As cases spike in California, a warning for Massachusetts

With Phase 3 reopening set to begin here, the explosion in infections in the Golden State suggests the Bay State should not act as if the disease has been conquered

In May, crowds of people packed the boardwalk at California’s Venice Beach on the first day of the Memorial Day weekend.AFP via Getty Images

A state that was once considered a road map for fighting COVID-19 now looks more like a warning sign.

Just one month ago, California seemed to have the coronavirus pandemic under control. Its cities were among the first in the country to implement strict lockdowns, and the state escaped the worst of COVID-19 in the spring. But in recent weeks, a dramatic surge in cases has torn through the state, from the beaches of San Diego to the streets of San Francisco.

For other states that now seem to have their outbreaks under control — Massachusetts, New York, and New Jersey among them — California’s seeming reversal of fortune raises a troubling question: Is success sure to be fleeting?

As Massachusetts proceeds with its reopening plan, embarking on Phase 3 beginning Monday, scientists say California’s turn for the worse holds crucial lessons for states that seem to have tamped down major outbreaks. Politicians and the public alike cannot afford to race back to normalcy, they say, rushing reopening plans and abandoning the strategies that have proven effective, including masks and social distancing. Because thus far, no victory has proven definitive.

“People should be very impressed with the job that we’ve done and yet be very cautious in their own behavior given what’s happening nationally,” said Dr. Sarah Fortune, a physician and chairwoman of the department of immunology and infectious diseases at Harvard T.H. Chan School of Public Health.

Phase 3 “does carry more risk, but that’s not insurmountable given just careful attention to risk mitigation,” Fortune said. “Our state can be more open, and we can keep the virus in check. We just have to be very careful.”

But to see what could happen if Massachusetts is not careful, look west.

In late spring, California seemed to be on track to contain the virus. Despite having more than five times the population of Massachusetts, the Golden State entered June with about the same number of COVID-19 cases and fewer deaths.

On June 1, Massachusetts reported 100,805 total COVID-19 cases and 7,035 deaths. California counted 113,006 cases and 4,251 deaths. Throughout the spring, the number of deaths each day in Los Angeles County, which has a larger population than Massachusetts, never reached above the mid-50s. Meanwhile, the daily death count in Massachusetts neared 200 in late April, the worst point of the outbreak here.

Now, the two states’ fortunes seem to have reversed. As Massachusetts sees a steady decline in infections and deaths, California is facing a crisis. Total infections have almost doubled in one month, and hospitals in several parts of the state, Los Angeles included, are rapidly approaching capacity.

Los Angeles County recorded 2,903 new cases on Monday, its highest count yet. The county is now the center of the state’s outbreak, accounting for nearly half of all confirmed cases. California now surpasses every state except New York for its number of reported COVID-19 infections.

Disease experts say California’s devastating turn for the worse should signal to all states that reopening plans and the public’s resumption of normal activities must proceed cautiously and deliberately, even if the pandemic seems to be in retreat.

“I think virtually everyone in every jurisdiction needs to be very concerned. Because this virus is absolutely relentless,” said Dr. Paul Simon, a physician and chief science officer with the County of Los Angeles Department of Public Health.

“The fact that some states and locales are trending in the wrong direction and others in a more positive direction doesn’t mean that those in the more favorable group can relax,” Simon said. “I think if we let down our guard anywhere, we’re going to see a resurgence.”

California’s path suggests that a false sense of security that comes with improving public health metrics can affect governments and individuals alike.

Anne Rimoin, an epidemiologist at the University of California, Los Angeles Fielding School of Public Health, leads a UCLA project that tests front-line health care workers in Los Angeles. She said the reality of the pandemic there changed rapidly due to a range of factors — with a false sense of security among them.

“It’s easy to get overconfident when you look at how we did flattening the curve in early days here. So I think it’s possible” that played a role in the virus’s resurgence, Rimoin said.

“I think the lesson for California — or from California — is that it doesn’t matter where you are in the curve, or in flattening the curve,” Rimoin said, “if you do not continue to be consistent.”

At the beginning of May, with cases and deaths holding steady, California began to reopen. Facing pressure from residents and local leaders, Governor Gavin Newsom allowed counties to make most decisions about lifting lockdown restrictions. By the end of June, most of the state could book hair appointments, work out in gyms, attend religious services, and dine indoors at bars and restaurants.

Disease experts in California said this rapid reopening coincided with events that only amplified the risk of people gathering in crowds and contracting the virus: Memorial Day, Father’s Day, and protests against police brutality and racism that swept the country.

“Reopening created new opportunities for people to be exposed,” said Michael Cousineau, professor of clinical preventive medicine in the Keck School of Medicine of the University of Southern California.

“The case rate had gone down quite significantly in the beginning of April and into May. So we began to lift the stay at home orders,” he explained. But he said early success in containing infections might have led Californians to let their guard down.

Cousineau described eerily conflicting scenes playing out in and around Los Angeles in recent days: unmasked crowds lounging on beaches while people filed into long lines at COVID-19 testing centers just miles away.

“It seems that the lesson from California and from the South is that we’re not done here,” Cousineau said. “We’ve got to continue to really protect people.”

Experts who spoke with the Globe agreed that this message applied even to states such as Massachusetts, which they said could risk losing hard-won gains against COVID-19.

“It’s great news that the number of fatalities have come down. It’s an important indicator that the sacrifices we all made worked, at least in the sense of bringing the outbreak back under control,” said Samuel Scarpino, a Northeastern University professor who specializes in infectious disease.

“But I think [the rise in infections in California and other states] tells us that we need to continue to take this very, very seriously,” Scarpino continued. “We should celebrate the fact that we have brought this back under control, but we also should not give up all of the sacrifices that we made by relaxing too quickly.”

“We still know that there’s still a lot of COVID in Boston and in Massachusetts, and a huge amount of COVID in the United States,” he said.

California is far from the only state seeing a surge in cases. Outbreaks in Texas, Arizona, Florida, and several other Sun Belt states have threatened to overwhelm medical resources and forced officials to pause or reverse reopening bars, beaches, indoor dining, and venues deemed high-risk. Even locations that have seemingly stamped out deadly outbreaks are considering delays.

Just two days before New Jersey was set to allow indoor dining, Governor Phil Murphy announced he would postpone that plan indefinitely in light of alarming spikes around the country. New York City, the epicenter of the outbreak earlier this year, abruptly canceled plans this past week to allow indoor dining to resume.

Massachusetts, meanwhile, has continued to press forward with reopening. Governor Charlie Baker announced on Thursday that the state would move to Phase 3 of its reopening plan starting on Monday. Gyms, museums, and fitness centers will be among the businesses allowed to open their doors. Baker also loosened restriction on gatherings, raising — but not eliminating — caps on how many people may congregate indoors or outdoors.

By Friday, the state’s key public health statistics still appeared to be on an encouraging trend. The latest rolling average of the rate of positive tests — a metric widely seen as key — remained below 2 percent.

Scientists told The Globe that for reopening to progress relatively safely, officials have to invest heavily in public health infrastructure and be selective about which restrictions to lift. They cautioned that indoor gatherings and large crowds should be especially limited.

“You can reopen, but if you reopen without adequate testing, tracing, capacity to isolate people who are sick and quarantine people who are exposed … it leaves a lot of opportunity for the virus to start spreading again,” Rimoin said.

Responsibility for limiting the virus’s spread falls to everyone, experts said. Mask-wearing is especially important, along with good hand hygiene and continued avoidance of crowds.

“I think we have to view this with a longer time horizon and recognize that we can control this epidemic. It’s been done in other countries, and it’s been done in certain places here in this country, but it really will rely on adherence to some basic principles,” Simon said.

Scarpino said he hopes Massachusetts will remain vigilant about observing safety measures, even as outbreaks worsen around the country, because residents have already seen how destructive COVID-19 can be. That knowledge, he said, is something worth holding on to.

“From a societal perspective, we have a lot more collective wisdom about how serious this disease can be, and we’ve all had to learn and adapt our lives as best as possible to dealing with those kinds of restrictions,” he said.

“There’s probably almost none of us that want to go back to that lockdown scenario, and so I think all of those things contribute to state and local leaders taking the public health measures more seriously.”