At the height of the pre-Delta strain of the COVID-19 pandemic, Stephen Rawlings, MD, PhD, was researching HIV and SARS-CoV-2 when a few men, a couple, approached him. Both had had COVID-19. Both wanted to donate convalescent plasma or contribute to stopping the virus in some other way. Rawlings had to say no.
It was a bizarre moment for Rawlings and his principal investigator (PI).
“Here the PI was a gay man, I was a gay man, and there were two men — and we couldn’t all donate,” Rawlings said. “But we were still, in our own way, forging better science.”
In this case, the potential volunteers could contribute antibodies, and not whole blood, that is, blood that has not yet been divided into its component parts, such as platelets and plasma. That’s because gay, bisexual and other men who have sex with men (MSM) have not been able to donate whole blood since the early HIV epidemic. Initially, that was once the case, even though they had had sex with one man in 1978 and never again. In 2018, the US Food and Drug Administration (FDA) allowed gay men to donate blood if they had abstained for 12 months. And then, in 2020, given the impact of the COVID-19 pandemic on the blood supply, the FDA changed the policy again to reduce the abstinence interval to three months.
Many, including White House officials, have recently argued that current blood donation policies are outdated and unscientific. But what could a more scientifically based blood donation policy look like?
What we call America’s blood donation policy is actually an amalgam of criteria that people must meet before they can donate. It covers everything from medical history and prescription history to a slew of questions about recent behavior. These include questions about having sexually transmitted diseases, using injection drugs without a prescription, and recent tattoos. In addition, men may not have had sex with another man in the past 3 months, and women may not have had sex with a man who has had sex with another man in the past 3 months. Once a person has overcome all these hurdles, staff at blood centers like Impact Life, which supplies blood to dozens of hospitals across the US, will inspect a person’s arms for needle marks.
Finding nothing, the visitor “lay down and bled,” says Louis Katz, MD, acting chief medical officer of Impact Life. Blood vials then travel down the hall, where they undergo blood typing and testing for everything from cytomegalovirus to West Nile virus to Zika to hepatitis B and C.
And then of course there’s HIV, “the childhood infection we’re concerned about,” says global blood consultant Jeffrey McCullough, MD, professor emeritus of laboratory medicine and pathology at the University of Minnesota Medical School.
Although all blood can now be screened, McCullough says blood banks would rather start with a clean sample than eliminate concerns later in the process.
“We want to start with a product of the highest quality,” he said. And while there are now seven HIV tests available to test the blood supply, including PCR, antigen, antibody and nucleic acid tests, tests are never 100% accurate, McCullough said. The question of how clean is clean enough is at the heart of the problem: is a long abstinence period really necessary, or is there a better, more scientific way to reduce the risk?
McCullough said the current blood supply is the safest it has ever been – even with the now three-month delay for donating blood to gay and bisexual men. And Katz said getting HIV through the blood supply is so rare that scientists have to estimate it using models.
As HIV testing and treatment have evolved over time, these models show that the risk of HIV entering the blood supply has also decreased, says Brian Custer, PhD, director of epidemiology and policy sciences at the Vitalant Research Institute. In 1986, models suggested that one in 22,000 units of blood could contain HIV. More recently, these models estimate the risk of HIV entering the blood supply at 1 in 1.5 million to 3 million.
But America’s blood donation policy is full of contradictions, says Jeff Crowley, former director of the White House Office of National AIDS Policy. Crowley, now a professor at Georgetown University Law School, describes these as the “hypocrisies” in the current system.
“With heterosexuals we tolerate a high level of risk and with gay men it’s almost like zero tolerance,” he said of the original lifetime deferment policy. “If you are a heterosexual man and have had condomless sex with a sex worker, you can get a six-month deferral. But it was a lifelong delay for gay men. There’s just no point in trying to protect people.”
So what protects the maximum number of people most efficiently, with the least risk and the least amount of discrimination? This is what the science says.
According to CDC data, receptive condomless anal sex carries the greatest risk of HIV transmission, followed by the insertive partner in condomless anal sex. Then receptive partners have the second highest risk during vaginal sex. The lowest risk is for two women who have non-insertive sex. And while gay men are the most likely to have receptive anal sex, they’re not the only ones doing so. A 2020 model study in the American Journal of Reproductive Immunology suggested that 41% of new HIV diagnoses in American women resulted from anal sex without a condom. There is also some data suggesting that, for unknown reasons, the rectal lining of cisgender women may be more vulnerable to HIV than that of men.
And gay men aren’t the only people who get HIV. For example, in 2019, nearly 1 in 4 new HIV transmissions in the US occurred among heterosexual adults. According to the CDC, people who inject drugs accounted for 7% of new diagnoses. However, at this time the FDA is not studying deferral policies for heterosexuals at higher risk for HIV, Custer said.
However, blood centers do discourage people from donating blood if they have a history of sex work or injecting drugs in the past three months.
A more science-based approach might be to ask everyone about their sexual behavior. But that is not what the ADVANCE study (Assessing Donor Variability And New Concepts in Eligibility) does. The study, designed and funded by the FDA, considers other options for determining when gay and bisexual men can donate blood. The study asks gay and bisexual men questions about their sexual behavior, such as how many partners men have had recently and whether they use condoms or HIV prevention drugs, known as pre-exposure prophylaxis (PrEP), Custer said. The study will not test these questions among heterosexuals.
“These are the questions that could one day be on a future blood donor history questionnaire,” Custer said. “A contemporary, science-based approach to policy is exactly what we are trying to do.”
When the ban on blood donation by gay men was enacted, there were no tests for HIV. A ban was a blunt instrument. But it has long been replaced by accurate HIV testing, Katz said.
“In the late 1990s we had nucleic acid tests – basically PCR – that could detect HIV within seven to 10 days,” he said.
And that should mean, Rawlings said, that a gay man who has been in a mutually monogamous relationship for the past decade and in which neither partner has HIV should be able to donate the same as anyone else. “I’m pretty sure it can be shown that monogamous gay men are safe” by donating blood, Katz said.
Rawlings himself is such a man.
“If I had a new sex partner and it was unprotected and within the last seven days, I would not donate blood,” he said. “The current policy does not take this into account.”
There could be one flaw in that recommendation, said Custer of the Vitalant Research Institute: HIV transmission while someone is inconsistently taking HIV prevention drugs, while rare, could result in just enough medication in the blood to keep the virus levels in the blood to maintain the level. very low. It’s unclear whether current testing would show that, he said.
That’s where the ADVANCE study comes in. In addition to asking questions about men’s sexual behavior and testing blood for HIV, researchers will also test blood for concentrations of one of the most common PrEP medications, tenofovir. After two weeks, participants return to hear the results of the HIV test and complete another, longer questionnaire about personal behavior. By correlating concentrations of the drug with HIV tests, they hope to find out whether that theoretical risk is a real risk. Custer said they hope to have the study results early next year.
It’s also possible, he said, that people taking PrEP may have a lower risk of donating blood containing HIV because the drug is 99% effective at preventing HIV. Right now it’s a paradox.
“I don’t know if it will be enough,” he said of the data they will collect. “Through a mix of testing biomarkers for infection and PrEP use, as well as self-reported behavior, we will get as close to the evidence as possible.”
But maybe it doesn’t have to be enough. Since the FDA reduced the grace period for MSM to three months in April 2020, the Transfusion-Transmissible Infection Monitoring System (TTIMS) has been monitoring whether there is an increase in the number of donations containing HIV. So far, researchers haven’t analyzed that data, but they expect to have results by the end of 2022.
It’s also unclear whether the ADVANCE study will result in changes to the FDA’s deferral policy for gay men. If so, the US will join the likes of Britain, France and Greece in donating based on behavior, not identity. That could make 4.2 million people eligible. Based on the percentage of eligible people who actually donate, that could be another 615,300 pints of blood.
Whatever happens, Katz said it’s clear the FDA needs new data to make a decision.
He said a better science-based policy could ensure that non-monogamous gay men do not donate blood for seven to 10 days after their last sexual experience, so that HIV testing can detect new infection, and then base donations on actual individual behavior. rather than a blanket postponement based on identity.
“There’s no reason why we can’t do better,” he said. “The bottom line is that we don’t yet have a good sense of the best behavioral approaches, and that’s what the research calls for.”