As coronavirus waves surge everywhere, with the only possible relief in hand being the imposition of new restrictions, a welcome piece of news reached us yesterday. Pfizer and German partner company, BioNTech, announced early and preliminary results that indicated that their vaccine was more than 90% effective.
Late-stage clinical trials for this vaccine commenced in July. There were almost 44,000 participants and half received the vaccine and the other half, a placebo (saline). The study then observed how many contracted COVID-19. Thus far, 94 participants became sick. An independent board of experts with an early analysis suggested that the vaccine is over 90% effective. The data was “blinded” - to date only the independent board knows how many of the 94 people got vaccine or placebo.
This is an excellent result, as the bar had been internationally set at 50% efficacy for vaccine makers for this early vaccine release under emergency authorisation. Thus far, for this particular vaccine, there were no safety concerns reported. Once rolled out with emergency authorisation, those vaccinated will continue to be monitored so as to ensure that there are no very rare side effects. Participants in this particular trial will also be more closely monitored for two years. This vaccine is administered as an initial dose, followed by a booster three weeks later. This particular trial will continue until 164 participants have contracted COVID-19.
Pfizer has stated that it could have 30-40 million doses of the vaccine before the end of the year (enough for 15-20 million people). It is likely that the vaccine will be prioritised for groups that are at higher risk for infection (such as healthcare workers) and the more vulnerable. Pfizer also say that they could ramp up production to 1.3 billion doses annually. Pfizer’s vaccine is an RNA vaccine that induces the body’s own cells to make a crucial viral protein against which the immune system mounts an antibody response.
Three caveats
1. It is uncertain how well this vaccine works on the elderly.
2. It is uncertain how well this vaccine works on children – the youngest participants were aged 16. A new trial was launched last month on children down to the age of 12 and as this progresses, additional trials are planned that will progressively reduce participant age.
3. It is uncertain for how long the vaccine will remain effective.
However, this is overall fantastic news that makes COVID-19 control all the more urgent, so as to reduce deaths and disability before the vaccine can start to roll out in large numbers next year. At the time of writing, there are 10 other vaccines in phase 3 trials across the world and if as effective, these should ensure more rapid global coverage.
We must continue to be careful while we go about our daily business: hand washing, masks, distancing and avoiding large groups – now more than ever.