Subvariants, vaccines and Nobel: Covid in 2023 – 12/21/2023 – Balance and Health

In 2023, we became aware that Covid-19 is here to stay. It is no longer a Public Health Emergency of International Concern, but it remains a pandemic.

“We no longer live in that tragic situation of the first three years, but Sars-CoV-2 continues to circulate and cause deaths. It is still a disease that has an impact”, says Alexandre Naime Barbosa, professor of medicine at Unesp and vice-president of SBI (Brazilian Society of Infectious Diseases).

In recent months, Sars-CoV-2 has altered the circulation of other respiratory viruses —which has caused unseasonal outbreaks and put pressure on hospitals—, triggered new health problems in millions of people and challenged governments, families and scientists.

In Brazil, we discovered that information about the pandemic was hidden from the population and we recorded the sad milestone of 700,000 deaths from the disease, a mourning that continues to reverberate in the lives of the victims’ parents and children.

The losses, reported by the now-defunct consortium of press vehicles, would be even greater without the vaccines. Immunizers have been updated according to the emergence of new strains of the virus, something possible thanks to the research of this year’s Nobel Prize winners in Medicine.

New subvariants

The identification of a new subvariant of the coronavirus in January scared the WHO. Called XBB.1.5, it was considered by the entity to be the most transmissible at that time and led to an increase in cases in the United States.

In Brazil, however, the growth was associated with the XBB.1.16 subvariant, with a profile similar to that of XBB.1.5 and also a descendant of XBB, a lineage of the omicron variant. The first case in São Paulo was confirmed in early May and doctors soon noticed a symptom different from those seen in previous strains: conjunctivitis.

Other lineages descended from the ômicron were identified in the following months. In August, EG.5 gained the attention of the WHO after spreading across the United States and China. Days later, France announced the rise in infections, this time due to the EG.5.1 subvariant, a variation of EG.5.

Still in August, the American CDC (Centers for Disease Control and Prevention) tracked a new lineage of the virus, BA.2.86, with more than 30 mutations in relation to XBB.1.5, and Brazil confirmed the first case associated with EG .5.

The new subvariants were associated with an 80% increase in cases worldwide at the beginning of the second half of the year. In the country, the rate of tests showing positive results for Covid reached 30% for the first time in nine months, and hospitalizations for the disease in São Paulo increased by 35%.

In November, hospitalizations in public and private units in São Paulo fell again, in a movement contrary to that observed in Ceará. The state was the first to register cases of subvariants JN.1 and BA.2.86.1 and the increase in hospitalizations led the Ministry of Health to bring forward the reinforcement of the vaccine against the disease.

JN.1 is also a concern in France, where it represents at least 30% of Covid cases diagnosed in December. Germany is another country that has seen an increase in the number of patients with the disease in recent weeks.

Vaccination

The year began with the announcement of the immunization of all children from 6 months to less than 3 years of age with doses of Pfizer baby, recommended for younger audiences.

Then, the Health departments expanded bivalent vaccination against Covid to all priority groups and, in April, the government released the booster with the updated dose for everyone over 18 years of age.

Initially, the possibility of taking the updated vaccine for the omicron variant drove the population to health centers, but soon demand decreased. In June, only 13% of adults had received the bivalent booster. Six months later, it was only 17%.

“Our main obstacle today in relation to Covid-19, without a shadow of a doubt, is vaccine hesitancy,” says Naime. “Those people who have not been fully vaccinated, that is, they have not received a booster with the bivalent vaccine, are five times more likely to be hospitalized or die,” she highlights.

Immunization among children was also below what is necessary. In August, only 11% of Brazilians up to five years old were vaccinated.

According to the Ministry of Health, from 2024 onwards, children will receive an annual dose of the vaccine. Elderly people, pregnant women, women who have recently given birth, healthcare workers and other priority groups will also be vaccinated annually.

The expectation, says Naime, is that this public will receive the Pfizer monovalent vaccine updated for the XBB subvariant. 1.15. The new vaccine was approved last Tuesday (19) by Anvisa.

long Covid

This year, we have also started to understand post-Covid conditions a little better (Covid
long). Studies presented at Unicamp showed that even mild SARS-CoV-2 infections are capable of causing structural and functional changes in the brain that can trigger neuropsychiatric manifestations, such as anxiety, depression, fatigue and drowsiness.

Impacts on brain function can persist for years after infection. Furthermore, researchers discovered that people with high blood pressure who had Covid may have damage to their heart muscle caused by the virus and that it can trigger antibodies linked to autoimmune diseases. Other studies have also shown that long Covid may be associated with abnormalities in the lungs and kidneys.

It is still unclear why this occurs. One hypothesis is that remnants of the virus that persist in the intestine trigger a reduction in serotonin levels. This decrease could especially explain memory problems and some neurological and cognitive symptoms of long Covid.

As for the number of people affected, a Brazilian study released in December revealed that 77.4% of people who had a confirmed diagnosis of Covid in Rio Grande do Sul developed symptoms lasting three months or more.

Vaccination, in addition to reducing hospitalizations and deaths, also reduces the risks of post-Covid conditions.