USA will apply booster doses against covid-19 1:24
(CNN) -
Johnson & Johnson's booster doses of the COVID-19 vaccine generated a large surge in antibodies, the immune system's first line of defense against infection, the company reported Wednesday.
People who received a booster dose six to eight months after the first J&J injections saw the antibodies multiply nine-fold compared to 28 days after the first injection, Johnson & Johnson said.
The data comes from two phase 2 studies conducted in the United States and Europe, the company said in a statement.
Some of the approximately 2,000 people who participated in the studies received booster doses six months after their first doses of J & J's Janssen vaccine.
"The new interim data from these studies demonstrate that a booster dose of Johnson & Johnson's covid-19 vaccine generated a rapid and robust rise in anti-spike antibodies, nine times greater than 28 days after the primary vaccination of a single dose, "the company said in its statement.
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Health personnel first to receive booster doses 3:16
"We have established that a single injection of our covid-19 vaccine generates strong and robust immune responses that are long-lasting and persistent for eight months. With this new data, we also see that a booster dose of Johnson & Johnson's covid-19 vaccine further increases antibody responses among study participants who had previously received our vaccine, "Dr. Mathai Mammen, Janssen's global head of research and development, said in a statement.
Dialogue with authorities and uncertainty in those vaccinated
J&J said it was in discussions with the U.S. Food and Drug Administration (FDA), the U.S. Centers for Disease Control and Prevention (CDC), the European Agency of Medicines, the World Health Organization and other health authorities on the need to offer a booster dose of the Janssen vaccine.
"We look forward to discussing with public health authorities a possible strategy for our Johnson & Johnson covid-19 vaccine, boosting eight months or more after the primary single-dose vaccination," Mammen added.
Many people who received the J&J vaccine have been asking for information about whether they will need a booster dose.
US federal government officials have said they are preparing to begin offering a booster dose to people who received the COVID-19 vaccine from Moderna or Pfizer.
It is after the data showed that boosters can increase the antibody response, and after studies began to show an increase in infections in both vaccinated and unvaccinated people.
Experts say that the more transmissible delta variant is partly to blame, as well as the decreased immune response.
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Janssen's vaccine was licensed in late February, more than two months after the Moderna and Pfizer vaccines were licensed.
About 14 million Americans have received the J&J vaccine, according to the CDC.
Dr. Dan Barouch, a vaccine researcher at Beth Israel Deaconess Medical Center and Harvard Medical School, who is not involved in the two clinical studies but is collaborating on the J&J vaccine study, said the results support the getting a booster shot, but only after a delay.
"The six-month boost is going to look very impressive and substantially higher than what has already been reported in terms of the two-month boost. That's significant because, in my opinion, the boost shouldn't be at two months, it really should be six months or later, "Barouch told CNN.
Researchers optimistic about immune protection
None of the studies looked at the efficacy of the vaccine in the real world.
For this reason, the company has not shown that people who receive boosters are less likely to become infected or develop a serious illness.
But researchers are beginning to agree that antibody levels indicate immune protection.
Johnson & Johnson's vaccine is manufactured differently than Pfizer and Moderna.
Those two vaccines use messenger RNA, or mRNA, enclosed in tiny lipid particles, to carry instructions to the body to initiate an immune response.
Janssen's covid-19 vaccine uses a crippled common cold virus, called an adenovirus, to convey similar instructions.
It was feared that a booster dose of this type of vaccine with viral vectors would not be effective due to the possibility that the organism could also generate an immune response against the vector.
We'll need booster doses for everyone, says expert 1:15
"There was a theoretical concern that the generation of vector antibodies from the first injection might preclude their use again," Barouch said.
"I think this data ends with that," he said.
Federal health authorities have said they believe a booster dose of Janssen's vaccine will be necessary at some point.
"I'm pretty sure the FDA, the CDC, the NIH and the White House will use this data to justify or probably recommend a booster for people vaccinated with J&J, probably with a second injection of J&J," Barouch said.
coronavirus vaccine against covid-19
