PLAINFIELD — For more than two weeks, 73-year-old Susan Kahn has been housebound with severe nerve pain due to shingles, which is caused by the same virus that causes chicken pox in childhood.

This “horrible experience” has kept Kahn, a Plainfield resident, away from her work as a therapist and reliant on her husband — who is recovering from a torn rotator cuff — to care for her.

“It’s unbearable pain, day after day after day,” she said.

Before the diagnosis, which required two trips to the emergency department at Alice Peck Day Memorial Hospital, “shingles wasn’t something I was familiar with,” Kahn said. But now, she is urging all of her friends to “get the damn shot” to avoid a similar situation.

Two doses of the vaccine Shingrix is more than 90% effective at preventing shingles, according to the Centers for Disease Control and Prevention. Due to this efficacy, the CDC recommends Shingrix over an older vaccine Zostavax, which first came into use in 2006 and reduces the risk of developing shingles by 51%.

Unfortunately, Shingrix’s manufacturer GlaxoSmithKline, Britain’s largest drugmaker, has struggled to keep up with demand since launching the drug in 2017. Kahn’s friends in the Upper Valley and beyond can’t seem to find Shingrix, she said.

“What’s going on?” Kahn said.

GlaxoSmithKline is “working as fast as they can to put Shingrix onto the market,” said Dr. Michael Calderwood, an infectious disease specialist at Dartmouth-Hitchcock Medical Center in Lebanon.

DHMC, like other providers, gets a monthly allotment of the vaccine, said Calderwood, who also is DHMC’s associate chief quality officer. It’s then distributed to clinics, which provide it to patients whom providers deem to be highest risk. The CDC recommends Shingrix for all healthy adults over 50, and it requires two doses to be effective.

“We’d love to give to everyone who needs it,” Calderwood said.

That’s not possible at present. The CDC’s webpage on vaccine shortages states that “due to high levels of demand for GSK’s Shingrix vaccine, GSK has implemented order limits and providers have experienced shipping delays,” which are forecasted to continue.

Jake Leon, spokesman for the New Hampshire Department of Health and Human Services, said in an email on Monday that those order limits are still in place “as far as we know.”

But he said that department staff have heard anecdotally that some patients have acquired the vaccine. “It may just require calling around,” he said.

Diana Lawrence, a 53-year-old from Grafton, Vt., said that her doctor’s office didn’t have the vaccine, but she got on a waiting list at the Walgreens in Walpole, N.H. They called her after two weeks and she was able to get it.

“It was difficult to find,” Lawrence, who works as a spokeswoman for Dartmouth College, said in an email.

Lawrence said she felt it was worth it because she has had friends and family who have had shingles, and she’d like to avoid the pain and the time away from work.

“I’m kind of a giant pincushion,” she said. “I’m a big believer in vaccination, so if there’s a shot out there that can be helpful, I’m on it. When it comes to shingles, you don’t want to get it and you don’t want to spread it.”

Shingles itself can’t be spread from person to person, but people with shingles — which like chicken pox is caused by the varicella zoster virus — can give the chicken pox to those who haven’t had it or been vaccinated against it, according to the CDC.

Shingrix has some side effects. It can cause a sore arm near the injection site, as well as fatigue, muscle pain, a headache, shivering, fever, stomach pain or nausea, according to the CDC.

Side effects go away within two or three days and patients are left with “good protection against shingles,” Calderwood said.

The less effective, but more accessible Zostavax can still be administered to provide some protection, according to the CDC.

Both vaccines — the single dose Zostavax and the double dose of Shingrix — cost more than $200 cash, according to Audra Burns, a D-H spokeswoman. The costs to patients depend on their insurance coverage, co-pays and deductible.

GlaxoSmithKline is working to boost production and earlier this month told Reuters that a new bioreactor facility would enable it to meet demand when it’s constructed in 2024.

DHMC’s monthly allotment has increased over time, which shows that things are “heading in the right direction,” Calderwood said. But it’s still not enough to meet demand.

Similarly, Colonial Pharmacy in New London has a waiting list for Shingrix that far outpaces the supply, said Glenn Perreault, the pharmacy’s owner. This summer, Perreault said his waiting list was at about 300 people and he was able to immunize five new patients per month. Now, Perreault said the list is down to around 200. Working through GlaxoSmithKline directly, as well as two other suppliers, he is able to immunize 20 to 30 patients per month.

Perreault still has to decide which patients get the vaccine first. He distributes his allotment first to patients over 65 and to those with chronic conditions that might put them at greater risk of developing shingles.

“It’s an incredible shortage,” he said.

While he wants to see the quantity of Shingrix available increase, Calderwood said he wants the company to do so in a safe way.

The medical community is being “careful not to rush them” at the risk of pushing the company to produce a lower quality product, he said.

Those interested in receiving the vaccine should first speak with their primary care provider, Calderwood said. If their provider doesn’t have the drug on hand, Calderwood said people can look for it at pharmacies through a vaccine locator on the company’s website: shingrix.com/shingles-vaccine-locator.html.

Valley News News & Engagement Editor Nora Doyle-Burr can be reached at ndoyleburr@vnews.com or 603-727-3213.