VANCOUVER -- In April 2020, Elya Martinson was busy figuring out how to navigate her family through the new reality of the COVID-19 pandemic, when she was diagnosed with stage-four lung cancer.

“Lung cancer when we have COVID that attacks the lungs,” she says with a chuckle. “Say what?”

The 37-year-old mother of three was deemed clinically extremely vulnerable to the virus and received one shot of the Pfizer BioNTech vaccine on April 14. Like everyone else in British Columbia, she’s slated to receive her second dose four months after her first. However, she wants it next week, in accordance with the 21-day interval recommended by Pfizer BioNTech.

“It’s not that we think we’re better,” she says. “It’s just in order for us to get the same protection as everyone else, we need two (doses).”

Martinson is referencing new data out of the United Kingdom. Researchers in London monitored 151 cancer patients to determine their immune response to a single dose of the Pfizer BioNTech vaccine. Their findings, which were published in the medical journal The Lancet this week, suggest one dose leaves many cancer patients unprotected.

Three weeks after being vaccinated, researchers found an immune response in 38 per cent of patients with solid cancer, and just 18 per cent of patients with blood cancer. Meanwhile, an immune response to COVID-19 was detected in 94 per cent of people who were cancer-free. Immunity response improved in cancer patients when they received a second shot 21 days after their first shot.

Ontario and Alberta have shortened the immunization interval for some cancer patients. For now, B.C. is sticking to a four-month gap, as officials try to get a first dose into as many people as possible.

“Just because one small study has shown that certain groups did not mount an antibody response, it does not take away the basic premise of the program,” said Dr. Bonnie Henry, B.C.’s provincial health officer, during a news conference on April 26.

“The best protection for all of us, including those who are immune compromised, is to get everybody with their first dose of vaccine as soon as possible,” Henry said at the time.

The Canadian Association of Pharmacy in Oncology (CAPhO) shares Martinson’s concerns around second-dose delays. Citing the research out of the U.K., the group is calling on the National Advisory Committee on Immunization (NACI) to create a nationwide framework that shortens the interval for cancer patients. CAPhO President Tina Crosbie says Canada should be willing to modify vaccination strategies as researchers learn more about the coronavirus.

“If we can follow the manufacturers’ instructions and have the doses on schedule, we’ll be able to see more people with cancer have some sort of immunity,” Crosbie says.

Martinson says her family has gone above and beyond the COVID-19 safety measures put in place by the provincial government. Because of her cancer diagnosis, she says her three children have stayed home from school for a year, and have not been able to visit any of their friends. Her second dose would be as much for her kids as it is for her.

“Please give me and my children that little bit of safety and protection, so we can return to some normalcy,” she says.