Q&A Can we cut isolation, do boosters last, and what hope for 2022?

Q Why don’t we cut isolation to five days, as the US has?

A

American officials last week halved the recommended isolation period for people with asymptomatic coronavirus to five days. Amid a surge in cases – there are more than half a million new cases in America every day at present – it is hoped this will ease staff shortages, with officials arguing that a person is most infectious two days before and three days after symptoms develop. There was no requirement to test negative before ending isolation.

UK officials have resisted following suit, instead requiring people to isolate for seven days, with two negative lateral flow tests on days six and seven, a move virologist Professor Lawrence Young from the University of Warwick calls ‘the right approach’.

He says: ‘There is no evidence supporting not being infectious after five days, particularly in the absence of a negative test. It’s very risky.’

He adds that Covid does not have ‘an off switch’ and that infectiousness gradually reduces over time, from a peak, around the time when symptoms develop, to nothing. Some people might still be infectious after five days.

US officials recommend that a mask be worn when around others for five days following isolation.

Dr David Strain, a senior clinical lecturer at the University of Exeter Medical School, says: ‘Masks reduce the spread by 80 per cent to 85 per cent. An 80 per cent reduction, by someone testing positive five days earlier who still has some virus, is still putting people at risk.’

Anecdotally, patients have reported night sweats and low appetite with Omicron – symptoms that are not officially listed by US officials.

Professor Andrew Preston, a biologist at the University of Bath, says: ‘Trying to balance the risks and harms has been at the heart of all the policies. It remains as difficult as ever.’

Q I’ve read that the booster lasts only ten weeks. Should I worry if I had mine longer ago than this?

A

As of Friday, every adult in the UK has been offered a booster – the programme began in September. But research does suggest that protection against Omicron begins to fade in just under three months. Among those who received two doses of the AstraZeneca vaccine, a booster of the Pfizer or Moderna vaccine was between 60 and 94 per cent effective at preventing symptomatic disease two to four weeks after the jab.

After ten weeks, the Pfizer booster was 35 per cent effective, and the Moderna booster 45 per cent effective.

Among those who received three Pfizer doses, vaccine effectiveness was 70 per cent roughly a week after the booster but dropped to 45 per cent after ten weeks.

At the same time, those who received an initial two-dose series of the Pfizer vaccine and then a Moderna booster seemed to have 75 per cent effectiveness after up to nine weeks.

However, Dr Clive Dix, former chairman of the UK Vaccine Taskforce, said this wasn’t necessarily cause for alarm.

‘To date the vaccines all protect against severe disease, including hospitalisation, and death. We should be optimistic that effectiveness against the latter two will remain.’

Q What’s going to happen with this pandemic in 2022?

A

Perhaps the most positive news is that the prevailing Omicron variant, thought to be responsible for many of the near-200,000 new cases a day in the UK, is less severe than the previous variant, Delta, with up to a 70 per cent reduced risk of being hospitalised. Viruses can evolve to be milder. However, widespread immunity from vaccinations is likely to be driving the reduced hospitalisations, say experts.

Dr Strain said: ‘We only have young unvaccinated people in our ICU.’

Even so, eight Nightingale ‘surge hubs’ are being set up across England to cope with an expected spike in demand.

Some 11,452 patients with coronavirus were on wards in England on Thursday – up by 61 per cent in a week.

However, Chris Hopson, head of NHS Providers representing hospital trust leaders, told

The Times: ‘Although the numbers are going up and going up increasingly rapidly, the absence of large numbers of seriously ill older people is providing significant reassurance.’

Dr Strain said: ‘I’m hoping by the time we’re further into the Greek alphabet [with naming new variants], we will see a version that is no more severe than the common cold. I don’t think we’re there yet.’