Two months have passed since the first cases of Omicron were identified in the UK. In the weeks after it emerged, modelling scenarios presented to the company suggested we were facing a situation worse than last winter, with tens of thousands of hospital admissions and thousands of deaths a day. Thankfully, these scenarios did not happen.
In the best-case scenarios, the numbers of admissions and deaths peaked below expectations. In most cases, the situation was better than feared because of the high pressure on hospitals. Richard Horton, editor of the Lancet, described the scientists' response to Omicron as a case study in error. He said that there was too little emphasis on the experience of health workers on the frontlines of care and too much reliance on mathematical modelling.
The science of restrictions was often uncertain, leading to models that provided a wide range of scenarios with different levels of restrictions. Many people are worried about the negative impact of ending plan B restrictions. It is important to see how effective these restrictions have been and whether they have led to better outcomes.
Plan B restrictions have been in place in Wales and Scotland since July. England has had the lowest death rates since 19 July. Case and hospitalisation rates are closely linked to death rates due to differences in how they are measured.
More and earlier restrictions are thought to lead to better outcomes. Evidence from the pre-vaccination era shows that countries that locked down quickly against Covid experienced fewer deaths and hospitalisations. Over the last few months, the real-world evidence no longer supports the assumption that the main determinant of hospitalisation and death rates is the level of immunity in a population. Older and higher-risk groups are more likely to be affected by this. England, where 98% of over 15s have some immunity to Covid-19, seems to have done well since July compared with other European countries.
Compliance to rules is one of the factors that play a role. There is evidence that household mixing in England rose and fell along with the perception of risk, rather than because of the rules at the time. Voluntary behavior changes, such as reducing contacts, have led to the same reduction in admissions and deaths that the models showed would be produced by a return to step 1 of the road map.
Even though the vaccine programme overwhelmed the health service, sceptics now say that there is no need for lockdowns or other non-pharmaceutical interventions.
Many of my colleagues on the frontline are physically and mentally exhausted due to the high pressure on the health service. Even after mandatory restrictions end, it is important for everyone to follow the public health guidance.
Do medical and public health interventions have a clinically significant benefit? Does the benefit outweigh the harms? Is spending money on something else more beneficial than using resources? The evidence was lacking during the first wave, which is why the measures were justified. In the second wave, there was enough evidence to show that the benefits of lockdown outweigh the costs, especially with the arrival of vaccines.
Vaccines have changed the situation. The benefits of lockdown restrictions do not outweigh the harms. We are trying to achieve more than just a reduction in harms from Covid, but also from the measures used to control it. Quality-adjusted life years (QALYs), not deaths, is the best measure of this and has been used in the most comprehensive analyses of the impact of Covid and restrictions. The key is to implement restrictions that are acceptable to the public and have the most favorable cost-benefit.
It makes sense to focus on interventions that cause the least harm and that people will comply with them. The use of flow tests in schools is one example. We must not ignore the needs and concerns of those who are most vulnerable to Covid, including those with long Covid and people who don't have vaccines. There are things that vulnerable patients can do to protect themselves, such as wearing well-fitting FFP2 or FFP3 masks, which have been shown in hospitals to greatly reduce the risk of infections. Additional protection from hospital admission and death will be provided by the arrival of antiviral drugs.
Before any potentially harmful restrictions are brought in again, we need to make sure their benefits outweigh the harms. Although restrictions are ending, Covid is not over. With our new freedom, we have a responsibility to protect others and be aware of those who are more vulnerable to the virus.
Raghib Ali is a clinical research associate at the University of Cambridge.
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