Vaccinated People Diagnosed With Cancer Have Higher Risk of Breakthrough COVID-19 Infection
People diagnosed with cancer who’ve received a COVID-19 vaccine have a higher risk of a breakthrough COVID infection than vaccinated people without cancer, according to a study.
The research was published online on April 8, 2022, by the journal JAMA Oncology. Read “Breakthrough SARS-CoV-2 Infections, Hospitalizations, and Mortality in Vaccinated Patients With Cancer in the US Between December 2020 and November 2021.”
COVID-19 vaccine recommendations for immunocompromised people
COVID-19 vaccine recommendations are different for people with weakened immune systems (called immunocompromised). Several breast cancer treatments — including chemotherapy, certain targeted therapies, and immunotherapy — can weaken your immune system. People with moderately to severely compromised immune systems are especially vulnerable to COVID-19, and may not build the same level of immunity to the virus after being fully vaccinated as people who are not immunocompromised.
If you’re currently receiving breast cancer treatment, it’s a good idea to ask your doctor if you should follow these recommendations from the Centers for Disease Control and Prevention (CDC) for moderately to severely immunocompromised people:
If your initial vaccine was Pfizer or Moderna, the CDC recommends you get a third dose of the same vaccine you received initially at least 28 days after your second dose.
After the third dose of either the Pfizer or Moderna vaccine, you should receive a booster dose of either of the two mRNA vaccines at least three months after your third dose.
After your first mRNA booster, you should receive a second booster dose of either of the two mRNA vaccines at least four months after your first booster.
If your initial vaccine was J&J, the CDC recommends you get a second dose of either the Pfizer or Moderna vaccine at least 28 days after receiving the vaccine. The CDC also recommends a booster dose of either the Pfizer or Moderna vaccine at least two months after your second dose and a second booster at least four months after your first booster. The FDA has limited emergency use authorization to people ages 18 and older who have had a severe allergy to an mRNA vaccine, are unable to get an mRNA vaccine because these aren’t available, or strongly prefer the J&J vaccine.
Even though being vaccinated helps protect you from serious illness, it’s still possible to get what’s called a breakthrough COVID-19 infection. People diagnosed with cancer may have lower COVID-19 antibody levels after being vaccinated. The researchers wanted to know how many people in the United States diagnosed with cancer who’d received a COVID-19 vaccine had a breakthrough infection. The researchers also wanted to see the outcomes of these breakthrough infections.
About the study
For this study, the researchers looked at the records of 45,253 people who had been diagnosed with at least one of 12 types of cancer and 591,212 people who had not been diagnosed with cancer. All the people had received a COVID-19 vaccine between December 2020 and November 2021 and hadn’t been diagnosed with COVID-19 before being vaccinated. The records came from 66 healthcare organizations from all 50 states.
People diagnosed with cancer were older and more likely than people without cancer to have other health problems.
Breast cancer was the most common cancer among people in the study:
13,032 were diagnosed with breast cancer
11,421 were diagnosed with prostate cancer
6,962 were diagnosed with hematologic cancer, including leukemia, lymphoma, and multiple myeloma
3,094 were diagnosed with colorectal cancer
2,926 were diagnosed with skin cancer
2,849 were diagnosed with lung cancer
9,833 were diagnosed with bladder, endometrial, kidney, liver, pancreatic, or thyroid cancer
These numbers total more than 45,253 because some people were diagnosed with more than one type of cancer.
The researchers measured the monthly rate of breakthrough COVID-19 infection as the number of new cases in every 1,000 people. The rate was higher in people with cancer than in people without cancer:
From February to March 2021, the rate was 19.6 in people with cancer versus 4.9 in people without cancer.
From April to May 2021, the rate was 43.1 in people with cancer versus 13.8 in people without cancer.
From June to July 2021, the rate was 30.6 in people with cancer versus 17.4 in people without cancer.
From August to September, the rate was 51.7 in people with cancer versus 41.3 in people without cancer.
From October to November 2021, the rate was 52.1 in people with cancer versus 46.9 in people without cancer.
The rate differences were statistically significant, which means they were likely because of the cancer diagnosis and not just due to chance.
Among the people diagnosed with cancer, the risk of a breakthrough infection was 13.6% during the study period. The risk among people not diagnosed with cancer was 4.9%.
People diagnosed with pancreatic cancer had the highest risk, and people diagnosed with thyroid cancer had the lowest risk. Breakthrough infection risk was:
24.7% for people diagnosed with pancreatic cancer
22.8% for people diagnosed with liver cancer
20.4% for people diagnosed with lung cancer
17.5% for people diagnosed with colorectal cancer
17.4% for people diagnosed with bladder cancer
16.0% for people diagnosed with kidney cancer
14.9% for people diagnosed with hematologic cancer
12.5% for people diagnosed with skin cancer
12.8% for people diagnosed with prostate cancer
11.9% for people diagnosed with endometrial cancer
11.9% for people diagnosed with breast cancer
10.3% for people diagnosed with thyroid cancer
Among the people diagnosed with cancer, people who visited a doctor because of certain cancers between November 2020 and November 2021 had a higher risk of a breakthrough infection than people who didn’t visit a doctor because of cancer. This finding suggests that people who were actively being treated for certain cancers had a higher risk of a breakthrough infection than people who’d completed treatment. Higher risk was seen in people diagnosed with:
breast cancer
hematologic cancer
colorectal cancer
bladder cancer
pancreatic cancer
The researchers then matched people with and without cancer on the basis of:
age, ethnicity, and other demographics
vaccine type
other medical conditions
People with cancer still had a higher risk of breakthrough infection than people without cancer.
The researchers also compared breakthrough infection outcomes in people with and without cancer:
The risk of hospitalization was 31.6% in people diagnosed with cancer and 25.9% in people without cancer.
The risk of dying was 6.7% in people diagnosed with cancer and 2.7% in people without cancer.
“These results emphasize the need for patients with cancer to maintain mitigation practice, especially with the emergence of different virus variants and the waning immunity of vaccines,” the researchers wrote.
What this means for you
This study’s results are concerning for people who’ve been diagnosed with cancer — especially for people who are actively receiving breast cancer treatment.
Other research strongly suggests that people diagnosed with cancer have a higher risk of getting COVID-19 than people who have not been diagnosed with cancer. This risk is higher for people who have been recently diagnosed with cancer.
But knowing you have a higher risk of getting a COVID-19 breakthrough infection and having serious complications and worse outcomes can be motivation to stay vigilant about your safety. This awareness also can encourage you to keep following COVID-19 precautions, even if the rest of the world isn’t. It’s extremely important that you:
practice physical distancing
wear a face mask that fits snugly when you go out of the house
wash your hands frequently and use hand sanitizer when you can’t wash your hands
avoid crowds and poorly ventilated spaces
clean and disinfect surfaces you touch frequently, including doorknobs, light switches, phones, keyboards, handles, and faucets
be alert for any COVID-19 symptoms, including loss of smell or taste, as well as fever, cough, and shortness of breath
talk to your doctor about COVID-19 vaccines and boosters, and get fully vaccinated as soon as you can if it’s recommended for you
Learn more about Coronavirus (COVID-19): What People With Breast Cancer Need to Know.
To talk with others about COVID-19 and breast cancer, join the conversation on All things COVID-19 or coronavirus in our community.
Editor’s Note: This article was updated on June 16, 2022, with additional information on second booster shots.
— Last updated on February 3, 2023 at 11:05 PM