Covid-19 variants: Understand the differences and what strains exist | Health

Transmission rate of variants worries scientists

Transmission rate of variants worries scientists

The terms ‘mutation’ and ‘variant’ quickly entered Brazilian vocabulary during the Covid-19 pandemic. The genetic alterations of the virus, which travel around the world, worry scientists and leave the population on alert.

For a new variant to emerge, a genetic alteration in the virus is necessary. It undergoes transformation processes recurrently, and not all reach worrying levels.

These changes can increase the capacity for infection or transmission, and in more severe cases, can make the disease even more devastating to the immune system.

Since the beginning of the pandemic, more than 11 variants of covid-19 have been identified worldwide. The World Health Organization divides the mutations into those of concern – which are more easily transmitted and cause serious infections; and of interest, which do not show a significant increase in these aspects. Understand:

Concern Variants

Delta – India (B.1.617.2)

The Delta variant was identified in India in December 2021, and has its transmission capacity increased. The mutation arrived in Brazil in May, and according to a report by the Pan American Health Organization (PAHO) of the United Nations, in July it was already prevalent in almost 90% of samples collected worldwide.

Delta currently circulates in more than 111 countries, and surveys show a level of transferability 50% higher than previous ones. At least 50 people have died from the strain in Brazil. Yesterday (31), São Paulo registered the first victim – a 74-year-old woman, who had already been vaccinated with two doses of Coronavac.

Alpha – United Kingdom (B.1.1.7)

In the British variant, dubbed Alfa, it spread in the first months of 2021, and caused the United Kingdom to postpone the country’s full reopening. In it, scientists hypothesized a higher lethality potential, which has not yet been proven by research; in addition to greater transmissibility. To contain the arrival of the strain, Brazil even temporarily suspended the arrival of flights from India, South Africa and the United Kingdom.

Beta – South Africa (B.1.351)

The Beta variant was identified in October 2020. In it, the virus causes the action of antibodies to decrease, hindering the body’s response to treatment and the recovery of the infected. Scientists are still researching whether the strain is related to the most serious cases. Unlike Delta and Alfa, the variant did not reach many countries, but it spread quickly throughout the region, as well as Gama, in Brazil.

Range – Brazil (P1)

The situation of chaos experienced in Manaus at the beginning of 2021 has a great contribution from the Brazilian variant Gama, called P.1. The transmissibility of the strain is 2.4 times greater than the main variant of the coronavirus, and it is able to neutralize the antibodies circulating in the body, increasing the risk of reinfection.

Variants of interest

In addition to the variants that focus the attention of researchers, there is also a list of strains that have a lower degree of transmission and severity. Are they:

– Epsilon variant (B.1427 and B.1429): found in California;

– Variant Zeta (P.2): found in Brazil;

– Eta variant (B.1525): found in Nigeria;

– Theta variant (P.3 and B.1.616): found in the Philippines and France;

– Iota variant (B.1526): found in the United States;

– Cover variant (B.1617.1; B1.620 and B.1.621): found in India and Colombia;

– Variant Lambda (C.37), found in Peru.

There is also the C.1.2 variation, which arose from the C.1 strain, which dominated the infections in the 1st wave of the pandemic in South Africa in 2020. It has not yet received any classification from the WHO, but it has similar characteristics to Alpha, Beta and Gamma, and is under observation. Since its appearance, the new strain has also been found in seven other countries in Africa, Oceania, Asia and Europe, such as Portugal, England and Switzerland, in addition to China, the Democratic Republic of Congo, Mauritius and New Zealand.

According to the Ministry of Health, all vaccines currently available in Brazil – Pfizer, Astrazeneca, Janssen and Coronavac, are effective against variants. According to the folder, more than 130 thousand people have already received the first dose. In all, 190 million doses have been applied since the start of vaccination.

It is necessary to be alert, however, for the second dose of immunization: with the exception of Janssen, which is applied in a single dose, all vaccines require two visits to the health center for protection to be complete.

Last Wednesday, the Ministry of Health announced the beginning of the application of booster doses for seniors over 70 and immunosuppressed people in September. In some states, the calendar has been brought forward, and the call for the 3rd dose has already started.