There is a lot of excitement about the new vaccines from AstraZeneca, Moderna and Pfizer as they have got some great results.

It was thought that these vaccines would be 40% to 50% effective, so the fact Pfizer has been able to achieve a 90% effectiveness rating is a really positive signal.

How does the vaccine work?

This vaccine is unlike any that has been developed in the past. It's based on a new technology called messenger RNA (mRNA).

Instead of using a piece of the virus, or a dead virus, this vaccine actually puts in the genetic code into the body which is deemed to be much safer.

The body thinks that the virus is there, thinks it's being attacked, and it mounts an immune response with antibodies and hopefully t cells as well.

If licensed, this will be the very first vaccine using this technology. It will also be the fastest one to have ever been approved.

The mumps vaccine was developed very quickly and that took approximately 5 years. This vaccine is only taking 1 year from the lab to use in humans.

How will it be distributed?

The world health organization has said that the most vulnerable people in every country must have the vaccine first which is going to include healthcare workers.

In North America, the first priority is going to be for care home residents and the people that work there because it has been very clear they have been at high risk for deaths from Covid-19. After that comes all healthcare workers and the over 80’s and then progressively younger and younger age groups down to the age of 50.

This is the first phase and the government scientists say this should cover 99% of people who are actually at risk of dying from this disease.

What are some limitations and concerns?

We haven’t had the full details yet from the clinical trials so there are a lot of things we don’t know. We don’t know if it works differently in different age groups,  we don’t know how long the effects of vaccination are going to last.

Crucially we don’t know if the vaccine is going to stop transmission of the disease. We know that it stops people from becoming ill, but we don’t know if it stops them from becoming infected and we don’t know if it stops them infecting other people, ie: transmitting to others.

This vaccine does have one major drawback, it has to be stored in what’s called ultra-cold chain, meaning it has to be stored in freezers at around -70 to -80 degrees, so that will be a serious problem for some of the low income countries who certainly don’t have freezers of that sort. It may even be a problem for some of the affluent countries who will have to step up their cold chain.

The other challenge is people will require two doses of this vaccine, three weeks apart. That means that you won’t be protected for about 28 days after the first injection because it takes about 7 days to take effect.

There is a lot of concern about these vaccines simply because of the speed they are being developed but the regulators have said they will not cut corners as safety is their number 1 priority.

Do we still need other vaccines?

The USA has pre-ordered 100 million doses of this vaccine while Canada has agreed to buy a “minimum” of 20 million doses of Pfizer’s vaccine. The government and the company have also struck a deal allowing Canada the option to buy another 56 million doses.

Pfizer has said they will manufacture 50 million doses in 2020 and another 1.3 billion in 2021. This is clearly not enough for the 7 billion people on the planet, so we will need other pharmaceutical companies to step up with their vaccines as well.

Some vaccines will have strengths that others don’t. They will all be slightly different and some may work better in some populations than others. For instance, they may work better in the elderly population. Only time will allow us to gain this knowledge.

When will we go back to normal?

Life won’t be going back to normal just yet as there are a lot of people that need to get vaccinated and before that we don’t know all the details of how this vaccine will work.

However these are very promising results and much better than most people expected. There is definitely no doubt that we are on the road to normality, unfortunately we just don't know how long that road is.