SAN DIeGO – He lives in La Jolla Village, near a cove that is attracting sunbathers this weekend, despite social distancing rules.

Peter Salk’s favorite stores and restaurants also are nearby. Many are beginning to reopen now that the pandemic is on the decline in San Diego County.

But after two months of hunkering down at home, the 76-year-old Salk won’t be venturing beyond his front porch during the long Memorial Day weekend. And it may be a while before he does.

“I’m not ready to run the risk of getting infected,” said Salk, a biomedical researcher who spent years working with his father, Jonas Salk, the man who developed the first successful vaccine against the deadly polio virus. “It seems clear that as we loosen up, the disease can come back.”

Customers are beginning to return to local restaurants after dine-in service was resumed countywide.

But many people share Salk’s concerns, especially older people. Salk’s thoughts about the threat carry weight because of his family name, as well as his deep understanding of communicable diseases and the promise and peril of vaccines. In 1953, at age 9, he became among the first wave of people to be inoculated with his father’s experimental vaccine.

His message has special meaning for people old enough to remember the era when polio paralyzed and killed thousands of people in what seemed to be a random way. Children were hit the hardest.

It wasn’t unusual for a parent to take their child out of school at the mere suggestion that another student had the virus, which is spread when people come into contact with an infected person’s stool. Polio also can be transmitted through the droplets in a sneeze or a cough from someone who is infected.

In the 1940s and ’50s, polio was the most feared disease in the country. Swimming pools and movie theaters were shut down. Things didn’t begin to change until 1955, when Jonas Salk’s vaccine was deemed safe and effective after seven years of research, development and testing. By 1961, the incidence of polio cases in the U.S. had dropped by 97%.

Salk eventually moved on to La Jolla, where he founded a biomedical research institute that bears his name.

On March 19, Gov. Gavin Newsom issued a decree that ordered Californians to shelter in place. “That was such a relief to me,” Salk said. “I haven’t left home since then.”

In the meantime, scientists around the world are feverishly trying to develop a vaccine against the virus.

“It important not to try to go too quickly, despite the pressing need for having a vaccine as soon as possible. I have read, for example, that some of the vaccine programs may be skipping animal studies and going straight into humans. You lose an opportunity to see how the vaccine will work in people.”

Salk is eager to see a safe vaccine emerge soon. He feels very unsettled about what’s occurring now.

“First of all, we don’t yet know the natural history of the disease as it occurs through seasons in the year,” Salk said. “In any case, the chances of the disease flaring up again, sooner or later, are real, particularly with the loosening up of social distancing restrictions.”

But he understands people’s need for good news.

“People were afraid of polio. It affected them for years,” Salk said. “It could be measured in the extraordinary relief that came when the [Salk] vaccine was found to be safe and effective. There was jubilation. Finally, we had a vaccine in hand so that we did not have to live in a constant state of fear.”