Q&A: Will COVID-19 become endemic?
During a recent WHO briefing, David L. Heymann, MD, chair of WHO’s Strategic and Technical Advisory Group for Infectious Hazards, said vaccines and good public health practice will help the world “learn to live with COVID-19.”
“It appears at present that the destiny of SARS-CoV-2 is to become endemic, as have four other human coronaviruses, and that it will continue to mutate as it reproduces in human cells, especially in areas of more intense transmission,” said Heymann, a professor of infectious disease epidemiology at the London School of Hygiene & Tropical Medicine.
We asked Heymann to further discuss the potential of COVID-19 to stick around despite the availability of effective vaccines.
Q: Will SARS-CoV-2 become endemic?
A: Many public health experts believe that SARS-CoV-2 will become endemic like the four other human coronaviruses, and like many other infectious diseases that emerged in the past — for example, tuberculosis and HIV.
Q: What does that look like?
A: It is not sure how the epidemiology of the virus might change, but as more and more people are exposed and develop some type of immunity or are vaccinated, the virus will find those who are not immune. There may be some type of herd immunity effect that will mean transmission is decreased in the entire population, but this cannot yet be predicted because the length and quality of protection against infection after natural infection and after vaccination is unknown, and as the virus mutates, the epidemiological characteristics may change as well. However, this likewise is unknown and cannot at present be predicted.
Q: Will it be seasonal, like influenza?
A: All respiratory infections have a greater possibility to spread during the winter months when people are closer together indoors in poorly ventilated spaces this includes the four endemic human coronaviruses. It may be that SARS-CoV-2 also transmits more frequently in the Northern Hemisphere because of this, but it transmits well during summer months as well at present.
Q: Where will it create the biggest problems?
A: If vaccines are effective in preventing infection — not only modifying disease in those infected — the epidemiology will be different in different parts of the world based on vaccination coverage. Vaccines do not remove the need for therapeutics such as antivirals and monoclonal antibody preparations, which will also have a role to play in the long term.
Q: Will COVID-19 vaccination have to be part of the routine childhood immunization schedule?
A: It depends on whether the vaccine interrupts transmission and how long immunity lasts after vaccination both are unknowns at present.