Masks protect against H3N2 epidemic; understand

The epidemic of the H3N2 strain of influenza A has generated comments that question the usefulness of vaccines and preventive methods capable of fighting viruses such as Covid-19 and influenza itself, known to be a seasonal flu.

An example of this is a publication on Twitter that questions the usefulness of the protective masks used against the new coronavirus if Rio de Janeiro and São Paulo have an epidemic of influenza, the virus that causes influenza.

Faced with the questions, the Comprova Project decided to explain why the masks are still effective in combating both viruses that qualify as epidemics in the country.

Flexibility and lack of vaccination

The increase in cases is actually happening —and has spread to other places, such as the state of Espírito Santo and the cities of Salvador, in Bahia, and Porto Velho, in Rondônia—, but this scenario does not invalidate the importance of masks, according to specialists. .

As vaccinologist and professor at UFPel (Federal University of Pelotas) Odir Dellagostin explained to Comprova, the flu vaccine offered this year “has low protection against Darwin, the strain of the influenza A H3N2 virus, which is causing the outbreak.” And to make matters worse, he says, the use of masks is decreasing. “People are getting back together, hugging, drinking coffee together, without a mask, which reduces her effectiveness.”

Still according to him, “the solution is to strongly recommend the continuation of the correct use of the mask, the distance and the use of alcohol gel”.

The same said to leaf Geraldo Barbosa, president of ABCVAC (Brazilian Association of Vaccine Clinics): “Now, (to protect us,) there are preventive measures, such as the use of masks, hand hygiene and avoiding agglomerations”.

Epidemic

On December 9, when the post verified here was published, the Health Department of Rio de Janeiro confirmed on social networks that the capital is experiencing an influenza epidemic. “Are we facing an influenza epidemic? The epidemic is located in the city of Rio and there is already an increase in the number of cases in other cities in the metropolitan region”, wrote the agency on Twitter.

In a note published in UOL, the secretariat stated: “This sudden growth, verified from November 22, when 505 assistances were registered, reached almost 6,000 assistances on the last 6th. This is the largest number of assistances by a single disease carried out in the state UPAs in a single day since the beginning of the pandemic”.

In the city of Rio de Janeiro, the city is installing five centers for the care and testing of people with the flu syndrome “to reinforce assistance to the population during the influenza outbreak”. The strategy is similar to the one adopted in 2009 during the H1N1 outbreak.

In São Paulo, according to an e-mail from the Municipal Health Department sent to Comprova, “there was a significant increase in people with flu-like illness” in the last week. The agency also informed that, in November, there were 111,949 consultations with people with flu-like symptoms, 56,220 of which were suspected of Covid-19 and, now in the first half of December, there were 91,882 consultations with respiratory conditions (45,325 suspected of Covid-19).

On December 15, the outbreak of the disease had already reached other places, such as Espírito Santo and the cities of Salvador and Porto Velho. Only in the capital of Bahia, according to the leaf, the Municipal Health Department “recorded 109 cases of the disease in 2021, 106 of which were reported between late November and early December.”

Recommendation

The mayor of Rio de Janeiro, Eduardo Paes (PSD), determined the end of the mandatory use of masks outdoors. The measure was defined through a decree, published on October 27 this year.

The change was announced live broadcast, with the presence of the municipal secretary of Health, Daniel Soranz, who recalled the need for people with flu-like symptoms to continue using the protection. The measure also provided for the release of the use of masks in places with a dance floor, with a public capacity of up to 50%.

Along with the decision on the masks, Rio suspended all other rules established to fight Covid-19 in the city, in a second decree, published on November 12 in the Official Gazette. This same decree maintained the mandatory use of masks in closed spaces and public transport.

In São Paulo, the omicron variant led the government and the city hall to maintain the mandatory use of masks in open and closed spaces.

The suspension of the mandatory use of masks was scheduled to take place in the state on December 11, and the mayor of the capital, Ricardo Nunes (MDB), had declared that he intended to follow the measures determined by the administration of João Doria (PSDB).

With the advancement of the new variant of Covid-19, the Health Surveillance recommended the cancellation of the flexibility of masks. The agency prepared a study with epidemiological and care indicators.

Importance of masks

Although the flu vaccine used in the country has the H3N2 mutation in its composition, the variant is not the same one that is currently circulating in Rio and São Paulo. The new strain, titled Darwin — the city in Australia where it was first identified — is not covered by the current vaccine.

Vaccinologist Odir Dellagostin detailed that the strain is not part of the formulation that the WHO recommended to be used in this year’s vaccine. “Therefore, the vaccine has a low protection against this strain, even more reduced by the timing in which the outbreak is occurring: more than 6 months after the vaccination campaign”, he explains.

In Dellagostin’s view, mask wear is decreasing and this poses an exposure risk for both Covid-19 and the new mutation of the common flu virus.

“People are going back to crowding, hugging, drinking coffee together, so without a mask. This is reducing effectiveness.”

Also according to the vaccinologist, the way to get around the H3N2 epidemic has to be based on prevention measures. “The solution is to strongly recommend the continuation of the correct use of the mask — covering the mouth and nose —, the distance, the use of alcohol gel”, he concludes.

The infectious disease physician Rodrigo Nascimento explained that, for the masks to properly filter the air from infectious particles, they must be manufactured properly and receive the seal of approval from Anvisa (National Health Surveillance Agency).

The most suitable models, according to the professional, are the PFF2 (filtering facepiece) or N95 masks — which are the same model, but the first is certified in Brazil and the second in the United States. “But simple, surgical masks are effective too, around 30% to 40% less than N95 and PFF2.”

Despite the effectiveness of masks against the spread of viruses, their use must be combined with other measures for better effectiveness. The disease prevention methods follow the same rules as other viral diseases as Covid-19 does, including proper hand hygiene; avoid contact with infected people; do not share personal items such as glasses, cutlery, towels; avoid places of great agglomeration and poor airing; maintain healthy habits.

In addition, state governments annually carry out free vaccination campaigns against influenza.

“The vaccines against influenza are very effective, they are revised annually. Through the previous strain, new vaccines are produced and after approximately 14 days, it already produces antibodies in people”, reported the doctor.

The priority public to receive immunization agents are the elderly, children and people with immunosuppression, as they are more susceptible to the virus and thus have more chances of progressing to serious conditions than a healthy young person, for example.

“Of course, they depend on each person’s organism, on the ability of each person to produce antibodies. These are individual immunological characteristics, which is why the vaccine is primarily indicated for elderly people and immunosuppressed people, who have a low capacity to defend themselves against microorganisms” , he pointed out.

questioning

The tweet that questions the effectiveness of masks and mentioned here was published by Flavia Ferronato (@flferronato). Following the post now checked, she writes: “And before they show their patience, I’m really trying to understand how this is possible, okay?”, which hasn’t stopped followers from interpreting the publication as a way of discrediting the masks and other countermeasures against Covid.

One follower comments: “Is it an epidemic of the vaccinated? Because of low immunity?”; another writes: “That’s right! Even in my house, everyone with the flu, for the time being except me who hasn’t vaccinated”; and, one more: “The masks are super effective against respiratory diseases, which is not the case with the infl… no, wait…”.

Ferronato has already appeared in a Comprova check in November 2020, when he made a misleading post on the Jornal da Cidade Online website —the subject of some checks by the project— and on his Twitter profile suggesting that the Butantan Institute had not reported on the death of volunteer for the Coronavac vaccine.

At the time, after being contacted by the report, she posted on her social networks criticizing the work of checking agencies and seeking to intimidate the checker who contacted her.

This time, she responded to the report saying that she wrote the tweet because she wanted to “understand why the masks couldn’t hold the flu.”

Why do we investigate?

In its fourth phase, Comprova checks suspicious content that has gone viral about the pandemic, public policies of the federal government and elections. The content verified here had more than 6,600 likes and was shared 1,200 times until December 17th.

Masks continue to be fundamental protection to prevent the contamination and spread of viruses such as H3N2 and Covid-19, especially in closed and unventilated environments. Little used before the pandemic in Brazil, facial protection is one of the main measures against Covid-19 and, consequently, against other viruses that spread through the air, such as influenza. Without the masks, citizens are more vulnerable to these viruses.

Comprova checks pieces of disinformation about the masks since last year. Some examples of verification are the influencer who said that the face protection was not effective against Covid-19 and the study without review used also to discredit the use of the equipment.

Comprova performed this verification based on information available on the 17th from December from 2021.