Researchers found that antibody levels from people who received the one-dose vaccine were twice as low compared to those given the two-dose Pfizer-BioNTech or Moderna vaccines.
The team says the findings add to the growing body of evidence that the 13 million Americans who received J&J will need boosters to protect against highly infectious variants.
It comes as Dr Rochelle Walensky, director of the Centers for Disease Control and Prevention (CDC), testified before the Senate Health, Education, Labor and Pensions committee on Wednesday that the variant makes up 83 percent of all new cases and is responsible for the rise in infections in nearly all 50 states.
The study represents yet another setback for J&J’s vaccine, which has plagued by pauses, ingredient mix-ups, federal health warnings and doses needing to be thrown out.
Antibody levels among people who received Johnson & Johnson’s COVID-19 vaccine were low against the Indian ‘Delta’ coronavirus variant. Pictured: Johnson & Johnson’s Covid-19 vaccines are seen on a table in Los Angeles, mAY 2021
Researchers say the findings suggest the 13 million Americans who received the J&J vaccine will need boosters to protect against variants
It comes as the CDC director Dr Rochelle Walensky revealed the Delta variant now makes up 83% of all new infections
‘The message that we wanted to give was not that people shouldn’t get the J.&J. vaccine, but we hope that in the future, it will be boosted with either another dose of J&J or a boost with Pfizer or Moderna,’ lead author Dr Nathaniel Landau, a virologist at NYU’s Grossman School of Medicine, told The New York Times.
For the study, which has not been peer-reviewed or published in a scientific journal, researchers looked at blood samples from 27 patients.
Of the group, 17 people had been immunized with two doses of the Pfizer or Moderna vaccine and 10 people with one dose of the J&J vaccine.
Researchers found that antibody levels in J&J patients were five to seven times lower when exposed to the Delta variant.
Comparatively, levels in Pfizer and Moderna patients were three-fold lower.
The findings are in line with a UK study, which found that the AstraZeneca vaccine – which is made with the same technology that the J&J vaccine uses – is 33 percent effective against symptomatic disease caused by Delta.
‘The lower baseline means that what’s left to counter Delta is very weak. That is a substantial concern, Dr John Moore, a virologist at Weill Cornell Medicine in New York, told The Times.
Antibody levels in J&J patients (black) were five to seven times lower when exposed to the Delta variant compared to three times lower in Pfizer (yellow) and Modera (red) patients
In real-world studies, other vaccines have been shown to be more effective against the Delta variant.
A May analysis from Public Health England found two doses of the Pfizer-BioNTech vaccine were 80 percent effective overall at preventing infection by the variant.
The vaccine was also 88 percent effective against symptomatic disease and 96 percent effective against hospitalization.
There is no specific data released yet on the efficacy of the Moderna vaccine against the Delta variant.
However, a Canadian study found the first dose of the Moderna vaccine was 72 percent effective against infection from the Delta variant.
There are few studies about how effective the vaccines are at preventing death from the variant, but a recent study from India – where Delta originated – found that only 0.4 percent of people who were vaccinated died from the virus.
Moore told The Times that J&J should start administering its vaccine as two doses.
He said several studies have suggested the J&J vaccine provides greater efficacy after two doses.
‘I have always thought, and often said, that the J&J vaccine is a two-dose vaccine,’ he said.
Seema Kumar, a spokeswoman for J&J, told The Times that the data from the NYU study ‘do not speak to the full nature of immune protection.’
She added that company-sponsored studies show its vaccine in its one-dose form ‘generated strong, persistent activity against the rapidly spreading Delta variant.’
The news comes just one week after it was revealed that the U.S. Food and Drug Administration (FDA) is adding a new warning to the label of J&J’s vaccine due to about 100 preliminary reports of the rare autoimmune disorder Guillain-Barré following the one-dose vaccine
In April, the J&J vaccine was paused by the CDC and FDA for 10 days after six women under the age of 50 developed Cerebral Venous Sinus Thrombosis (CVST), a rare blood clot that forms in the venous sinuses in the brain.
The women developed CVST in combination with a low platelet-count condition known as thrombocytopenia.
This figure was later updated to include 28 people, including one 45-year-old woman who died.
The pause was lifted and the FDA added a warning to J&J’s coronavirus vaccine that rare blood clotting events might occur, primarily among women under age 50.
The company then face production problems when workers at Emergent BioSolutions, a plant in Maryland, ruined millions of doses of J&J’s COVID-19 vaccine with an ingredient intended for the AstraZeneca vaccine.
J&J was forced to throw out about 75 million doses of the vaccine worth $750 million, according to the contract it signed with the federal government pricing each dose at $10.