The story at a glance
- Johnson & Johnson is a safe and effective coronavirus vaccine.
- Data suggests it may be less effective than mRNA vaccines from Pfizer/BioNTech and Moderna, but it may have long-lasting and long-lasting efficacy, according to a new study.
- A CDC study finds that a J&J vaccine with one mRNA booster shot was more effective than two J&J shots in preventing hospitalizations during the recent omicron wave.
The Johnson & Johnson coronavirus vaccine, also known as the Janssen vaccine, is given as a single injection, but a booster dose is recommended two months later, according to the Centers for Disease Control and Prevention (CDC). Overall, the efficacy of the Janssen vaccine appears to be lower than that of mRNA vaccines from Pfizer/BioNTech and Moderna. Recent studies have provided insight into vaccine durability and recommended booster shots.
Several studies of efficacy against severe COVID-19, hospitalizations and deaths show that one dose of Janssen is less effective than two doses of either mRNA vaccine. This has been noted and suspected by health officials since last year. However, these studies only include a single dose of Janssen, not the booster dose two months later. They were also conducted before the emergence of the omicron variant.
New studies on the durability of vaccine efficacy and booster combinations add to what we know. A study uploaded to a preprint server in January suggests that there is a decrease in protection against hospitalization in the Pfizer/BioNTech and Moderna vaccines after five months after vaccination, but no evidence of a decrease in protection against the Janssen vaccine.
Infection protection began to decline in the second month for people who received the Pfizer/BioNTech or Moderna vaccines. For the Janssen vaccine, protection against infection began to decline after the fourth month.
Protection against hospitalizations began to decline for the Pfizer/BioNTech vaccine at month two and for Moderna at month three. The research also suggests that protection against intensive care unit admissions remains the same for all three vaccines.
However, there are some limitations to the study. The data is from January 1 to September 7, 2021, so it does not take into account whether people were exposed to new omicron variants. This study has not yet gone through the peer review process for publication in an academic journal, so the results should be taken with a grain of salt.
This week, the CDC published a study on the effectiveness of combining a Janssen primary dose with a Janssen booster dose compared to mRNA booster doses. During the omicron wave, people who received one dose of Janssen and an mRNA booster had better protection against hospitalizations than people who received two doses of Janssen. The study authors include the caveat that the median time from the most recent dose to a medical event was between 48 and 59 days and the maximum was 120 days. This study therefore does not take into account decline in protection or considerations of durability of vaccine efficacy. They also had a small number of Janssen recipients and that might mean we’re not seeing the full picture.
The CDC recommends that people who received a primary dose of the Janssen vaccine follow up with a booster dose of an mRNA vaccine at least two months later, or receive a booster dose of the Janssen vaccine if other vaccines are not available. or that they cannot obtain a vaccine mRNA for any other reason.
Posted on March 31, 2022