Pfizer and German partner BioNTech said on Monday they had sought US authorisation for a Covid-19 vaccine <a href="https://www.thenationalnews.com/coronavirus/2022/06/26/pfizer-tweaks-covid-vaccine-to-offer-better-protection-against-omicron/" target="_blank">retooled to target the Omicron subvariants</a>. The request to the Food and Drug Administration was for a so-called bivalent vaccine containing the dominant BA. 4 and BA. 5 variants of the virus, along with the original coronavirus strain. It is intended for ages 12 and above. Pfizer said it was ready to deliver doses for September under a $3.2 billion deal in place with the US government for 105 million doses, including the Omicron-tailored shots. “Having rapidly scaled up production, we are positioned to immediately begin distribution of the bivalent Omicron BA. 4, BA. 5 boosters, if authorised,” Pfizer chief executive Albert Bourla said. Countries including the UK, the US and EU members have been preparing for vaccination campaigns in the autumn to protect against future surges. Britain <a href="https://www.thenationalnews.com/world/uk-news/2022/08/15/worlds-first-approval-of-next-generation-moderna-coronavirus-booster/" target="_blank">became the first country to clear a bivalent vaccine, made by Moderna</a>, last week. The FDA in June asked Covid-19 vaccine makers to tailor shots to target the two subvariants. It said it would not require new studies testing the shots in humans for authorisation, similar to how annual changes to flu vaccines are handled. A mid-to-late-stage study of Pfizer's older BA. 1-tailored vaccine has shown that the new shot generated a superior immune response against the subvariant compared with the original one. A study of the BA. 4 and BA. 5 vaccine in people aged 12 years and older is expected to start this month.