A significant percentage of people with certain blood-related cancers don’t develop COVID-19 antibodies from vaccinations, leaving them potentially vulnerable to COVID-19 after they get their shots, according to findings by UPMC that were discussed in a virtual news conference Friday.

Tests done on 67 fully vac­­­­­­­cinated people with “hematologic malignancies” — which include non-solid cancers like leukemia, myeloma and lymphoma — showed 46% didn’t produce COVID-19 antibodies, according to Ghady Haidar, transplant infectious diseases physician.

Moreover, of the patients among them with chronic lymphocytic leukemia, 77% failed to produce the antibodies, Haider said.

That doesn’t necessarily mean that the vaccinations won’t help those cancer patients, because the immune system is complex and there are many other elements besides antibodies that can fight off disease, but it does mean that patients with hematologic malignancies — who tend to be especially vulnerable to COVID-19 anyway — plus those who associate with them, should be vigilant about masking and distancing, Haider said.

It also means that if they begin to develop COVID-19 symptoms, they should get tested immediately and if positive, seek monoclonal antibody treatment, Haider said.

Monoclonal antibody therapy can prevent hospitalization and death if given within 10 days of the onset of symptoms, UPMC and other organizations have found.

The antibody response among hematologic cancer patients is “strikingly low,” and the organization is working to find the reason for that, according to Mounzer Agha, a hematologist at UPMC’s Hillman Cancer Center, cited in a news release.

Ultimately, though, they weren’t all that surprising, because the patients involved had weakened immune systems, Haider said.

UPMC will try to determine whether such findings apply to other maladies that weaken the immune system, such as “solid tumor” cancers and HIV, according to Haider.

UPMC published its findings in the “preprint” journal medRxiv, without obtaining peer review, so that it can “alert the world” as soon as possible to the risks, UPMC officials said, while adding that there have been some other reports of similar findings from other organizations.

Peer review delays are significant, and UPMC doctors have seen published material on COVID-19 as long as two months after they knew the basics from their own observations, according to David Nace, chief medical officer for the UPMC Senior Communities.

UPMC will still pursue peer review of the hematological findings.

In its study of the hematologic cancer patients, UPMC didn’t find a link between the therapies used to treat the cancer and the lack of antibody response.

But it did find that the older patients in the study tended to be the ones with lesser antibody production.

Another recent study by UPMC of vaccinated residents in the organization’s senior facilities showed better results than the study involving the cancer patients.

All 70 of those tested mounted a detectable antibody response, Nace said.

Still, the levels of those antibodies varied widely, he said.

And it’s not clear how protective those antibodies will be or how long the protection will last, he said.

Older adults typically have less robust and less durable immune responses to vaccines like those for the flu, Nace said.

“We’re seeking answers,” he stated.

There have been residents of UPMC senior communities that have developed COVID-19 infections after being fully vaccinated, but they were asymptomatic, which indicates that the vaccines were at least somewhat effective, Nace said.

The uncertainty about how protective COVID-19 vaccinations can be for some older people makes vaccinations more important than they would be otherwise for senior community staff, Nace said.

UPMC has not made COVID-19 vaccinations mandatory for staff yet, but some organizations around the country have started doing it, said Tami Minnier, the organization’s chief quality officer. UPMC has taken a “thoughtful approach” with vaccines for the flu and has achieved “nearly 100%” compliance that way, Minnier said.

It wouldn’t have been appropriate to have mandated COVID-19 vaccinations for staff early on, because the vaccines were new and some people were “scared,” Nace said.

Their continued use and success, however, coupled with the organization’s educational efforts about the benefits are building trust, which is critical, he said.

While not definitive, the senior community findings on vaccination effectiveness point the way toward cautious reopening for visitation in long-term care facilities, especially with the weather getting nicer and outdoor settings becoming available, according to Nace.

But challenges remain, he said.

There has been guidance from the state for nursing homes, and just recently, for assisted living facilities, but none for independent living, he said.

There are lots of details to work out, like whether visits should take place in specially designated visiting areas, or in residents’ private rooms or in semi-private rooms and in dining rooms, he indicated.

There are also the unnerving, almost instantaneous shutdowns that occur when an infection is discovered, he said.

Repeatedly, homes have green-lighted visitation after a hiatus only to have to rescind it two hours later, he said.

“Until we get enough vaccinations, we will continue to see that cycle,” he said.

People who think they may be candidates for monoclonal antibody therapy can visit UPMC.com/AntibodyTreatment; or call 866-804-5251 between 7 a.m. and 8 p.m. seven days a week or can ask their doctors, according to a slide shown during the news conference.

Mirror Staff Writer William Kibler is at 814-949-7038.