Long COVID Antibody Trial: Safe, but It Did Not Work Better Than a Dummy Drug

TALMedora Editorial | October 2026 | 3 min read

Millions of people have long COVID, and there is still no proven treatment. A new trial tested one idea. The result: the drug was safe, but it did not work better than a dummy drug.

In Short

• 36 people with long COVID took part.

• Most got one infusion of an antibody drug. The rest got a dummy infusion (placebo).

• Nobody knew who got which one.

• The drug was safe.

• After 90 days, the two groups were about the same in health, energy, walking tests, thinking tests and blood tests.

Why Did They Try It?

Some scientists think tiny bits of the virus may stay in the body for months. If that causes long COVID, then removing them might help. Antibodies can attach to the virus. So the team tested one to see if the idea was true.

Who Took Part?

The 36 people had many symptoms, such as tiredness and brain fog. Their average age was 42. They were followed for a full year, and everyone finished the study.

What Did They Find?

• Safety: the drug was safe.

• Health and energy: no real difference from the placebo.

• Walking and thinking tests: no real difference.

• Blood tests: no real difference.

• How people felt: some people felt better, but that happened in both groups, even among people on the placebo.

Why Might It Not Have Worked?

• Long COVID may not be caused mainly by leftover virus.

• The study was very small, so it could miss a small benefit.

• The drug works less well on newer virus types.

• It was only one dose.

What Should You Take From This?

This study does not support using antibody drugs for long COVID today. It does help scientists plan better, bigger studies. If you have long COVID, talk to your doctor before trying any new treatment, and be careful of anyone who claims a quick cure.

Common Questions

Is there a proven treatment for long COVID?
Not yet. Doctors mainly help with the symptoms.

Did the antibody work?
It was safe, but it did not work better than the placebo here.

Does this mean leftover virus is not the cause?
Not necessarily. This was one small test of one idea.

Where was it published?
In Nature Communications, 2026.

Read the Original Study

Nature Communications, 2026: https://doi.org/10.1038/s41467-026-77925-y

This article is for general awareness and is not medical advice. If you have long COVID, please speak to your doctor.