The record-setting surge in COVID-19 cases nationwide – including more than one million new infections reported on Jan. 3 – raises questions about whether the higher Omicron variant transmissibility will accelerate a transition from pandemic to endemic disease.
Furthermore,
Infectious disease experts weigh in on these possibilities.
An endemic eventuality?
Whether the current surge will mean the predicted switch to endemic COVID-19 will come sooner “is very hard to predict,” Michael Lin, MD, MPH, told this news organization.
“It’s an open question,” he said, “if another highly transmissible variant will emerge.”
On a positive note, “at this point many more people have received their vaccinations or been infected. And over time, repeated infections have led to milder symptoms,” added Dr. Lin, hospital epidemiologist at Rush Medical College, Chicago.
“It could end up being a seasonal variant,” he said.
COVID-19 going endemic is “a real possibility, but unfortunately ... it doesn’t seem necessarily that we’re going to have the same predictable pattern we have with the flu,” said Eleftherios Mylonakis, MD, PhD, chief of infectious diseases for Lifespan and its affiliates at Rhode Island Hospital and Miriam Hospital in Providence.
“We have a number of other viruses that don’t follow the same annual pattern,” he said.
Unknowns include how long individuals’ immune responses, including T-cell defenses, will last going forward.
A transition from pandemic to endemic is “not a light switch, and there are no metrics associated with what endemic means for COVID-19,” said Syra Madad, DHSc., MSc, MCP, an infectious disease epidemiologist at Harvard’s Belfer Center for Science and International Affairs, Boston.
“Instead, we should continue to focus on decreasing transmission rates and preventing our hospitals from getting overwhelmed,” she said.
A hastening to herd immunity?
“The short answer is yes,” Dr. Lin said when asked if the increased transmissibility and increased cases linked to the Omicron surge could get the U.S. closer to herd immunity.
“The twist in this whole story,” he said, “is the virus mutated enough to escape first-line immune defenses, specifically antibodies. That is why we are seeing breakthrough infections, even in highly vaccinated populations.”
Dr. Mylonakis was more skeptical regarding herd immunity.
“The concept of herd immunity with a rapidly evolving virus is very difficult” to address, he said.
One reason is the number of unknown factors, Dr. Mylonakis said. He predicted a clearer picture will emerge after the Omicrons surge subsides. Also, with so many people infected by the Omicron variant, immune protection should peak.
“People will have boosted immunity. Not everybody, unfortunately, because there are people who cannot really mount [a full immune response] because of age, because of immunosuppression, etc.,” said Dr. Mylonakis, who is also professor of infectious diseases at Brown University.
“But the majority of the population will be exposed and will mount some degree of immunity.”
Dr. Madad agreed. “The omicron variant will add much more immunity into our population by both the preferred pathway – which is through vaccination – as well as through those that are unvaccinated and get infected with omicron,” she said.
“The pathway to gain immunity from vaccination is the safest option, and already over 1 million doses of the COVID-19 vaccine are going into arms per day – this includes first, second, and additional doses like boosters,” added Dr. Madad, who is also senior director of the System-wide Special Pathogens Program at New York City Health and Hospitals.