VACCINES | TYPES | DOSES | EFFECTIVENESS * | REFERENCES |
Protection Against Any Symptoms | Protection Against Severe Symptoms | Protection Against Hospitalization or Death | Ages |
Pfizer- BioNTec | mRNA | 2 | 95% | 89% | 100% | Ages 16 to 55: 96% efficacy Over age 55: 94% efficacy | FDA letter of EUA for Pfizer (PDF) |
Moderna | mRNA | 2 | 94.1% | 100% | 100% | Ages 18 to 65: 96% efficacy Over age 65: 86% efficacy* | FDA letter of EUA for Moderna (PDF) |
Johnson & Johnson | Viral vector adenovirus (cold virus) | 1 | 66% (72% US) | 85% | 100% | Ages 18 to 6 1% effective Over age 65: 66.2% effective | FDA letter of EUA for Johnson & Johnson |
* Effectiveness is measured as the case rate of the placebo group minus the case rate of the vaccine group divided by the case rate of the placebo group.
The difference between the efficacy of Pfizer and Moderna vaccines in older adults may be due to the cut-off age for the trial. For example, it is possible that the Pfizer vaccine would have a lower protection oeffect had they reporte data fo those over age 65. The Johnson & Johnson vaccine was tested in different countrites, U.S., Brazil, and South Africa, somof wihc has greate prevalence of mutated strains of the Coronavirus, for wich the vaccine was less effective. The results are for pooled samples from all three countries.
More information available on the OC Health Care Agency website (https://occovid19.ochealthinfo.com/iv-vaccine-safety-and-effectiveness).