Comparing three Covid-19 vaccines: Pfizer, Moderna, J&J
In some respects, it's easy to make direct comparisons between the three vaccines; in others, it's more complicated.
In an ideal world, a pandemic vaccine could be delivered in a single shot, so supplies could be stretched to cover a lot of people. It would trigger no side effect more significant than a sore arm. And it would be easy to ship and store.
We now have one such vaccine.
On Feb. 27, the Food and Drug Administration announced it had issued an emergency use authorization for Johnson & Johnson’s one-dose Covid vaccine. Developed by J&J’s vaccines division, Janssen Pharmaceuticals, it was shown to be 66% protective against moderate to severe Covid infection in a multi-country study. Importantly, it was 85% effective in protecting against severe disease. And there were no hospitalizations or deaths among people in the vaccine arm of a large clinical trial.
Overall efficacy varied a bit geographically, especially in South Africa, where a new variant appears to evade to some degree the immunity induced both by infection and by Covid vaccines, which were designed to target earlier strains of the SARS-CoV-2 virus.
Rollout of the vaccine has already started, though the company is not expected to be able to supply substantial numbers of doses until April.