The race to approve and distribute a vaccine for COVID-19 got a huge shot in the arm this week.

On Tuesday, the United Kingdom approved a vaccine developed by pharmaceutical giant Pfizer. On the same day in the United States, a panel of experts advising the Centers for Disease Control and Prevention recommended a first-stage plan for distributing the vaccine to some of the most at-risk Americans. Separately, another advisory committee is set to meet twice in the coming weeks to evaluate for the U.S. Food and Drug Administration the safety and efficacy of both the Pfizer vaccine and a similar one produced by Moderna.

To better understand the impact of these developments, Harvard Law Today recently spoke with public health expert Carmel Shachar J.D./M.P.H. ’10, the executive director of the Petrie-Flom Center for Health Policy, Biotechnology, and Bioethics at Harvard Law School, about the vaccine, who is likely to get it first, and whether employers and states can require people to get vaccinated.


Harvard Law Today: The CDC advisory panel met this week to discuss the vaccine allocation plan. What did they recommend?

Carmel Shachar: The CDC advisory panel was considering a narrow but important question: Who will be prioritized to receive the vaccine first, once it is rolled out? And they identified two important categories. The first are health care workers, people who have been on the front lines of treating this disease. Keeping them healthy is really important for enabling our health care system to keep up with the pandemic.

Portrait of Carmel Shachar
Credit: Martha Stewart Carmel Shachar J.D./M.P.H. ’10 is executive director of the Petrie-Flom Center for Health Policy, Biotechnology, and Bioethics at Harvard Law School.

The second category are residents and workers in long-term care facilities, such as nursing homes. We know that people who are older are at much more risk of developing severe COVID or perhaps even dying if they contract the coronavirus. About 6% of COVID cases in the U.S. come from these facilities, but they are the source of about 40% of the deaths. So, in distributing the first doses of the vaccine, it makes sense that they’ve identified workers who are vulnerable because of the nature of what they do, and a population that is vulnerable because of the nature of who they are.

HLT: What other populations that might be considered next?

Shachar: The CDC advisory committee talks about phase 1a, which are health care workers and long-term care facilities. Then they talk about phase 1b, which are essential workers, such as teachers, meatpacking workers, police and firefighters. Then they have phase 1c, which includes adults 65 and older with high-risk medical conditions.

And here is where things start to move around a little bit. Because this framework, while it makes a lot of sense, differs from other frameworks, like the World Health Organization’s framework, which prioritizes older adults and adults with underlying health conditions either right next to, or immediately after, health care workers, instead of essential workers.

HLT: When do you think the general population in the U.S. might receive access to a vaccine?

Shachar: Many public health experts estimate that the vaccine will be available to Americans who want it by the end of the second quarter of 2021. We’re producing an incredible amount of vaccine and, between Pfizer and Moderna, there’ll be enough in the first go-round to vaccinate 20 million Americans. But remember that these groups are fairly large. So, the initial vaccine doses will get quickly consumed by health care workers, and by people in nursing facilities, and then, by essential workers and by older Americans. So, it may be a little while until the average 34-year-old can call up their doctor and say, “Hey, I’d like to start getting the COVID vaccine.”

HLT: When and if there are multiple vaccines, how will it be decided who gets which one? And should people try to get one rather than another?

Shachar: From a patient standpoint, there won’t be a big difference in your experience if you get one vaccine over the other, especially with the Moderna and Pfizer vaccines, because they’re built on the same platform. Their success rates are basically the same, in the range of 94 to 95%. I also haven’t seen a lot to suggest that the side effects would be any different. The only difference may come with the AstraZeneca vaccine, because it’s built on different older technology. And the efficacy data varies a little bit more, with one study saying that a protocol of a half dose followed by full dose results in great protection rates, but that when we use two full doses, it’s only 60% effective. So, you might see some movement as to whether patients trust the vaccines from Moderna and Pfizer over the one from AstraZeneca.

This is really a landmark historic achievement. What the scientific community has done has been just such a huge service to the planet. And I really hope that the public health community, healthcare leaders, employers, the federal government, and states will do something equally impressive with the distribution to make sure that it is ethical, that it is fair, and that everybody who needs the vaccine gets the vaccine.

But it may come down to the feasibility of distribution. All the vaccines need to be kept cold, but what level of cold differs between the vaccines. The Pfizer vaccine needs to be kept at negative 80 degrees [Celsius], which is incredibly cold. Most average physician’s offices or local pharmacies do not have freezers that are cold enough. And while there are a lot of those freezers around Boston, they’re all filled with very expensive academic research and cancer cell lines. Which is why Pfizer has been pioneering these kinds of dry ice cases. But it may be that certain areas of the country get Moderna’s vaccine, which doesn’t need to be kept quite as cold or maybe the AstraZeneca vaccine, because it’s more feasible to get those vaccines out to those areas.

HLT: The United Kingdom this week became the first nation in the western world to approve a vaccine. What does that mean for the United States and the FDA’s approval process?

Shachar: The U.K.’s approval of the Pfizer vaccine is a really positive development that bodes well for Pfizer’s chances of getting an emergency use authorization in the U.S. The FDA has been very aware of needing to get the vaccine out as fast as possible, while also being the responsible custodian of the nation’s health. And even with the emergency use authorization process, which is much more streamlined than the typical process, the drug companies are still submitting thousands and thousands of pages of data to be evaluated. The FDA is moving things along as fast as possible, without falling into the pitfall of either seeming like this is just a political process and they’re rubber stamping whatever pharmaceutical companies send their way, as well as making sure that they really understand what is in these documents.

The FDA advisory committee will meet on December 10 to discuss the Pfizer vaccine and on December 17 to consider Moderna’s. And as soon as they give their seal of approval, I’m assuming the FDA will move to approve them. Approving a vaccine in December for a virus that wasn’t fully sequenced until maybe March or April is incredibly, incredibly fast.

HLT: With the U.K. getting a head start on vaccinations, do you think there will be any lessons from their experience we can apply in the U.S.?

Shachar: The most likely scenario is that it’s not going to teach us all that much, because there will only be a couple weeks of data about people’s reaction to the vaccine, both in terms of developing the response, as well as any sort of potential side effects. That probably isn’t enough time for us to learn anything meaningful. The less likely scenario is that, if for some reason, there was a very serious, previously unknown side effect that developed in a majority of people very quickly, the earlier administration of the vaccine in the U.K. might serve as a warning to us. But I would be very, very surprised if that scenario emerged. The FDA is really poring over the data to make sure that there’s no nasty surprise waiting.

HLT: Once the vaccine is fully approved in the U.S., can the government or employers require people to get vaccinated?

Shachar: We have a history of certain employers requiring vaccines. The most obvious case that comes to mind involves health care workers; if you want to work in a hospital, you need to get a ton of vaccines. That somebody who is a physician or a nurse at the hospital is required to get vaccinated is pretty much settled law. And in fact, in a lot of states, health care providers are required to make sure that their workforce gets vaccinated. You’ll probably also see it in schools, for instance, both for teachers and for students. I don’t think there’s anything in the law that would strictly prevent this, as long as employers make accommodations for any disabilities or underlying health conditions that would make it inappropriate for the employee to take the vaccine.

Until literally everybody has been vaccinated, you really still need to stay at home. If you go out, you need to wear your mask and avoid gatherings. If you can stay home, sit on the couch with some hot chocolate, or wear a mask and avoid traveling or indoor gatherings, that’s absolutely what you should be doing.

The states have a very broad mandate to require vaccinations, which was established by the Supreme Court in 1905 in Jacobson v. Massachusetts. In that case, which dealt with compulsory smallpox vaccination laws, the Court gave states very broad leeway to act for the good of society by keeping the public health strong. What’s interesting about Jacobson is it is a constitutional law case, but it’s also from 1905. And as our students know, there’s been a lot of constitutional law since that decision. So, Jacobson doesn’t use very modern constitutional law frameworks.

We may see some litigation around states mandating the vaccines that might even bubble up to the Supreme Court. But I ultimately think that, while we’ll update the constitutional framework, we’ll probably end up in the same place as Jacobson: upholding the idea that states have a strong public interest in, and are therefore empowered to protect, the public’s health.

HLT: What kind of exceptions do you expect? For instance, will people be able to avoid being vaccinated on religious liberty grounds?

Shachar: Exceptions are always a challenge when it comes to vaccinations. And we saw this over the last several decades, with states getting really permissive about exceptions for school vaccinations, until herd immunity was lost in places like Oregon and California. Now, you see the pendulum swinging back the other way to say that religious exceptions don’t count: “If you want to send your child to school, unless they have a health issue, they need to have their vaccinations.” Of course, schools are a little different than just existing in society, because you can always choose to homeschool or send your child to some sort of charter school or alternate arrangements.

I think that states will really struggle with the scope of vaccinations, what do you do about certain religious groups that traditionally do not embrace modern medicine. They have very legitimately held beliefs about whether medical intervention is appropriate. Of course, if you write an exception for them, then you’re really opening the door to people who say, “Well, I personally think my religion doesn’t allow this.” And then you’re down the path of trying to evaluate sincerity, including asking for proof that people claiming exceptions didn’t take any other vaccines.

Under the Religious Freedom Restoration Act, the government really isn’t allowed to evaluate the sincerity of your belief, you just need to establish that you have this belief. That’s going to make states nervous about instituting broad religious exemptions, because in order for the COVID vaccine to be effective, we need to get it to herd immunity levels, which is going to be somewhere between 60 to 80% of the population. And when you already give exceptions for legitimate health conditions — for babies who are too young to get vaccinated, maybe for pregnant women until the data suggests that it’s safe for them to take it — you don’t have a lot of room to grant exceptions to people for non-medical reasons.

I think this is where we are going to see litigation go up to the Supreme Court. And I think that this Court is certainly very friendly and sympathetic to the arguments of religious advocates. So, it may be a tight case. But ultimately, the data is so in favor of taking these vaccines to end an epidemic that we need basically everybody who can to be vaccinated.

HLT: Will this be like the flu vaccine? Will we need to get a new one every year?

Shachar: This is likely to be different than the flu vaccine. Flu mutates very, very fast. And there’s a ton of strains. Because we can’t get vaccinated against every single flu strain, we’re constantly guessing at the beginning of flu season about which strain we think will hit it big this year. And like all speculation, some years you get it right, but some years you’re off and the vaccine is less targeted than we’d like.

With COVID, there’s a lot less variety. Right now, there are few different strains, but they’re not as different from each other as the wild world of flu strains. And my impression from the literature I’ve read — and I’m not a virologist — is that it doesn’t seem to mutate as fast. So, it may be that there is a new strain in five or six years, and they need to tweak the vaccine. But I don’t think that we should be expecting to get our COVID shot every year, the way that we do with our flu shots. Instead, I think it will be a lot like vaccinations for the measles, mumps, and rubella. You get them as a child, and then forget about it. Maybe as an adult, they test to make sure that it’s still effective. But generally, you don’t need to get it again.

HLT: With the vaccine presumably on the way, should people continue to observe public health precautions like wearing masks and socially distancing?

Shachar: So here, I will follow in the footsteps of Anthony Fauci and say that social distancing and masking are not dead. They’re not going away anytime soon. Until literally everybody has been vaccinated, you really still need to stay at home. If you go out, you need to wear your mask and avoid gatherings. It’s going to be hard in the winter because we won’t have that social outlet that we had being outside. And it’s going to be hard next spring when some people are vaccinated, but some people aren’t. The COVID numbers in America, frankly, are scary right now. If you can stay home, sit on the couch with some hot chocolate, or wear a mask and avoid traveling or indoor gatherings, that’s absolutely what you should be doing.

HLT: Is there anything else you’d like to add?

Shachar: This is really a landmark historic achievement. What the scientific community has done has been just such a huge service to the planet. And I really hope that the public health community, healthcare leaders, employers, the federal government, and states will do something equally impressive with the distribution to make sure that it is ethical, that it is fair, and that everybody who needs the vaccine gets the vaccine.

No system is perfect. Your uncle will always be able to tell you a problematic story. “Oh, well, my friend works in a doctor’s office, but he doesn’t see patients, and he got it before us.” But on the whole, we have some frameworks to make it fair overall, even if you might know individual stories that don’t feel fair.

I also think paying attention to the role of essential workers is really important for considering issues of equity and fairness in society. A lot of these essential workers are people like grocery store workers, or people who don’t have the financial savings to work from home, to quit their job, and who don’t have the kind of jobs who allow them to work from home. These people have been really on the front lines for a while. A good portion of these essential workers are people of color. And I would hope that we make this vaccine very accessible to communities of color and other groups that have been historically marginalized or excluded from the benefit of scientific progress. And part of that is really incorporating issues of racial equity and access to care into the vaccine allocation plan.