New Studies Show Covid-19 Vaccines' Effectiveness Against Variants

CNN recently reported on 'a batch' of new studies published Wednesday — with one quantifying how much immunity improves after the second dose, and others showing how well coronavirus vaccines work against new variants of the virus:

The first nationwide study of coronavirus vaccination, done in Israel, showed Pfizer/BioNtech's vaccine works far better after two doses. Two shots of the vaccine provided greater than 95% protection from infection, severe illness and death, Dr. Eric Haas of the Israel Ministry of Health and colleagues reported in the Lancet medical journal. 'Two doses of BNT162b2 are highly effective across all age groups in preventing symptomatic and asymptomatic SARS-CoV-2 infections and COVID-19-related hospitalizations, severe disease, and death, including those caused by the B.1.1.7 SARS-CoV-2 variant,' they wrote. The B.1.1.7 variant, first seen in Britain, has spread widely and is now the most common new variant seen in the US. It was also common in Israel when the study was done...

'By 14 days after vaccination, protections conferred by a second dose [of the Pfizer vaccine] increased to 96.5% protection against infection, 98% against hospitalization, and 98.1% against death,' the team wrote. But people who got only one dose of the vaccine were far less protected. One dose alone gave just 57.7% protection against infection, 75.7% against hospitalization, and 77% against death....

Separately, a team in the Gulf state of Qatar looked at the efficacy of Pfizer's vaccine in the population there when B.1.351 and B.1.1.7 were both circulating. They found reassuring results. 'The estimated effectiveness of the vaccine against any documented infection with the B.1.1.7 variant was 89.5% at 14 or more days after the second dose. The effectiveness against any documented infection with the B.1.351 variant was 75%,' the researchers wrote in a letter to the New England Journal of Medicine...

Vaccine maker Moderna reported Wednesday that a booster shot delivering a half-dose of its current vaccine revs up the immune response against both B.1.351 and P.1. And a booster dose formulated specifically to match B.1.351 was even more effective, Moderna said in a statement...

In another study, vaccine maker Novavax confirmed earlier findings that showed its vaccine protects against B.1.351.

Read more of this story at Slashdot.