Studies Show Vaccines Are Effective Against Delta Variant
Israel reported that the Pfizer vaccine was 64 percent effective against the Delta variant, even as other studies suggest a higher rate. All of the research so far indicates that vaccines help prevent hospitalization.
In Britain, researchers reported in May that two doses of the Pfizer-BioNTech vaccine had an effectiveness of 88 percent protecting against symptomatic disease from Delta. A June study from Scotland concluded that the vaccine was 79 percent effective against the variant. On Saturday, a team of researchers in Canada pegged its effectiveness at 87 percent.
And on Monday, Israel’s Ministry of Health announced that the effectiveness of the Pfizer-BioNTech vaccine was 64 percent
Although the range of these numbers may seem confusing, vaccine experts say it should be expected, because it’s hard for a single study to accurately pinpoint the effectiveness of a vaccine. But once vaccines hit the real world, it becomes much harder to measure their effectiveness. Scientists can no longer control who receives a vaccine and who does not. If they compare a group of vaccinated people with a group of unvaccinated people, other differences between the groups could influence their risks of getting sick.
https://www.nytimes.com/live/2021/07/07/world/covid-19-vaccine-coronavirus-updates-
