We Need to Know Who’s Developed Immunity to Coronavirus
To restart the economy, the government needs to set up immunity registries similar to those for childhood diseases.
The Ebola virus spread rapidly in Sierra Leone in 2015 and killed many. One of us (Dr. Mores) was there and saw the local health-care system get overwhelmed. Without enough personal protective equipment, doctors and nurses worked tirelessly, always fearing infection. The economy was destroyed.
Eventually, Ebola was contained. The new coronavirus will also be contained. Everyone is looking forward to the end, trying to figure a way out of the crisis. Social distancing reduces the virus’s ability to spread, but until cures and vaccines are discovered, the only way out is naturally occurring immunity.
Both of us have experience documenting immunity. Sen. Cassidy is a gastroenterologist who founded an immunization program that protected 36,000 children in Louisiana against hepatitis B. Dr. Mores followed patients in Sierra Leone who were immune to Ebola after recovery. Experience informs our ideas.
Coronavirus spreads rapidly. One person typically infects two or three other people, who then infect two or three others and so on. Most recover or never have symptoms, and most likely become immune. A vaccine works by mimicking the immune response of a naturally occurring infection. Herd immunity develops when 40% to 70% of a population becomes immune. The “herd” of people who are immune blocks the virus from taking hold and infecting others. A person’s immunity to the novel coronavirus could last 12 months. By then, a vaccine could be ready.
In the U.K., officials pursued an initial strategy of allowing herd immunity to develop. When they realized that waves of Covid-19 patients would overwhelm National Health Service hospitals, they abandoned the approach. A successful strategy combining herd immunity with social distancing for the vulnerable requires that the authorities know and record who is and isn’t immune.
The U.S. has experience recording immunity. States currently use online immunization registries to estimate herd immunity for a variety of vaccine-preventable diseases. These registries were paid for by taxpayers and comply with the Health Insurance Portability and Accountability Act. Doctors can enter information. Schools can look up student vaccination records.
When Dr. Cassidy vaccinated 36,000 children, their records were added to Louisiana’s immunization registry. When Dr. Mores knew an African patient was immune to Ebola, the patient was employed to relieve exhausted health-care workers. Increasing the number of immune people and knowing who is immune fundamentally changes things in a health crisis.
To restart the economy, the government needs to set up coronavirus-immunity registries. At the same time, widespread testing is necessary to document immunity in those who haven’t fallen sick. A recent report from China found that 100% of patients tested two weeks after symptoms cleared had antibodies for the coronavirus. Recovering from a known coronavirus infection or having a positive antibody test is likely to indicate immunity lasting for at least some time. Those who so demonstrate that they are immune can be allowed to return to work. The whole community is freer when herd immunity is established.
Healthy young people appear to be at lower risk of contracting Covid-19. This, combined with herd immunity, would allow children and college students to return to school. Any adult who is immune could safely teach. As herd immunity establishes itself, the 30% of Americans who are under 25 could safely return to shops and restaurants.
There’s obviously still much more we need to learn about the new coronavirus. What we learn may change how we respond. But our suggestions here are based on sound public-health principles to address the medical crisis. Only when we find a way out of the medical crisis can we find our way out of the economic crisis.
Dr. Cassidy, a gastroenterologist, is a Republican U.S., senator from Louisiana. Dr. Mores is a professor of global health at George Washington University’s Milken Institute School of Public Health.