5 things about covid vaccines as Johnson & Johnson enters market

The United States seems to be turning a corner on the pandemic as more Americans are getting vaccinated each day.

The Food and Drug Administration has approved Johnson & Johnson’s one-shot covid-19 vaccine for emergency use. Combined with the Pfizer and Moderna vaccines, President Biden said Tuesday, the U.S. would have enough vaccine doses by the end of May to cover every American adult. That is two months earlier than Biden previously estimated.

Questions have emerged about the effectiveness of the vaccines and their side effects, as well as how they work compared to other vaccines. The Tribune-Review put these questions to Pittsburgh-based infectious disease expert Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security.

Question: Does it matter which shot we get?

Answer: I don’t think it matters which shot we get. All of these vaccines are really excellent at stopping what matters — serious disease, hospitalization and death. So, whatever vaccine you’re offered, take the one you get first.

Q: Can you get one shot from one brand and then another shot from a different brand? For example, one shot from Pfizer and the second shot from Moderna?

A: There is some guidance from the CDC that you can mix and match in extraordinary circumstances with the Moderna and Pfizer vaccines because they are of the same technology. But that’s really not something that we are trying to encourage. We’re trying to keep people with the same brand and the same style of vaccine unless there is some extenuating circumstance. The Johnson & Johnson vaccine, since it’s a single-dose vaccine, that really doesn’t apply to it.

Q: Will the Johnson & Johnson vaccine eventually need a booster?

A: It’s unclear if any of the vaccines are going to need a booster. The only way that you’re going to know that is when you’ve got people vaccinated, you follow them over time in a natural history study and see if they get reinfected after some period of time and whether a booster might be indicated. So, it’s going to take some time to understand what the timing of boosters is going to be on any of the vaccines. There is a study going on for a two-dose regimen of the Johnson & Johnson vaccine.

But I think it’s unclear and premature to know what level of booster shots are going to be needed for any of the vaccines until we actually get people vaccinated and see how they do.

Q: Do the side effects differ from one brand to another?

A: Some of the side effects overlap. All of them are going to have injection site reactions — headaches, muscle aches and pains, maybe a low-grade fever. We haven’t really heard about any allergic reactions with the Johnson & Johnson vaccine, but, again, we haven’t really given it to a lot of people. That will be something to watch for. Some people who get the Moderna vaccine gave reports of a red rash around the injection sites.

That seems to be a little more unique with the Moderna vaccine, but, in general, it’s basically the same kind of injection site muscle aches and pains, headaches, those types of issues.

Q: Will we ever know which vaccine is the most effective and, if so, when?

A: I think it depends on how you’re defining effective. If you’re talking about what I talk about — serious illness, hospitalization and death — they’re all basically equally effective at preventing those outcomes.

We’re not likely to see a head-to-head trial. The only way that you could know that for sure is to do a randomized, controlled trial where one arm was randomized to Johnson & Johnson, another to Moderna, another to Pfizer, and you did a specific trial like that. There’s no real incentive or need to do a trial like that because the whole reason we embarked on a vaccine program, the whole reason covid-19 became a headline, was because of its ability to cause severe disease, hospitalization, death and compromised hospital capacity. That’s what the vaccines are designed to stop.

So, because all of our vaccines seem to do very well at that, there’s really no reason to continue to compare these vaccines in a head-to-head manner because all three of them solved the problem that they’re designed to solve.