Harvard expert says coronavirus surge could arrive in November

Coronavirus testing earlier this month in Winthrop.Erin Clark/Globe Staff

The coronavirus pandemic could surge as early as November or December, according to a Harvard epidemiologist.

Stephen Kissler, research fellow in the Department of Immunology and Infectious Diseases at Harvard T.H. Chan School of Public Health. said that other coronaviruses peak “pretty reliably in December or January” in the Northern Hemisphere.

“To the extent that SARS-CoV-2 follows the pattern of the other coronaviruses, we’re a little bit more likely to see these resurgences of infection a little bit later in the year,” Kissler said in a briefing Wednesday with reporters.

Kissler noted that cases have been on the rise recently, saying, “We may be starting to see that second surge now.”

But, he added, “I really expect transmission to increase sort of later in the year, probably November, December. And the reason I’m shifting that a little bit earlier than December-January is just because there’s still so many susceptible people in the population that it’s easier for SARS-CoV-2 to spread than the seasonal coronaviruses. So it can sort of take off a little bit earlier.”

Kissler said a combination of behavioral and weather factors would likely play a role in the rise of cases and were difficult to tease apart. With colder weather, more people are likely to gather indoors where the virus can build up in the air.

At the same time, he said, the virus may prefer drier, colder air. Both the flu and coronaviruses spread through respiratory droplets and aerosols, “bits of water that can hang in the air for various periods of time. And there have been experiments to show that those can sort of survive and spread a little bit easier in conditions that match up with weather conditions that you see during winter."

Kissler joins a chorus of experts who are expecting a surge in cases in coming months unless the United States steps up its effort to prevent it.

Massachusetts Governor Charlie Baker has acknowledged a recent rise in cases in the state, but says the state is prepared to deal with more infections.

“We all acknowledge [a surge] is on the horizon," Cassandra Pierre, an assistant professor of medicine at Boston University School of Medicine and a physician at Boston Medical Center, said Tuesday. “We just don’t how far off it is.”