A booster dose of Johnson & Johnson's COVID-19 vaccine appears to produce a robust increase in antibodies, according to interim data from two small, early-stage trials, the company said on Wednesday.
"Johnson & Johnson COVID-19 vaccine booster, after single dose primary regimen, provided rapid and robust increase in spike-binding antibodies," the company said.
The booster dose generated an increase in spike-binding antibodies, nine-fold higher than 28 days after the primary single-dose vaccination.
Significant increases in binding antibody responses were observed in participants between ages 18 and 55, and in those 65 years and older who received a lower booster dose.
The study summaries were submitted to medRxiv on August 24.
The US is set to roll out a booster campaign from September and J&J has been under pressure to produce evidence of whether a booster shot would increase protection from its vaccine.
The company said it plans to discuss the data with US regulators as they devise their booster regimens.
“We look forward to discussing with public health officials a potential strategy for our Johnson & Johnson COVID-19 vaccine, boosting eight months or longer after the primary single-dose vaccination," said Mathai Mammen, M.D., Ph.D., Global Head, Janssen Research & Development, Johnson & Johnson.
The news comes as several countries, including the US, have started offering booster doses of other vaccines to vulnerable individuals, including the immunocompromised, as the Delta variant surges.
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