# It’s time to consider delaying the second dose of coronavirus vaccine



## Becky1951 (Jan 3, 2021)

Single dose 80-90% effective?

But Pfizer has said only *some *protection from single dose, and *two doses of the vaccine — separated by three weeks — is the only regimen that proved to be 95% effective in Phase 3*

("Pfizer said in a statement that there are "no data" to demonstrate that a single dose of its coronavirus vaccine will provide protection from infection after 21 days."

"Pfizer confirmed in response that although some protection appears to begin as early as 12 days after the first dose, two doses of the vaccine — separated by three weeks — is the only regimen that proved to be 95% effective in Phase 3 trials."

https://www.axios.com/pfizer-single...referrer=https://www.google.com&_tf=From %1$s )
_______________________________
In the news today

"In both trials, by the time of the second shot, the first was already 80 to 90 percent effective in preventing covid-19 cases."

It’s time to consider delaying the second dose of coronavirus vaccine

Jan. 3, 2021 at 8:00 a.m. EST

Robert M. Wachter is chair of the department of medicine at the University of California at San Francisco. Ashish K. Jha is dean of the Brown University School of Public Health.

Until recently, we supported the strict vaccine regimen, requiring two doses within a month. Both the Pfizer and Moderna clinical trials were carried out this way, and the much-touted 95 percent efficacy rates were drawn from those trials.

But as Mike Tyson famously said, “Everybody has a plan until they’ve been punched in the mouth.” When it comes to covid-19, we’re being punched in the mouth over and over again. It’s time to change the plan; namely, we should give people a single vaccination now and defer their second shot until more doses of vaccine become available.

What changed? First, there’s simply a supply constraint. We hoped that additional vaccines would be available by now. But only the Pfizer and Moderna vaccines have been authorized, and they’re being produced more slowly than hoped. Even more worrisome are the distribution bottlenecks that are making it difficult to vaccinate people as quickly as possible.

As of Jan. 1, the United States has given first vaccine doses to about 1 percent of our population. Contrast this with Israel, which has vaccinated 10 percent of its population, including more than 40 percent of people older than 60. The benefits of the immunity these shots produce accrue not just to those getting vaccinated, but to broader society as well by slowing the virus’s spread. Until a lot more people are vaccinated, this latter benefit will be minimal.

Another factor is the state of the pandemic: Hundreds of thousands of people are being infected and thousands are dying every day. Any high-risk person who isn’t vaccinated today could be infected tomorrow and die in a month. But we are holding back half of the doses in reserve for people to get their second shots. That slows things down.

Now comes another punch to the mouth: the new variant of the coronavirus, which is likely much more contagious and is spreading rapidly in multiple U.S. communities. Epidemiological models and Britain’s experience indicate that, while only a few cases of the variant have been identified in the United States, it will likely become our dominant strain within a few months. Although the new variant doesn’t seem deadlier at the individual level, a more infectious virus means more cases, which means more hospitalizations and deaths. We need to vaccinate as many people as quickly as possible to save the most lives.

Whether the bottleneck is due to vaccine production or distribution, giving people a single shot now and waiting on the second until the shortage abates will get more people vaccinated sooner. But will it work? Here, the clinical trial results for the Pfizer and Moderna vaccines are reassuring. While they were designed to test the effectiveness of two shots given about a month apart, both showed that the first shot had a substantial benefit beginning around 10 days afterward. In both trials, by the time of the second shot, the first was already 80 to 90 percent effective in preventing covid-19 cases.

We are not arguing against people receiving two shots. The second shot adds a measure of effectiveness and likely makes vaccination-derived immunity more durable. That’s why we’re advocating that it be delayed, not dropped altogether. And a reasonable argument can be made that for groups at highest risk for exposure (such as health-care workers) and for death (such as Americans over age 75), sticking with the early second-shot strategy is reasonable. But for everyone else, the deferral strategy makes sense.

Is there any potential downside to a delay? Yes. The strategy hasn’t been studied, so we don’t know if and when the immunity from the first shot begins to wane. But data from Moderna, for example, is reassuring. It shows robust immune response four weeks after the first shot, and most experts believe it is extremely unlikely immunity would somehow plummet by week eight or even week 12 following a single shot. Another concern is that with a delay, some people may forget to get their second shot. It will require effort to track people and remind them to receive it.

A more general risk is that this would be yet another change in our pandemic strategy at a time when people have grown weary of our ever-changing response regarding opening schools, touching surfaces and wearing masks. If this change causes them to become exasperated and choose not to be vaccinated at all, that would be a problem. But we believe the advantages of rapidly vaccinating twice as many people would outweigh these potential disadvantages.

In a perfect world, there would be no trade-offs. But if 2020 taught us anything, it’s that we don’t live in a perfect world. Between 50,000 and 100,000 Americans will die of covid-19 this month alone. Giving 100 million people — particularly those at high risk — a single shot that is 80 to 90 percent effective will save far more lives than giving 50 million people two shots that are 95 percent effective. It’s what we should do.

https://www.washingtonpost.com/opin...der-delaying-second-dose-coronavirus-vaccine/


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## Jules (Jan 3, 2021)

Becky1951 said:


> But we believe the advantages of rapidly vaccinating twice as many people would outweigh these potential disadvantages.


Agreed.


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## Becky1951 (Jan 3, 2021)

Actually I agree also. Especially with the new mutation causing it to be more easily spread. 

I was surprised to read the 80-90% effectiveness with one shot, so why not give one shot now?


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## Mike (Jan 3, 2021)

Becky1951 said:


> I was surprised to read the 80-90% effectiveness with one shot, so why not give one shot now?


If it is so good, why did the manufacturers insist on a second
shot after 3 weeks, somebody is playing with the truth and it
is probably a politician.

Mike.


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## JustBonee (Jan 3, 2021)

Since getting the first dose seems to be a luck of the draw,    how confident do people feel that they can get the 2nd dose when they are supposed to anyway?
Just so much disarray everywhere with this.


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## Becky1951 (Jan 3, 2021)

"somebody is playing with the truth and it
is probably a politician."

And playing with the truth is playing with our lives.


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## Becky1951 (Jan 3, 2021)

"Just so much disarray everywhere with this."

And that's what makes it so hard to trust anything that's being reported.


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## Kathleen’s Place (Jan 3, 2021)

Do you think we would be better off without all of the media interference?  I mean if they just came out and said , “We have a vaccine...you need to get it.”  And then no further articles on who thinks we should and who thinks we shouldn’t and a myriad of different opinions?  Or is that not the American way?  Confusion seems to be the biggest culprit in this whole pandemic


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## StarSong (Jan 3, 2021)

I can just hear the rabble, rabble, grumble, grumble that will immediately ensue if the clinical trial formats of two doses 3-4 week apart are eased without more testing.

Should these protocols be messed with, the people who've been solidly against the vaccines will be gleefully proclaiming, "See! I told you they rushed these vaccines and didn't know what they were talking about.  First they need to be 3-4 weeks apart, now 12 weeks are ok.  Which is it? Do they even know?"

*They will most assuredly NOT be saying,* "Kudos to various governments for responding to overwhelmed hospitals and health care workers by using a less perfect, but far better than nothing, vaccine schedule. I salute their efforts to reduce the terrible spike in virus cases and deaths."

Talk about a no win situation.


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## Treacle (Jan 3, 2021)

So today on the radio an 'expert' used an analogy to justify the delay for a second jab.  It was to be 3 weeks now 12 weeks.
It is  better to vaccinate 2 grandmothers, he said,  with the first vaccine for a 70%+ efficacy than one grandmother with the first vaccine and second vaccine (3 weeks later) for a 90%+ efficacy. 
He then referred to the new variant and said that they cannot be sure that the vaccines already produced can provide the same protection against this new variant but not to panic as they would be able to produce something within about 6 weeks. But what if there are other variants? How often will we need to be vaccinated and with what vaccine? Vaccines cannot be mixed!!!
https://www.bbc.co.uk/news/uk-55519042
Where is this all heading...........? 
Confused


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## Becky1951 (Jan 3, 2021)

What about those over 55? I'm sure they had people over 55 in their trial.

Another article but about Moderna's vaccine.

U.S. officials consider half-doses of Moderna’s vaccine to give more people some immunity.

A top official of Operation Warp Speed floated a new idea Sunday for stretching the limited number of coronavirus vaccine doses in the United States: halving the dose of each shot of Moderna’s vaccine to potentially double the number of people who could receive it.

*Data from Moderna’s clinical trials demonstrated that people between the ages of 18 and 55 who received two 50-microgram doses showed an “identical immune response” to the standard of two 100-microgram doses, said the official, Dr. Moncef Slaoui.*

Slaoui said that Operation Warp Speed was in discussions with the Food and Drug Administration and the pharmaceutical company Moderna over implementing the half-dose regimen. Moderna did not respond immediately to a request for comment.

Each vaccine would still be delivered in two, on-schedule doses four weeks apart, Slaoui said in an interview with “CBS’ Face the Nation.” He said it would be up to the FDA to decide whether to move forward with the plan.

Slaoui was asked whether the United States would follow Britain’s lead on another tactic for getting shots to more people: delaying second doses of newly authorized vaccines to immunize a larger swath of the population. There is little or no data on dose delays, Slaoui said, but “injecting half the volume” might constitute “a more responsible approach that will be based on facts and data to immunize more people.”

Natalie Dean, a biostatistician at the University of Florida, agreed that there might be more data to support a vaccine strategy that relied on half-doses rather than delayed doses.

“There is a path forward if you can show that two lower doses yield a similar immune response,” Dean said.

As caseloads continue to surge upward around the globe, and concerns mount over a new and potentially more transmissible variant of the coronavirus, “everyone is looking for solutions right now, because there is an urgent need for more doses,” Dean added. “But the dust has not settled on the best way to achieve this.”

John Moore, a vaccine expert at Cornell University, pointed out that the approach wouldn’t necessarily work for all vaccines. Injections are already doled out in very small volumes, and some might be harder to halve than others, he noted.

While Moore agreed that halving doses has more scientific backing than dose delays, he noted that “this is not something I would want to see done unless it were absolutely necessary.”

https://www.seattletimes.com/nation...as-vaccine-to-give-more-people-some-immunity/


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