Skip to main content

Advanced Search

Advanced Search

Current Filters

Filter your query

Publication Types



The Dose


Boosters, Omicron, and What’s Next in the Pandemic

Creative illustration of people, COVID particles, and vaccine syringes

Illustration by Rose Wong

Illustration by Rose Wong

  • While the Omicron variant may cause milder illness, it is highly transmissible. Booster shots offer the best protection against the virus. Listen to the latest episode of #TheDosePodcast to learn more.

  • Each day, the United States and countries are seeing record breaking COVID numbers. @Alison_Galvani of @YaleSPH brings us up to speed on the #Omicron phase of the pandemic, and how boosters can help.

The Omicron variant is sweeping across the United States and the rest of the world, breaking previous records of COVID-19 cases and hospitalizations. While it may cause milder illness, its transmissibility and ability to evade vaccines make this surge particularly challenging to navigate.

On the latest episode of The Dose podcast, host Shanoor Seervai asks Alison Galvani, founding director of the Yale Center for Infectious Disease Modeling and Analysis, to bring listeners up to speed on this phase of the pandemic. Galvani and her colleagues have found that increasing the number of boosters administered each day could save thousands of lives.

Vaccination is relatively inexpensive, particularly compared with the costs associated with hospitalizations and productivity losses, even from mild cases, she says.


SHANOOR SEERVAI: Each day, the United States and countries across the globe are seeing record-breaking COVID numbers. In this phase of the pandemic, the Omicron variant is spreading faster than ever, even though it may be causing milder disease.

This is our first episode of 2022. And as you know, The Dose typically focuses on emerging voices and ideas for the future of health care. Of course, that includes topics beyond COVID-19, but it’s hard to think about the future when so much of our future is tied to the pandemic and how to make sense of the latest disruptions the virus is causing.

I’m your host, Shanoor Seervai, and my guest today is Dr. Alison Galvani, founding director of the Yale Center for Infectious Disease Modeling and Analysis. We spoke to Dr. Galvani a couple of months ago about her research on the importance of vaccines in saving lives. That was before boosters were widely available and before the new challenges posed by Omicron. Today it all looks very different. So I asked Alison to update us on where things stand and where we are headed.

Alison, thank you for joining me.

ALISON GALVANI: Thank you. It’s great to talk to you again.

SHANOOR SEERVAI: So we’re recording on January 11th and things may have changed by the time this conversation goes live, but can you give us a snapshot of this moment in this phase of the pandemic?

ALISON GALVANI: Sure. As you just mentioned, Omicron has emerged with high degree of transmissibility and also the ability to partially evade preexisting immunity. That’s the bad news. The good news is that an extra dose of Pfizer or Moderna, so going from two to three doses, makes a big difference in protecting against hospitalization and death from this new variant.

SHANOOR SEERVAI: Now, your research shows that the booster campaign is saving lives — that if the United States doubled the December pace of boosters to 1.5 million per day, it could prevent approximately 41,000 deaths and more than 400,000 hospitalizations by the end of April. I wonder how to make the case to people who thought that they would be “vaccinated and done” that they need to get a booster — and potentially will need to get more boosters in the future — to gain immunity to COVID.

ALISON GALVANI: There are some diseases to which people typically develop lifelong immunity. Unfortunately, COVID is not one of those diseases. So immunity elicited by both natural infection or vaccination wanes relatively quickly. And this is also what makes booster doses so important. So as the virus evolves, so too must our understanding of what it means to be fully vaccinated.

SHANOOR SEERVAI: So is the definition of being fully vaccinated going to change, do you think?

ALISON GALVANI: In my mind it has changed, and I would only consider someone who’s had three doses to be fully vaccinated. Three doses gives us less protection than two doses did against the original strain, but it’s still highly protective. It’s above 70 percent efficacy for three doses against Omicron protecting against symptomatic disease, as opposed to being like 90 percent against the original strain.

SHANOOR SEERVAI: So do you think that we’re going to need mass vaccination sites across the entire country? Some cities have already opened these up to increase uptake.

ALISON GALVANI: We know from work on flu vaccination and other vaccinations that convenience is a key factor in uptake. So as the pandemic continues to rage around us, it may feel like our extraordinary efforts aren’t paying off. However, in the first year of the vaccine campaign, we estimate, again in collaboration with Dr. Eric Schneider from the Commonwealth Fund, that over a million lives have been saved. So without vaccination that has been achieved, the crisis would’ve been so much worse.

SHANOOR SEERVAI: So what’s the biggest challenge to you and your peers who work in epidemiological modeling and analysis?

ALISON GALVANI: Well, when a new variant emerges, there’s — just as data is still accumulating — there’s uncertainty about the parameters of that new variant, how transmissible it is, can it evade immunity? And we need . . . it’s not until it starts to spread and we have more and more data points that we’re able to narrow that empirical uncertainty. Yeah, that’s a major challenge.

SHANOOR SEERVAI: We’re at the beginning of the year and things are just changing so drastically. How should we think about, or plan for, let’s say the first quarter of 2022?

ALISON GALVANI: Well, I think we can expect that cases, hospitalizations, and deaths will continue to rise in the near future. The extent to which that’s blunted will depend on how many people get booster vaccines and take other precautions. But you know, cases will start to decline again after that happens. My concern, though, is that a new variant will emerge and that variants will continue emerging. The probability of emergence is also in proportion to how many cases there are, which in turn is in proportion to how much vaccination there is. So the more unvaccinated people, the more infections, and each infection is an opportunity for the virus to mutate and evolve into a more transmissible variant. So the precautions that we take are important for the immediate future, but also for the long-term sort of evolutionary pace of this outbreak.

SHANOOR SEERVAI: Should we expect this to continue for the rest of the year? Is it just going to be another year of the pandemic?

ALISON GALVANI: Unfortunately, I think so. Well, the virus has longer viability the colder it is and the lower the humidity. So during the winter, you know, I would expect more transmission, everything else being equal. The pandemic is not going to be over in a matter of weeks.

SHANOOR SEERVAI: Mm-hmm. So what’s the new work you’re doing at Yale to look at this? What are you modeling right now?

ALISON GALVANI: So in ongoing work and collaboration with the Commonwealth Fund we are considering the return of investment for funding spent on COVID vaccination in the U.S. So cases, averted by vaccination, saves treatment and hospitalization costs, particularly ICU hospitalization and ventilators are extremely expensive. In addition to maintaining productivity of people who would otherwise be out sick. So I think we’ll find that not only does COVID vaccination save lives, it also saves dollars, too. We’re going to be evaluating the extent to which that’s the case in the next couple months.

SHANOOR SEERVAI: Why are you focusing on this ROI aspect?

ALISON GALVANI: Well, economic investment in COVID vaccination — if policymakers are considering these policies in relation to their financial repercussions, this is an important dimension to help guide the cost effectiveness of those policies.

SHANOOR SEERVAI: I do want to ask though: The Omicron variant was first detected in South Africa, and we still do have large parts of the developing world where people have no access to vaccines. What can the United States do to reduce the number of unvaccinated people in the global south?

ALISON GALVANI: I think that’s really important. Distributing vaccinations to the entire world. It’s, I think, both the moral thing to do for the sake of humanity, globally and pragmatically. As you said, variants, even if they don’t arise in the U.S., they can still affect the U.S. So, from the U.S. taxpayer perspective, it’s just pragmatic as well. There was a just recently very exciting development of a low-cost, patent-free vaccine by Peter Hotez and colleagues at Baylor. That’s effectively his gift to the world, and he and his colleagues are scaling up production. But the faster we can get his vaccine and other vaccines to the rest of the globe, I think is paramount.

SHANOOR SEERVAI: Last week advisors to President Biden suggested that it’s no longer realistic or productive to talk about defeating the virus and that we should now shift to accepting that COVID will be endemic, and that mitigation is the best thing we can do. Can you talk about what that means scientifically, medically, and practically to accept that this virus is here to stay?

ALISON GALVANI: Sure. So the use of the term endemic is simply recognition that given how widespread COVID now is globally it’s unlikely that we’ll be able to eradicate it. Regardless, risk mitigation remains key to minimizing the burden of the virus.

SHANOOR SEERVAI: So if the disease does become endemic, as you describe, do you anticipate think we will need to administer boosters regularly, each year or multiple times a year?

ALISON GALVANI: I do anticipate that. Israel is already rolling out four doses now, and I expect we’ll need to do the same intermittent boosting every five, six months, depending on how the virus evolves. I mean, in the same way we vaccinate every year against flu, we’ll need to do something similar, I think, against COVID if not more frequently than for flu.

SHANOOR SEERVAI: You’re just starting out to do some of this modeling work, but do you anticipate that people getting boosted twice a year will be more cost effective than the alternative, which is no boosters?

ALISON GALVANI: Absolutely. Vaccination is relatively inexpensive, particularly compared with hospitalization or even with relatively mild cases where people are out of work for many days. And a substantial proportion of even mild cases have led to long-term COVID, with its own repercussions on productivity and medical expenses.

SHANOOR SEERVAI: So you think the attitude that some vaccinated people have, which is “we’re vaccinated and we’re done” is unsafe?

ALISON GALVANI: Well, I don’t blame anyone for feeling that because that was the initial mantra. And I think we genuinely thought that might be the case. We didn’t know that immunity would wane as quickly as it has, both for natural infections, so, you know, reinfections and then, you know, so-called breakthrough infections. And then on top of that, that the virus would evolve quite as rapidly as it has in really significantly detrimental ways.

SHANOOR SEERVAI: Mm-hmm. So before I let you go, Alison, and if there was one thing that you could really encourage policymakers in the U.S. to do right now to help mitigate the impact of Omicron, what would it be?

ALISON GALVANI: Well, to encourage boosters, and from leaders from all political parties to do so. The antiscience aggression has been undermining the uptake of lifesaving vaccines, and I never anticipated that public of health measures could become so polarizing or politicized. So to whatever extent we can get accurate narratives communicated, I think will benefit the entire country and the globe.

SHANOOR SEERVAI: Dr. Alison Galvani, thank you so much for joining me today.


SHANOOR SEERVAI: This episode of The Dose was produced by Jody Becker, Julia Melfi, Naomi Leibowitz, and Joshua Tallman. Special thanks to Barry Scholl for editing, Jen Wilson and Rose Wong for our art and design, and Paul Frame for web support. Our theme music is “Arizona Moon” by Blue Dot Sessions. Our website is There you’ll find show notes and other resources. That’s it for The Dose. I’m Shanoor Seervai. Thank you for listening.

Show Notes

Bio: Alison Galvani

Publication Details



Shanoor Seervai, Former Researcher, Writer, and Lead Podcast Producer


Shanoor Seervai, “Boosters, Omicron, and What’s Next in the Pandemic,” Jan. 14, 2022, in The Dose, produced by Jody Becker, Julia Melfi, Naomi Leibowitz, and Joshua Tallman, podcast, MP3 audio, 14:29.