I don’t want to put a damper on all this excitement, but need to make a plea to you all: please continue to wear your mask, to wash your hands regularly, to social distance and to follow the rules.

The fact is we are no different from where we were a few weeks ago. We still need to protect those with compromised immune systems who cannot be vaccinated as we do not know if we can still be spreaders. There is currently no evidence having had the vaccine will stop you getting the virus and passing it on. But one thing we do know is we are not fully protected after the first dose. Once you’ve had your first dose, I urge you to just pretend it didn’t happen.

I have heard stories about people who have been “hibernating” for almost a year who now feel invincible. They feel as though they have been let out of prison and I worry they may take risks they would not have taken before. I fully understand why they feel this way. They have been waiting eagerly to be invited for their appointment. When the day finally arrived, they prepared with anticipation to attend and had some exciting news for family and friends – “I’m getting my jab today”.

They had their vaccine and everything went so smoothly. They anticipated side effects, but only felt a heavy arm, which may even be psychological as they wanted an excuse to not have to do the dishes that evening. It takes a couple of weeks to build immunity, so they waited but started planning.

Meanwhile, they saw others starting to meet up again. They had been longing to go out and see loved ones. They have had the vaccine now, so they must be safe? No!

If you’ve only had the first dose then you are most definitely not immune. You cannot start meeting people again. You must not start hugging people again. In fact, if you have not had your booster dose, you might as well assume you have not been vaccinated at all.

Although we need to celebrate the fact these incredibly effective vaccines have been developed and were nothing short of amazing in terms of turnaround, there are already post-vaccine Covid cases emerging. Brit Colin Horseman, 85, was among the first in the world to receive the vaccine – the Pfizer-BioNTech version. After the first dose, according to the Pfizer data, he would have been only 52 per cent immune. He was due to receive the booster but sadly died two days prior to his appointment from Covid-19.

Let me explain very simply how the immune system works when you get vaccinated. When you have your first dose you start producing troops of B cells, which make antibodies. These cells are short-lived. Next, your immune system will activate an army of T cells, these are soldiers and trained to identify a particular pathogen and kill it. Some of these are called memory T cells and these are able to survive for a longer period of time. Some may be ten years and some may be for ever. This is why some vaccines require a top-up every few years and some last a lifetime.

When you are given your second, booster, dose there are already enough short-lived B cells, so your body can concentrate on mass production of T cells. After your booster dose, you end up with a larger and stronger army of T cells and memory T cells and to some extent a larger troop of memory B cells.

Let me also remind you there is controversy over the efficacy of doses.

Even once we have had the vaccines and they start preventing illness, we do not know if they also prevent transmission.

Some pregnant women, people who are allergic, with chronic medical conditions or low immune systems may not be able to have it. The main concern is vaccinated people may still be able to become infected without symptoms and spread it to others.

Achieving herd immunity with effective vaccines makes diseases rarer and saves lives – a high portion of the population needs to be vaccinated with both doses. The proportion that must be vaccinated against Covid-19 to begin inducing herd immunity is not known.

The percentage varies with diseases. Herd immunity against measles requires about 95 per cent of a population to be vaccinated. For polio, it is about 80 per cent.

Unfortunately, getting vaccinated does not instantly mean we can go back to how life was before. Until we have some level of herd immunity, it is now just another layer of protection. A couple of weeks after the first dose, you do get a partial immune response. A couple of weeks after the second, you will reach higher levels of immunity – all good news. However, just remember you may be a non-symptomatic spreader and it doesn’t mean you’re protected the minute the needle goes in your arm. So, my advice is to get your jab, then go back home and stay safe. Don’t fool yourself, just pretend you never had it.