Do vitamins help? Is it seasonal? When will it end?

So many great questions. Here are some answers from various experts.

Stuck at home, readers have plenty of things to wonder about. So we asked the experts and offer our second grab bag Q A:

QI can sew. Do homemade fabric masks help?

AHomemade cloth face masks don’t perform as well as professional face masks. Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection and are not recommended for health care workers, particularly in high-risk situations.

But there is CDC guidance that says that if there’s truly nothing else, one can consider face masks. We’re in a situation where we don’t want to leave any option off the table going forward. — Dr. Paul Biddinger, director of the Massachusetts General Hospital Center for Disaster Medicine

QWhat kind of supplements should I be taking? What about that weird internet rumor that holding my breath for 10 seconds will tell me if I am infected?

ANone. Holding your breath? That just astounds me because it’s so blatantly crazy.

QI’ve heard ibuprofen can worsen symptoms. Is that true?

AThere’s nothing that’s been published in peer reviewed literature that suggests that it’s a problem. It’s anecdotal. Maybe they had had a patient who took ibuprofen, then got worse or had complications. But there’s a simple way to get around it: Take acetaminophen, such as Tylenol. — Dr. John Swartzberg, clinical professor emeritus of infectious diseases and vaccinology, UC Berkeley

QHow reliable are the tests? And why bother being tested if it doesn’t change the medical plan of treatment?

AWe can’t answer that reliability question with precision at this point. In terms of “false positives,” the test is very, very good at picking up the coronavirus. So there probably are not a lot of “false positives.” There probably are quite a few “false negatives.”

That’s because after you’re infected, there’s a period of time when you’re not making virus. So your test will be negative, but it could become positive a day or two later.

From a clinical perspective, testing won’t change your treatment. From an epidemiological perspective, testing provides data about the disease — how it’s distributed in our population. — Dr. John Swartzberg, clinical professor emeritus of infectious diseases and vaccinology, UC Berkeley

Q

Do any drugs work? A

It may be another month before results roll in from very large and important studies of the promising antiviral agent remdesivir, made by the Foster City-based biotech company Gilead. Six large remdesivir studies are underway, and hundreds of patients are now getting it on a “compassionate use” basis.

But there are early results from smaller studies, such as:

Chloroquine and hydroxychloroquine: French doctors at IHU-Méditerranée Infection in Marseille, France, gave it to 26 patients three times per day, over 10 days, sometimes combined with the antibiotic azithromycin.

Patients on the treatment had less virus in their system after six days than other patients at a different center, who didn’t get the treatment. But because the study was so small and not double blind, we can’t say it works. Some U.S. hospitals, including UC San Francisco, are including the the drugs in their treatment guidelines, so we’ll soon have more data.

Favipiravir: In a Chinese study of 240 patients who were moderately ill, fevers and coughs went away faster on favipiravir than on a comparison drug. But similar numbers in each group ended up needing oxygen or a ventilator, so it’s no silver bullet.

Lopinavir and ritonavir: In a Chinese study of 1,999 patients who were very ill, no benefit was seen. And 20% of the patients died. Researchers are now studying whether the combination would be more helpful for healthier patients.

Convalescent plasma: The concept here is to give sick patients the plasma from the blood of people who have recovered. The plasma contains viralfighting antibodies. One recent study from China reported that of 10 patients given convalescent plasma, seven saw their viral loads become undetectable; it noted other improvements in their condition.

Q

Where’s a vaccine? A

Hopes are pinned on a new approach to a vaccine which could deliver help faster than others. It uses a molecular courier, called “messenger RNA,” to trigger the production of protective proteins. The biotech company Moderna is the farthest along, but others are crafting a similar approach. It could take 18 months to prove safety and efficacy. Then supplies must be scaled up. But it might be available in the fall of 2020 to certain high-risk groups, such as health care workers, Moderna

said.

QWhen will our outbreak peak? Two experts from different ends of the country offer perspectives:

AWe don’t know. But we can look at some of the projections, based on the experience in other countries. With a lot of the modeling, the suggestion is that we’re going to reach our peak in around 45 days (from March 18). That’s a number that people are kicking around. But frankly, it’s all a guess right now. — Dr. John Swartzberg, clinical professor emeritus of infectious diseases and vaccinology, UC Berkeley, citing projections from March 18

AI think “soon” is exactly the right word there. Where I am here (Tuesday) in Boston, we think that we may be three, four or five weeks away from our peak of wave of illness, which means we have very little time to adapt. — Dr. Paul Biddinger, director of the Massachusetts General Hospital Center for Disaster Medicine

Q

Will this coronavirus be seasonal?

A

Though the flu virus has been shown to be affected by weather, it’s unknown if the COVID-19 virus behaves similarly.

A new Massachusetts Institute of Technology analysis found that the majority of coronavirus transmissions so far have occurred in regions with low humidity and low temperatures, between 37.4 and 62.6 degrees Fahrenheit. But correlation doesn’t prove causation.

If weather does matter, we could have seasonal bouts, with the virus bouncing back and forth between the Northern and Southern hemispheres. This remains just speculation. And it shouldn’t change our public health interventions. — Qasim Bukhari and Yusuf Jameel, Massachusetts Institute of Technology Dr. David Ho, Aaron Diamond AIDS Research Center, Columbia University

Q

Will there be subsequent waves?

A

It’s so hard to predict. We expect that this wave may last three months, give or take. In previous pandemics, we have seen later waves that are delayed by a number of months. During the 1918 flu pandemic, for example, there were multiple waves.

We’re going to have to figure it out, as we get through this wave, how much of the population has immunity. Because ultimately — whether we see another wave, and how big that wave is — is going to depend on how much immunity there is in the population. If it’s 70% to 80% immunity across the population, we may not see much of a wave.

But unfortunately, it’s far too soon to know. Before we can make that sort of prediction, we’re going to have to do blood tests in search of protective antibodies. That will show us the level of community immunity. — Dr. Paul Biddinger, director of the Massachusetts General Hospital Center for Disaster Medicine