An important reason to be excited about the new Johnson & Johnson vaccine against Covid-19, which was approved by the Food and Drug Administration for emergencies in the USA at the weekend: In contrast to the vaccines already used by Moderna and Pfizer is only this required One shot for full protection.
It's a big deal. From a practical point of view, this means that the new vaccine could really speed up the American vaccination campaign – certainly more than any other two-dose vaccine. It also addresses an issue that is lengthy medical treatments that require multiple doses: many patients tend to drop out after the first appointment.
"Especially if you're trying to think about a large public health program like this vaccine rollout, a single-dose vaccine would have made it much, much easier," if Amesh Adalja, a senior scientist at Das, had been the first to get approval Johns Hopkins Center for Health Safety told me.
Some were skeptical of the Johnson & Johnson vaccine, as reported data on its effectiveness were lower than that of the Moderna and Pfizer vaccines. Initially, the vaccine was reported to be 66 percent effective against Covid-19, which pales in comparison to more than 90 percent for the other two approved vaccines.
However, in many ways it is the wrong number. The effectiveness of the vaccine in preventing the disease in people with symptoms is arguably much less important than the effectiveness of the vaccine against hospitalization and death. And there's the promising news: In studies, the Johnson & Johnson vaccine zeroes both of them. It crushes the greatest thing that Covid-19 has made so threatening to humans: its ability to kill.
Given the ongoing supply restrictions and high demand, experts say people should get the vaccine that is available to them first – this is how we will beat Covid-19 as soon as possible.
But for people who are bad at follow-up appointments (including me) and from a broader public health perspective where speeding up and smoothing the vaccine rollout is critical, the Johnson & Johnson vaccine and other one-shot Vaccinations are real game changers.
1) The one-time vaccine we have is really effective
In times without a pandemic, Americans face common infectious diseases that don't force society to close schools, businesses, and other interactions with people outside of our homes. Nobody likes catching the flu or cold, but because most of us don't expect them to take us to hospital or kill us, we by and large live with them only. (Seriously, more people should get their flu shots – that would still save lives.)
This is the miracle of the previously approved Covid-19 vaccines: They turn the coronavirus into something much more manageable, like a cold or the flu. Some people who receive the vaccine may still develop a cold or even a fever if the virus infects them. Based on the clinical study and some real-world data, the risk of serious illness, hospitalization and death drops massively – to zero or almost zero, especially for hospitalizations or deaths.
The Johnson & Johnson vaccine is no different in this regard. According to the FDA last week, clinical trials in the US have found an effectiveness rate of about 72 percent. But that is the number that only informs us about symptomatic infections up to a runny nose or short-lived fever. In hospitalizations and deaths, the Johnson & Johnson vaccine reported 100 percent effectiveness after 28 days (all vaccines used to take weeks to build up the body's defenses).
Johnson & Johnson's vaccine may not be as effective as the competition against the milder symptomatic cases, but it's just as effective on the types of diseases that make Covid-19 really scary.
"I would take it," said Jen Kates, director of global health and HIV policy at the Kaiser Family Foundation. "Many of us looking at the data say we would definitely get a vaccine that was that effective."
One of the big concerns right now is whether the vaccines against Covid-19 variants will work. Here, too, there is good news: Johnson & Johnson conducted some of its studies in South Africa, which revealed the variant with the most confirmed effects on immunity. The vaccine was still effective with an overall effectiveness of 64 percent against symptomatic illness and an effectiveness of 100 percent against hospitalizations and death.
There are still some real unknowns about the vaccine. We don't know how much it stops the disease from spreading, although early data suggests it is likely to have at least some effect. Some of the data indicated that the vaccine might not be quite as effective in older populations with comorbidities like heart disease or diabetes, but the sample size was too small to draw firm conclusions.
For the vast majority of people, however, the Johnson & Johnson vaccine does exactly what you want it to do: With it, Covid-19 is no longer fatal – the type of pathogen that you can think about as much as the flu or the flu in any case Cold.
2) Having a vaccine that doesn't require follow-up care is a big deal
In healthcare, getting people in the door can be the first major hurdle. People in need may not have health insurance or they may not be able to afford care. Even with insurance, they can face other issues – inconsistent transportation or an inflexible work schedule – that reduce the chances of ending up in a doctor's office. Or people may think too much about their own health because they are young and fit, or they may not enjoy going to the doctor.
This is a known public health problem. For some people, receiving multiple doses of one treatment is "a lot", told me Saskia Popescu, an infectious disease epidemiologist at George Mason University. "So it's really difficult to get people to get their full Hep B vaccine."
Studies prove this. As Dylan Scott wrote for Vox:
(B) Based on research evaluating compliance with other multiple dose vaccines, patients are really, really bad at getting their second dose. Bad as in, as much as half of the patients never. Studies in both the United States and Great Britain on the hepatitis B vaccine, which, like the Covid-19 vaccines, is said to have a period of about a month between the first and second dose, found that about 50 percent of patients do not Vaccine received her follow-up shot within a year of her first.
Perhaps the numbers for the Covid-19 vaccines are looking better. The stakes in a deadly pandemic are much higher, and perhaps people will respond accordingly. But if a significant number of people don't get their second shots and the first dose of Moderna and Pfizer's vaccines aren't enough, it could ruin the chances of herd immunity if enough of the population is vaccinated to stop the spread of the Virus.
On the other hand, some people may simply not be able to make a follow-up appointment, especially as problems with vaccine supply and distribution persist. This is likely to become less of a problem over time as the adoption of the vaccine continues to grow and improve. In the meantime, however, there is an added risk of people missing their second shot.
All of this is no longer hypothetical. In the United States, about 14 percent of the population received the first dose of a Moderna or Pfizer vaccine, while only 7 percent received the second dose, according to the New York Times. Part of this is because the rollout is still in the early stages, but nearly 3 million Americans failed to get their second dose of vaccine on time.
How much the gap between the first and second dose closes or widens, the need for Johnson & Johnson's vaccine and other one-shot vaccines becomes clear.
3) A one-time vaccine could really speed up our path to herd immunity
One of the most obvious advantages of a one-off Covid-19 vaccine is that it could dramatically speed up and literally double the launch of vaccines in the US.
America has been giving around 1.5 million doses of vaccine a day for the past few weeks. That number had been steadily increasing until the recent snowstorms, which temporarily slowed things down. But imagine if the US is kind of stuck on current rates.
Under this 1.5 million doses per day scenario, requesting two shots means the U.S. wouldn't hit an 80 percent herd immunity threshold – a number that could be too high or too low. We just don't know yet – until spring 2022.
But if the US somehow replaced all of its vaccines with a one-shot vaccine – not likely at all, but helpful for demonstration purposes – the current pace would be enough to achieve herd immunity towards the end of summer. In a more realistic scenario, in which a third of the vaccines are given once, the US would achieve herd immunity by the end of this year.
Now imagine if the US manages to get 3 million shots a day (which no longer seems unlikely). At this rate, two-dose vaccines would get us herd immunity at the end of summer, and a one-shot-only approach would get us there before summer. If a third of the vaccines are one-shot versions, we'll get herd immunity by midsummer. The rest of the summer will hopefully stay a lot closer to normal than last year.
You shouldn't take these numbers too seriously. We don't know how much the US vaccination campaign will ramp up in the coming months as we don't have a crystal ball. We don't know how much Johnson & Johnson, which has already reported manufacturing issues, will scale its vaccine production from the 20 million the company promised by the end of March to the 100 million it promised total. We don't know if the 30 percent of Americans who currently report vaccine reluctance will hesitate, which would ruin the prospect of herd immunity. And we don't yet have a vaccine approved for use in children – and with those under 18s making up around 20 percent of the population, it could ruin the chance of herd immunity as well.
But at least the numbers show the potential of a one-shot vaccine like Johnson & Johnson's. This could speed up the vaccination process in the US by weeks or even months.
With thousands of people dying from Covid-19 every day, this surge could result in more than tens of thousands of lives being saved.
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