Mask is mandatory again on buses, subways and trains in SP this Saturday (26)

When entering São Paulo public transport this Saturday (26), don’t forget your mask. Protection against Covid is once again mandatory as of a decree published this Friday (25) in the Official Gazette of the state.

Decree 67,299 basically just re-establishes previous rules for wearing a mask in public transport and in places that provide health services.

The measure is taken at a time of rising cases of Covid in Brazil and also in the state. In São Paulo, this week, the growth of the moving average of infections, in relation to the data of two weeks before, exceeded 70%, according to data from the consortium of press vehicles.

There is a similar perception in the data collected by the Union of Hospitals, Clinics and Laboratories of the State of São Paulo. An increase in consultations was noticed, in November, of patients with suspected Covid, although cases were not serious, in general. In any case, hospitalizations had a relatively small increase.

In early November, the state government issued an alert about the increase in ICU admissions.

Experts believe that the measure is right, however, that it could have been taken earlier. The World Cup and the end of year festivities can also contribute to the increase in cases.

The mask was off the face of people who use public transport in São Paulo for a short time. The mandatory protection fell in September.

The increase in Covid cases in Brazil as a whole – the moving average growth exceeded 300% – also led to the return of the mandatory use of masks on planes and airports this Friday.

The return of mandatory is not the only action taken amid rising Covid infection rates. The City of São Paulo restricted visits to municipal hospitals to one hour. In the ABC region, the three cities suspended the entry of relatives and friends of patients into hospitals.

How do masks protect against infection?

Knowledge about mask protection to prevent infections has grown a lot in the first year of the pandemic, and there is no longer any doubt that the mask is capable of reducing the transmission of Sars-CoV-2.

The evidence in favor of the use of masks both for individual protection and to prevent the spread of viral particles in the air has already been well demonstrated. Thus, masks protect both directly, functioning as a physical barrier against droplets of saliva expelled when talking, coughing or sneezing, and filtering the air that may be full of aerosol microparticles (invisible to the naked eye) containing the virus.

The protective capacity of the masks varies according to the type of material used and the weave. A study carried out by USP evaluated the filtering efficiency of different types of masks sold in Brazil and concluded that N95 or PFF2 masks are the most indicated, with efficiency above 98%, followed by TNT or surgical masks (between 80% and 90% %), and finally cloth, with an average of 40%. Knitting masks, with open weaves or synthetic fabrics such as lycra and microfiber are not effective in protecting (around 15%).

Another survey carried out in the United States pointed to an effectiveness of up to 95% when combining a surgical mask under a cloth one.

In a collective sense, if everyone in a closed environment is wearing masks, the chance of transmitting the virus is reduced by up to 70%, according to an article published in the journal Aerosol Science and Technology.

I am vaccinated against Covid. Should I continue to wear masks?

Yup. In general, Covid vaccines were developed to protect especially against hospitalization and death, but they do not have the power to fully contain the contagion itself. Thus, even vaccinated people can contract the virus and become ill, so it is important to continue wearing masks after immunization.

However, the chance of a vaccinated person becoming infected with the disease is lower than that of those who have not received any immunization, and the size of this protection varies according to the vaccine used.