Janssen vaccine: this is the drug that comes and immunizes in a single prick

Science

By CAPosts 10 April, 2021 - 10:20pm 2 views

The first vials of the vaccine from the pharmaceutical subsidiary of Johnson & Johnson arrive next week.AF

P The Minister of Health, Carolina Darias, said last Monday that on April 15 the first batch of Janssen vaccines would arrive in Spain. There are 300,000, but being single-dose it is as if 600,000 of the others arrived. Its main advantage is precisely that it only requires a single puncture. It has not yet been decided who will be the first to receive it, but the criteria for so far, age and risk of exposure will be followed. Shares technology with Oxford / AstraZeneca vaccines and Russian Sputnik. Highly effective, also against the new variants, on Friday the first dark clouds loomed over it: the European Medicines Agency (EMA) opened an investigation for four cases of thrombi after inoculation, although they are very rare: one case each 3.5 million vaccinated

What type of vaccine is it?

Janssen (a Johnson & Johnson affiliate) already had a candidate coronavirus vaccine in March of last year. They tested various formulations in the laboratory and non-human primates and found that their Ad26.COV2.S, as they have called it, generated enough neutralizing antibodies to stop the infection. To activate the immune system, it uses a viral vector, specifically adenovirus 26. It is a human virus, which causes colds, but here it has been modified to be safe. What it continues to do is produce the SARS-CoV-2 spike protein , endings that the coronavirus uses to sneak into human cells and infect them. In the case of the vaccine, it does not infect them, but it does activate the defenses. This viral vector is the same one on which the Oxford / AstraZeneca formulation is based. Also the Russian Sputnik is based on adenovirus, but uses two, Ad26 in the first dose and another, Ad5, in the second .

How did you get here?

The first human trials began last summer in the US and Belgium, with a small sample, to test its safety and its ability to activate the immune system. In September they began another already massive trial (phase III) in a dozen countries on three continents with almost 45,000 volunteers. In Spain they have recruited some 2,000 vaccinated volunteers in eight hospitals . Unlike other vaccines, from the beginning they included a significant proportion, around a third, of those over 65 years of age. In parallel, they have just expanded the sample to include several hundred young people aged 12 to 17 years .

Although the trials are still ongoing and will last a year, it has taken a relatively long time to determine the efficacy of the vaccine. In that global trial with thousands of participants, it demonstrated an efficacy of 66.9% at 14 days after the injection. The percentage rises to 85% when it comes to preventing the disease from progressing seriously or critically. And up to 100% protection against death. As for the duration of immunity, it has not been established, but the first vaccinated were in September last year. With these data, on March 11 last the EMA gave its approval to the results and the European Commission authorized its use.

How many doses will arrive?

To the 300,000 announced by the minister, up to five million will be added in this second quarter. Janssen and the European Commission agreed to purchase 200 million doses plus another 200 optional ones. With the problems that have occurred with the other vaccines and those that have fallen by the wayside, everything indicates that Brussels will exercise the option. Spain is responsible for the distribution of 10.47% of the vaccines of the centralized purchase. So it could go up to 42 million doses

Vaccines arrive frozen. Keeping them between -25º and -15º they can be kept for two years. But, unlike those of Moderna or Pfizer, it can be transported refrigerated between 2º and 8º, lasting up to three months in the refrigerator. Its distribution is made in vials of five doses of 0.5 milliliters each. Once out of the refrigerator it must be administered within 12 hours maximum. And after opening a vial, all five punctures must be used in three hours, otherwise it must be discarded.

Janssen and the European Commission agreed to purchase 200 million doses plus another 200 optional

Who will be vaccinated?

The vaccine is licensed for use in those over 18 years of age. The Government and the autonomous communities designed a vaccination strategy based on the criteria of age, degree of exposure and whether an essential function is performed. The plan is updated periodically as vaccines arrive or problems arise like the last one from AstraZeneca. In the last update of the document, on March 30, it is recalled that the Janssen vaccine, as it is a single dose, will not be administered to those who have already passed the covid.

Based on the age criteria, this vaccine will be injected at those that the strategy includes in group 5, that is, people who are vulnerable due to their age, over 65 years old, not residents of senior centers. Although, from the Ministry they assure that it has not yet been decided, but reality leaves little margin: Vaccination of those over 80 years of age with Moderna and Pfizer vaccines is well advanced. Meanwhile, AstraZeneca's has been reserved for those between 60 and 69 years old . So it is most likely that those between 70 and 79 years old are the ones who premiere Janssen's, followed by those under 60 most exposed and essential jobs such as health, security or education.

What risks does it have?

Like all drugs, it is not recommended for those allergic to any of its components. According to the information provided to the health authorities, the most frequent local adverse reaction was pain at the site of the puncture. Regarding systemic adverse reactions, one third of the trial volunteers had headaches, fatigue or myalgia. 10% also had some fever and nausea. These effects disappear in one or two days.

On Friday, the EMA announced an investigation into four cases of thrombosis in vaccinated with the Janssen inoculate. One occurred among participants in clinical trials, and the other three are Americans who have already been vaccinated. In the US they have been vaccinating with Janssen's since March 1. 10.6 million people have already been inoculated. That yields one case for every 3.5 million vaccinated.

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Source: Elpais

Science Coronavirus covid 19 Coronavirus Vaccines Vaccination Janssen

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