Christmas is coming, borders are opening and cases of COVID-19 are rising. Understandably, many of us are feeling nervous about the weeks ahead.
There were 3057 new cases of COVID-19 recorded in NSW on December 20th, with 284 of these people in hospital and 39 in intensive care. This is a stark increase in comparison to the 271 new cases recorded less than a month earlier at the beginning of December.
Much of the rapid increase is due to the emergence of Omicron, yet another more contagious variant. While evidence is still emerging, data collected so far suggests that not only is this variant more infectious, but two dose vaccination is less effective against symptomatic infection. This means we are all at higher risk, even those who are currently fully vaccinated (excluding a booster). And as has been shown consistently, those most at risk of infection remain the unvaccinated population.
This inevitably means that children, not yet able to be vaccinated, will bear the highest burden of infection leading to increased sick days and absence from childcare and school. As with many aspects of the pandemic, this will unduly impact women who are most often primary carers. The increased childcare burden will create additional work for those already affected by increases in unpaid work which has disproportionately fallen to women.
One preventative measure that could help to curb the current spread is the use of face masks indoors. Currently mandates regarding the use of face masks differ across Australian States and Territories. This may be about to change with an emergency national cabinet meeting planned for Wednesday to discuss, among other things, mandated mask wearing in indoor areas.
Australia’s Chief Medical Officer, Dr Paul Kelly, has already written to the Prime Minister and Premiers urging the implementation of mask mandates indoors. The Chief Health Officer of NSW, Dr Kerry Chant, has also been encouraging everyone to wear face masks despite no formal mandate in place. Clearly our senior public health officials think masks are a good idea.
What does the evidence say?
There has been a great deal of research conducted regarding the efficacy of face masks since the beginning of the pandemic. One US based study which looked at states with and without mask mandates found that in states that implemented mandates, 200 000 COVID-19 cases were prevented by May 2020.
Another global study comparing preventative COVID-19 measures across 183 countries found that countries with mandates or cultural norms regarding the use of face masks, had significantly lower COVID-19 related mortality.
What these studies do is look at the population level protection provided by face masks. Early in the pandemic a lot of the research focused on how well face masks protect the individual from infection, with some results inconclusive. What we now know is that whilst they may not be 100% effective at stopping a person becoming infected, they can slow the overall spread of community transmission. To reduce the spread we need to ensure each infected person is passing the virus on to as few people as possible. The wide-spread use of face masks decreases the number of people a person infected with COVID-19 will pass the virus on to.
This is most important indoors, where air may be stagnant, resulting in the majority of COVID-19 transmission occurring indoors.
Why do we need to mandate masks instead of simply recommending their use?
Face masks are most effective when worn by the majority. A number have studies have shown that when 80% of the population wear masks, this can help curb the spread of COVID-19, with lower rates of mask wearing less effective. If not mandated, most people do not wear face masks. This is understandable, given that they can be uncomfortable and annoying. A mandate provides additional incentive for people to put in place a preventative measure they may not otherwise due to inconvenience, much like seatbelts. History shows us this is effective with the rate of seatbelt usage increasing significantly from 20-25% to 75% following the introduction of their use into law.
If the evidence is so strong, why has there been hesitancy to put mask mandates in place?
There are a number of likely reasons that mask mandates have not been used more widely in the pandemic response. As mentioned above, some of the initial research regarding the use of face masks focused on the individual level of protection provided and did not look at how a high level of population usage might curb overall spread. We now know that this is an important preventative measure which works, which was highlighted in a recent large-scale review of the evidence to date.
Researchers such as myself are also generally weary to recommend the use of something that isn’t evidence based. In the initial stages of the pandemic this type of evidence did not exist. Large scale randomised control trials are often used to test and provide evidence for interventions before they are implemented, such as in the case of vaccines. However, these types of studies could not be conducted in relation to mask wearing. So, whilst no such study has been conducted regarding the use of face masks, we now have enough observational data and evidence from natural experiments to know that this type of intervention works.
If the large numbers of infections, hospitalisations and deaths to date have taught us anything, it should be that a more cautious approach to the virus is most sensible, particularly when new variants are circulating. Whilst many of us may not be enthusiastic about the use of face masks in public indoor spaces, we need to consider not just the risk of ourselves and others, but the inequities that inaction are likely to compound.