The Middletown Press (Middletown, CT)
Experts: J&J vaccine appears less effective against delta
Evidence is beginning to mount suggesting that Johnson & Johnson’s COVID vaccine may not be as effective in fighting the delta variant, which is believed to be dominant strain in Connecticut.
“Literature certainly suggests that the mRNA vaccines, after being fully vaccinated, do provide somewhat more robust immune response against the delta virus,” said Michael Parry, chair of infectious diseases at Stamford Health.
Though Parry said all three available vaccines “seem similarly effective at preventing severe disease, hospitalization and death,” he believes that “breakthrough cases are perhaps a little bit greater with J&J than with the mRNA vaccines.”
A study released this week by researchers at New York University Grossman School of Medicine supported the contention that the Johnson & Johnson vaccine is not as effective at generating antibodies to help the body fight the virus.
That study showed that all three available vaccines did generate neutralizing antibodies, but Johnson & Johnson’s “showed a more pronounced decrease” over time, “raising the potential for decreased protection” against variants of concern.
The delta variant is continuing to spread, CDC Director Rochelle Walensky saying Tuesday that the delta variant accounts for 83 percent of all the COVID-19 cases in the United States that have been genetically sequenced.
In Connecticut, 80 percent of all sequenced samples last week were delta, said Acting Commissioner of the Department of Public Health Dr. Deidre Gifford, up from 42 percent two weeks ago.
The strain is believed to be upwards of 60 percent more transmissible than the alpha variant, which was first found in the U.K. and was previously the dominant strain in Connecticut.
On Wednesday, the state’s positivity rate for new COVID-19 tests dropped to 1.95 percent from 2.71 percent a day earlier. The state also said an additional four residents had been admitted to the hospital with a coronavirus infection, for a total of 58 COVID hospitalizations statewide.
Gov. Ned Lamont reiterated Wednesday that unvaccinated residents should continue to wear a mask indoors.
The vaccines developed by both Pfizer and Moderna are built using relatively new mRNA technology, which the Centers for Disease Control and Prevention said “teach our cells how to make a protein — or even just a piece of a protein — that triggers an immune response inside our bodies.”
Johnson & Johnson’s vaccine works differently. Called an “adenovirus” vaccine, it uses a version of the virus altered so it cannot replicate, which triggers the body into making antibodies, according to the CDC.
Because the vaccines are designed so differently, and since comparatively so few Johnson & Johnson vaccines had been administered, Parry said comparing them is “a little bit comparing apples and oranges.”
“We have no data that’s head-to-head, randomized between the three vaccines at the same time,” he said.
The vast majority of vaccines administered in Connecticut have been mRNA, made by Pfizer of Moderna. After a 10-day pause on administration of Johnson & Johnson’s vaccine was lifted in April, the state had a stockpile of more than 125,000 doses.
“We’re not ordering more from the federal government,” Josh Geballe, Lamont’s chief operating officer, said in May of the Johnson & Johnson vaccine.
Parry said Wednesday that so few of the singleshot vaccine had been administered that it would be difficult to draw conclusions.
“We haven’t given enough Johnson & Johnson vaccine to make any statement about our own personal experience,” he said.
The NYU study suggests that boosters may be a solution to waning immunity after the Johnson & Johnson vaccine, either “with a second immunization or by a heterologous boost with one of the mRNA vaccines.”
“While a single-dose vaccination has advantages, the benefit provided by a second immunization may be well worth the inconvenience,” the study said.