How effective is the monkeypox vaccine? Scientists scramble for clues as trials ramp up

When mo nkeypox suddenly started spreading globally in May, the world was fortunate in one respect: a vaccine was available. MVA, originally developed by Bavarian Nordic as a smallpox vaccine, was already licensed for monkeypox in Canada and the United States. EU regulators have since followed suit. Vaccine supplies are limited, and no doses have been shared with countries in Africa that have long been affected by monkeypox. But in Europe and North America, clinics have by now delivered thousands of doses to people in high-risk groups. There’s little doubt the vaccine can help, but that’s about all that’s certain. Exactly how well MVA protects against monkeypox and for how long is not known. Nor is it clear how much protection is lost by giving just a single dose rather than the recommended two doses, as some countries are doing to stretch supply, or how much protection a vaccine given after exposure can offer. But the ethical and logistical complexities of the monkeypox crisis, which is overwhelmingly affecting men who have sex with men (MSM), are making these questions hard to answer. Placebo-controlled clinical trials are fraught because MVA is already licensed and people are clamoring to get it. And vaccine clinics are often set up at short notice as doses become available, making it harder to organize a trial and enroll subjects. Researchers are responding with a plethora of inventive trial designs. The first evidence that smallpox v...
Source: Science of Aging Knowledge Environment - Category: Geriatrics Source Type: research