There may soon be several effective vaccines available to fight Covid-19.
But while many people want an injection as soon as possible, others are worried about putting something unknown in their body.
How do we know that a vaccine is safe?
This is the first and most important question scientists ask themselves when they start to design and test a new vaccine or treatment.
Safety testing begins in the laboratory, with tests and research in cells and animals, before moving on to studies in humans.
The idea is to start small and only move on to the next stage of testing if there are no outstanding security issues.
What is the role of testing?
As long as the laboratory safety data is good, scientists can verify that the vaccine or treatment is also working.
This involves testing a large number of volunteers.
Half get the vaccine and the other half get a sham or placebo dose. Researchers and participants are not informed which group is which until the results have been analyzed, to avoid bias.
All work and results are independently verified and verified.
The Covid vaccine trials have gone at breakneck speed, but they haven’t skipped any of those steps.
The Oxford / AstraZeneca Covid vaccine trial was voluntarily suspended at one point to determine why one participant – in several thousand – had died. He restarted once it was clear he was not related to the vaccine.
Who approves vaccines or treatments?
Approval for a vaccine will only be granted if the government regulator (the Medicines and Health Products Regulatory Agency or MHRA) is satisfied that it is both safe and effective.
After approval, checks continue to ensure that there are no other side effects or long-term risks.
If anyone suspects that they are suffering from a side effect of a vaccination, they can report it to the MHRA.
What do Covid vaccines contain?
Many Covid vaccines are in development.
Some contain the pandemic virus itself in a weakened form.
The Oxford AstraZeneca vaccine uses a harmless virus modified to look much more like Sars-CoV-2 – the virus that causes Covid-19.
The Pfizer / BioNTech and Moderna vaccines use pieces of genetic code to elicit an immune response and are called mRNA vaccines.
These do not affect human cells. They only present the body with instructions to boost immunity against Covid.
Some Covid jabs contain coronavirus proteins.
Vaccines sometimes contain other ingredients, such as aluminum, which make the vaccine stable or more effective.
Will a vaccine make me sick?
There is no evidence that any of these ingredients are harmful when used in such small amounts.
Vaccines don’t give you sickness. Instead, they teach your body’s immune system to recognize and fight the infection they were designed to protect against.
Some people experience mild symptoms, such as muscle pain or a slight fever, after being vaccinated.
It is not the disease itself, but the body’s response to the vaccine.
Allergic reactions to vaccines are rare. For any approved vaccine, the ingredients will be listed.
Be aware that anti-vaccine stories are being disseminated online through social media. These may not be based on scientific evidence.
Is it safe for someone who has had Covid to get vaccinated?
If a vaccine for the coronavirus is approved, it is likely that people will still be offered the vaccine even if they have already had Covid-19.
This is because natural immunity may not last long, and vaccination may offer more protection.
How animal friendly are vaccines?
Some vaccines, such as the shingles vaccine and the nasal flu vaccine for children, may contain pork gelatin.
And some vaccines are grown on chicken eggs or cells from chicken embryos.
Hundreds of Covid vaccines are in development. We don’t have details on each ingredient yet, but many Covid vaccines are expected to be vegetarian or vegan.
If everyone gets vaccinated, surely I don’t need to worry?
There is overwhelming scientific evidence that vaccination is the best defense against serious infections.
Covid vaccines appear to be keeping people from getting seriously ill and could save lives.
The first doses that become available will likely be offered to those with the greatest need – such as the elderly – who could become seriously ill.
It is not yet clear what protection vaccines could offer to prevent people from spreading Covid.
If they can do it well, vaccinating enough people would eliminate the disease.
What should I know about the coronavirus?