Cases are down in the U.S., hitting their lowest point since last July. And while the BA.2 subvariant of Omicron has become the dominant form of COVID in America and globally, the low numbers have many people approaching this booster differently.

Some, in fact, are hoping to time the shot with the next surge in cases—something health officials are trying to dissuade. Bob Wachter, chair of the department of medicine at the University of California, San Francisco, says these attitudes are similar to people who think they can time market rallies—and about as successful.

Weighing whether you should get a second booster? Here are a few things to consider.

Who’s eligible for a second booster shot?

The FDA has cleared the additional COVID-19 booster for people age 50 and older. In addition, people who have severely weakened immune systems are also now eligible for this booster, which could be a fifth shot for many. Pfizer shots are available to anyone 12 or older with certain immunocompromised conditions, provided it has been at least four months since their last dose. Moderna boosters can be given to anyone 18 or older.

The age range caught many by surprise, as Pfizer was only seeking clearance for people 65 and older, while Moderna was hoping to provide another dose for all adults.

Who benefits the most from a second booster?

The older you are, the more you’re likely to benefit from a second booster, say health officials. COVID risks increase as people age, so anyone in their 60s and beyond will see the greatest advantages. Additionally, anyone who is immunocompromised or has underlying conditions (such as heart disease, lung disease, obesity and diabetes) should get another shot, say experts, as those can increase the risk of severe illness or death.

Additionally, if it has been six months or more since your first booster, it’s a good idea to get another, Wachter notes

I’m in my 50s. Do I need a second booster?

A lot of that depends on your health status. If you’re in good shape and have no underlying conditions, you might be able to wait a bit. Dr. Carlos del Rio, an infectious disease researcher at Emory University, tells NPR that it’s reasonable for people under 60 to wait, noting that current vaccines are still offering good protection against severe disease and death.

The research about who should get the second booster is still limited, with much coming from an Israeli study. That report, which has not yet been reviewed for publication in a scientific journal, suggests the booster is supported only for people 65 and older or who have underlying conditions that put them at high risk.

Should I time my booster to coincide with travel or a new wave?

As Dr. Wachter notes above, that’s a strategy that carries some risk. Omicron spread like wildfire when it hit late last November, quickly overwhelming healthcare providers. And BA.2 is even more contagious. (Remember, it wasn’t long ago that finding a COVID test was an exercise in frustration.)

Vaccine protections don’t last forever, though. The protection against hospitalization for people two months after they got their first booster was about 91%. But by four months, that protection dropped to 78%. So if you’re planning a late summer trip, it’s questionable how effective this booster will be in protecting you.

Doctors advise getting the second booster, but if you’re planning to delay, they urge you to carefully monitor infection levels—and to rush to get a booster if they start to rise.

Is it dangerous to get a second booster?

No, the vaccines are incredibly safe. So there’s no danger in getting an additional shot. As with other doses, though, you could experience brief bouts of fatigue, muscle pain and fever.

I had Omicron. Do I need to get another booster?

If you contracted COVID during the Omicron wave, you probably don’t need to rush out for another booster, say experts. Any infection in the past three months gives you about the same level of protection against reinfection as a booster will.