Following a recent string of emergency use authorizations (EUA) for their jointly developed COVID-19 vaccine, BNT-162b2, Pfizer Inc. and Biontech SE said Dec. 14 that results from an ongoing German trial have helped illustrate "the multiple arms of the immune system that are activated" by the product to fight SARS-CoV-2. Separately, Moderna Inc. raised to 200 million the number of doses of its COVID-19 vaccine candidate, mRNA-1273, it will supply to the U.S. government while also confirming a new agreement to supply the vaccine to Singapore.

The Pfizer/Biontech updates arose from an analysis of 37 participants immunized with BNT-162b2 in a phase I/II study. Data so far show what the companies characterized as "a broad immune response with SARS-CoV-2-specific neutralizing antibodies, TH1 type CD4+ T cells, and strong expansion of CD8+ T cells of the early effector memory phenotype."

“While there is a broad consensus that vaccines should induce antibody responses against the virus, experiences from the prior SARS pandemic indicate that CD8+ T-cell responses may be of critical importance to achieve long-term protection," said Biontech CEO and co-founder Ugur Sahin.

The results, published on the preprint server Medrxiv and thus not peer-reviewed, also showed a "robust induction of antibody responses" with a follow-up period of 85 days, the companies said.

The non-randomized open-label trial (NCT04380701) is being conducted in Germany in parallel to a phase I/II/III trial (NCT04368728) that started in the U.S.

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Though not really the same as the ever-present option offered on all manner of goods at the global retailer Amazon.com, the U.S. government's option on Moderna's COVID-19 vaccine candidate, mRNA-1273, at least has a similar feel. After an initial order of 100 million doses of the candidate, just ahead of a Dec. 17 FDA advisory committee meeting on the it, the government has exercised its option to purchase 100 million doses for delivery in the second quarter of 2021. Briefing docs for the adcom are expected to be available on the morning of Dec. 15.

The initial order is set to be delivered in batches, with 20 million doses to be delivered by the end of December 2020 and the balance to be delivered in the first quarter of 2021, Moderna said. Fulfillment of the new order is due by the second quarter of 2021. In each case, the deliveries are subject to Moderna's receipt of an EUA for the asset. As part of Operation Warp Speed, the U.S. government has the option to purchase up to an additional 300 million doses.

Moderna, which continues to seek a conditional marketing authorization for mRNA-1273 with the EMA, also has confirmed supply agreements with the EU, Japan, Canada, Switzerland, the U.K., Israel and Qatar. On Dec. 14, it added Singapore to the roster with a deal for an undisclosed number of doses. The city-state's population was about 5.7 million people in June 2020, according to national statistics.

News of the Moderna deal arrived on the same day that the country's Expert Committee on COVID-19 Vaccination welcomed an interim authorization of the Pfizer/Biontech COVID-19 vaccine by the Health Sciences Authority, for use in Singapore in individuals 16 and older, the same population as other countries.