Instructions from hep A immunization clinic cause confusion for Airdrie residents

For Christina Grant and her husband's wedding anniversary earlier this month they ate at Thang Long Vietnemese Cuisine on Main Street inAirdrie, Alta.

Days later, Alberta Health Services issued a warning over a potential exposure to hepatitis Aat the restaurant after it was learned someone was infectious while preparing food there. The warning also saidAHS would be hosting two immunization clinics in the city later that week on June 18 and 19.

• Airdrie restaurant worker has confirmed hep A case, says AHS

When Grant learned of the clinics through a news story posted on Facebook by a friend, she and her husband immediately decided they would go.

"If I end up with it and then my kids end up with it because I got it it wouldn't be good, sothat was what I assumed the clinic was about," she said.

Grant said after getting their free immunization she was told by the nurse who'd administered the shots that they'd need to get a second dose in six months time.

"She said any time after Dec.18,we were supposed to go and get a second dose that would not be covered," she said."And she estimated it was up to $50."

Grant saidthis was the first mention of a second dose.

"It's not as big of a deal with my husband and I because we can afford for each of us to get a $50 vaccine.But there are people who maybe can't," she said.

In an emailed statement Alberta Health Services saida single dose is effective at preventing disease and addresses immediate risk.

"The second dose can provide ongoing future protection but only the first dose is needed to deal with the immediate risk situation. If individuals wish to complete the series they can pay for the second dose," reads the statement.

The biggest risk here is not the lack of protection but it's the perhaps the patient's perception that they have long-term protection.- Craig Jenne, infectious disease expert

But, Grant said it wasn't clear that the second dose wasn't required for the vaccine to be effective.

"It seemed as though it was an important thing.I can remember exactly what she had said but she did say, 'you will need your second dose for this and you should monitor yourself for symptoms for up to 50 days after exposure.'"

Craig Jenne, from the University of Calgary's department of microbiology,immunology and infectious diseases saidit's important people understand that a single dose will only work for approximately a year.

"The biggest risk here is not the lack of protection but it's the perhaps the patient's perception that they have long-term protection."

Jenne said the second dose of the hepatitis A vaccine gives that long-term protection.

"Not all vaccines provide lifelong memory. Things like measles, when done properly, would be multiple boosters and most people will have long-term memory 30 plus years protection," he said.

But, other vaccines, like tetanus, require shots every 10 years.

"So you don't end up with lifelong memory to tetanus for example," said Jenne. "The second shot of hepatitis is to help establish that long-term memory. That memory that can last for 20 or 30 years."