On July 1, Johnson & Johnson announced in a press release that its Ad26.COV2.S vaccine, administered as a single dose, can combat the rapidly spreading Delta variant and provide durable protection to prevent widespread transmission of the virus. Following vaccination, individuals remain effectively protected against SARS-CoV-2, including the Delta variant, for at least eight months. The company has now submitted summaries of two preprint studies tobioRxiv。
Image courtesy of Johnson & Johnson
Ad26.COV2.S utilizes a common cold virus known as adenovirus serotype 26 (Ad26) to deliver the SARS-CoV-2 spike protein into host cells, thereby stimulating the body to enhance its immune response against SARS-CoV-2. Reportedly, the vaccine remains stable for two years at -20°C and can be stored stably for up to four and a half months at standard refrigeration temperatures of 2°C to 8°C.
Notably, both reports include an analysis of blood samples obtained from a subset of subjects (n=8) in the Phase 3 ENSEMBLE study. These data indicate that,After vaccination, the serum neutralizing titers in volunteers decreased 1.6-fold against the Delta variant and 3.6-fold against the South African Beta variant., by comparison, the single-dose vaccine demonstrated significantly greater protective efficacy against the Delta variant.
According to data from the U.S. Centers for Disease Control and Prevention (CDC), the Delta variant is expected to become the dominant strain in the United States in the coming weeks. Current evidence indicates that the variant is more transmissible than the original virus, prompting experts to evaluate whether booster doses of existing vaccines could provide enhanced protection, while scientists and vaccine manufacturers are concurrently developing new versions of vaccines targeting the variant.
These two latest studies reveal,Within 29 days following a single dose of the Johnson & Johnson COVID-19 vaccine, volunteers demonstrated the ability to neutralize the Delta variant, and over time, the protective immunity gradually matured and improved.ExceptDeltaVariant strain andBetaIn addition to (B.1.351), this vaccine againstgamma（P.1）、Alpha（B.1.1.7）、Epsilon（B.1.429）、Kappa（B.1.617.1）andD614G variant virusandOriginal SARS-CoV-2 strain(WA1/2020) all demonstrated varying degrees of efficacy.
In two reports, a sub-study (n=20) of Johnson & Johnson’s Phase 1/2a COVID-19 vaccine trial showed that,The humoral and cellular immune responses elicited by a single dose of the Ad26.COV2.S vaccine persisted for at least 8 months, which is the latest time point recorded in the study to date.. Data show that T cell responses (including CD8+ T cells that identify and destroy infected cells) persisted over the 8-month observation period, indicating that vaccination can enhance T cell immunity against the virus and its variants.
Head of Vaccine Research, Johnson & JohnsonJohan Van Hoof indicates,Individuals who have received this vaccine do not require further vaccination within one year of administration; even if additional doses are necessary, the vaccine formulation does not need to be modified.。Currently, the company plans to release clinical trial data for the two-dose vaccine regimen at the end of August.
References:
[1]https://mp.weixin.qq.com/s/KxuvwgUKedPlbLSjWm8I_A
[2] Johnson & Johnson Single-Dose Vaccine Protects Against Delta Variant for Over 8 Months