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There have been several news reports suggesting what the Prime Minister is set to announce this afternoon about introducing further restrictions in England.
Prof Adam Cunningham, Professor of Functional Immunity at the University of Birmingham, said:
“All the evidence points towards large numbers of people becoming infected with Omicron all across the globe. Because of this, there are additional concerns about Omicron that this is just the starting point for more variants to emerge, potentially maintaining its high levels of transmissibility but with maybe greater virulence. Each new variant deriving from Omicron could challenge the efficacy of any cumulative, existing immunity to infection we have obtained from vaccines or previous infections, slowing down how quickly we can emerge from the pandemic. A worrying possibility is if the profile of the groups at risk from infection were to change. For instance, children are relatively spared from severe disease after infection with the other variants, and hopefully this remains the case with the Omicron variant. Nevertheless, if the susceptibility of young children were to change, then it would alter how we approach the control of SARS-CoV-2 infections. The key point is that just because the virus has followed a particular pattern before, it does not mean this will be followed in the same way in the future.
“Early assessments suggest that antibodies induced after vaccination with the Pfizer vaccine give quite modest protection against infection. Most likely, because of T cells, there will be better protection by vaccines against the most serious presentations of COVID-19, but these are early days in our understanding of this. We do not know yet how the antibodies induced by the AstraZeneca vaccine will work, which is an area that needs addressing. Boosters most likely will enhance this protection, irrespective of whatever vaccine was given before, and really importantly, the benefit from boosting is likely to occur really quickly, within a few days of receiving the additional boost. It is likely that those who have been vaccinated and previously infected will have the best protection against Omicron, and it would be reasonable to think that a vaccine boost would help temper the spread and severity of infection with the Omicron variant.
“The appearance of new variants is not unexpected. What has been surprising has been the speed of appearance of Omicron and the sheer number of mutations observed in this virus. One possibility is that the variant emerged from an individual who was immunocompromised in one way or another and this individual acted as an incubator allowing the variant to develop over time. Another possibility, is that people with normal immune systems can maintain the virus for longer than we originally thought, or that it came from another source. If it did come from an immunocompromised patient then this would be especially concerning as it means such variants can emerge at multiple and near-random times in the future. That said, if infections with Omicron turn out to be less severe, and it’s a big if, then maybe evolving within an individual could help explain this. The overarching point is that the longer the pandemic continues, the longer infection rates are maintained at high levels, aided by low levels of vaccination and the limited use of other control measures, then the more likely that the groups at risk of severe disease may alter too. There are millions of new infections each month, which of course means we are more likely to see new variants emerging, each one challenging our ability to control these infections. Omicron shows why it is vital to vaccinate people, not just in the UK, but worldwide, as this virus does not respect borders.”
Dr Simon Williams, Senior Lecturer in People and Organisation, Swansea University, said:
“Aside from vaccines, working from home – for those who can – can help to reduce transmission by substantially reducing unnecessary contacts over the coming weeks.
“Data suggests that far fewer of us are working from home this winter compared to last, and so there is potential to significantly reduce the total amount of contact currently taking place. Research has shown how those who go into work have on average twice as many close contacts as those who don’t. Telling people to work from home has been shown to effectively reduce contacts. And if we reduce contacts we reduce transmission opportunities. Of course, working from home is much easier for some than others, and the government and employers also need to play their part to make working from home easier. The first step is clear and consistent guidance for employers and workers.
“Vaccine passports or covid passes have been controversial, and to date there is no clear evidence that they have worked to significantly reduce transmission or drive up vaccine uptake. Nevertheless, there is an argument that they remain a sensible precaution in theory to ensure that risk is reduced in venues (by showing that those entering are less likely to be infectious).
“Also, it is likely that many in the UK public will be supportive of additional Plan B measures. For example, a majority tend to support vaccine passports in the UK – and an added benefit would be that England’s policy would be brought more in line with the other three UK nations, and consistency and clarity are always good from the perspective of the public’s understanding of, and thus potentially compliance with, the rules.”
Prof Christina Pagel, Professor of Operational Research, UCL, said:
“With Omicron doubling every two or three days in England right now, it is on track to become dominant by Christmas and continue growing rapidly potentially putting huge pressure on the NHS which is already under immense strain. Plan B measures will not be enough to stop its path to dominance as the suggested measures won’t be enough to bring R under 1, but they will slow it down. The latest studies show that a third vaccine does will likely be needed for Omicron, just as the second dose was crucial for Delta. Every week we delay, allows another 2 to 3 million people to be offered the protection of that third dose. However, with many reports of superspreading Omicron events among fully vaccinated people, it is not clear that vaccine passports will do much to slow it down and risk distracting the government and the public from other more effective measures. In addition to Plan B protections such as work from home where possible and increased use of face masks, the government could extend support for those needing to isolate, require all household members (including children) of covid positive cases to isolate, urge the public to use FFP2 masks or higher and urge people to restrict their contacts in the run up to Christmas as much as possible. There also need to be urgent plans for how to prevent Omicron spreading through schools next term as Delta did this term. Rolling out vaccination for 5-11 year olds is a key step as is increasing the use of HEPA filters within poorly ventilated classrooms and other indoor school spaces.”
Prof Jim Naismith, Director of the Rosalind Franklin Institute, and Professor of Structural Biology, University of Oxford, said:
Does Omicron spread faster?
“The virus has two speeds Ro (roughly speed in a population of totally unvaccinated or infected people) and Rt (the current spread in the UK population which consists of vaccinated and infected individuals). Rt above 1 means the virus is spreading, the bigger the number the faster the spread.
“In terms of Rt, Omicron is significantly faster (higher Rt) than Delta in the South African population and early data suggest this will be true here. This is a critical measure of how fast the variant will spread in the population. The higher the Rt the faster the doubling time. (Any new future problematic variant will have a higher Rt than Omicron). Thus using selected travel bans in the future would be similarly likely to be ineffective. Omicron reached the UK before it was detected. In practice, international travel seems to be all or nothing activity. Similarly track and trace, local restrictions and voluntary / poorly implemented control measures have proven ineffective barriers to the disease.
“In terms of Ro we do not yet know, you might think it does not matter since such a population does not exist anymore. However, Ro does matter because it gives us a clue as to how effective social distancing, mask wearing etc will be. A full lockdown is effective against all plausible values of Ro, but as we saw with Delta, measures effective against a lower Ro variant were less effective against a higher Rt. As a guide the higher the Ro the tighter the restrictions required to lower the Rt to 1.
“Could Omicron have a lower Ro than Delta, yes this is possible. This would occur if Omicron was more able to evade immunity than Delta. Think of racing Usain Bolt, I could beat him over 100 m if he had to run in knee deep mud carrying weights while I was jogging on a smooth track. We will need to understand the extent to which Omicron evades immunity before we can estimate Ro.
Does Omicron evade immunity?
“Almost certainly it evades immunity to a greater degree than any other variant known but it does not appear to completely evade immunity (nor would we expect it to). Immunity is not an on and off switch. The evidence, still early, suggests that for previously infected and vaccinated people, the virus produces lower numbers of seriously ill people. The milder illness is a direct result of some immunity to the virus.
“This is currently true in the UK for Delta variant. Delta can to a limited extent infect vaccinated people but the disease is on average MUCH milder. We have had a high number of infections but relative to previous waves lower hospitalisation and death. Each death represents a tragedy for those left behind.
Does it cause a worse disease?
“For the unvaccinated, there is NO evidence that Omicron will be milder (or worse) than Delta.
Unvaccinated people continue to run risks of serious illness from Delta and soon Omicron.
Vaccination and thus immunity massively reduces the probability of serious illness and death.
What is the risk of Omicron and what can we do as individuals?
“The risk is it will spread quickly enough to fill up the hospitals and overburden the NHS, this will lead to people dying who would otherwise not. For those who once against advocate toughing it out, it would be helpful for them to estimate the cost benefit ratio.
“Get vaccinated be it your first, second or third shot as quickly as possible. Take steps to reduce transmission, we know ventilation, universal masking and social restrictions in combination are effective. These measures can buy time for vaccination. It is for elected politicians to impose restrictions not scientists.
When will this end?
Some combination of: enough immunity from vaccination and waves of infections for the disease to be so mild, hospitals will not fill and effective medicines that prevent serious illness. It is unlikely to disappear.
How can the end be made quicker?
“Vaccinate the world as quickly as possible, it is not enough to ship doses, we will need to give aid to get them into arms.”
Dr Simon Clarke, Associate Professor in Cellular Microbiology, University of Reading, said:
“Against the initial research we’re seeing on Omicron and a continued high level of Delta in the community, Plan B provides a patchwork of restrictions to try and limit the spread of COVID at the busiest time of year for our health services.
“Working from home has previously been advised by SAGE as the single most beneficial measure to reduce the spread of Covid. Now, early signs are that the new variant is at the least more transmissible than other variants and may be more likely to evade vaccine-acquired and post-infection immunity, Plan B and other measures should slow community prevalence while we wait to learn more about how our defences stack up.”
Prof Alex Richter, Professor in Clinical Immunology at the University of Birmingham, said:
“Omicron appears to be highly transmissible and governments are right to be concerned. The evidence for this, is the rapid increase in cases which have been detected in so many different countries around the world. The concern is not just a rise in cases, but the potential to evade the success of vaccinations and also monoclonal antibody therapies. We don’t yet know the extent of this evasion but there is the potential to impact whole strategies aimed at reducing transmission and treatment protocols. We also need to consider that, whilst cases remain high, more variants are highly likely to emerge.
“We know there is significant waning of immunity generated by vaccines from four months after the second dose, therefore the assumption is that we need the higher antibody and T cell levels that we have seen following booster vaccines to reduce infection risk against the current predominant delta variant. We know this will definitely help against delta and we hope that these higher levels will provide at least some protection against Omicron.
“What the future looks like is dependent on what we learn about immune evasion of Omicron over the next two weeks, which will be a critical period. If there is a significant impact on the efficacy of vaccines and monoclonal antibody therapies, then we will have to rely on the reduction of transmission of infection as a primary strategy, making the UK Government’s Plan B more likely.
All our previous output on this subject can be seen at this weblink:
www.sciencemediacentre.org/tag/covid-19
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