Public Health Note: Covid-19 in Winter 2022

The winter season

Respiratory viruses, including Covid-19, are more prevalent in winter. Numerous biological, environmental and behavioural factors contribute to this. However, in winter, the primary reason is that people spend more time in enclosed spaces with low ventilation. For some, the consequences of infection are also more serious in the winter: many cardiovascular and respiratory conditions become worse in this period, which can make a simultaneous Covid-19 infection more serious. 

How will the virus behave?

Covid-19 is a living virus that mutates and changes. We have seen previously that these changes can facilitate transmission of the virus between individuals or change the effect it has on the host. Although we don’t know what to expect from future mutations, the concern is that a more dangerous mutation could lead to a virus that evades existing vaccine protection.

At this time, we don’t know which variants will be prevalent, what proportion of the population will receive boosters to protect them, or how effective that protection will be against the variants present. ⁱ 

Protection against Covid-19

The foundations of public health controls in the UK have been behavioural controls (mask use, social distancing, testing and isolation), and vaccination. The vaccination program has been very successful in providing immunity to Covid-19 infections, though there is a concern that the ability of existing vaccinations to offer continued defence will decline over time. There is an ‘Autumn Booster’ campaign to offer another vaccination to vulnerable groups (front line healthcare workers, people over 50 years old, people in care homes, and all people over 5 years old in clinical risk groups). This includes the option to receive a new version of the vaccine which targets both the omicron variant and the original Covid-19 variant targeted by the first generation of vaccines. ⁱⁱ

Existing variants of Covid-19

Technical bulletins about the situation of current variants are published by the UK Health Security Agency. 

In the UK, the dominant Covid-19 variant last winter was the Omicron variant (B.1.1.529). Omicron is more transmissible than the previously dominant Delta variant, and the vaccines available provided less protection from Omicron. However, Omicron also causes milder disease than Delta, meaning that despite lower vaccine protection and higher infectiousness, the wave of infections caused by Omicron resulted in fewer deaths and hospitalisations. A variant with, for example, Omicron’s high transmissibility, vaccine escape capability, and Delta’s severity, could at any time cause a new wave of severe Covid-19 cases. ⁱⁱⁱ

Infection levels in the UK and Europe are currently high, and the protection people received from their last booster vaccine is waning. Combined with increased infection rates in winter and the lack of any restrictions which prevent disease transmission make the approaching months a period where a new variant could easily take hold and spread rapidly. ^iv  

Availability of Covid-19 testing

Many countries have scaled back Covid-19 testing or stopped providing free testing kits, so forecasting future waves of infection is more difficult. This could mean that approaching waves of infection are harder to detect. 

Current high-level recommendations

The World Health Organisation (WHO) and the European Commission have published recommendations for governments to prepare for winter 2023. These include increasing vaccine and booster uptake among those eligible, increasing ventilation in crowded spaces, and promoting mask use indoors and on public transport. 

Implications for the Rail Industry

We are in a period of uncertainty about the trajectory of infections during the 2022 Winter period. Rail potentially needs to prepare outcomes, such as: 

• Periods of high staff absence
• Clinically vulnerable staff needing to shield if a new variant of higher severity emerges 
• Reintroduction of behavioural infection controls by the government, or recommendations that people wear masks in enclosed spaces
• Reduced ridership if people are asked to work from home or avoid social gatherings
• Increased strain on the mental wellbeing of staff and passengers.

Work done by RSSB

Our work to understand the Covid-19 transmission risks on rail services found the following underpinning primary factors:

• The rate of infection in the population
• The amount of time spent on the train (more time results in more risk of infections)
• Train loading (the more passengers are on a train, the higher the individual risk).

These indicate that there are no specific risks posed by the rail environment that increase the risk of Covid-19 beyond any other enclosed location. Spending the same time in a shop or a pub with a similar level of ventilation and occupancy would create the same level of risk. Therefore, for staff and passengers in rail environments the best practises to mitigate the risks of Covid-19 and other seasonal respiratory diseases are like those for other enclosed environments. These are:

• Getting vaccines or boosters you are eligible for 
• Practising good cough and sneeze hygiene 
• Washing hands 
• Encouraging staff and passenger to remain at home if they feel unwell
• Increasing ventilation
• Using masks 
• Social Distancing

We provide tools, analysis and guidance to help you mitigate the risks of Covid-19 and navigate new information as it emerges. Many of our resources are available online. Additionally, you can contact our public health manager for any bespoke concerns you have related to Covid-19 or any other public health issues.