Compared with those who received mRNA Covid-19 vaccines, recipients of Johnson & Johnson's (J&J) vaccine have received less guidance from public health officials, particularly when it comes to booster doses—which has led some to consider a third shot on their own, Bernard Wolfson writes for Kaiser Health News.

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J&J recipients feel left out of the public discourse

According to Wolfson, when J&J's vaccine was first rolled out, it was billed as a "one and done" shot compared with the two-dose series needed for both Pfizer-BioNTech's and Moderna's mRNA vaccines. Although the J&J vaccine's efficacy appeared to be lower than the mRNA vaccines, it was still protective against severe disease and had other advantages, such as being easier to store.

However, since then, J&J's vaccine has been linked to a rare but serious blood clotting disorder and experienced production mishaps that contaminated millions of doses. In addition, federal health authorities in December recommended Pfizer-BioNTech's and Moderna's vaccines over J&J's, citing concerns about potential clotting risks.

Currently, around 17 million Americans have received the J&J vaccine, much fewer than the 92 million Americans who have received either of the mRNA vaccines. As a result, public officials have often left J&J recipients out of public discourse and guidance, leaving some "feeling a bit like neglected stepchildren," Wolfson writes.

Should J&J recipients get another booster?

In October, federal health officials recommended booster doses for all J&J recipients at least two months after their initial dose. According to several members of FDA's vaccine advisory panel at the time, the J&J vaccine should have initially been given as a two-dose regimen, particularly given the lower effectiveness of a single dose compared with mRNA vaccines.

"A lot of us believe it should have been a two-dose vaccine all along," said Bradley Pollock, associate dean for public health sciences at the UC Davis School of Medicine.

Because of this, many J&J recipients, including Wolfson, have expressed concerns that they may be less protected against Covid-19 than those who received mRNA vaccines. Unlike mRNA recipients who received a two-dose initial series and were also authorized to receive a booster, J&J recipients have only been authorized two doses total, their initial and a booster, unless they are immunocompromised.

This has led some J&J recipients to seek out a third Covid-19 vaccine dose on their own, but health experts say that this is likely not necessary, as even two vaccine doses provide substantial long-term protection against severe illness and death.

According to George Rutherford, a professor of epidemiology at the University of California, San Francisco, since the J&J and mRNA vaccines work differently, "it's not like one J&J plus one Moderna equals 1.5 Pfizer doses." He added that, while he doesn't think a third dose will make J&J recipients sick, he'd just "sit tight" for now.

Overall, Wolfson notes that, even though use of the J&J has largely declined, it remains a good alternative for individuals who may be cautious about the mRNA vaccines and would not otherwise get vaccinated. In addition, future research or new variants may change the guidance for how many vaccine doses are needed.

"It may turn out to be true that three doses or two doses and a variant-focused booster are going to turn out to be best. We don't know yet," said Gregory Poland, director and founder of the Mayo Clinic’s Vaccine Research Group. "And the way things have been going, we will barely be getting the answers to those questions, and more time will have passed, and a new variant will arrive." (Wolfson, Kaiser Health News, 3/1)