One dose of a Covid-19 vaccine may not solve the problem
University of Brighton virologist Dr Sarah Pitt believes more than one dose of a potential Covid-19 vaccine, or boosters, are likely to be needed to help wipe out coronavirus.
Nine potential vaccines are currently at the final phase 3 trial stage, which involve thousands of people around the globe. While these are at an advanced stage, Dr Pitt has also warned nations and pharmaceutical companies not to rush through a vaccine for the advantage of geopolitical gain.
In an interview with the university, Dr Pitt, Principal Lecturer in the School of Pharmacy and Biomolecular Sciences, said: “There are very careful safety precautions, which all have to be met, before a vaccine can be approved for use. There is no doubt there are political pressures in the race to be the first, and there are then further pressures on scientists to do their work faster and speed up the process. Biology does not work like that.
“It just takes time. My big concern is that a rushed vaccine can lead to issues in trust, however good it might turn out to be. We have seen a rise in the anti-vaccination movement – this needs to be reversed and that comes with safety guarantees and effective messaging from governments. If there are doubts about a Covid-19 vaccine, will people stop taking other, completely safe vaccines, like polio? We need to be careful”.
When, or if, a vaccine is approved, Dr Pitt believes one dose might not be sufficient to make the world’s population immune: “You may need at least one booster. First of all, you would need to vaccinate everyone in the whole world, because it is so infectious.
“But then because of the way the virus behaves and the nature of what the vaccine is protecting against, you will probably need a booster – so that means 10s of billions of people will need two doses within something like 12 months. The initial version might work, but we have seen cases where people have tested positive for SARS-CoV-2 more than once, so you will need a top up.”
Even if there is a vaccine, Dr Pitt says measures such as social distancing and the wearing of face coverings will be needed for some time and may be something people will have to get used to for years to come. She does, however, offer a hint of optimism.
Dr Pitt said: “If we have one dose of a working vaccine, maybe by the mid-summer of next year we might be back to something like normal. But that depends on people taking the virus seriously – it’s very dangerous and it has not gone away.
“We have already seen measures brought back in across the world and more restrictions may need to come in before the situation gets better – we are no-where near close to the end of
this pandemic. I cannot stress enough how important it is to follow the basic guidelines of social distancing, wearing a face mask and washing your hands”.
Dr Pitt has previously discussed the possibility of the virus mutating to a version which may be less sinister, but she says there is no evidence of that yet: “It is mutating – but not in areas which really make any difference to the seriousness of its threat to humans.
“For a disease which has transferred from animals to humans, it is still very early. The virus and humans are, essentially, still getting used to each other. It will, I believe, eventually either die out completely, like we saw with SARS-1, or it come into equilibrium with us, but I stress it is not happening yet. This is still a very dangerous disease”.