Woodkirk Stone
As vaccine makers turn to boosters, new studies unveiled Wednesday by Johnson & Johnson and Pfizer-BioNTech demonstrated that additional injections can dramatically increase antibodies to the coronavirus.
The companies said they were submitting the new data to the Food and Drug Administration for evaluation, and Pfizer formally asked the agency to authorize a recall. The Biden administration said last week it wanted to provide boosters to all Americans eight months after vaccination.
The single Johnson & Johnson vaccine was absent from the government’s recall plan announced last week. But with the new data, the company hopes to be part of the initial distribution of additional shots, which could take place as early as September.
“We look forward to discussing with public health officials a potential strategy for our Johnson & Johnson Covid-19 vaccine, increasing eight months or more after primary single-dose vaccination,” Dr Mathai Mammen, Global Director of Janssen Research & Development at Johnson & Johnson, said in a statement.
In February, the FDA granted emergency clearance to Johnson & Johnson for its injection, which showed 72% effectiveness against infection in its US clinical trial. This study was carried out before the Delta variant became widespread. But in another study published earlier this month, South African researchers found that the vaccine was up to 95% effective against Delta’s death and reduced the risk of hospitalization by 71%.
In its new study, Johnson & Johnson followed 17 volunteers from last year’s clinical trial. When they were boosted at six months, their antibodies to the coronavirus jumped nine times higher than after the first dose. The data has not yet been published in a scientific journal.
Small studies of booster shots from Moderna and Pfizer-BioNTech found comparable jumps in antibody levels, as the companies reported in recent earnings calls.
On Wednesday, Pfizer and BioNTech released new data from 306 people showing that a third dose given five to eight months after the second elicited a strong immune response. The level of antibodies to the coronavirus in volunteers more than tripled, the companies reported.
Side effects from a third injection were about the same as after the first two doses, the companies said. The underlying data was not included in the press release, nor the dates or location of the study specified. The companies said they were preparing a scientific publication describing the research.
Pfizer and BioNTech said they are now asking the FDA for further approval of a coronavirus vaccine booster for people aged 16 and older, and will submit all of their supporting data by the end of this week.
News of the recall request came two days after the FDA fully approved the company’s two-dose vaccine for those 16 and older, making it the first to go beyond emergency use status.
Since booster shots from different companies have not been tested in a direct comparison, it is not possible to determine which provides the biggest boost.
It is also difficult to say if these large antibody jumps will result in a very effective booster.
A number of studies have suggested that higher levels of antibodies provide better protection, especially against the Delta variant. But other parts of the immune system, such as T cells, are also important. These data cannot therefore give a precise estimate of the effectiveness of a booster against Covid-19.
“It’s too early to estimate protection,” said Dr. Dan Barouch, a virologist at Beth Israel Deaconess Medical Center in Boston, who led some studies for Johnson & Johnson but was not involved in the booster trial.
The new data from Johnson & Johnson could allay some initial concerns about the effectiveness of more than one dose of the vaccine. The Johnson & Johnson vaccine uses an adenovirus to introduce coronavirus genes into cells. When the company launched its trials, some experts questioned whether people would make antibodies against adenoviruses, which could make a booster unnecessary.
“What we would previously have considered a major hurdle may not be such a huge hurdle,” said Lynda Coughlan, a virologist at the University of Maryland School of Medicine, who was not involved in the ‘study.
The Johnson & Johnson vaccine is the only vaccine in the United States or Europe authorized as a single dose. Since November, the company has been running a clinical trial to determine the level of protection people get from two doses, two months apart. This trial should give results in the coming weeks.
After the volunteers in this trial received the second dose, their antibody levels increased threefold. The much larger increase in the new booster study is likely due to the longer wait between doses: a six-month hiatus gives the immune system time to develop a more mature response to the coronavirus.
According to the Centers for Disease Control, only eight percent of Americans vaccinated – or about 14 million people – have received a Johnson & Johnson vaccine. A federal official said the government had enough reserves in reserve to give reminders to anyone who received a first dose of Johnson & Johnson, if allowed.
News of potential Johnson & Johnson boosters for Americans could sting in other countries still awaiting the first doses of the vaccine. South Africa, for example, has ordered 31 million doses of the vaccine, but only two million people have received it.
It remains to be seen how long the high levels of antibodies produced by the booster will last. “We don’t have long-term human studies, but my prediction would be that these responses should be sustained after the boost,” Dr Coughlan said.
Noah Weiland contributed reports.