The coronavirus vaccine created by Johnson & Johnson is effective against the new, highly transmissible Delta variant of the virus, according to two infectious disease experts at the University of Alabama at Birmingham. But a booster might not be out of the question, despite what the federal government is saying.
“Great news on the J&J vaccine,” Dr. Jeanne Marrazzo, the director of the division of infectious diseases at UAB, said in a press conference on Thursday. She cited two recent studies, one confirming that the vaccine creates strong immunity for COVID-19 in general, and that the immunity lasts for at least eight months. The other shows it’s effective against Delta, too.
“The message is the J&J vaccine is inducing really good, really long term immunity, at least right now,” she said. “It appears to be about 90% effective against the Delta variant, very similar to the mRNA vaccines, which is really, I think, really exciting and good news.”
Because of the vaccine’s effectiveness, she said it’s unlikely people who got the J&J vaccine will need to get a second “booster” shot any time soon.
There has been mixed news on possible need for vaccine boosters. The Centers for Disease Control and Prevention and the Federal Drug Administration released a joint statement Thursday saying no boosters for any vaccine are needed at this time. But on the same day, Pfizer, the company that produces the most widely used vaccine the country, said it is seeing waning immunity from its vaccine and a second dose may soon be needed.
There is some research that shows a J&J booster may produce a stronger immune response, but that still doesn’t mean people need a second dose, according to Dr. Paul Goepfert, director of the Alabama Vaccine Research Clinic and a professor of medicine and microbiology at UAB who helped work on the clinical trials that proved the J&J vaccine works.
“My understanding is, if you get two doses, your antibody production is better after one month than it is after one dose,” he said. He mentioned that early in the pandemic there was concern that the single dose may not be strong enough, but the vaccine has proven very effective.
Marrazzo said she doesn’t think people who got the J&J shot will need a second dose of that particular shot, but said some so-called “mix and match” studies have shown that early data suggest mixing a J&J shot with one of the mRNA vaccines – either Pfizer or Moderna in the U.S. – could “boost your immune response to COVID dramatically.”
“Theoretically, and at least in the clinical cases, it looks like a good idea,” she said of getting a second, different kind of vaccine as a booster. But she urged that there is not nearly enough real world data to prove that yet, or to recommend it to everyone.
“It almost certainly can’t hurt,” she said. “There’s no downside to it, as far as we know, other than the inconvenience, the side effects, and of course the cost, if you’re paying for it. And there could be a potential benefit.”
But she said she’s not comfortable making that public policy at this point, for a number of reasons. One is the federal guidance. At the time of her press conference, the CDC and FDA had yet to release any guidance on booster shots, and Marrazzo said she was hoping they would release guidance soon. Now, they’re saying not to get a booster.
Another reason Marrazzo doesn’t suggest getting a booster is because the world’s vaccine supply is still very low – even if vaccines are abundant in the U.S.
“Look at the global supply of vaccines,” she said. “Talk about inequity… You look worldwide at the number of people who are vaccinated, it is really pretty dismal… Should we go ahead and tell everyone in the United States to get a second and third vaccine just because it may boost immunity? That’s a really important philosophical question and I’m personally not comfortable saying that yet until we know what the clear benefits are.”
Outside of booster talk, there is other good news about the J&J vaccine, Goepfert said. Unlike the Pfizer vaccine, the J&J shot has actually gotten stronger over time.
“The antibodies actually improve over time,” he said, mentioning a study that shows antibody response created by the vaccine was stronger after eight months than it was after just one month.
The J&J shot is different than the other vaccines currently available in the United States. It’s the least common of the three, making up less than 4% of all vaccine doses administered in the country, according to the Centers for Disease Control and Prevention. Because of this, there has been less real-world research on its efficacy against variants like Delta.
It also works slightly differently. The vaccines created by Pfizer and Moderna are both mRNA vaccines that require two doses, while the J&J vaccine is an adenovirus vaccine, and requires only one dose. J&J uses a different mechanism, but all three vaccines work in “exactly the same way,” Goepfert said.
“They basically employ the cells in your body to make the COVID spike protein,” he said. That spike protein that helps the coronavirus attach to a person’s body and replicate. It’s mutation in that spike protein that has created variants like the Delta strain, and the more vaccine resistant Beta strain, Goepfert said.
The fact that all three of the vaccines available in the U.S. are effective against Delta means the U.S. is likely in a good place as a country to beat Delta, Marrazzo said. The vaccine made by AstraZeneca is less effective against this strain, for example, according to Marrazzo. But conditions may be ripe for a new, worse variant to develop.
“I worry that Alabama is going to have the next variant that’s going to be completely vaccine resistant,” Goepfert said. Conditions here are perfect for such an outcome, he said. A low vaccination rate means viruses can spread, but there are enough people who are vaccinated that the virus will inevitably reach a vaccinated person and have the opportunity to mutate to get around those defenses.
Marrazzo and Goepfert both said that future boosters, or new versions of the vaccines, may be needed if such variants develop. And that’s all the more reason for more people to get vaccinated now, according to Goepfert.
“These are the best vaccines we’ve ever made for an adult vaccine,” he said. “They are highly effective, highly effective in older adults, which is very unusual for a vaccine like this… I urge everyone, get information, talk to someone you trust, a healthcare provider, and get vaccinated.”