COVID vaccine protection stayed strong in teens during Delta, data show
Vaccine effectiveness (VE) for the two-dose Pfizer/BioNTech COVID-19 vaccine was up to 91.5% in Israeli teens 12 to 15 years old during the Delta (B1617.2) variant outbreak, according to a study published yesterday in Emerging Infectious Diseases.
Israel made the Pfizer vaccine available for teens starting Jun 2, and by Aug 26, 46.1% of those who were eligible were partially vaccinated and 31.2% were fully vaccinated. To estimate VE, the researchers looked at those who received their second dose between Jul 1 and Jul 24, excluding those who had a history of COVID-19 infection.
VE against lab-confirmed infection was 55.3% in the first week post-vaccination, rising to 87.1% in the second week, 91.2% in the third week, and then dropping slightly to 88.2% in the fourth week post-vaccination (95% CIs, 41.3% to 66.0%, 81.0% to 91.2%, 87.4% to 93.8%, and 95.0% to 90.7%, respectively). Adjustments for sex and epidemiologic week for weeks 2 to 4 post-vaccination suggested an adjusted VE of 91.5% against infection (95% CI, 88.2% to 93.9%).
By Aug 26, no vaccinated teenager who became infected by COVID-19 within 4 weeks after their second dose needed hospitalization, while 0.33% of the 9,969 unvaccinated COVID-19 teenage patients did. No deaths occurred in either group.
“The effectiveness estimate of 55.3% in the first week after the second dose probably reflects the effect of the first vaccine dose,” write the researchers. Despite lower VE than in people 16 to 39 years old, the researchers conclude, “Our findings indicate that the BNT162b2 vaccine provides adolescents with highly effective short-term protection against the SARS-CoV-2 Delta variant.”
Sep 27 Emerg Infect Dis study
Trump’s COVID vaccine endorsement this year appears to have worked
A political support video earlier this year by former President Donald Trump swayed more Trump voters to consider COVID-19 vaccination than a video by an expert, according to a study published yesterday in PLOS One.
On Mar 23, 387 Trump voters experienced one of three options prior to taking an online survey regarding the COVID-19 vaccine: a video of Trump taking pride in America’s efforts to develop a COVID-19 vaccine, a scientific expert giving facts about the vaccine, or no video at all. All respondents were either unvaccinated (87.1%) or partially vaccinated (12.9%), with most under 50 years of age (71%), college educated (59% had bachelor’s degrees or more), and White (83%). About 42% were in a household with $60,000 to $149,999 in income.
Participants were able to respond that they would be vaccinated, they would not be, or they were unsure. In the control group (no video), 35% of respondents said they would not be vaccinated, compared with 34% in the expert group and 24% in the Trump group (95% confidence intervals [CIs], 27% to 44%, 26% to 44%, and 17% to 32%, respectively).
Those who saw the Trump video were 85% more likely to say they would be vaccinated compared with the control group (relative risk reduction [RRR], 1.85; 1.01 to 3.40, p = 0.048). No significant likelihood was found between those who were in the control group versus those who watched the expert video. Additionally, those who saw the Trump video rated the vaccine’s safety and efficacy 0.3 points higher on a 5-point scale compared with the control group, whereas the expert video had no significant effect.
The researchers add that when they excluded those who were partially vaccinated, the RRR for the Trump video was unchanged, with the P-value remaining below 0.06.
“Contrary to highly-publicized focus group findings, our randomized experiment found that an expert’s factually accurate message may not be effectual to increase vaccination intentions,” the researchers conclude.
Sep 27 PLOS One study