The Infectious Diseases Department at St. Jude Children’s Research Hospital has been at the forefront of influenza research since virologist Robert Webster, PhD, first set foot on campus in 1968. Webster, who is responsible for finding the link between the world’s influenza virus reservoir and migratory aquatic birds, dedicated his career to hunting the flu virus and helping the world better prepare for the next pandemic.
Now retired, Webster joined Richard Webby, PhD, and Stacey Schultz-Cherry, PhD, of St. Jude Infectious Diseases along with Paul Thomas, PhD, of Immunology to discuss the coronavirus pandemic and vaccine development. St. Jude is home to the World Health Organization’s Collaborating Center for Studies on the Ecology of Animals and Birds.
How is COVID-19 different from influenza?
Schultz-Cherry: There are many parallels between COVID-19 and influenza. Both are caused by viruses that circulate in animals but under certain conditions can jump into humans. Both COVID-19 and influenza can spread quickly and cause severe disease. But there are differences and plenty of unanswered questions. For example, SARS-CoV-2, the virus that causes COVID-19, penetrates deeper into human lungs than flu does. One of the many unanswered questions we have about COVID-19 involves the long-term consequences of the infection on lung function and how susceptible COVID-19 survivors are to other respiratory infections.
What are the steps to developing a safe and effective vaccine?
Schultz-Cherry: Once you have an experimental vaccine that is safe and effective in the laboratory, the next step is a clinical trial, and those are all about safety. That’s why vaccines take so long to develop. An unsafe vaccine would do more harm than good. Phase I clinical trials are small and focus on safety. Phase II trials are larger, and you start focusing on effectiveness—like the antibody response, how long immunity lasts and related questions.
How soon could we see a vaccine?
Webby: While opinions differ, I believe it will be 2021 before a vaccine is widely available. The two experimental vaccines that are furthest along in the development process could fail. Once approved, vaccine production, distribution and delivery would also take time. I think the chances of having a COVID-19 vaccine this year are slim.
Schultz-Cherry: I would say we’re nine months to a year away from a vaccine. We have had experience with the production and distribution of flu vaccines. There are systems in place. But SARS-CoV-2 is a new virus. That requires extra precautions when developing a vaccine.
What role will antibodies play in treating the virus?
Thomas: It does seem that some patients who have recovered from the infection mount protective immune responses, including productive antibody and T cells. Such an immune response can clear the virus or limit the severity of infection to the point where if you were infected again you wouldn’t know if you had it. We also know that antibodies in some COVID-19 survivors can help other patients recover faster. But there are some things we don’t understand, including how the antibodies work and how long they persist following the infection.
Webby: The big question is how long the immunity will last— six months, 12 months, a lifetime. But we don’t know yet.
What have scientists learned about the virus?
Webster: People have learned it is extremely transmittable. It is a frightening virus that has many side effects in elderly people that can last for weeks and weeks. We’ve learned it won’t be easy to control, but it is possible with testing, testing and more testing. That is the key along with tracing people who have been in close contact with COVID-19 patients so they can also be tested for the infection.
Schultz-Cherry: We’re looking at the impact on different populations because we don’t know all the complications and long-term effects. That will be one of the next things to address. The genie is out of the bottle, but we can still control how the genie behaves.
From Promise, Autumn 2020