This spring, as a new vaccine for shingles was made widely available at local pharmacies, health officials urged older adults to go to their doctor's office or pharmacy to get it to avoid a debilitatingly painful rash and possibly more serious symptoms.

Many older adults had already received a previous shingles vaccine released in 2006, but when the Centers for Disease Control reported that pharmaceutical company GlaxoSmithKline's Shingrix, administered in two doses, was 97 percent effective in preventing shingles for adults from 50 to 69 years old, they were encouraged to seek it out.

But many people who took that advice have found themselves on waiting lists or hearing "no" from local pharmacists as the Centers for Disease Control reports GlaxoSmithKline has been having trouble keeping up with demand.

The CDC says almost one of every three people in the United States will develop shingles, also known as herpes zoster, which emerges when the virus that causes chickenpox reactivates in older adults.

Lisa Herzig said she got the first of the two identical shots that make up the vaccine this winter and recently went to two CVS pharmacy locations near her home in Stonington looking for the second, which the CDC recommends people get within six months of the first shot.

"It's nowhere to be found," she said. "They have no idea when they will get it, (or) if they will get it."

Mick Bolduc, an epidemiologist with the state Department of Public Health and the coordinator of the department's vaccine program, said Shingrix is still available but might be in short supply through the end of the year.

"Depending on which pharmacy, and the time that they call, if an individual is looking to get the vaccine, they may have a vaccine in stock or it may be in stock in three days," Bolduc said. "It's kind of hit-and-miss."

Bolduc said GlaxoSmithKline is trying to meet demand with more shipments to the United States, but the intermittent shortages might continue until the end of 2018.

Bolduc said company officials have explained they didn't anticipate that the Centers for Disease Control's Advisory Committee on Immunization Practices would give the vaccine a preferential recommendation, which fed into the high demand.

"Everyone starts taking a look at it and saying... 'it's being highly recommended, let's take a closer look at it.' Before you knew it they couldn't keep the vaccines in the refrigerator."

Bolduc said public health officials still recommend people over age 65 try to get the vaccine. The second dose can still be effective even if more than six months have passed after someone gets the first one. So people who have already been injected with the first shot should keep calling pharmacies or doctors' offices until they find it.

GlaxoSmithKline also maintains a feature at the website shingrix.com that provides information about where the vaccine is available based on data updated once a month.

"If it's a little longer (than six months) it's really not an issue," Bolduc said. "At this point in time people just need to be diligent — the vaccine is going to be out there and supply will get better."

The availability of Shingrix varies at local pharmacies. Some, including the Walgreen's pharmacy that serves Electric Boat employees, have implemented a wait list.

The vaccine causes soreness, and sometimes redness and swelling in the spot where the shot is injected. According to the CDC, it can also cause fatigue, muscle pain, headaches, shivering, fever, stomach pain or nausea. It is 91 percent effective at preventing shingles in adults age 70 and older, and it stayed at about 85 percent effective for people over 70 in the four years after the vaccination.

m.shanahan@theday.com