Moderna, citing variants and waning immunity, expects COVID-19 boosters to become a fact of life

For anyone thinking aggressive COVID-19 vaccine rollouts would bring a quick end to the pandemic, Moderna has a word of caution. While U.S. authorities aren’t yet ready to recommend vaccine boosters, the company believes that add-on shots will become a fact of life for some as the virus sticks around and continues to put up a fight.

As the world battles the Delta variant, Moderna believes the stronger form of the virus—combined with waning immunity for early vaccine recipients—will lead to breakthrough infections in the months to come, company president and R&D chief Stephen Hoge told analysts on Thursday. The company expects a third dose of mRNA vaccines will “likely be necessary” before the winter to keep people “as safe as possible,” Hoge added.

Still, U.S. authorities haven’t yet recommended boosters, as experts debate whether lower neutralizing antibodies will translate into lower protection. In one of its vaccine studies, Moderna said that "neutralizing antibody titers had waned significantly" prior to boosting at six months. 

On the flip side of the argument, Moderna also released data on Thursday showing that its vaccine remains 93% effective six months after the second dose. While those data look solid, the Delta variant has “taught us to be incredibly humble in the face of the virus’ ability to fight back and increase transmission,” Hoge said.  

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For potential boosters, Moderna is exploring a three-pronged strategy. First, the company is testing a third dose of its original shot, dubbed mRNA-1273 or Spikevax. In addition, the company is testing variant-specific boosters and multivariant shots. 

The follow-up shots are intended to act as a safeguard against viral mutations and waning immunity, Hoge explained. While Delta is posing serious challenges right now, the company is anticipating future mutations that will serve as moving targets.

In addition, existing mutations could combine in “new and scary ways," Hoge said. With Moderna’s multivalent approach, the company is trying to get ahead of that threat, Hoge said. 

For its part, the World Health Organization this week called for a moratorium on coronavirus booster shots until poorer countries can get parts of their population immunized. Disregarding that plea, France and Germany plan to start offering boosters next month, Reuters reported Thursday. Israel has started offering booster doses, as well.

Moderna plans to comply with health officials’ recommendations and is only offering its own viewpoint on the evolving situation, Hoge said.

A Massachusetts mRNA specialist, Moderna has made a global name for itself during the pandemic. The company has taken COVID-19 vaccine orders worth about $20 billion in 2021, and its supply for the year of up to 1 billion doses is all bought up.

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For next year, Moderna expects to produce between 2 billion and 3 billion vaccine doses. The company has already inked supply deals worth $12 billion for next year, and those agreements include options worth another $8 billion. In the longer term, some “forward-thinking” countries are negotiating 2023 supply deals, Moderna said.

Moderna believes this is “not the last round of the fight” with SARS-CoV-2, Hoge said. In fact, the company expects several more challenges from the virus in the years to come.

While the company hopes the virus will get weaker with time, Moderna thinks the virus is “here to stay” and that high-risk populations will need regular boosters to stay protected, the exec said.