Cancer vaccines: how they work, what to ask your doctor

But such miracles of science exist today. And while there’s still work to be done, they’ve been preventing cancer and saving lives for more than four decades.

“If you took a poll and asked people, ‘Do we have a vaccine for cancer?’ people would say no,” says Karen Knudsen, CEO of the American Cancer Society Wealth.

“They really don’t know that we know.”

Pharma giants BioNTech and Moderna made headlines recently when they explored the potential of mRNA vaccines, first used in COVID to treat cancer. Such vaccines use messengers made in the lab that teach the body how to mount an immune response.

However, clinical trials of more traditional vaccine technologies have long been ongoing — and participants are already receiving cancer vaccines, many of them personalized. A handful of vaccines have already been approved by the US Food and Drug Administration. And vaccines to prevent cancer have been around since the 1980s.

If this is new to you, you are not alone. Doctors do not always offer patients vaccines for cancer prevention or cancer treatment – due to a lack of knowledge or bias towards certain races, genders or age groups.

“Patients need to stand up for themselves,” says Dr. Nina Bhardwaj, director of immunotherapy at the Vaccine and Cell Therapy Laboratory and co-director of the Cancer Immunology Program at the Tisch Cancer Institute at the Icahn School of Medicine at Mount Sinai in New York City.

We tend to think “that the doctor is absolutely right,” she says. “But that’s by no means always the case.”

What is a cancer vaccine?

Cancer vaccines aren’t that different from vaccines for infectious diseases like the flu, measles, mumps and COVID, says Dr. Keith Knutson, a professor of immunology at the Mayo Clinic who researches and develops cancer vaccines Wealth.

Vaccines stimulate the immune system to fight a target – usually a virus. In this case, however, the goal is cancer.

Currently, the majority of cancer vaccines are therapeutic – they are used to treat patients who already have advanced cancer, often in conjunction with other interventions such as chemotherapy, surgery or radiation. According to the Cancer Research Institute, there are currently two approved by the FDA: one for early-stage bladder cancer and one for prostate cancer.

But there are also vaccines for cancer survivors. They’re given to those in remission at high risk of recurrence, Knutson says. He is leading a Defense Department-funded study testing vaccines designed to prevent triple-negative breast cancer from recurring.

Then there are the vaccines, which can prevent cancer altogether. There are four that are FDA approved: three for HPV, or human papillomavirus, and one for hepatitis B. All work to prevent infections that can later lead to cancer. The HPV vaccine is recommended for men and women around the age of 11 or 12, but can be given as young as 9 and up to 26 years of age. The Hep B vaccine is recommended for everyone aged 59 and younger and adults aged 60 and older who are at risk of infection.

Although approved vaccines for cancer prevention are few, they have outsized effects. According to data released last month by the American Cancer Society, between 2012 and 2019 the HPV vaccine resulted in a 65% reduction in cervical cancer in women in their early 20s FDA approved vaccine.

Similar reductions should eventually be seen in other HPV-caused cancers that usually appear later in life, such as head, neck, mouth, rectum and vulva cancers, Knudsen said.

“This is a great win for science,” she says, referring to the new data on the success of the vaccine. “We really can end cervical cancer as we know it for everyone if we get vaccinated”—and the same should be true for other HPV-related cancers.

Another target that many researchers have in mind: breast cancer. Laboratories around the world, including Knutson’s, are particularly interested in developing vaccines that could prevent the world’s most common cancer — or at least prevent it from coming back in survivors.

Knutson’s lab is working on a vaccine that targets six targets commonly found in breast cancer. Fortunately, many are also found in lung, ovarian, and pancreatic cancer.

“We may generate immunity that specifically targets breast cancer, but we think immunity may also protect against other types of cancer,” he says.

How cancer vaccines work

Currently, with few exceptions, vaccines for the treatment of active cancer are in trials. However, they are not cures – and getting one is a lot more complicated than going to a pharmacy and getting a COVID or flu vaccine.

Personalized cancer vaccines are common in clinical trials. However, their development is a lengthy process. And like dr. Phillip Febbo, chief medical officer at biotechnology company Illumina, says, “Cancer doesn’t wait.”

Febbo calls personalized cancer vaccines “tailored therapies”. For each patient, a specialist must determine which tumors can be reached via a biopsy. Then the patient has to undergo the biopsy and have their tumor cells genetically sequenced by a company like Illumina. The sequence is analyzed to determine which vaccine composition is likely to be most effective in the particular patient. Then the personalized vaccine has to be manufactured and delivered to the patient.

Each step can take weeks, if not months — typically around six months total, according to Knutson. Time is “something we struggle with every day,” he says.

Illumina is providing Moderna with genetic sequencing capabilities for its melanoma-prevention vaccine, which is given to those who have been diagnosed and have their tumors removed, Febbo says.

Patients taking both their new vaccine and Merck’s Keytruda, a monoclonal antibody therapy that helps immune cells kill cancer cells, were 44% less likely to die or come back, compared with a group taking only Keytruda, the companies said known December. The drug is moving into a Phase 3 trial, the last before potential FDA approval.

Febbo’s company has reduced the time it takes to sequence the entire genome to about a day instead of weeks, he says — a move that allows for faster delivery of custom vaccines.

Knudsen, Knutson and others are intrigued by the apparent success of Moderna’s cancer vaccine. They hope mRNA technology holds the key to speeding up the process of personalizing cancer vaccines, whose side effects are much more tolerable than those of chemotherapy.

“We’re in a new era now, having just seen mRNA vaccines,” says Knudsen. “Is mRNA vaccine technology a new frontier for us? That is still an open question.”

How to get a cancer vaccine

The future of cancer vaccines is bright, experts say — but it may not be equally rosy for everyone.

All experts wealth spoke of his concern that new medical technologies such as cancer vaccines could disproportionately benefit the privileged – and remain out of reach for many in marginalized communities.

It’s a trend we’re seeing more commonly in clinical trials, and one that’s not new to healthcare, says Bhardwaj.

“The poor or underserved populations are less likely to be involved,” she says.

There are unconscious and other prejudices – often against non-white patients, women and the elderly. Because of this, doctors may not recommend clinical trials or some treatments, and “patients need to advocate for themselves,” she says.

Case in point: Black men are about twice as likely to die from prostate cancer as white men. “Part of it is because we don’t understand enough the genetics of risk,” she says. “But part of that is the lack of access to care and clinical trials” that provide “the most advanced form of care.”

If patients are interested in vaccines that may exist for their cancer — approved or in clinical trials — they shouldn’t wait for their oncologist to point out the possibility, experts say wealth.

“Ask them, ‘Am I eligible? What would be the benefits and concerns? What treatment options do I have?’” advises Knudsen. “Get a second opinion if you can.”

How close are we to widespread availability of cancer vaccines?

The majority of current cancer vaccines are intended for patients with advanced disease. It is the “natural progression of medicine” to start with those most in need, says Febbo. “We make progress, and then we take that progress and march up earlier and earlier” in the disease stage.

Knutson predicts that an increasing number of therapeutic cancer vaccines will be developed over the next decade. There’s plenty of ongoing phase 2 and some phase 3 clinical trials for such, which means more help should be on the way relatively soon, he says — emphasizing “should.”

Sometimes the problem isn’t a lack of new successful treatments, but a lack of funding to push them to the finish line.

“Part of the problem is and remains — in all areas, whether it’s a cancer vaccine or some other type of treatment — someone has to foot the (cost of) higher-level clinical trials,” like phase 3 trials, he says.

“An academic like me can probably get through phase 1 or 2 and show promising results, but the competitive landscape and what’s popular with investors and what’s not will dictate whether you participate in phase 3 clinical trials.”

There’s no question that many opportunities have been missed over the years, says Knutson. Worst-case scenario, his team is developing a successful cancer vaccine but cannot secure the resources for a Phase 3 trial needed for FDA approval.

Under such circumstances, he finds it encouraging that future researchers will be able to build on his team’s progress by reading their publication results.

“While it may be disheartening that I’m not seeing this particular vaccine or vaccine making progress, I will know that I have contributed to a scientific base that guides the future,” he says.