Study finds differing antibody responses

Confirms who is at risk of virus infection

A new UPMC study has found COVID-19 vaccines do not adequately help with the ability to form antibodies among some members of the immunocompromised community.

The interim analysis of the study found that the effects of the COVID-19 vaccine on people whose immune systems are compromised shows a “wide range of neutralizing antibody response.”

“The study is one of the first to verify that the ability of blood from immunocompromised participants to neutralize the virus closely mirrors their antibody levels measured by a Food and Drug Administration-approved test,” UPMC said in a news release.

This means that the antibody testing accurately shows the lower levels of antibodies in the blood of vaccinated immunocompromised people, according to the UPMC release.

Between April 14 and June 14, the study tested blood samples from 598 volunteers, 489 of whom were immunocompromised and 107 who were health care workers who were not immunocompromised.

The preliminary data showed that 98.1% of the health care workers had antibodies after vaccination.

Lung transplant patients had “a particularly poor response to vaccination,” with only 22.2% producing antibodies, the study concluded. However, 94.6% of patients with HIV produced the antibodies.

“This is important because we’ve seen several studies indicating that immunocompromised people are less likely to produce antibodies in response to COVID-19 vaccination,” said Dr. John Mellors, chief of the Division of Infectious Diseases at UPMC and a professor at the University of Pittsburgh. “And we can assume this means they’re less likely to be able to fight the virus, but until we were able to test for virus neutralization, that was only an assumption. Our results give us more confidence in saying that people who do not produce antibodies truly are at greater risk of COVID-19 infection.”

In an effort to share crucial information to guide clinical and public health decisions, UPMC and University of Pittsburgh School of Medicine physician-scientists published the findings this week in medRxiv, a preprint journal, and announced the results ahead of

peer-reviewed publication.”

“Our study highlights the urgent need to optimize and individualize COVID-19 prevention in patients with immunocompromising conditions and have other treatments — such as monoclonal antibodies — available should vaccination fail,” said lead author Dr. Ghady Haidar, a UPMC transplant infectious diseases physician.