European restrictions, India's declining curve - how masks save lives

When both an infected person and a non-infected person wear masks, the probability of Covid-19 transmission is reduced by up to 80 per cent

This new pandemic called Covid-19 has ravaged nearly all countries of the world and yet this alarming global scourge is still not showing any signs of slowing down. As of this writing, there are about 42.5 million (425 lakh) cases of infections globally, with over 1.15 million (11.5 lakh) deaths (Worldometers data, worldometers.info/coronavirus, last accessed, Oct 24, 2020). The world has added about 29 new infections in the past week and about 5 lakh deaths.

India is the second worst affected country, with over 78 lakh (7.8 million) cases of infections, and nearly 1.18 lakh (118,000) deaths. The situation in our country is still serious as daily rises have been in the range of 50,000 or above for the past several days! Our country has added about 4 lakh new cases and 8,000 deaths in the past week.

Till date, the number of cases in Manipur have shot up to 16,777 cases with 12,562 recoveries, and 4,083 active cases and the number of deaths stand currently at 132 (as of Oct. 16, 2020). Our state has added around 2,062 new cases of infection and 23 deaths in a week. That amounts to a whopping 294 new infections and about 3.3 deaths per day. Our case fatality rate is moving close to 1% (currently it's about 0.79%), and recovery rate stands at 74.88%. We need a mass awareness campaign to ensure strict observance of mask-use, physical distancing, hand hygiene, tracing, isolation, and crowd-avoidance protocols to prevent further rise in infections and deaths.

In today's column I wish to broach the topics of European surge, India's easing, scientific evidence for benefits of using masks and other non-pharmaceutical interventions, and the current status of Covid treatments.

The Indian Situation

India seems to be in a better position as of October end. Daily new cases have dropped to just around 50,000, recovery rate is inching towards 90%, and CFR has decreased to around 1.51%. 

However, the rosy picture cam turn gloomy any time soon. We must not afford to let our guards down. Unlocking and more movements of people, Covid fatigue (many people seem to be fed up of mask-wearing, and watching physical distancing etc.), big gatherings due to festivals and election campaigns etc, compounded by air pollution in many big cities, higher spread of virus in winter months, and even the possibility of the virus mutating may precipitate a sudden spike in Covid infections and deaths. 

How to reduce morbidities and mortalities?

The best way to prevent, control and treat Covid-19 is definitely pharmaceutical interventions such as anti-SARS-CoV-2 vaccines, mAbs, drugs such as dexamethasone and other supportive care such as non-invasive oxygen therapy. But we still do not have an approved cure or vaccine for Covid-19. So, what must we do?

Non-pharmaceutical interventions

In the interregnum before the arrival of a vaccine (and drug), we must perforce rely on major non-pharmaceutical interventions: masks, physical distancing, personal hygiene, testing, tracing, isolation, and rapid treatment. These have been repeatedly mentioned in both online and offilne publications ad nausea. However, majority of the people still fail to observe these control and preventive measures. But they indeed help prevent infections; more importantly, they help save precious lives! Let's look at masks, for example.

Benefits of wearing masks

As has been mentioned in an earlier column, when both an infected person and a non-infected person wear masks, the probability of Covid-19 transmission is reduced by up to 80% (medRxiv, Oct. 5, 2020). Coronavirus can be transmitted through droplets emitted by coughing, sneezing, and speaking. The last aspect hasn't been researched intensively so far. However, a recent research paper (Physical Review Fluids, Oct. 2, 2020), considers the contribution of speaking to be very significant.

The findings of this study Drs. Manouk Abkarian, University of Montpellier and Howard Stone, Princeton University, report that unlike sneezing, which are audible, speaking may spread virus without you being aware that it's being spread. The study also showed that asymptomatic carriers can spread the virus just by speaking to someone else (contrast this with SARS, which can only be transmitted by symptomatic individuals). Speaking loudly especially ones using hard consonants ("P", "B", "T" sounds in English) can spread the virus the farthest. This is even riskier in indoor environments and all the more so in winter months. In winter months, the virus particles survive longer and as the air is drier; water in droplets evaporates quickly, leading to smaller-sized droplets which travel faster and longer. So meetings and gathering where people speak (or sing) loudly is highly risky; the more so, if the event takes place indoors and in winter season. In such situations, the virus particles may travel more than the "six feet" recommended in social distancing protocol.

Hence, masks reduce transmission in outdoor public spaces, in indoor gatherings, and in close-contact situations. Prof Stone says, not wearing masks, especially in indoor settings, is "very risky."

Latest research from IIT Bombay (Economic Times, Oct. 23, 2020) also indicate that masking controls the size of the "cough cloud" and acts as a social vaccine against the coronavirus. Use of masks can reduce the size of the virus-containing cough cloud emitted from a patient's mouth, thus reduce viral loads in the droplets and risk of transmission and disease.

Masks can save lives

According to a recent study published by the prestigious journal, Nature Medicine (Oct. 23, 2020), in the US alone, near universal mask use could save nearly 1,30,000 lives from now till February end. The paper discussed 5 scenarios:

Scenario 1: Social distancing norms eased: the worst-case scenario; more than 1 million Americans would die (> 152 million infections) by end of February 2021.

Scenario 2: Restrictions imposed e.g. social distancing & shutdown of economic activity: estimated 5,11,468 deaths, i.e. about 5,41,738 American lives saved.

Scenario 3: Universal mask use and Shutdown: If scenario 2 conditions are reinforced with mask-wearing by 95% people, about 1,30,000 lives would be saved in the US (compared to situation of shutdown without mask use).

Scenario 4: 85% mask use plus shutdown: even here, about 96,000 lives would still be saved (compared to that in scenario 2).

Scenario 5: Universal mask use, social distancing norms removed: even in this unsavoury situation, nearly 563,000 lives could still be saved. 

Every society must decide which scenario is the best for it, depending on its local context, social wisdom, community networking, public policy robustness, and trust of scientific and academic professionals working in universities and institutes and peer-reviewed findings in mainstream journals. It's apparent to most of us that scenarios 1 is the least desirable option and scenario 3 would be the most preferred one. 

The Virus and drug hiccups

Some bad as well as good news. First the bad news. A volunteer has died in AstraZeneca vaccine trial in Brazil and Eli Lilly monoclonal antibody had to be halted. An Indian study found that plasma (liquid portion of blood) from recovered patients has limited potential to prevent serious disease and deaths by SARS-CoV-2 (BMJ 2020; 371:m3939).

Another happy news is that though remdesivir has been rejected by WHO as not beneficial, the US FDA has recently made it the first approved drug for Covid-19 (for moderate to severe cases). J&J and Oxford vaccine trials are set to resume in the US. Three vaccine candidates in India are about to begin phase 3 trials soon. Let's fondly hope that a safe, affordable, and efficacious vaccine gets approved and released for limited use by mid-2021!

The silver bullet for Covid-19 is an efficacious, safe, and affordable vaccine and/or drug. But we don't have it yet. But as Derek Thompson writes in The Atlantic magazine (Oct. 12, 2020), there are "bronze bullets abound." The 3 Ws and 3 Cs are some of these bronze bullets. At this critical point of the pandemic, it's we-hoi polloi, common people-who with our (in) appropriate behaviour will determine the trajectory of Covid-19 in Manipur. Once again I humbly appeal to fellow citizens to abide by the 3 Ws and 3 Cs guidelines strictly!

In addition, the public health authorities may consider a few things, if feasible: localized, focused lockdowns in specific areas, mass testing at containment zones and hotspots of infections, rapid contact tracing and isolation/quarantining of potentially infected cases/sick patients, weekly publications of Covid graphs with categories of infected people and mortalities, strengthening of healthcare facilities, timely supportive care and treatment of serious Covid (and non-Covid) cases, and clear and accurate messaging from a designated public health official (just one designated person) on a regular basis (say weekly, if not daily).

(The views expressed are the writer’s own)

First Published:Oct. 25, 2020, 4:32 p.m.

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