Victor F. Zonana was deputy assistant secretary for public affairs at the Department of Health and Human Services from 1993 to 1998. He is a Sir Edmund Hillary fellow and co-founder of Global Health Strategies and GlobalHealthNZ.org.

In 1997, President Bill Clinton, invoking President John F. Kennedy’s 1961 pledge to land an American on the moon by the end of the decade, set a noble and ambitious national goal: to develop a safe and effective vaccine against AIDS within 10 years.

“It is no longer a question of whether we can develop an AIDS vaccine. It is simply a question of when,” Clinton declared.

Clinton wasn’t the first politician to succumb to wishful thinking when it came to vaccines. Sixteen years earlier, at the dawn of the AIDS epidemic, President Ronald Reagan’s secretary of health and human services promised a vaccine would be ready for widespread testing within two years.

As a political appointee in Clinton’s Department of Health and Human Services and a keeper of the department’s reputation, I was painfully aware of the earlier instance of premature triumphalism. HHS tried to warn Clinton off, but the president would not be denied: He wanted his moonshot moment.

We know how that turned out. Nearly 40 years after AIDS was discovered, we still don’t have a preventive vaccine. But — here’s the good news — what we do have is an arsenal of effective antiviral drugs. And they’ve allowed us to treat and even prevent cases of the once universally fatal human immunodeficiency virus.

This history is doubly instructive given President Trump’s convention speech pledge on Thursday that we “will produce a vaccine before the end of the year, or maybe even sooner.”

Lesson one: Humility is in order for those who predict a vaccine is just around the corner. Lesson two: We should hedge our big bet on vaccines, giving equal priority and funding to treatment research.

The current research agenda is anything but balanced. Consider that the U.S. government, as listed by the Biomedical Advanced Research and Development Authority, has so far invested $10.7 billion alone on manufacturing support for vaccines vs. about $1 billion on treatment.

I’m as pro-vaccine as anyone, having devoted much of my career to their development and distribution, including at the International AIDS Vaccine Initiative and the Gavi Alliance. And at 66 years old, I’d ordinarily be first in line to take a Food and Drug Administration-approved vaccine.

But what if all the current candidates fail or offer just limited protection? What if immunity wanes after a few months? What if the first vaccines protect young people but are useless for at-risk seniors? What if vaccines have unacceptable — or even fatal — side effects?

Each of these is theoretically possible. “I think when people tell the public that there’s going to be a vaccine by the end of 2020, for example, I think they do a grave disservice to the public,” said Kenneth C. Frazier, chief executive of vaccine powerhouse Merck, in an interview with the Harvard Business School.

Frazier dismissed the positive initial reports from rival vaccine manufacturers. “There are a lot of examples of vaccines in the past that have stimulated the immune system, but ultimately didn’t confer protection,” he said. Worse, he added, some vaccine candidates “actually helped the virus invade the cell.”

Again, this is a remote but real possibility. Merck, which has developed more novel vaccines than any other company, was suddenly forced to stop its AIDS vaccine trial in late 2007 after investigators realized the vaccine offered no protection — and even made some volunteers more susceptible to HIV.

Crash programs to develop vaccines can be risky. President Gerald Ford’s effort to vaccinate all Americans against swine flu ended in disaster in 1976 after 450 vaccinated individuals were paralyzed with Guillain–Barré syndrome. Tellingly, like Trump, Ford was running to stay in the White House that year.

Meanwhile, some potentially promising therapies languish. Two antiviral drugs used against hepatitis C have demonstrated anti-covid-19 potential in laboratory tests and small clinical trials. Three Iranian studies published in the Journal of Antimicrobial Chemotherapy on Aug. 19 suggest that the drugs, sofosbuvir and daclatasvir, are effective against the virus. Yet scientists have struggled to raise the money needed to confirm these results in larger trials. Other researchers have told me its taken months to get the National Institutes of Health to commit lab space to test potential antiviral treatment candidates.

More than 30 years ago, a small band of AIDS activists — many fighting for their own lives — changed history by demanding better treatments. Let’s follow their example, hedge our bets, and give equal priority and funding to covid-19 treatment research.

As is written in the Bible, “Divide your investments among many places, for you do not know what risks might lie ahead,” (Ecclesiastes 11:2). It’s time to apply this ancient wisdom to a modern plague.

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