The Mail responded to the urgent questions regarding the Omicron-related Omicron version of Covid-19 on Sunday last week. This was in an attempt to provide some clarification and hopefully reassurance. The situation changed at lightning speed, just as it has with the pandemic.

Now, seven days later, with the world’s scientific community uncovering crucial data about the behaviour of Omicron, the UK Government has jumped into action with dreaded restrictions that we long feared would return. But what exactly do we know now that we didn’t last week? These restrictions are what they mean for you.

Here, leading scientists reveal everything you need to know about the picture right now – and what could be to come.

Do things turn out better or worse as expected or are we still in the dark?

Data published by Pfizer and BioNTech last week regarding Omicron looked alarming at first. Pfizer, BioNTech and others revealed that two doses of the vaccine they used were significantly less effective in preventing Omicron infection than previous versions. A South African study found that the vaccines are 41 times less effective in stopping people who have been fully vaccinated from becoming infected.

Prime Minister Boris Johnson, pictured in Downing Street on Wednesday, announced new restrictions - his Plan B - to counter the threat posed by the Omigcron

Boris Johnson, Prime Minister, was photographed in Downing Street, Wednesday. On Wednesday, he announced that he had added restrictions to his Plan B, which aims at countering the Omigcron threat.

Scientists are currently examining the new Omicron variant to determine the level of protection offered by vaccines

Researchers are currently investigating the Omicron variant in order to assess the degree of vaccine protection.

There were also positives. Crucially, Pfizer’s data suggested that two doses of the jab were still effective at preventing serious illness. While the number of protective antibodies – defensive cells that stop the virus from entering the body – fell sharply when exposed to Omicron, the number of T-cells – fighter cells that attack foreign invaders – did not.

Experts believe that the immunity system of someone twice-vaccinated would still be capable to neutralize the virus and prevent severe illness. Pfizer tested the effects of booster vaccinations and found that the amount of antibodies rose 25-fold, drastically reducing the chance of getting infected.

Based on these results, Ugur Sahin, founder of BioNTech, said: ‘We expect significant protection against Omicron in those who have received the third vaccine.’

Scientists expect similar outcomes to those of AstraZeneca and Moderna vaccines, although they are still being studied.

Professor Paul Hunter, an infectious diseases expert at the University of East Anglia, said: ‘Previous studies have shown that AstraZeneca and Moderna produce just as many antibodies and T-cells as Pfizer, so it’s very likely they will provide equally good protection against Omicron.

‘Mixing jabs provides a stronger response, so if you had two AstraZeneca jabs and a Pfizer booster you’re likely to be in a really great position to fight off this variant.’

South Africa has provided encouraging evidence that Omicron may be milder than previously thought. Gauteng Province is where Omicron first emerged. Infected persons are twice as likely to be admitted than they were in the Delta summer wave. The UK is likely to see a similar pattern but scientists warn it’s not certain because our population has aged and been exposed more variants.

On Friday, analysis by the UK Health Security Agency of Britons with the new variant suggested two doses of AstraZeneca and Pfizer vaccines provided ‘much lower levels’ of protection against infection compared with that provided against Delta, but it also suggested that booster jabs provided 70 to 75 per cent protection.

If experts are still saying it is too early to know much about Omicron, but that there’s no need to panic, why did the Government announce new restrictions?

It can be broken down into two main reasons: increasing the number of potential infections, and buying additional time to obtain boosters for millions more arms.

Although scientists believe that the Omicron variant won’t be more deadly than Delta for vaccinated people, they expect it to spread faster.

Thursday saw 448 Omicron cases in Britain, which brings the total to 1,265.

The substantial wave of Omicron infections, combined with the already above-average number of Delta cases, could cause figures to rise to record levels

Omicron-related infections and the high number of Delta patients could lead to record numbers.

According to this data, Omicron infection rates are expected to double every 3 days. It is predicted that it will be the most prevalent variant by Christmas.

Combining the above-average numbers of Delta cases with Omicron infections could result in record numbers.

And even if only a small number of these people become sick enough to be hospitalised – either they haven’t had a booster or have health conditions that mean they don’t respond to jabs – the figure will be high enough to overwhelm the NHS.

Many millions of Britons still remain unvaccinated.

So scientists believe that implementing some restrictions now will slow the virus’s spread, offering more time to get more people boosted.

Only about one third of British adults currently have their third dose.

Professor Martin Hibberd, an infectious diseases expert at the London School of Hygiene & Tropical Medicine, said: ‘We need to get those numbers up quickly. Any measures that buy us more time will help.’

Are you sure Plan B is enough to get out of a lockdown or will there be more?

Plan B won’t be enough to stop the prolific spread of Omicron, say experts. But that doesn’t mean we’re heading for another full lockdown.

This is unlikely. The saving grace isn’t the set of restrictions brought in by the Government, but the increased speed of the booster programme.

With most adults getting three jabs, it is unlikely hospitalisations could rise to the peak levels seen in January – of more than 4,000 a day.

‘The only way out of this is more jabs in more arms,’ says Professor Lawrence Young, a virus expert at the University of Warwick.

Omicron is growing in South Africa and scientists keep an eye on Omicron’s hospitalisations.

Plan B won¿t be enough to stop the prolific spread of Omicron, say experts. But that doesn¿t mean we¿re heading for another full lockdown, pictured here revellers enjoying a night out in Leeds

Plan B won’t be enough to stop the prolific spread of Omicron, say experts. But that doesn’t mean we’re heading for another full lockdown, pictured here revellers enjoying a night out in Leeds

‘If it causes hospitalisations to increase by even a small percentage, then the NHS will really feel it,’ says Prof Hibberd.

‘We already have an uncomfortable number of people in hospital with Delta – and this has a knock-on effect on non-Covid conditions. Cancer treatments will be cancelled as we make room for extra Covid patients.’

This is why the government has not ruled out any additional restrictions such as extending vaccination passports to public spaces.

Health Secretary Sajid Javid said: ‘We could have the Covid pass in more settings, we could have masks in more settings.’

Are vulnerable people supposed to continue shielding themselves?

Official Government position is that it’s not. Science agrees, acknowledging the grave mental health risks of self-isolation that was apparent in the two previous lockdowns. Omicron does not merit the risk of being taken again.

For those with conditions which make it less likely that they will respond to vaccinations (blood cancer patients for example), the health chiefs offer advice. You should only meet with those you are sure have been fully vaccinated. Avoid crowds and ask visitors for face covers. Practise social distancing. Ask friends to do a Covid test.

In light of Omicron, which may affect other people’s response to the jab, clinically vulnerable people, such as those with heart conditions and diabetes, may also wish to take precautions.

However, they might not be required to endure such extreme measures too long because new drugs are coming on line to replace the jab.

These drugs, molnupiravir/ronapreve are effective in reducing the chance of severe illness if taken promptly after a Covid-related infection.

Thursday’s announcement by the government stated that 10,000 patients in the UK who are clinically fragile would receive the drug via their GP. They are likely to be available to all patients who have clinically compromised status by the beginning of next year if they prove successful.

Is it possible for Covid vaccines to be made mandatory, and if so would that help?

It is unlikely that vaccines would be made mandatory – although the Prime Minister has not ruled it out. At last week’s press conference, Boris Johnson said that although he doesn’t want ‘a society where we force people to get vaccinated’, it may be time for a ‘national conversation’ about mandatory jabs as the UK can’t go on imposing restrictions because ‘a proportion of the population’ aren’t vaccinated.

The idea was dismissed by Mr Javid the next day, who stated that he didn’t want to take mandatory jabs. Downing Street has also downplayed the PM’s comments.

In the UK, just under 20 per cent of people aged over 12 have not received both vaccine doses

Just under 20% of the UK’s over-12-year-olds haven’t received both vaccine doses.

Austria, Greece, and other European countries will soon make mandatory vaccines for people over 60.

Just under 20% of adults over 12 years old haven’t received the vaccines in the UK.

This country is known for its long history of making medical intervention voluntary. Experts believe this partly accounts for the high levels of vaccination against other illnesses. The low take-up rate of flu jabs for children and young adults in the US stems from a rebellion against strict vaccination policies like banning non-jabbed students from schools. An EU-funded study examining the effect of mandatory vaccination in several countries, has not found a clear connection between it and an increase in take-up.

Dr Simon Williams, senior lecturer in people and organisation at Swansea University, says that while bringing in Covid passport systems may persuade those who haven’t had jabs to get them, mandatory vaccinations won’t necessarily change the mind of anti-vaxxers.

‘Vaccine mandates are unlikely to persuade those who are anti- vax or opposed to vaccines to get vaccinated,’ he says. ‘Mandates may have the opposite effect and encourage them to double down in their opposition.’

What will it take to get vaccine passports? What will be the enforcement process?

Any venue with more than 500 indoor and outdoor visitors in England, will have to legally ask them to produce proof that they’ve had two jabs.

Any venue that serves alcohol between the hours of 1am to 5am or has a dancing floor, other than weddings or family celebrations, is subject to this rule. The rule will affect nightclubs as well as concert halls, stadiums, and music venues.

Proof of vaccination will be in the form of what’s called an NHS Covid pass, downloaded on to a smartphone via the NHS app.

The pass can be printed or mailed to you by calling NHS 119. If you order a Covid pass this way, be aware that it is valid for only 30 days, after which you’ll need to order a new one.

Digital Covid passes, on the other hand, automatically update and don’t need to be renewed.

Scotland already has a similar passport program, as does Wales. In Wales, the rule extends to cinemas and theatres regardless of their number of visitors.

The Covid passport rules are not being enforced by Ministers. It’s also unclear if premises will be subjected to spot inspections.

What happens if my colleague, or someone with whom I live gets Covid now?

Gone are the days of entire families being cooped up inside when one member tests positive – if you’ve had two Covid jabs, that is.

Conforming to new rules, people who have been double-vaccinated will no longer be required to segregate themselves from anyone they have tested positive, if that person is someone they share a home with or had frequent contact with.

The same applies to under-18s who haven’t been vaccinated and those who have taken part in a Covid-19 vaccine trial. You can request a PCR testing via gov.uk in order to determine if the virus is present.

However, there’s a caveat. Contacts with Omicron-positive individuals must be isolated if they have been in recent contact. Contacts should call NHS Test and Trace and be instructed to self-isolate if this happens.

The Government last week announced that daily, lateral flow testing will replace the 10-day self-isolation for Covid-infected contacts. The exact date of when these tests will be in force is unknown.