COVID-19 Vaccines: Are they safe? For everyone? What do they mean for the pandemic?
November 27, 2020
This article has not been updated recently
Three vaccines have now announced promising trial results, bringing us all hope that the pandemic will be over soon, and we will all be able to resume our lives.
But how do they work? Are they safe? And when will we get back to normal?
To find out, Professor Tim Spector, ZOE COVID Symptom Study lead, spoke to leading immunologist, Professor Peter Openshaw from Imperial College London, to answer some of your top questions about COVID vaccines.
How do the vaccines work?
Four vaccines have announced successful large-scale clinical trial results so far:
The Pfizer-BioNTech vaccine uses mRNA, a messenger molecule that tells your cells to produce the coronavirus spike protein, which triggers an immune response. Showed 94% efficacy in clinical trials.
The Moderna vaccine is also an mRNA vaccine and showed 95% efficacy in clinical trials.
The Oxford-AstraZeneca vaccine uses a weakened harmless common cold virus which can’t replicate in your body to deliver genetic material to your cells, telling them to produce the COVID spike protein. It showed 70% efficacy in clinical trials.
The Sputnik V vaccine - also uses a weakened common cold virus to deliver genetic material. Showed 95% efficacy in clinical trials.
How can we be sure that COVID-19 vaccines are safe?
“Although they’ve been developed with incredible speed, safety has not been compromised,” says Prof Openshaw.
He likens normal vaccine development processes, which often takes years, to trying to drive a milk float across a city at rush hour. You inevitably sit in traffic, wait at lights, and maybe even run out of battery, so you have to stop to recharge halfway, which all slows you down.
“In this case, there’s been so much money poured into the process that it’s like the milk float has a police escort and all the traffic lights are on green,” he says. “But it doesn’t mean to say that the route that has been taken is any different. All the normal safety checks are in place.”
All vaccines undergo stringent laboratory testing before going into clinical trials in human volunteers, and researchers continue to monitor trial participants to check for any side effects and long term impacts.
How will COVID-19 vaccines affect different people?
Ahead of our webinar, many people raised concerns about how the vaccine might affect them if they have already had COVID-19, are suffering from long COVID, or have a pre-existing health condition.
“We have no reason to think that people who have antibodies because of natural COVID-19 infection would behave any differently from people who haven’t, except that they would have a higher baseline of protection,” says Prof Openshaw.
Right now, we can't be sure of the effects of the vaccine on people with long COVID, partly because we don’t fully understand what is going on with the immune system in people who experience long term symptoms. However, based on the evidence we have so far, Prof Openshaw doesn’t believe the vaccine would be harmful to people living with long COVID.
If you are in a high COVID-19 risk group due to an underlying health condition, you may be worried about how the vaccine will affect you as an individual.
But many of the vaccine studies were designed to include a wide variety of people with a range of risk levels, such as the elderly, pregnant women, and ethnic minorities so that they could observe if the vaccines are safe and effective in all these different groups.
We’ll know more about the effects of the vaccines on different groups when the full results are published, but right now, there’s no cause for concern.
When the time comes for national roll-out of vaccination, some people may be unable to receive a COVID-19 vaccine due to underlying health issues or allergies. In this case, your doctor will be able to advise on whether the vaccine is right for you.
How will COVID-19 vaccines change the course of the pandemic?
The UK government has taken out contracts to buy 340 million doses of COVID-19 vaccines, including the Pfizer, Moderna and Oxford vaccines, which is enough to cover the entire population.