Citing a 77% decline in new COVID cases nationally since early January, Dr. Martin Makary, a surgical oncologist and professor at the Johns Hopkins School of Medicine and Bloomberg School of Public Health, expects COVID-19 "will be mostly gone by April, allowing Americans to resume normal life."

Makary wrote about this forecast in a recent opinion column for the Wall Street Journal, setting off a range of reactions.

This trend is mirrored in Austin, where the daily number of new confirmed COVID cases fell nearly 60% between Jan. 17 and Feb. 12. (More recent data is not yet available due to case reporting delays caused by the winter storms last week.)

"From a scientific standpoint, there must be some reason for it," Makary told Austonia. "And it cannot be explained by vaccination rates or a sudden change in behavior."

Instead, he argues that natural immunity from prior infection—especially among asymptomatic patients—is more common than previously thought, in part because "antibody studies almost certainly underestimate natural immunity." He cites a recent Nature article by researchers at Sweden's Karolinska Institute, who found that T-cell immunity can be present even when antibodies are not detectable.

"Not all models have to be grim and bad news," he said. "And while it appears that we're on a good path, we cannot let up our guard until we're in a safer place."

Dr. Scott Gottlieb, former commissioner or the Food and Drug Administration, told CNBC on Monday that he agrees with Makary's sentiment even though he thinks the path forward will not be linear, with a likely increase in cases next fall and winter. "I think things will be normal in the spring and the summer of this year," he said.

But not everyone agrees with this timeline.

Local feedback

Dr. Katelyn Jetelina, a Texas epidemiologist who writes the blog Your Local Epidemiologist, responded to Makary's column, raising questions about the statistics he cited, his assumptions around natural immunity and the role of behavioral changes. "Herd immunity in 6 weeks sounds really nice, but it's important to keep realistic expectations," she wrote in a post published Monday. "I am doubtful this will happen."

Jetelina responded to individual claims made in Makary's column.(Your Local Epidemiologist)

Herd immunity is achieved when a majority of a population is immune to a disease, either because they've been vaccianted against it or have recovered from it themselves.

Jetelina also disputed Makary's claim that many medical experts "are afraid to talk about herd immunity" because some politicians suggested the U.S. let the pandemic run its course as a way to achieve it. "Epidemiologists aren't afraid to talk about herd immunity," Jetelina wrote in response. "This is, quite frankly, our job."

Ultimately, Jetelina argues that there is not yet enough evidence to support Makary's claims about natural immunity, about which there remains many questions, including how it might be impacted by new variants, the threshold needed for community protection and how long it lasts after infection.

Austin Public Health said experts are still working to arrive at answers to these questions in a statement shared with Austonia. The department also pointed out that herd immunity from natural infections was never achieved for diseases such as smallpox, polio and measles, which were only eradicated through widespread vaccination efforts.

"(R)eaching herd immunity by April through vaccination efforts is very optimistic and likely not the case for our community with current state allocations," according to the statement. "While we diligently work to vaccinate everyone over the coming weeks and months, it continues to remain incredibly important to keep wearing your mask, watching your distance and washing your hands."

Planning ahead

Makary, who said he frequents Austin, believes that natural immunity combined with rising vaccination rates could augur a return to normal as soon as late April or May. "Herd immunity is not binary," he said. "It's already kicking in."

Not talking about its impact is irresponsible, in Makary's view, although he understands that people may be skeptical. "It's been a very morbid season," he said. "It's hard, quite frankly, to trust projections. But at this point the trends are promising, and it's good for us to start planning accordingly. Also, I think it's important for people to have hope."

Makary argues that the U.S. pandemic strategy has been, so far, reactionary. By anticipating a plateau this spring and summer, local, state and federal governments can begin planning for a return to pre-pandemic activity.

This is not to say that another surge is not possible, especially considering the emergence of new, more contagious variants. "We need to be prepared to flip the switch on in the fall and go back to masking and maybe even distancing," he said.

But for now Markary thinks a dose of optimism is just what the doctor ordered: "By pointing out the light at the end of the tunnel, it's my hope that people will continue to be compliant with all the public health mitigation for a little bit longer until we get to that point."