COVID-19 briefing – December 2021

Our Chief Medical Officer Dr Mark Simpson addresses the Omicron variant and the vaccination programme.

The situation in the UK is changing at a fast pace in terms of COVID-19 case rates, and there will be significant challenges from now until Spring 2022.

And while none of us have a crystal ball, I’d like to share my thoughts on the nature of these emerging issues.

 

Virus variants

Delta had remained the predominant variant accounting for approximately 99.8% of sequenced cases in England from 10 October to 22 November 2021. However, the detection of the Omicron variant on 25th November will change this picture.

Although the majority of new infections will continue as Delta at present, it is likely that this will be replaced by Omicron in the coming weeks.

Initially detected in South Africa, this variant contains a “unique constellation” of more than 30 mutations to the spike protein - the component of the virus that binds to cells. This is significantly more than in the delta variant.

Many of these mutations are linked to increased antibody resistance, which may affect how the virus behaves with regard to vaccines, treatments and transmissibility.

At present, intensive research is being undertaken to look at these factors and this will inform future government actions. The initial clinical experience has suggested that this variant causes relatively mild symptoms for those who are fully vaccinated.

This further underlines the importance of full vaccination and booster doses when needed. The UK government has accelerated its booster programme in recognition of this urgent need.

The previous controls (mask wearing, social distancing and hand washing) that have been in place will continue to be helpful in reducing the risk of infection. Despite the inevitable – and understandable “Covid fatigue” with such measures, it is important that we comply with them until there is a better understanding of the risks posed by Omicron.

I would estimate that we will be in a much better position in the next four weeks to understand much more about the variant behaviours described above.

 

Therapeutic Interventions

Vaccines

Vaccine development continues across all the major interventions – RNA (e.g. Pfizer, Moderna), viral vector (e.g. AstraZeneca) and inactivated (Sinovac).

The main aim will be to increase the duration of antibody response, and also to quantify the T-cell activation - which provides longer-lasting protection than antibody production alone.

It is likely that enhanced vaccines providing higher levels of protection against the newer variants (especially Delta and Omicron) will become available in 2022. If based on existing vaccines, it is also likely that the clinical trials phase can be shortened - allowing earlier access to distribution.

The thorny issues of mandating vaccination and the requirement for vaccine passports will continue to be debated.

In some countries, such as Germany, employers are distancing their workforces dependent on vaccination status. This includes access to different workplace canteens and communal eating areas.

Austria is moving towards mandating compulsory vaccination for all its citizens and other countries are now giving serious consideration to taking similar actions.

The winter will continue to see a steady decline in protection for those individuals who have not had a booster vaccine - and this may lead to an increase in hospitalisation and deaths in this group over the coming months.

Global vaccine rollout needs to ramp up, but many third world countries have significant vaccine scepticism - which also needs to be addressed to ensure limited supplies do not go to waste.

 

Therapeutics

Trials of established anti-viral medications such as remdesivir have been disappointing, however new bespoke Covid drugs are showing greater promise. These are given at home to those who are vulnerable on confirmed diagnosis - rather than waiting for hospital admission.

Recent announcements have given further cause for cautious optimism.

Ronapreve uses a pair of laboratory-made antibodies to attack the virus and was approved for use in the UK in August 2021. However, it is expensive at £1,000 to £2,000 per course, and requires intravenous administration. It may also be less effective against the Omicron variant strain.

Molnupiravir shows greater promise, as it is taken orally as soon after confirmed diagnosis as possible.

It works by introducing errors into the virus’s genetic code, and clinical trials have shown a 50% reduction in hospitalisation or death in mild-to-moderate COVID-19 among at-risk individuals. It was licensed in the UK in early November 2021.

The UK has now agreed to purchase 480,000 courses - with the first deliveries expected in November.

Initially it will be given to both vaccinated and unvaccinated patients through a national study, with extra data on its effectiveness collected before any decision to order more.

Paxlovid is in the final stages of approval. It is produced by Pfizer and is known as a protease inhibitor, thus having a different mechanism to molnupiravir.

Clinical trials have suggested that it cuts the risk of hospitalisation or death by 89% in vulnerable adults. The UK has ordered large stocks of this drug, pending regulatory approval.

However, it cannot be stressed highly enough that vaccination remains the most-effective intervention we have to tackle COVID-19. These drugs are no substitute for vaccination.

We know some people, especially the more vulnerable with underlying health conditions, remain susceptible to COVID-19 - and these drugs will significantly reduce the chances of hospitalisation - while helping to ease the pressures on the NHS this winter.

 

Flu

In the 2020 to 2021 season, extremely low levels of influenza activity were seen across the UK - largely due to lockdown measures preventing infection.

There is concern that loss or reduction of natural immunity will lead to a flu epidemic this winter - placing additional pressures on care facilities.

We also know that having flu and COVID-19 doubles the risk of death. Despite some supply challenges, this year has seen the largest-ever flu vaccination campaign - with the widened eligibility retained from last year.

If there is a significant flu outbreak, hospitals in all countries will face infection control challenges in diagnosing and then separating those with flu and Covid, to try to prevent cross infection.

The use of masks in crowded settings, hand hygiene and social distancing where possible will help to reduce the risks of catching both flu and COVID-19.

 

Testing

The UK Government and those of France and Germany have talked about ending the blanket provision of free lateral flow tests. However, my best guess is that this will continue until Spring 2022 at least.

As above, it will become even more important to differentiate between flu and COVID-19 – which can present with similar symptoms – over the coming months.

 

Dr Mark Simpson, Chief Medical Officer

Health Management