Johnson & Johnson Says Single Vaccine Dose Protects Against ‘Breakthrough’ COVID-19 for 6 Months

Johnson & Johnson said its single-dose vaccine protects against breakthrough COVID-19 for up to six months.

Citing a study that it sponsored, Johnson & Johnson said in a release Thursday that protection against infection from its single-dose vaccine starts to wane only from the fourth month compared to the second month in the case of two-dose vaccines from rivals Pfizer and Moderna, which use mRNA technology whereas the J&J shot uses an adenovirus.

The study was conducted between Jan. 1 and Sept. 7, and it was before the Omicron variant was discovered in late November. Published in MedRxiv, the study hasn’t been peer-reviewed.

No waning of protection was found for ICU admissions for all three vaccines, J&J said. The company said the study was carried out by collecting claims and laboratory data covering 168 million people.

“We continue to undertake extensive efforts to study the durability of protection offered by the Johnson & Johnson vaccine amidst the ever-changing COVID-19 pandemic,” said Mathai Mammen, J&J’s executive vice president of pharmaceuticals, in the news release.

Mammen added that “while these are rapidly evolving data, we are seeing vaccine effectiveness against COVID-19-related hospitalization of approximately 80 percent from a single shot of the Johnson & Johnson vaccine, and this level of protection holds steady across the length of time studied thus far—up to six months.”

Despite the study being completed before the spread of Omicron, Mammen argued that the J&J shot produces a strong enough COVID-19 antibody response that “is consistent across variants, including Omicron.”

About three weeks ago, federal drug regulators expanded their warning about a severe condition linked to the J&J vaccine—known as thrombosis with thrombocytopenia syndrome. The regulators listed it as a medical-related issue for someone not to get the shot.

The condition has been reported in “a wide range of individuals 18 years and older” since the administration of the Johnson & Johnson vaccine started earlier in 2021, officials said.

And about a week ago, a recent study indicated that individuals who initially received Pfizer’s COVID-19 vaccine and got a Johnson & Johnson booster saw a 41-fold increase in antibody responses and a jump in T-cells within several weeks.

“We provide the first evidence of the effectiveness of a homologous Ad26.COV.2 vaccine boost given 6–9 months after the initial single vaccination series during a period of Omicron variant circulation,” authors wrote in the preprint study, which evaluated data sourced from South Africa.

COVID-19 is the illness caused by the CCP (Chinese Communist Party) virus.

Reuters and Zachary Stieber contributed to this report.