Kidney transplant patients to test for COVID-19 booster in new trial

National Institutes of Health give a boost dose to 200 kidney transplant patients who have not had an immune response to the COVID-19 vaccine in a new trial launched yesterday.

Many transplant patients, who must take immunosuppressive drugs to prevent their body from rejecting a new organ, do not produce enough antibodies – or do not produce antibodies at all – after receiving the COVID-19 vaccine. The study will test whether a third injection of an mRNA vaccine, given in addition to the normal two-shot regimen, will generate antibodies closer to the levels seen in healthy people.

There are some indications that a third dose might help some people. In France, health authorities began recommending in April that immunocompromised patients receive a third injection of the COVID-19 vaccine. Half of the patients who did not respond to two injections produced antibodies after the third, according to an analysis of 159 kidney transplant patients. The other half, however, still had no answer. In Germany, a study of 48 transplant patients found that 40 percent of those who failed to respond to two doses had a response after the third.

Two other trials involving kidney transplant patients are also launched in Israel and Switzerland.

It is possible that the existing body of research is sufficient for health officials in the United States to begin recommending that immunocompromised patients receive a third injection. The Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices will address the issue at its meeting on Friday.

Currently, COVID-19 vaccines are available under an emergency use authorization in the United States that specifies two doses for Pfizer / BioNTech and Moderna injections. In order for a third shot to become the norm for any group, one of two things would have to happen: The Food and Drug Administration (FDA) would need to change this clearance to include the option of an additional shot, or the agency would have to fully approve the vaccines. Once approved, doctors can prescribe a third dose in a practice called off-label use, which allows doctors to use pharmaceuticals based on their judgment even if they are not technically authorized for any particular use.

Some people in the United States are already bypassing the FDA and looking for third shots. More than 900 people have received a third injection in the United States, according to data collected by the CDC, and this is likely an undercount.