Vaccine Q&A: How testing went, what are the side effects and more

FILE - In this Nov. 9, 2020, file photo, an ad for COVID-19 testing reflects on glass at a bus stop, as pedestrians walk past Pfizer world headquarters in New York. Pfizer and BioNTech say they've won permission Wednesday, Dec. 2, 2020, for emergency use of their COVID-19 vaccine in Britain, the world’s first coronavirus shot that’s backed by rigorous science -- and a major step toward eventually ending the pandemic. (AP Photo/Bebeto Matthews, File)

The vaccine will arrive in Utah soon.

Yes, it hasn’t quite received the go ahead yet — that comes from the Food and Drug Administration. But we’re at the point where packages are getting ready to be shipped and states are making final plans on how best to give people the vaccinations.

With that in mind, let’s dive deep into these game-changing vaccines. Before we begin, I want to give a shoutout to Derek Lowe at Science Magazine and the entire staff at STAT News for staying on top of the vaccine process, making it easy to put an article like this together. For more scientific detail, check out their reporting.

How were the vaccines tested?

Essentially, vaccine testing works the way you think it would. To test a vaccine, you have to give it to a whole lot of people. Then, you compare the health of those people to a group that didn’t get the vaccine. You also watch for any side effects.

To make sure people don’t change their behavior simply based on whether or not they got the vaccine, you give the control group a placebo saline shot. And neither doctor nor patient can know whether the patient is in the placebo group or the vaccine group.

That’s exactly what the scientists did, and in record time, too. There are now three big vaccine makers who are in final testing.

In the case of the Moderna vaccine, researchers gave shots to more than 30,000 people. Then, they saw who experienced symptomatic COVID-19. Moderna found that 185 people in the placebo group got the virus, while just 11 in the vaccine group did. That’s a 94% efficacy rate, which is wonderful for a vaccine. Pfizer delivered shots to 41,135 people, and saw 162 coronavirus cases in the placebo group against eight in the vaccine group. That’s about 95% effective.

Oxford’s vaccine trial got a little more complicated, because researchers tested two different dosing schemes. One showed 62% effectiveness, and one showed 90% effectiveness. More testing will happen on that latter group, to be sure.

Now, the studies and vaccines themselves just need to be approved by the FDA. The U.K. just approved Pfizer’s vaccine Wednesday. The U.S. FDA advisory panel is meeting next Wednesday to discuss the Pfizer results, and Dec. 17 to discuss Moderna’s results. They should approve the vaccines relatively quickly after that — especially now that the U.K. has done the same with a vaccine produced by an American company, it won’t look good to lag.

What are the side effects?

Two companies released information on side effects. Moderna found fatigue in 9.7% of patients, muscle pain in 8.9%, joint pain in 5.2%, headache in 4.5%, and just plain old “pain” in 4.1%. There’s likely very significant overlap between these categories, so roughly 15-20% of people who got the vaccine experienced these side effects. But all of them were what are called “Grade 3″ side effects — which means they lasted only a short time, a day or two, and never required hospitalization.

Pfizer’s vaccine had fewer side effects, reporting fatigue in 3.8% of patients and headache at 2.0%, with everything else less than that.

Oxford/AstraZeneca didn’t give percentages in its news release, instead saying just that there were no serious side effects found. And any hospitalization would have be considered serious.

That side effect profile compares similarly to other vaccines, by the way. You can find a breakdown here.

It’s possible we’re missing some extremely rare side effects — side effects that didn’t appear when you only inject 30,000-50,000 people, but you’d find when you inject 300 million. It’s also possible that we’re missing side effects that take longer than a few months to appear. Frankly, that’s unlikely, according to the scientists.

And of course, you’re comparing the side-effect risk profile of the vaccine to the risk profile of having the coronavirus itself. The latter is significantly more dangerous.

How will the vaccines be distributed?

The Tribune, and especially my colleague Sean Means, has had some good explainers recently.

Let me give you the SparkNotes version: Remember that the vaccine requires two doses — one administered 3-4 weeks after the other. The vaccine will be free; the government is buying it for everyone.

There’s roughly 6.4 million doses of Pfizer’s vaccine prepared to go out across the United States in the first shipment, with Utah slated to receive roughly 1% of that. That means, extremely roughly, that 64,000 doses of the Pfizer vaccine are coming to Utah immediately. Those will be distributed among Utah’s 126,000 health care workers first, targeted to those most at risk.

After that comes nursing home residents, and then first responders. After that, the current plan is to distribute the vaccine in public health clinics.

Moderna and Pfizer both say they can make roughly 20 million doses each in December, and 25 million each in January. Essentially, that’d mean roughly 400,000 doses for Utah in December (enough to vaccinate 200,000 people) and 500,000 doses in January (enough to vaccinate 250,000 people).

We’ll see, though — I’m a little skeptical we’ll get that much, that fast. How much vaccine we will have in early 2021 also depends on if Oxford/AstraZeneca and Johnson and Johnson can get their vaccine candidates approved. (Johnson and Johnson’s vaccine only requires one dose, so that would be nice.) Essentially, the thinking is that it’ll be at least spring before supply exceeds demand.

How long will the vaccine protect people?

One good thing about the pandemic: it’s accelerated our understanding of our immune system. For example, in the last year we’ve had more and better studies on how long antibodies last than we ever had before 2020.

One study is maybe the best of the bunch, in which 185 people with COVID-19 were periodically checked in on to see where various antibody, T-cell, and B-cell levels were at after they recovered.

And here’s the good news: 90% of the subjects were still found to have neutralizing antibodies when they were tested six to eight months after infection. There’s been some worry about those antibody levels declining, but it turns out that it probably doesn’t matter much: when we test primates, we find that even very low levels of antibodies are good enough to fight off infection.

But the news gets better: high levels of virus-specific B-cells and T-cells were found in these patients tested half a year later too. Those are the cells that allow the immune system to quickly ramp up again once an infection occurs, likely precluding serious disease.

This kind of immunity can last for a really long time. For example, people who experienced the 1918 pandemic tested positive for B-cells 90 years later. And it appears that the leading vaccine candidates do provoke this kind of immune system response.

Now, it turns out that there are a ton of differences from one immune system to another — this seems to be why a very small number of people can be reinfected with the coronavirus. But for most, the news is really promising.

So, then why is a flu shot necessary every year?

Well, a couple of reasons. First, there are a bunch of different types of flu, some of which spread hugely in one year but not very widely in others. Scientists try to anticipate which flu viruses will reign, and tailor the vaccine that year to that flu.

Relatedly, flu viruses also mutate much more quickly than coronaviruses do. That means it’s much more likely accumulated mutations will make the flu vaccine ineffective, while coronaviruses change slowly enough that the vaccine should work for a long time. In fact, the coronavirus lives in a relative sweet spot: it mutates quickly enough that we can track its spread across the world but slowly enough that vaccines are likely to be effective for a while.

There was some worry that a mutation found in mink in Denmark would be vaccine-resistant, but after tests, scientists were pleased to find out that the mutation wasn’t dangerous.

It’s possible the picture could change in the next few years — normal evolutionary processes might cause the coronavirus to duck a vaccine, for example. But, again, there’s reason to be optimistic about the coronavirus vaccine being effective for longer than the flu vaccine.

Are there situations where you shouldn’t get the vaccine?

There are two big groups that the vaccine hasn’t really been tested on: children and pregnant mothers. Pfizer extended its vaccine trial to 12-18 year olds, but the other vaccines have only been tested on those 18+. And Pfizer hasn’t released the results from the teens they tested, so we don’t know how well it worked.

Pregnant mothers also haven’t been tested, though some of the vaccine makers say they’ll start testing them after they finish the current Phase 3 testing. It looks likely that pregnant moms will be allowed to take the vaccine if they’d like to, but they’ll have to weigh the risks of coronavirus for them against the risks of a vaccine that hasn’t been tested in regards to pregnancy.

So far, we’ve seen stronger side-effects with younger people than older people who are getting the vaccine. Remember, the vaccine triggers your immune system, which is stronger in younger kids. So the risk may outweigh the reward for minors — we’ll have to do some testing to find out. Still, given the smaller risks for children who are infected with coronavirus, it makes sense that they’d be in the back of the line to get the vaccine anyway.

We do know that the vaccine is very effective in the elderly. Pfizer, for example, tested those over 65 and found a 94% vaccine efficacy rate. It was also tested in all sorts of racially and ethnically groups, and they found no discrepancies in efficacy.

Andy, be straight with me. This is the fastest vaccine ever produced. It uses new technology and was done under immense political pressure. Do you really believe in it?

Yeah, I do.

Yes, this was the fastest human vaccine ever produced, but we’ve had a lot of advantages from a research point of view. We knew that COVID-19 was caused by a virus, SARS-CoV-2, that was pretty similar to the original SARS virus from 2003. While we never finished those vaccines because SARS stopped spreading, we used a lot of information from that effort.

With that, we were able to develop a vaccine in just 42 days after the SARS-CoV-2 genetic code was released. We had a vaccine candidate ready to go on Feb. 24, weeks before Tom Hanks or the Utah Jazz’s Rudy Gobert had even considered the coronavirus.

The time spent since then has been on testing these vaccine candidates thoroughly: on just a few people at first, then hundreds, then tens of thousands. At every stage, it’s worked. And it’s been able to be tested more quickly than usual in part because millions of people have contracted the virus. We just don’t see this kind of viral spread often.

The mRNA delivery technology used by Pfizer and Moderna hasn’t been used in a human vaccine before, true. But we’ve approved multiple animal vaccines that use mRNA, and we’ve known about the possibility of mRNA vaccines for decades. And it doesn’t fundamentally change what the vaccine does. Vaccines work by informing the body of what a pathogen looks like, so it can respond later more effectively. Injecting the genetic code directly makes sense — why mess around with the risk of dead or weakened viral cells if you don’t have to?

As for the politics of it all, I’m encouraged by how the process worked. The U.S. companies waited until after the presidential election to announce preliminary results of the late-stage tests. Pfizer’s candidate never took funding from the government’s Operation Warp Speed. And other countries are beginning to approve the vaccine before the United States, because the latter wants to wait until all the data is in to examine it. That’s the right process, because the scientific community has maintained control the whole way through.

So yes, we’ve set records with the speed of this vaccine production. But given the situation — the importance of the effort, the huge resources thrown at the problem, and our previous understanding of the disease — it makes sense that we did.

And it’s desperately needed. With health care workers already overwhelmed — Utah hospitals are over effective capacity now, and over 11,000 Utah healthcare workers contracting COVID-19 during the pandemic — help is finally on its way.

Andy Larsen is a data columnist. He is also one of The Salt Lake Tribune’s Utah Jazz beat writers. You can reach him at alarsen@sltrib.com.