Infectious Disease

The challenges of introducing the COVID-19 vaccine

January 25, 2021

6 min read

Source / information


Healio interview.

Creech reports that he is a principal phase 3 researcher on COVID-19 vaccine studies by Moderna and Johnson and Johnson, whose funds were paid for by the NIH, which sponsored the studies.


Receive an email when new articles are published

Please enter your email address to receive an email when new articles are published . “data-action =” subscribe “> subscribe

We could not process your request. Please try again later. If you continue to have this problem, please contact

Back to Healio

By January 24, the United States had distributed more than 41.4 million doses of COIVD-19 vaccine, and just over 18.5 million people had received at least one dose, according to CDC data.

Put another way, the US has given 6.6 doses of COVID-19 vaccine per 100 people in the country, according to Our World in Data, a research group affiliated with Oxford University. By comparison, the UK has given 10.4 doses per 100 people and Israel has given 44.2 doses per 100 people, a world leader.

Why is the US behind the pace of other countries? We spoke to the editor on infectious diseases in children C. Buddy Creech, MD, MPH, Director of the Vanderbilt Vaccine Research Program, on vaccine distribution.

Question: What is the downside of the COVID-19 vaccines?

Reply: It’s interesting. If this were any other vaccine launch we would be amazed at how many people we vaccinated so quickly. But we certainly live in a time where every day it matters how quickly we can get this vaccine into the arms of the people of the United States. So it’s a challenge.

We want to do it well and we want to get it to the people who need it most. And I think one of the challenges is that, as we’ve seen, some states have been a little more organized and effective in introducing vaccines than others.

This has been a challenge, and I think it’s a challenge, in part because – at least from my reading of the situation – we don’t necessarily know how many doses are coming on a regular basis. Hence, this is really hard to plan. The other aspect, however, is that the original plan was to give just enough vaccine to make sure these people could get their second vaccine 3 to 4 weeks later.

I think many of us have seen the difficulty with this plan. I would rather have 100 million people one dose than 50 million people two doses. However, we are aware that I think this has created confusion about how many doses people received, when they would get their supplies, whether or not those production numbers would match. I think there has been a lot of confusion about how to do this at the local level.

Q: In retrospect, do you think it was the right decision to make vaccination available to more people?

A: Well it’s hard to know because we really need to make sure that those older than 65 are living in nursing homes and long-term care facilities and taking care of people with COVID. 19 and those at highest risk of exposure and disease that they are prioritized. That sounds simple enough, but the real challenge is how to actually operationalize it. Do we have a database of people over the age of 65 in our communities? How shall we do it? Do we rely on doctors’ offices? Are we relying on public health authorities? Are we inviting SignUpGenius or other electronic means by which we ask people to sign up themselves and confirm that they belong to this group? There are a lot of questions here and I think we have problems with that because frankly this is the first time we have had to do it. This is the first time we have introduced a vaccine during a pandemic where we had to strategically layer the eligible groups. We didn’t have to do this in 2009 when we had the H1N1 pandemic. We could really start it up for most people at one time. So we’re still learning the best ways to do this.

Q: Recently the CDC said that second doses can be delayed by up to 6 weeks after the first dose instead of 21 days for the PfizerBioNTech Vaccine and 28 days for that Modern Vaccine. Is there any science to support this and will it help supply it?

A: Well, I think the science that supports this is our basic understanding of the immune system. Our immune systems are really smart. And for most vaccines, the longer you wait between those first and second doses, the better the response. The disadvantage of a pandemic is that it increases the length of time people are not maximally protected.

So we’d like to be careful to allow a bigger window there as this period of vulnerability is longer, but we also don’t want it to be enforced so rigorously that it actually acts as a deterrent to receiving that first vaccine.

I agree that this gives our public health partners a little more flexibility when they start making plans for vaccination because it may allow them to open more jobs than if they disrupt the vaccine supply chain 2 until 4 weeks later, it’s not like they’re trying to find a vaccine that will give people in a very narrow window. You now have a little more leeway to get second vaccines to individuals when it comes to that.

Again, I think this is our first time doing this in relation to the operational aspect, and I think our CDC colleagues and FDA colleagues, and certainly those in the public health sector, will be taking even more leadership on this a little more clearly. I think a lot of people look to those states that have done well or that are doing well for best practices. One of the first things that needs to happen is to make sure that we not only have a really good understanding of the current vaccine supply, but also the outlook for the next 8 to 16 weeks. Without knowing it, it is really difficult to plan vaccinations for our citizens.

Q: Are there any? How can we estimate when family doctors can count on reliable vaccine supplies?

A: Well, I think that will vary by location, and I think a lot depends on what happens to the Johnson and Johnson vaccine and the AstraZeneca vaccine here in the US. I think until we have more vaccines ready and until Moderna and Pfizer have a little more time to keep increasing their production, we will live with a relatively scarce raw material. I’ll say succinctly, but we’ve already vaccinated 20 million people, so this is a good start. It’s not where we’d like it to be. We’re just on the right track based on the estimates I’ve seen we’re vaccinating about a million a day, which would be a really good number for any other vaccine, but we have a lot of work to do.

Q: Do you think the U..S.. ordered enough cans?

A: Well, we’d have to do the math, and I don’t know what the current estimates are. But when we calculate that there are well over 300 million people in the country, the majority of whom are eligible for the vaccine and can safely get it, you can imagine it won’t take us long to need half a half Billion doses of vaccine to vaccinate the majority of our population.

There are some unanswered questions that greatly affect this vaccine, such as: B. “Does everyone need two doses?” Perhaps those who have had COVID-19 only need one dose because they have seen this virus, have already developed an immune response, and perhaps this is a method of expanding our vaccine supply.

Perhaps while we are studying children, they need less dose than the doses used in adults. If so, we can expand our vaccine supply even further.

But I realistically think we’re going to vaccinate individuals well in the summer and fall, and that will either include the current vaccine or possibly introduce newer booster vaccines – as Moderna said – to cover some of these known variants.


CDC. Preliminary clinical considerations on the use of m-RNA COVID-19 vaccines currently approved in the U.S. Accessed January 25, 2021.

Our world in data. Vaccinations against coronavirus (COVID-19). Accessed January 25, 2021.


Receive an email when new articles are published

Please enter your email address to receive an email when new articles are published . “data-action =” subscribe “> subscribe

We could not process your request. Please try again later. If you continue to have this problem, please contact

Back to Healio

COVID-19 Resource Center

Related Articles