Three new machines, mRNA, viral vector and protein particle, are explained honestly, with their real engineering trade-offs and the documented rare safety signals named plainly. That clear naming lets myths be dismantled, including the claim that mRNA enters the nucleus, which it never does.
Timeline
- January 2020SARS-CoV-2 sequence published; mRNA candidate designs drafted within days
- December 2020First mRNA COVID-19 vaccines authorized, initially needing ultra-cold storage
- Early 2021Adenoviral-vector vaccines roll out as refrigerator-stable, single-dose options
- Summer 2021Surveillance confirms rare clotting after vector vaccines and myocarditis after mRNA in young males
- 2022Novavax protein-nanoparticle vaccine authorized
Still debated
Myocarditis rates vary by country, age and product, roughly 50 to 110 per million in young males after the second dose, and its mechanism is still studied. The clotting figures are an international composite, and durability and how best to combine platforms are still being worked out.