As the Delta variant of COVID-19 circulates more widely through the United States, people are glancing nervously at England. They’ve used a controversial vaccination strategy: one shot of either Pfizer or AstraZeneca, wait 12 weeks (rather than the standard three), then another shot. But data has shown that one shot of either Pfizer or AstraZeneca just isn’t as effective against the Delta variant as vaccination with both shots.
Additionally, data shows that AstraZeneca is less effective against Delta than the Pfizer vaccine. And people who’ve gotten similar vaccines are getting nervous. Namely, those who got jabbed with a Johnson & Johnson vax.
Real talk: the Johnson & Johnson vax was never the most effective vaccine at preventing infections. According to the CDC, it’s only 66.3% effective at preventing COVID-19 infection; though clinical studies showed that by 4 weeks after inoculation, no one who received the vaccine had to be hospitalized. Efficacy rates at preventing COVID-19 infections are 95% for the Pfizer vaccine and 94.1% for Moderna. That’s a huge difference.
Then there’s the blood clot issue. Johnson & Johnson vaccines were briefly pulled because of what the CDC calls “rare risk of blood clots with low platelets” in women under fifty. But as of April, the FDA has re-authorized the vaccine. Moderna and Pfizer, meanwhile, show reports of myocarditis and pericarditis (inflammation related to the heart) in adolescents and young adults after receiving the vaccine. All of these side effects are super-rare, and the benefits of the vaccine (i.e, the risks of getting COVID-19) outweigh the risk of the vaccine (i.e., the risk of blood clots or heart issues).
But the Johnson & Johnson vaccine got the worst press.
However, the Johnson & Johnson vaccine is a great option for developing nations. It only requires one-and-done jabs — important in rural areas where people may travel far for vaccinations and record-keeping is difficult. It also lasts longer when refrigerated than the other vaccines, so it’s easier to transport to remote locations. And while preventing COVID-19 infection is important, preventing severe COVID-19 infection and death is far more important.
But with the Delta variant taking over, people are beginning to have major questions about the Johnson & Johnson one-and-done strategy, which has to do with its mechanism.
So How Is The Johnson & Johnson Vaccine Different?
Time to get scientifical. The Johnson & Johnson vaccine, along with the AstraZeneca vax they’re using in England, is what the CDC calls a “viral vector” vaccine. Viral vector vaccines work by using a harmless virus — in this case, an adenovirus — to deliver part of the COVID-19 virus to a cell. The cell produces that magic COVID-19 spike protein, which the immune system recognizes as dangerous and learns to fight off. Pfizer and Moderna vaccines are mRNA vaccines. These use messenger RNA to create the spike protein, which the cells learn to fight off, blah blah. These are two very different approaches. mRNA vaccines are the newer approach — and seem super-effective.
One viral vector round, like people have in the UK? Not as effective against the Delta variant.
Angela Rasmussen, a virologist at the University of Saskatchewan, boosted her Johnson and Johnson vaccine with a Pfizer topper because of the delta variant spread and its effects in the UK. She told Slate, “We know that at least two doses of an adenovirus vector vaccine [a full round of AstraZeneca or one Johnson & Johnson] and an mRNA vaccine provide protection equivalent to having two mRNA vaccines. So, it was really just to be safe.”
Canada’s already telling people who have had the AstraZeneca vaccine to add an mRNA booster.
Why Are We Losing It Over Delta, Anyway?
The CDC declared the Delta variant a “variant of concern” on June 15th. Variants of concern are more transmittable and cause more hospitalizations and deaths. Even worse, vaccines don’t protect against them as well. The Delta variant was first identified in India, and now accounts for one in four cases of COVID-19 in the United States.
Delta’s also worrisome because a recent U.K. study showed that it was 2.5 times more likely to infect children and adults over fifty. There’s no vaccine for kids yet, and they seem more susceptible to delta. Delta also doesn’t respond as well to conventional COVID-19 treatments.
So What Should We Do?
Canada is already telling people with a full round of AstraZeneca shots to get an mRNA booster.
After receiving the Johnson & Johnson vaccine, many doctors are getting boosters — for themselves. Jason Gallagher, a clinical professor at Temple University School of Pharmacy, recently got a booster as part of a clinical trial. But he says that others should talk to their doctors. So does Rasmussen. Paul Sax, an infectious disease doctor, told Slate that, “It’s very reasonable for people to worry about the effectiveness of the J&J vaccine with Delta [becoming] the dominant variant, and to consider boosting.” But like almost every other doctor, he recommended that people talk to their doctor, since the CDC has not released any guidelines about mixing different types of vaccines.
Meanwhile, epidemiologists are calling on the CDC to do something.
Lin points out that this would also use the supply of about-to-expire mRNA doses.
But Johnson & Johnson has released preliminary data showing that the vaccine is effective against the Delta variant. It’s a small study, but it’s been accepted for publication. So for now, recipients can rest easy. They shouldn’t run out and get a booster — against CDC recommendations. (If you got a Johnson and Johnson vaccine and think a booster might be a good idea for you, your doctor is the person to consult on this.)
Breathe easier. But since it’s a small study, we may want more data — and there’s evidence that Johnson & Johnson may cause more breakthrough infections. We’ll see what the future brings. Mutations continue to happen, and we have a predicted winter surge ahead of us. Right now, it’s simply important to be vaccinated, period.