly growing pandemic could also speed up treatment trials for Covid-19.
Pharmaceutical company Regeneron, for example, is testing the antibody treatment President Trump received after catching Covid-19. A spokesperson for the company said recruitment into its trial – the participants are Covid-19 patients who have not been hospitalized – accelerated slightly this month.
Even if the grim situation in the United States ultimately helped vaccines and treatments become available sooner, the country would have been far better off had it kept the pandemic under control, public experts have said.
“This is not how anyone would want it to be,” said Natalie Dean, biostatistician and vaccine trial design expert at the University of Florida. “I’d rather be South Korea,” which has kept the virus at bay since the start of the year, she said.
Vaccines are unlikely to be widely available for months. By then, tens of thousands more Americans will likely have perished.
Pfizer and Moderna, whose vaccines appear to be effective, are waiting to see if any side effects appear in participants before the companies submit their data to the Food and Drug Administration for approval to distribute the vaccines. Once the FDA gives them the go-ahead, manufacturers will need to ramp up production and work with governments to distribute the vaccines. Injections will initially only be available to health workers and other vulnerable groups. When vaccines become widely available, it is not clear whether their protection will last for months, years, or decades.
In hopes of speeding up their testing, drugmakers have set up trials in Covid-19 hotspots all over the world – not just in the United States.
In China, where the virus was endemic earlier this year, new cases have slowed to a trickle. As a result, Chinese vaccine makers are conducting late-stage trials of their candidates in countries like the United Arab Emirates, Morocco, Argentina and Peru.
Maryland-based Novavax, which is developing one of 12 vaccines in the final stages of clinical trials, has recruited more than 9,000 participants in Britain since a phase 3 trial began in September. Novavax’s president of research and development, Dr Gregory Glenn, told analysts last week that he “feels very good about our ability to collect cases.”
Britain reported more than 21,000 new cases on Monday, in a wave that accelerated around the beginning of October.
Dr Glenn added: “If you’re in the right place at the right time, you can rack up cases very quickly. I think we are in the right place at the right time in the UK ”Novavax plans to start a phase 3 trial in the US this month.
Vaccine developers select different regions of the world to conduct their trials for several reasons. They should ensure that the vaccine has been tested in populations that reflect global diversity. They should also make sure that they can register participants in areas where the virus is spreading.
“What is a hot spot initially won’t necessarily remain a hot spot,” said Dr. Dean of the University of Florida, who has studied how to make clinical trials flexible enough to work during epidemics.
That’s why the developers who are testing the Covid-19 vaccines have been watching carefully where the virus is growing to make decisions about where to set up sites to enroll participants.
Johnson & Johnson is testing a version of its vaccine in the United States and other countries. The trials – which are set up or planned at more than 200 sites around the world, including 30 states – were chosen in part by modeling the number of cases in different regions, said Jake Sargent, spokesperson for the society.
Johnson & Johnson announced Monday that it has started another trial of its vaccine, testing two doses instead of one. The company aims to recruit 30,000 participants in Belgium, Colombia, France, Germany, the Philippines, South Africa, Spain, Great Britain and the United States. Johnson & Johnson said the locations were chosen “in countries and areas with high incidence of Covid-19”.