The trend lines are as stark as they are puzzling: Daily COVID-19 infections in New York have plunged by more than 90% from their mid-April peak, while California’s new cases have soared tenfold during that time.

New York, a coronavirus horror in the spring, has since won praise for corralling the contagion. California, a model for its first-in-the-nation statewide stay-home order to slow the virus’s spread, is now a cautionary tale as it reverses reopenings in a struggle to contain outbreaks. The state’s public health director resigned without explanation last weekend, and New York insists visiting Californians quarantine for two weeks.

What in the world happened?

There are no easy answers. Infectious disease experts cite a number of things that influenced the states’ outbreak trajectories, from the way state leaders managed reopenings to public compliance with health orders, different immunity levels and viral strains and even just plain luck.

Workers move bodies to a refrigerated truck from the Andrew T. Cleckley Funeral Home in the Brooklyn borough of New York, Wednesday, April 29, 2020. (AP Photo/Craig Ruttle) 

But many point out that the virus was so apocalyptic for New Yorkers — with the nightly sirens of ambulances rushing the stricken to overwhelmed hospitals where lobbies were turned into ERs and cooler trucks into sidewalk morgues — they remain far more vigilant.

“The cases just erupted, and the deaths — I’m still freaked out about it,” said Maureen Miller, an infectious disease epidemiologist at Columbia University’s Mailman School of Public Health in New York. “The in-your-face-ness of it was really terrifying.”

That wasn’t so in California, where makeshift surge hospitals and ERs sat mostly empty in the early months of the pandemic – but on Friday the state had totaled more than 600,000 cases and 11,000 deaths. Miller noted that a relative in San Diego only recently started regularly wearing a face mask, something she and other New Yorkers have been doing since April.

Unlike Republican-led Texas and Florida, which also have seen cases soar over the summer, California and New York are run by Democrats. But though New York Gov. Andrew Cuomo and California Gov. Gavin Newsom share similar politics, they differ in style.

David Vlahov, an infectious disease epidemiologist at Yale University who lives in New York, found Cuomo, 62, to be more effective in communicating what was needed to tamp down the virus than Newsom, 52.

“Cuomo was able to take very complicated information and make it accessible,” Vlahov said. “When he was having his daily briefings, the world stopped, people would stop and watch it. He really oozed empathy, people connected with that. I saw Gavin once and thought, this guy is really gabbing. It’s not inspiring, not informative.”

Hundreds of people gather in Newport Beach to cool off on a hot day despite the state’s stay at home orders on Saturday, April 25, 2020. (Mindy Schauer, Orange County Register/SCNG) 

A close look at how each state reacted as their outbreaks surged shows they took broadly similar approaches with a few notable exceptions, suggesting there’s more to the results than their policies.

“The policy is only one part of it,” said Dr. Amesh A. Adalja, senior scholar at the Johns Hopkins Center for Health Security in Baltimore. “Compliance with policy is another factor.”

California saw its first COVID-19 cases in January. By mid-March, Bay Area and Southern California counties were ordering residents to shelter in place, followed by Newsom’s March 19 statewide stay-home order.

Meanwhile in New York, which didn’t see its first case until March, Cuomo and New York City Mayor Bill de Blasio were still debating the need for such drastic measures. Cuomo’s equivalent New York State on Pause order took effect March 22. Epidemiologists have said even that few days of delay could have allowed the virus to spread exponentially in New York.

But if New York leaders were slow to react at first, the unfolding nightmare quickened their pulse. On April 15, as daily cases peaked in New York, Cuomo became the first U.S. governor to require residents to wear masks. Los Angeles and San Francisco issued similar mandates around the same time, but Newsom didn’t make it mandatory statewide until June 18, more than two months later.

Amid protests from residents urging reopening, both states in May began laying ground rules for regions to relax lockdowns in phases as they met criteria for lowering hospitalizations and deaths and raising testing and case investigation capacity. In mid-May, Newsom loosened some requirements after criticism that some of California’s reopening criteria — such as no deaths over the last 14 days — would be impossible for most counties to meet.

Rural and suburban communities across both states began reopening over the next several weeks, but the picture was quite different in their biggest and hardest-hit cities. For example, in Los Angeles, bars, restaurants, gyms, wineries and nail salons welcomed customers back inside, even as new cases and hospitalizations rose. In New York City, even now restaurants and bars still cannot serve customers indoors.

On July 7, California’s new daily cases had more than doubled in a month while New York was holding steady with about a tenth as many cases. That’s when Newsom ordered a second shutdown on indoor dining and other businesses in Los Angeles and other urban counties where cases were skyrocketing.

And, then it happened: On July 22, California overtook New York in logging the most total COVID-19 cases in the country over the course of the pandemic: 413,576. The day before, California logged its most new daily cases ever, 12,807, prompting San Francisco Public Health Director Dr. Grant Colfax to warn darkly that “it’s plausible we could get in a New York-like situation in the late summer or early fall.”

New York’s highest daily new case tally April 15 was 11,571 — on July 21 it had just 855.

To be clear, with half of California’s population and more than double the deaths so far, New York has had it worse. But if you wanted to choose a place today to be safer from the coronavirus, there’s no question it would not be California. Dr. Bob Wachter, who chairs the University of San Francisco’s medical department, said when it comes to the virus, New York “is now probably the safest place in the country to be.”

But the question here remains: Did California invite catastrophe by reopening too fast?

Experts like Adalja say New York did a better job at having a solid case investigation system in place before reopening to trace the close contacts of the newly infected and alert them to get tested and isolate — a standard public health practice in containing outbreaks.

California Health and Human Services Secretary Dr. Mark Ghaly defended California’s response to the pandemic.

“This notion that we did something completely wrong is something I dispute strongly,” Ghaly said in an interview with the Bay Area News Group.

Ghaly added that while the state provided reopening guidance, it wasn’t always followed.

“In Los Angeles, the county I live in, they had many restaurants for example that were not implementing the guidelines as well as we’d like,” Ghaly said. “They saw masking in restaurants that was low, and overcrowding bars.”

SAN FRANCISCO, CA.- MAY 1: After weeks of the coronavirus shutdown, protesters call for the reopening of California during a noontime rally in front of City Hall in San Francisco, Calif. (Karl Mondon/Bay Area News Group) 

That wouldn’t surprise Mindy Yuen, 34, a digital designer who, after recovering from the virus herself, left New York City in June with her husband and son to stay with her parents in Vacaville before giving birth to their second child. She was stunned at how cavalier Californians seem about the pandemic.

“In New York, it was like super serious the way people talk about the virus,” said Yuen, who is preparing to return to the Big Apple, where the spring nightmare remains a vivid memory. “You’d hear sirens every night, you’d drive around and see those freezer trucks outside of hospitals – it was very real.”

Yuen understands things weren’t nearly so bad in California, where temporary hospitals like one set up at the Santa Clara Convention Center in anticipation of a patient surge saw little use. But she laments that California’s more relaxed attitude is rubbing off on her and makes her uneasy.

“Here, it’s like not a big deal,” Yuen said. “It’s kind of not taken seriously. I felt it was so weird.”

Still, experts aren’t convinced either the pace of reopening or social observance of public health measures fully explains the different outcomes. Miller points to a preliminary study by the Scripps Research Institute that suggests the strain of the new coronavirus that took off in Europe and then New York spreads far more easily than the early strains in California from China. That European strain has since made its way across the country and may be behind summer surges in the South and West.

Wachter isn’t persuaded by that theory, but points to other studies indicating one in five New Yorkers now have antibodies from exposure to the virus compared to one in 33 Californians, a level of immunity that can tamp down spread back East. And he notes that California was lucky to avoid a “superspreader” event early in the year like those that hit New York.

“We were good in the beginning,” Wachter said, “and we got lucky.”

Ghaly said experiences in different states at different times don’t lend themselves to easy comparison, noting that knowledge of the virus has been evolving. It’s become increasingly evident, for example, that the virus spreads more easily indoors than out, something California learned as it reopened and that he said New York City was able to learn from the Golden State. California, in turn, learned better treatment methods from New York’s early experience, helping reduce the death toll.

And he said it’s too early to look back on a pandemic that is still unfolding — there are indications California’s summer case surge has already peaked.

“We’re in a moment in time in this entire response in COVID-19,” Ghaly said. “To critics who attempt to draw conclusions now, I would say … we are still writing our story.”