What the world had feared is happening now. The emergence of the Delta variant of the SARS-CoV-2 has set off the bid to develop a booster dose of the COVID-19 vaccine. US pharma giant Pfizer is planning to approach regulators to authorise a booster shot of its vaccine in view of the global spread of the highly transmissible Delta variant which may increase the risk of reinfection after vaccination.
On Thursday, Pfizer and its German partner BioNTech made the announcement to specifically develop a vaccine to neutralise the Delta variant which has spread to at least 98 countries now. In a statement, the companies claimed that they have seen encouraging data in the ongoing booster trial of a third dose of the current BNT162b2 vaccine and initial data from the study demonstrates that a booster dose administered 6 months after the second dose increases the effectiveness of the vaccine against both Delta and Beta variant by 5 to 10 times.
What US regulators say as Pfizer seeks clearance for a booster shot
Meanwhile, according to media reports, the US regulators have categorically said that at this point in time fully vaccinated American citizens do not need a booster COVID-19 vaccine.
First identified in India, the Delta variant is considered twice as contagious as the original SARS-CoV-2 virus and around 60% more transmissible than the Alpha variant. Currently, the Delta version of coronavirus is the dominant variant in the US and is the prime cause of outbreaks in Malaysia, Portugal, Indonesia and Australia precipitating the need to give shots to the unvaccinated population.
Notably, the announcement by Pfizer and BioNTech came days after a new study claimed that a single shot of Pfizer-BioNTech or AstraZeneca vaccines could hardly produce neutralising antibodies against the Delta variant in those who were not infected with SASR-Cov-2 previously. However, the study published in the Nature journal, said that fully vaccinated individuals retained considerable protection against the Delta variant.
Delta variant 8 times less sensitive to COVID vaccines: Study
In a study conducted in India, the Delta variant showed approximately 8 fold reduced sensitivity to vaccine-elicited antibodies as compared to the original SARS-CoV-2 virus. The study was collectively conducted over 100 healthcare workers at three centres in India by scientists from India and the Cambridge Institute of Therapeutic Immunology and Infectious Disease.
Earlier, the World Health Organization (WHO) had warned that in the coming months the Delta variant of COVID-19 would become the dominant variant of the coronavirus globally.