How does the Oxford / Astra Zeneca vaccine against Covid-19 work?

The anti-Covid vaccine, produced by the University of Oxford and the AstraZeneca company, received approval on Wednesday for mass distribution in the UK. But how does this vaccine work? The vaccine, called ChAdOx1 nCoV-19, uses a harmless and debilitating version of a common virus that causes a cold in chimpanzees.

Researchers have already used this technology to produce vaccines against a number of pathogens including influenza, Zika and Middle East Respiratory Syndrome (MERS). Scientists have transferred to the vaccine the genetic instructions for the riveted protein, which coats the coronavirus from the outside, and which it needs to invade cells.

When the vaccine enters cells inside the body, it uses this genetic code to produce coronavirus protein. This induces an immune response, starting the immune system to attack the coronavirus if it infects the body. The virus is genetically modified, so it is impossible for it to grow in humans.

How effective is the Oxford vaccine? Data published in the medical journal The Lancet in early December showed that the vaccine was 62 percent effective in preventing Covid-19 among a group of 4,440 people who received 2 standard doses of the vaccine, compared with 4,455 people who received a placebo medicine.

Of the 1,367 people who received half the first dose of the vaccine followed by a second full dose, 90 percent had protection against Covid-19 when compared to a control group of 1,374 people. The overall Lancet data, which was reviewed by colleagues, presents complete results from clinical trials with more than 20,000 people.

In an interview with the Sunday Times, AstraZeneca chief executive Pascal Sorio suggested that other data submitted to the regulatory authority showed that the vaccine could have a 95 percent efficacy achieved by Pfizer / BioNTech and Moderna vaccines. .

"We think we have understood the winning formula, and how to be effective after two doses," he said. Among the people given the placebo drug, 10 were admitted to hospital with coronavirus, including 2 in severe form, with one dying.

Por midis atyre që u vaksinuan, nuk kishte shtrime në spital ose raste të rënda. Por a funksionon kundër llojit të ri mutant të koronavirusit? Profesori i Oksfordit Endrju Polard thotë:”Për momentin nuk ka asnjë provë që vaksinat, nuk do të funksionojnë kundër një varianti të ri, Por kjo është diçka që duhet ta shohim hap pas hapi. Ne nuk mund të jemi të vetëkënaqur për këtë variant, ose ndoshta edhe variantet e së ardhmes.

Një nga gjërat më të rëndësishme që shkenca duhet të vazhdojë të bëjë tani ndërsa ecim përpara, është të monitorojmë viruset që janë përreth, dhe të sigurohemi që vaksinat janë ende jenë efektive kundër tyre”- theksoi ai.

Po si u krijua “kaq shpejt” vaksina e Oksfordit, dhe a është e sigurt? Kjo vaksinë (ashtu si ajo e Pfizer) është zhvilluar më shpejt se vaksinat e tjera, për disa arsye. Asnjëra prej tyre nuk ka të bëjë me mungesën e sigurisë apo djegien e etapave. Së pari, puna për një plan për të trajtuar pandeminë tjetër të madhe në botë nisi vite më parë, me shpërthimin e Ebolës në vitet 2014-2016.

Ndërkohë financimi është një element kryesor për zhvillimin e vaksinave. Dhe paratë ishin me bollëk. Për më tepër vaksina ka nisur të testohet tek njerëzit që në prill. Dhe që atëherë, vaksina i ka kaluar të gjitha fazat e nevojshme. Faza e tretë përfshiu 30.000 vullnetarë.

But how does the Oxford vaccine differ from the Pfizer-BioNtech vaccine? It does not need to be stored at -70 degrees Celsius as the Pfizer vaccine does. Andrew Hayward, professor of epidemiology at Infectious Diseases at University College London, says it will make "a big difference". "This means that we can take vaccines where they are needed, instead of bringing people to confined places where we can distribute them," he said.