US President Joe Biden has urged people to get vaccinated against Covid-19 “to protect you and your family before the holidays”. The head of state has asked US residents to get the most up-to-date version of the vaccine.

“Even if you’ve been vaccinated or boosted, even if you’ve had covid before – get the updated vaccine before the holidays to protect you and your family,” he wrote on Twitter.

The US has already updated vaccines specifically targeting the omicron variant. Next-generation bivalent immunizers target both the original strain and strains of the coronavirus. BA.4 and BA.5 omicron variant. The latter represents over 90% of cases in the United States today.

What are bivalent vaccines?

According to a report by Live wellhealth and wellness platform UOL, bivalent vaccines are immunizations adapted to protect against forms of the omicron variant. These doses use the same technology as the first generations of messenger RNA, which stimulates the body to synthesize a protein and stimulates the immune system to fight the new coronavirus.

Pediatric infectologist Renato Kfouri, head of the immunization division at SBP (Sociedade Brasileira de Pediatria), says, “Studies have shown that giving a vaccine with micron alone provides less protection than combining it.

Updating vaccines is natural. Consider the forms of flu shots that are often replaced with each new annual campaign. In Covid-19, this process waited until one species proved to be dominant, as in the case of the omycron. South Africa became the first country to report this to WHO (World Health Organization) on 24 November 2021. Today, the BA.1 and BA.5 subvariants are the most widely circulated. The first is linked to an increase in cases in Brazil.

“In order to develop new vaccines, manufacturers had to make sure that the vaccine would not get old and would be ideal for the time it takes to develop them. With this long-term lead from Omicron, one year already in circulation would be conceivable. A vaccine with it would be fine,” explains Kfouri.