In the summer, Dr. Michael Mina signed a contract with a cold storage company. With many of its restaurant customers closed, the company had freezers available. And Dr. Mina, epidemiologist at Harvard T.H. At the Chan School of Public Health, half a million vials of plasma made from human blood came to his laboratory from around the country. The samples come from the carefree days in January 2020.
The vials that are now in three huge freezers in front of Dr. Mina's laboratory is at the center of a pilot project for what he and his staff call the Global Immunological Observatory. You envision an immense surveillance system that can check blood from all over the world for the presence of antibodies to hundreds of viruses simultaneously. This will give scientists real-time detailed information about how many people have been infected with the virus and how their bodies have responded to the next pandemic.
It could even provide early notification, like a tornado warning. Although this surveillance system cannot directly detect new viruses or variants, it can show when large numbers of people are beginning to gain immunity to a particular type of virus.
The human immune system records the pathogens it has previously hit in the form of antibodies that fight against them and then stay lifelong. By testing for these antibodies, scientists can get a snapshot of what flu viruses you had, what rhinovirus pierced you last fall, even if you had respiratory syncytial virus as a kid. Even if an infection had never made you sick, this diagnostic method called serological tests would detect it.
"We're all like little recorders," said Dr. Mina to track viruses without even realizing it.
This type of immune system display is different from a test that looks for an active viral infection. The immune system starts producing antibodies one to two weeks after an infection starts. So the serology is retrospective, looking back at what you caught. Closely related viruses can also produce similar responses, producing antibodies that bind to the same types of viral proteins. This means that carefully designed assays are required, for example to differentiate between different coronaviruses.
But serology reveals things virus testing doesn't, said Derek Cummings, an epidemiologist at the University of Florida. With a large database of samples and clinical details, scientists can see patterns in how the immune system reacts in someone without symptoms compared to someone who has difficulty clearing the virus. Serology can also tell before an outbreak begins whether a population has robust immunity to a particular virus or if it is dangerously low.
"You want to understand what has happened in a population and how well that population is prepared for future attacks from a particular pathogen," said Dr. Cummings.
The approach could also detect events in the viral ecosystem that would otherwise go unnoticed, said Dr. Cummings. For example, the 2015 Zika outbreak was discovered by doctors in Brazil who noticed a group of babies with unusually small heads who were born seven to nine months after their mothers were infected. "A serological observatory might have picked this up beforehand," he said.
Serological tests are often small and difficult to perform because they require blood draws from volunteers. For several years now, Dr. Mina and his colleagues came up with the idea of a large and automated monitoring system using sample residue from routine laboratory tests.
"Had we set it up in 2019, when this virus hit the US, we would have had instant access to data that would have enabled us to see it floating around, for example, in New York City without doing anything else," said Dr. Said Mina.
Feb. 15, 2021, 2:42 p.m. ET
Although the observatory could not have identified the new coronavirus, it would have detected an unusually high number of infections from the coronavirus family, including those that cause colds. It could also have shown that the new coronavirus interacted with the patient's immune system in unexpected ways, leading to tell-tale markers in the blood. This would have been a signal to start genetic sequencing of patient samples to identify the culprit and possibly have provided reasons to close the city earlier, said Dr. Mina. (Similarly, serology would not be able to detect the emergency of a new virus variant, such as the contagious coronavirus variants discovered in South Africa and England, before they spread elsewhere Leave standard genomic sequencing of virus test samples.)
A powerful investment
The observatory would require agreements with hospitals, blood banks and other blood sources, as well as a system for obtaining consent from patients and donors. It also faces the problem of funding, noted Alex Greninger, a virologist at the University of Washington. Health insurance companies are unlikely to pay the bill, as serological tests are typically not used by doctors to treat people.
Dr. Mina estimated the observatory would cost about $ 100 million to start operating. He pointed out that, according to his calculations, the federal government provided diagnostics company Ellume with more than twice as much to produce enough rapid Covid tests to meet American needs for just a handful of days. A pathogen observatory, he said, is like a weather forecasting system based on a variety of buoys and sensors around the world that passively reports events where and when they occur. These systems were funded by government grants and are widely valued.
The predictive power of serology is worth the investment, said Jessica Metcalf, Princeton epidemiologist and member of the observatory team. A few years ago, she and her staff found in a smaller survey that immunity to measles in Madagascar was threateningly low. In fact, there was an outbreak in 2018 that killed more than 10,000 children.
Now the half million plasma samples in Dr. Minas freezers, collected last year by plasma donation company Octopharma at sites across the country, underwent serological testing focused on the new coronavirus, funded with a $ 2 million grant from Open Philanthropy. The tests had to wait for the researchers to set up a new robotic test facility and process the samples. Now they are working on their first batches.
The team hopes to use this data to show how the virus has made its way into the US week after week and how immunity to Covid has grown and changed. They also hope this will spark interest in using serology to shed light on the movement of many more viruses.
"The big idea is to show the world that you don't have to spend huge bucks on this type of job," said Dr. Mina. "We should let this happen all the time."