When the Coronavirus pandemic hit at the start of 2020 countries around the world knew that one of our most powerful weapons in the fight against COVID-19 would be a vaccine.
The problem facing leaders, scientists, and policy-makers was that vaccines typically take years if not decades to develop and roll-out. Thankfully, a coordinated and concerted global effort has resulted in several COVID-19 vaccines being available after only 12 months. Here we look at the vaccines that are available for the coronavirus known as COVID-19 and how they work to protect us.
COVID-19 vaccines: what’s currently available?
At the moment, in the US, there are two vaccines currently authorised for use.
- Pfizer-BioNTech COVID-19 vaccine
- Moderna COVID-19 vaccine
Pfizer-Bio-NTech were the first to announce results from their phase 3 COVID-19 vaccine trials. The Pfizer-BioNTech trial data showed 94% effectiveness in over 65s. Rollout of this vaccine has already started in countries such as the US and the UK.
Moderna announced the results of its phase 3 trials hot on the heels of Pfizer-BioNTech and the data were similarly impressive. Moderna’s vaccine showed 95% effectiveness among the 30,000 trial participants.
There are three further vaccines undergoing phase 3 trials in the US, including one from Janssen, Novavax, and the Oxford AstraZeneca vaccine that has been approved for use in countries such as the UK. A vaccine developed by Russian scientists called Gamaleya has been approved for use in Russia, however, questions remain about the level of its effectiveness. In total, there are more than 50 vaccines in trials so our hopes of stopping this pandemic have never been higher.
COVID-19 vaccines: how do they work?
The two vaccines currently approved for use in the US are both mRNA vaccines. This is a new type of vaccine that has been shown to be incredibly effective, not least because they are relatively cheap to manufacture.
Traditional vaccines contain a weakened version of the virus we’re trying to protect ourselves against. This is used to trigger an immune response so that if and when the virus does enter the body, our immune system can recognise it and defeat it.
mRNA vaccines are considered more sophisticated because they send a set of instructions to our cells. In this case, the instructions are to replicate the protein spikes found on the surface of COVID-19. Once the vaccine virus is inside our cells, our cells’ protein-making functions recreates the spikes. This in turn triggers the immune system’s white blood cells to attack the spikes. The immune system remembers these spikes so, in the case of infection with COVID-19, it knows what to do to keep us from becoming sickened.
For both of these vaccines, two doses are required within a 28-day timeframe. Although the first dose does offer a level of protection against COVID-19 after day 12, the second dose is required between day 21-28 to achieve the effectiveness seen in the trials.