Vaccine to Stop Recurrent Strokes Shows Promise in Mice

MONDAY, Oct. 29, 2018 — Stroke remains a major killer. But could a simple vaccine help prevent a recurrence in stroke survivors someday?

That’s the promise from new Japanese research conducted in mice.

A vaccine that would replace or be used alongside standard heart pills might help prevent secondary strokes and possibly heart attacks, saving many lives, said study co-author Dr. Hironori Nakagami, a professor at Osaka University.

“Many stroke patients don’t take their blood-thinning drugs as prescribed, which makes it more likely they will have another stroke,” he explained. “This vaccine might one day help solve this issue since it would only need to be injected periodically.”

As the researchers noted, people who’ve suffered a stroke caused by a blood clot often taken blood-thinning drugs afterwards, to cut the risk of a second stroke. But these drugs can also raise the odds of serious bleeding.

However, in mice at least, the experimental vaccine protected against blood clots for more than two months. It did so without increasing the risk of bleeding or causing any autoimmune response, and it worked as well as the blood-thinner pill clopidogrel (Plavix), Nakagami’s team reported Oct. 29 in Hypertension.

Of course, many findings from animal studies fail to pan out in humans. But Nakagami said his team members plan to test the vaccine in people in the future.

“We are continuing our research in hopes of being able to start clinical trials between five and 10 years from now, but there are differences between mice and humans in how the vaccine will be recognized by the immune system,” Nakagami said in a journal news release. “We should be able to overcome such problems and believe this vaccine provides a very promising strategy in secondary prevention of stroke.”

One U.S. stroke expert believes the strategy may hold promise.

“Experimentally, this sounds promising,” said Dr. Satjit Bhusri, a cardiologist at Lenox Hill Hospital in New York City.

However, the vaccine’s effectiveness in stroke survivors “may be more complicated,” Bhusri noted. For example, a long-acting vaccine “may increase the risk of bleeding around the prior stroke,” he said.

“Also, the lack of a reversal agent or an antidote if such an event occurs is an important factor in deciding the vaccine’s overall utility,” Bhusri said.

More information

The National Stroke Association has more on ischemic stroke.