Each week, we answer "frequently asked questions" about life during the coronavirus crisis. If you have a question you'd like us to consider for a future post, email us at [email protected] with the subject line: "Weekly Coronavirus Questions."

I got my COVID-19 vaccine and didn't feel any pain after nor experience any symptoms. Could it be that it didn't work?

Our experts agree: If you received your two doses of COVID-19 shots and made sure to follow up with your second dose on time — within 28 days after your first prick for the Moderna vaccine or 21 days for the Pfizer option — you really shouldn't worry.

Current trials show that post-injection symptoms vary significantly among people who've received the vaccine, so how you feel after the shot isn't a litmus test for whether the immunization worked.

In other words, it's possible to receive a (perfectly administered) vaccine and suffer no symptoms whatsoever. Just "consider yourself lucky," says Harvard Medical School physician Abraar Karan.

So the idea that our physical responses can tell us if a vaccine worked is a misconception. "The fact that [an individual] did not see a reaction is not a reason to believe that their body did not develop an appropriate response that will be protective," says Jonathan Runstadler, a professor at Tufts University's Department of Infectious Disease and Global Health. Especially, he adds, as our bodies' tendency to react to a vaccine "varies a lot between individuals and the individual's circumstances, like where the needle went into the [patient's] arm or where in the arm the shot was deposited."

But there are some obvious red flags in vaccine administration that should be pretty easy to notice. For example, Karan says, if you see lots of liquid from the tip of the needle squirting out before it even enters your skin, then, of course, it might be a good idea to alert the nurse or doctor.

The by-and-large wisdom here, the doctors concur, is that you're probably fine if you've gotten the shot. But it never hurts to stay vigilant — at all stages of the process.

When my mom got her shot, the nurse told her she had to get it in her arm in two minutes – or else the vaccine would expire! Now my mom is worried that she could have gotten an expired dose.

Every vaccine has a shelf life, explains Dr. Hana El Sahly, associate professor of molecular virology, microbiology and medicine at Baylor College of Medicine in Houston. "Vaccine-administering facilities have to abide by those windows of time because the vaccine is tested for stability at this room temperature and it doesn't stay good forever."

For the COVID-19 vaccines Pfizer and Moderna, you have six hours from the time the vial is punctured. After that, El Sahly says, "the vaccine will no longer be stable, and its biologic effect will vary after that."

However, if you're anywhere within that window, there is no cause for concern.

"All it takes is five seconds to get it in the arm," El Sahly says. "Two minutes to me sounds good!"

And if it took three minutes for someone to roll up their sleeve? Sadly, the vaccinator wouldn't have a choice.

"Throw it away," she says.

It's important to note that being injected with an expired vaccine wouldn't be cause for safety concerns. The concern would be that it might not be as effective in preventing infection with the coronavirus.

Which vaccine should I get?

Right now, the two authorized vaccines in the U.S. — Pfizer's and Moderna's — are so close in efficacy, and so scarce, that the vast majority of us would be thrilled to get either. But what if a vaccine with less efficacy is approved?

The advice doesn't change, says Ravina Kullar, an infectious disease expert and spokesperson for the Infectious Diseases Society of America: Get whatever you're offered first.

"When you are given the opportunity to get the vaccine, get that vaccine," she says. If, when your turn comes, it's not Moderna or Pfizer, remember that the FDA's efficacy goal was over 50% effective. "It's phenomenal that they're all over 50%," Kullar says.

Another way to look at it: Consider what could happen if you don't get it, Kullar says. "COVID is so prevalent right now that people's risk of getting it if they exit their house is very high."

Do I need to do any blood work first?

El Sahly and Kullar have the same answer:

No.

What if I've had a different vaccine recently? Can I still get the COVID-19 vaccine?

Yes, but wait two weeks first, say El Sahly and Kullar.

"It is generally recommended to wait 14 days between the other licensed vaccine you received for your health and your COVID-19 vaccine," El Sahly says.

The other day I wore my mask in the grocery store but then kept it on as I drove home because I didn't want to touch it without washing my hands first. I took a deep breath while driving and it caused me to wonder: If I had walked through a cloud of virus and it was stuck to my mask, was I sucking it through the mask closer to my nose and mouth with every breath I took? Is it important to take masks off as soon as you can, or does the virus get stuck and stay there?

Once a virus particle gets blocked by your mask, "it's pretty stuck there," says Linsey Marr, a researcher at Virginia Tech who has spent years studying airborne virus transmission. Marr says it's possible that you might potentially loosen some particles if you were to say, flick or disturb the mask in some way while taking a sharp breath in, "but I imagine that would be rare."

So the importance of taking off your mask as soon as you can would be more for your own comfort. But do remember to take off the mask by handling the ear loops, head ties or headband – and avoiding touching the front of the mask. Because any virus particles your mask stopped would be stuck on the front, so you wouldn't want to get those on your hands. It's also good practice to wash or disinfect your hands after removing your mask.

I was wondering if it is safe to cuddle baby goats during COVID-19? It would be a private cuddle session, so only my household, but the goats might cuddle other people that same day. I figured "Goats and Soda" may be able to help!

Sterling news for the baby goat-cuddling industry: If you're generally careful, do a private cuddle sesh and follow all the usual pandemic precautions — it's a go!

"In the general sense, it's safe to do," says Jonathan Runstadler, who studies how emerging viruses transmit in animal hosts at the Cummings School of Veterinary Medicine at Tufts University.

To understand the mechanics of why that's the case, Runstadler points to two possible transmission pathways that might cause COVID-19 to move from an animal to a human, particularly in the goats scenario — both of which are pretty low risk.

The first risk is the chance that the adorable goats contract COVID-19 themselves (oh heavens no!) — maybe from another group of people who played with them — and transmit the virus to an unlucky bunch of cuddle-loving humans.

But while COVID-19 has been detected in animals — a handful of documented infections of cats and dogs, some infected tigers at the zoo and minks in mink farms — Runstadler says it's "really unlikely" for transmission to happen directly from animal to human, based on what current studies are showing.

Even though some cases of animal-to-human transmission have been documented, particularly in the case of high-intensity mink farming, it's usually not a huge risk.

A bigger concern, says Dr. Douglas Kratt, president of the American Veterinary Medical Association, is the possibility that an infected person could expel viral particles onto the animal's fur, which could then be picked up by humans who pet the animal. Runstadler agrees.

In technical terms, this is the route of fomite – or surface-level – transmission. That is a higher risk than direct goat-to-human transmission through airborne particles. But experts agree it's still pretty low in the grand scheme of things. Especially because studies show that the virus does less well at spreading via surfaces than through the air.

Plus, the fur of a goat might have an advantage over other surfaces here: "There's some work that shows that the virus can be picked up much less frequently from organic surfaces," Runstadler says. "So, for example, the hair of a goat."

Runstadler says there's a "low possibility" of infection happening this way. But the risk is certainly not nonexistent. The best thing to do is follow all of the typical guidelines to prevent infection when you go to cuddle the goats, and the risk will likely be "negligible," Dr. Abraar Karan says.

"I would wear a mask and wash hands and use hand sanitizer after playing with the goats," Kratt says. "Practice social distancing [with other goat-cuddlers] and try not to touch your face or eyes before washing your hands."

And perhaps this is a good time to pivot away from the pandemic and share another bit of goat advice from those lazy, hazy days before the pandemic. If a goat eats poison ivy (and they can with no ill effect) and you drink that goat's milk — no worries, it won't give you a rash!

Sheila Mulrooney Eldred is a freelance health journalist in Minneapolis. She's written about COVID-19 for many publications including Medscape, Kaiser Health News, Science News for Students and The Washington Post. More at sheilaeldred.pressfolios.com. On Twitter: @milepostmedia

Pranav Baskar is a freelance journalist who regularly answers coronavirus FAQs for NPR.

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