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Solving COVID: March 31, 2021

1. Pfizer says trial showed its COVID-19 vaccine was 100 percent effective in adolescents Pfizer and BioNTech announced Wednesday that its COVID-19 vaccine demonstrated 100 percent efficacy among adolescents aged 12 to 15 in a phase 3 study. The vaccine also demonstrated "robust antibody responses, exceeding those recorded earlier in vaccinated participants aged 16 to 25 years old, and was well tolerated." This trial consisted of 2,260 adolescents between 12 and 15, and there were 18 cases of COVID-19 in the placebo group but none in the group that was vaccinated. BioNTech CEO Ugur Sahin said the initial results suggests "children are particularly well protected by vaccination," which he called "very encouraging" news, and the companies plan to submit this data to the FDA with "the hope of starting to vaccinate this age group before the start of the next school year." [The New York Times, The Week]

2. Moderna and Pfizer vaccines 'highly effective' at preventing infections in CDC study Moderna's and Pfizer's COVID-19 vaccines have been found to be "highly effective" under real-world conditions in a new CDC study, preventing both symptomatic and asymptomatic infection. Centers for Disease Control and Prevention researchers found that two vaccine doses prevented 90 percent of infections by two weeks after the second dose, while one dose also prevented 80 percent of infections after two weeks. The study consisted of 3,950 essential workers, and the CDC said its findingsdemonstrated that "vaccines can reduce the risk of all" COVID-19 infections, "not just symptomatic infections." The findings also do not support fears that COVID-19 variants might render vaccines less effective, as variants were circulating while the study was being conducted from December through March. CDC Director Rochelle Walensky said the findings "should offer hope to the millions of Americans receiving COVID-19 vaccines each day and to those who will have the opportunity to roll up their sleeves and get vaccinated in the weeks ahead." [Centers for Disease Control and Prevention, The New York Times]

3. Trial to study delivering AstraZeneca COVID-19 vaccine as a nasal spray Oxford is seeking participants for a trial to deliver the vaccine it developed with AstraZeneca as a nasal spray, with a phase 1 trial including around 30 healthy participants. It's reportedly expected to take about four months, and the efficacy could then be studied in a larger trial. "Some immunologists believe that delivering the vaccine to the site of infection may achieve enhanced protection, especially against transmission, and mild disease," Dr. Sandy Douglas said. "We hope this small safety-focused study will lay the foundation for future larger studies." AstraZeneca's revised data shows its vaccine was 76 percent effective in a large U.S. trial. Russia's Gamaleya centre, which developed the Sputnik V vaccine, is also starting trials of a nasal spray vaccine. "This is a very gentle and patient-friendly form of vaccination for children ... who can be traumatized when they see a syringe," said director Alexander Gintsburg. The AstraZeneca nasal spray trial could start "as early as next week." [Financial Times]

4. Only 17 percent of Americans now say they won't get a COVID-19 vaccine A new poll suggests COVID-19 vaccine hesitancy is on the decline. In a Census Bureau survey conducted with the Centers for Disease Control and Prevention, 17 percent of adults said they definitely or probably wouldn't get vaccinated against COVID-19, a decline from 22 percent in January. The decline was more prominent among those who said they "probably" would not get vaccinated, as 13 percent said as much in January compared to nine percent in March. Eight percent of respondents said they "definitely" won't get the vaccine, down only one point from January. Though hesitancy was highest in the South, there were notable declines in Alabama, Louisiana, North Carolina, and South Carolina. Among Black Americans, 22 percent said they probably or definitely wouldn't get the vaccine, down from 34 percent in January. [The Wall Street Journal]

5. Canada halts AstraZeneca COVID-19 vaccine for people 55 and under, citing 'uncertainty' on blood clots Canada suspended use of AstraZeneca's vaccine on people 55 and youngerMonday. An advisory committee said its recommendation was a "precautionary measure" due to "rare" cases of blood clots in Europe, mostly affecting women under 55. "There is substantial uncertainty about the benefit of providing AstraZeneca COVID-19 vaccines to adults under 55 given the potential risks," said Dr. Shelley Deeks, the committee's vice chair. Europe's drug regulator said there is no evidence of an overall increase in blood clots and the vaccine is safe and effective to use. There have been no reports of blood clots in Canada, and the country is still using the vaccine for those over 55. Canada approved the vaccine in late February, but only for people under 65. When British data came in showing its effectiveness on older people, Canada reversed itself. "The messaging has been brutal overall," said Dr. Andrew Morris, a professor of infectious diseases at the University of Toronto. "I am fearful it is toast. It shouldn't be." [The Associated Press]

Source: here

One of the featured articles which should draw most attention this week is that after a trial involving 2260 participants receiving the Pfizer vaccine, adolescents age between 12 and 15 years of age, is 100% effective in preventing COVID-19. This trial was carried out in the United States and it is most reassuring this particular subgroup of recipients can be effectively immunized against COVID-19. This news comes on the back of the trial which has just commenced in North America using the Moderna vaccine (also an mRNA based vaccine) which will look at over 7000 healthy volunteers between the ages of six months and 11 years of age. While the global effort has been directed at protecting adults against COVID-19 due to the fact that as you get older, your susceptibility to severe illness and mortality rises significantly, particularly above the age of 60 years. In my last commentary, we discussed different ways of administering the vaccine pioneered by the Israelis and also in Hong Kong University using oral and nasal dispersal techniques. A further study with the Astra Zeneca Oxford vaccine is looking at a small group of healthy volunteers to have the vaccine administered nasally and will take approximately four months to complete. Currently, The United States is vaccinating 2.5 million patients per day which is likely to increase over the coming weeks to almost double this. While there has been some expression of vaccine hesitancy by the American public, particularly amongst Donald Trump Republican supporters, the latest poll indicates that there are now only 17% of Americans who are hesitant about receiving a vaccine for Covid. It is disappointing that ex-president Donald Trump has nor chosen to publicly encourage his Republican base to get vaccinated. Finally, returning to the Astra Zeneca Oxford vaccine and the issue regarding blood clots in a very small sub segment of young women, Canada has recently followed suit after the Germans, and has mandated that the Astra Zeneca Oxford vaccine will only be given to individuals over the age of 55 years of age. In my view, delaying the widespread vaccination of a population which is at risk of COVID-19 mortality and long Covid symptoms , irrespective of the age the issue of blood clots in a very small percentage of vaccinated individuals by comparison to the protective effect in the wider population is far outweighed by the latter. The UK government which has the largest roll out of the Astra Zeneca Oxford vaccine has no such intentions to limit the use of the vaccination since they have not found blood clotting to be problematic or higher than would be expected for a population. - Doctor Donald Greig


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