Initial lab investigations show that a third dose of the Covid-19 vaccine may be required to neutralize the Omicron variant, according to Pfizer Inc. and BioNTech SE. This new update on the Omicron variant will hasten booster-shot campaigns around the world and may lead to the development of new strain-specific vaccinations.
After three doses, serum antibodies elicited by the Pfizer-BioNTech COVID-19 Vaccine (BNT162b2) neutralize the SARS-CoV-2 Omicron variant, according to preliminary laboratory findings. Sera collected one month after receiving the booster vaccination, which is the third dosage of BNT162b2 vaccine, neutralized the Omicron variant to levels comparable to those seen after two doses of the wild-type SARS-CoV-2 spike protein.
Sera from people who got two doses of the current COVID-19 vaccination had more than a 25-fold lower neutralization titer against the Omicron variant than wild-type, implying that two doses of BNT162b2 may not be enough to protect against infection with the Omicron variant. However, because the mutations in Omicron have no effect on the vast majority of epitopes targeted by vaccine-induced T cells, the companies believe that vaccinated individuals may still be protected against severe forms of the disease. They are closely monitoring real-world effectiveness against Omicron around the world.
Covid-19 vaccine being drawn from the bottle with an injection syringe
A third dose could provide more strong protection, according to results from the firms' additional tests, which show that a booster with the current COVID-19 vaccine from Pfizer and BioNTech increases antibody titers by 25-fold. According to preliminary data from the firms, a third treatment produces neutralizing antibodies against Omicron at the same level as two doses against wild-type and other variations that appeared before Omicron. Antibody levels this high are linked to great efficacy against both the wild-type and mutant viruses. A third dose significantly raises CD8+ T cell numbers against numerous spike protein epitopes, which are thought to be linked to disease protection. The great majority of these epitopes are unchanged in the Omicron spike variation compared to the wild-type virus.
According to Albert Bourla, Chairman and Chief Executive Officer of Pfizer, more evidence on the existing vaccine's potential to repel the Omicron variety will be available by the end of the year. The test results were acquired using a laboratory construct known as a pseudovirus, which was revealed on Wednesday. He claimed the company is still working with the real virus and gathering data on how well the vaccination works in the community.
Four bottles labelled Covid-19 coronavirus vaccine alongside an injection syringe and Pfizer logo
However, the latest findings cast even more doubt on the future of Covid immunization initiatives. Researchers had hoped that a third booster dose would provide long-term protection against Covid and subsequent versions until recently. That has become considerably less obvious in light of omicron's substantial immunological evasion.
"While two doses of the vaccination may still provide protection against severe sickness caused by the Omicron strain," Albert Bourla said, "it's obvious from these preliminary data that protection is better with a third dose of our vaccine." "The best course of action to prevent the spread of COVID-19 is to ensure that as many people as possible are fully vaccinated with the first two dose series and a booster."
"Our preliminary studies suggest that a third dose could still provide enough protection from disease caused by the Omicron variation of any severity," stated Ugur Sahin, M.D., CEO and Co-Founder of BioNTech. "Global vaccination and booster campaigns could help us better protect people around the world and get through the winter season." We are continuing to develop an adapted vaccination that, in comparison to the current vaccine, we believe will help to induce a high level of protection against Omicron-induced COVID-19 disease as well as a longer duration of protection."