A coronavirus vaccine developed by the University of Oxford seems safe and provides an immune response to the virus. The study, which involved 1,077 people, shows that the injection made antibodies and T cells able to fight the virus. The findings are very promising, but it is still too early to know for sure, as an even larger number of people must be involved. The UK has ordered 100 million doses of the vaccine.
How does the vaccine work?
The vaccine, called ChAdOx1 nCoV-19, is evolving at breakneck speed. It is created by a genetically engineered virus, which causes the common cold in chimpanzees. It has been heavily modified to achieve the final result, firstly so as not to cause infections in humans and "look" more like a coronavirus.
The scientists did this by transferring the genetic instructions for the "spike" protein of the coronavirus, which is the main tool it uses to invade our cells, into our vaccine. This means that the vaccine resembles the coronavirus and the immune system can learn how to attack it.
What are antibodies and T cells?
The biggest focus on fighting the coronavirus has been on antibodies, but they are only part of our immune defenses.
Antibodies are small proteins made by the immune system that attach to the surface of viruses. Neutralizing antibodies can inactivate the coronavirus.
T cells are a type of white blood cell. They help coordinate the immune system and are able to detect which of the body's cells are infected and destroy them.
Almost all effective vaccines contain both: antibodies and T cells.
T cell levels peaked 14 days after vaccination and antibodies peaked 28 days after vaccination. The study did not last long enough to see how long each of them might eventually last. According to the results, 90% of people developed neutralizing antibodies after a dose. Only 10 people were given two doses and all the people in the study produced neutralizing antibodies.
"We do not yet know the level of protection needed, but we can maximize the level of protective response with a second dose," said Professor Andrew Pollard, of the Oxford Research Group.
Is it safe?
Yes, the vaccine is safe, but it has some side effects, especially dangerous. During the study it was found that 70% of people had a fever or headache. Researchers say this can be easily managed with paracetamol.
Professor Sarah Gilbert, of the University of Oxford in the UK, says: "There is still a lot of work to be done before we can confirm whether our vaccine will help manage the Covid-19 pandemic, but these early results are very promising. "
What are the next steps?
The study could not show whether the vaccine could prevent people from getting sick or even reduce their Covid-19 symptoms.
More than 10,000 people will take part in the next phase in the UK. However, the study will also focus on people from other countries, as coronavirus levels in the UK are low, making it difficult to know whether the vaccine is effective or not. It will involve 30,000 people in the US, 2,000 in South Africa and 5,000 in Brazil. Some challenging experiments are also being considered, such as intentional coronavirus infection of vaccinated persons, but this includes a number of other ethical concerns.
Will we be able to get a vaccine?
Sure, the vaccine will be fully ready by the end of the year, however, it will not be widely available. Priority will be given to hospital staff and people at risk of Covid-19 due to their age and medical condition. While, if all goes well, vaccination could spread widely next year.
On the other hand, Boris Johnson, the British Prime Minister, says: "Obviously I am hoping for the best, but to say that I am 100% sure that we will have a vaccine this year or next year, seems to me an exaggeration."
Source: BBC
