Boston’s convention halls once again have a busy schedule of conference and trade show bookings for the coming months. But many of the events are expected to be much smaller than they were before the pandemic, which will limit local economic recovery.

The Massachusetts Convention Center Authority, which operates the Boston Convention & Exhibition Center and the Hynes Convention Center, expects attendance in the first quarter of next year to be only 50% to 60% of what it was in 2019.

The low turnout was on display at a medical conference at the Boston Convention Center last week.

Stephanie Ambuehl, who flew in from Seattle to recruit doctors and nurse practitioners for healthcare company Optum, noted that foot traffic at her booth was “definitely a little slower than 2019.”

Ambuehl is the kind of business traveler who helped the convention center authority generate an estimated $870 million for the state’s economy in 2019. Returning to Boston this year, she stayed at a hotel and ate out, as she did before the pandemic. “It looks like things are almost back to normal,” she said.

Still, it could take at least two more years for convention attendance to return, predicted Jim Rooney, who ran the convention center authority and now heads the Greater Boston Chamber of Commerce.

“What this means for local businesses – restaurants and tourist attractions and other suppliers to the convention industry – is that they will continue a slow recovery,” he said.

Rooney predicted that foreign visitors, who are often the biggest spenders, may be the slowest to return to U.S. conventions, due to international travel restrictions. This in turn could harm many hotels, restaurants and other businesses that rely on conventions to attract visitors and open their wallets.

Convention center authority sites, including those in Boston and the MassMutual Center in Springfield, typically operate at a loss. But the buildings are subsidized by tourism-related taxes on accommodation, car rental, guided tours and other services.

While many conventions that rely on business travelers from other states and countries expect attendance to drop next year, hopes are higher for some events aimed at local or regional crowds.

Organizers of the Boston RV & Camping Expo in mid-January, for example, expect around 20,000 people. That would be about 15% more than before the pandemic.

Still, coronavirus variants, like delta and omicron, have created uncertainty for conventions across the country.

JPMorgan said this week that a major health care conference planned for San Francisco will be virtual. And Boston RV & Camping show director Carolyn Weston couldn’t rule out the Boston show going live if the pandemic worsens in Massachusetts.

“I would never say it’s off the table,” she said. “We don’t know, a month from now, what’s going to happen in our area. We’re very careful to check in regularly with state and city officials.”

In the meantime, people who feel comfortable attending conventions are savoring the experience.

The Boston Medical Conference this month initially attracted nurse practitioner Sandy Hunt because she offered continuing education credits for attending certain sessions.

Then she dragged on for a few more hours.

“It’s fun to walk around and learn, and there’s nothing quite like being in person,” she said.

Convention organizers hope the lure of the in-person gathering will attract more people like Hunt in the coming year. And local businesses hope to open their wallets during their stay.