** Update April 14: Janssen stops delivery to Europe when six thrombus cases are detected in the US and are being investigated.
This week the first 300,000 doses of Janssen’s vaccine arrive in Spain, the first single-dose applied in Spain and which will give a new boost to vaccination campaigns. This vaccine will be used in parallel to the other three, prioritizing the older age groups, so it will foreseeably begin to be applied to the group between 70 and 79 years old and in parallel with the mRNA vaccines. Furthermore, according to the latest update of the Ministry of Health’s vaccination strategy, “ it will not be used in people who, due to a history of SARS-CoV-2 infection, only require one dose . There is no contraindication for this, but it will be preferred to use the other vaccines that usually have a two-dose regimen ”.
Characteristics of the Janssen vaccine
The Janssen vaccine is indicated for active immunization to prevent COVID-19 caused by SARS-CoV-2 in people over 18 years of age. This drug uses a technology similar to that of AstraZeneca and Sputnik V: by means of DNA recombination techniques, a non-replicative human adenovirus type 26 vector (Ad26) is produced, which cannot cause infection but includes genetic material that codes to produce the famous protein S from the SARS-CoV-2 virus, which activates the body’s immune response.
Another advantage of this vaccine is its conservation and transport: it can be kept at a temperature between -25 ° C and -15 ° C for two years. Once removed from the freezer, the unopened vaccine can be stored refrigerated between 2 ° C and 8 ° C, protected from light, for up to 3 months, facilitating logistics in a mass vaccination scenario.
Janssen vaccine efficacy
Clinical trials have not included people with immunosuppression or pregnant women, but they have included people over 65 years of age and people with diseases such as obesity, hypertension, diabetes, stable HIV infection, severe heart disease and asthma.
Protection begins around 14 days after vaccination and the results of clinical trials available so far report an efficacy of 66.9% for all ages. In addition, this efficacy increases to 82.4% in the group over 65 years of age . The efficacy of the vaccine against severe COVID-19 was 76.7% at 14 days after vaccination and 85.4% at 28 days. The World Health Organization has recommended its use also in countries where new variants of COVID-19 circulate.
Side effects
The most common side effects are similar to those of other COVID vaccines: injection site pain, headache, fatigue, nausea… Most adverse reactions occurred within 1-2 days after of vaccination and were of mild or moderate intensity and of short duration.
The European Medicines Agency is also investigating the appearance of four cases of blood clots (the same reaction that is being studied in the AstraZeneca vaccine). One occurred in a clinical trial and the other three during the vaccination campaign in the US, where more than 5 million people have already received the Janssen vaccine.
