Positive news comes from Pfizer this week as they announced the Phase 3 study of their Covid-19 vaccine prevented symptomatic disease and was well-tolerated by adolescents ages 12 to 15. The BNT162b2 vaccine demonstrated 100% efficacy and robust antibody responses. Trials have also been initiated for the use of the vaccine in children 6 months to 11 years of age.
The Pfizer trial enrolled 2,260 adolescents 12 to 15 years of age in the United States. In the trial, 18 cases of COVID-19 were observed in the placebo group and none were observed in the vaccinated group. Vaccination with BNT162b2 elicited SARS-CoV-2–neutralizing antibody geometric mean titers (GMTs) of 1,239.5, demonstrating strong immunogenicity in a subset of adolescents one month after the second dose. Pfizer will now move quickly to provide this data to the FDA and the European Medicines Agency as soon as possible to request expansion of the Emergency Use Authorization and EU Conditional Marketing Authorization for BNT162b2.
This news is particularly important as a new study demonstrates that reopening schools in the UK is one factor slowing the steady decline in UK coronavirus cases in recent weeks. Data released by the Office for National Statistics last week found that infection levels were mostly even across England compared to the week before, at 1 in 340 people. However, the main exception to this trend was a rise among school children, especially those in secondary education. The findings show a slight rise in children testing positive in years 7-11, from 0.31% the previous week to 0.43% this week. However, in primary schools the trend among younger children is less certain and much flatter, and in children in year 12 and upwards, the ONS estimates that infections fell. In Scotland, infection rates were found to have risen by 14 percent to 1 in 240 people, where schools started to reopen two weeks before England.
As always we must observe trends occurring abroad and treat them as a warning for what could occur in the U.S. Schools are reopening in most states in the US on the precipice of a potential fourth wave. Teachers are not required to be vaccinated to return to in-person teaching and currently, only 15.8% of the U.S. population is vaccinated. The mingling of teachers and students from different environments is likely to cause an increase in infections similar to UK schools, but the question remains how much.
We know now that children are just as likely to contract and transmit Covid-19 as adults. New research shows that testing methods of Covid-19 may be biased against children as they may shed infectious viruses for a shorter period than adults and their antibody response may be less broad. Research from the CDC also shows that over 90 percent of Covid-19 cases under the age of 18 may have been missed during a surge in Mississippi in August 2020.
In Michigan, we have seen hospitalizations jump 633 percent for unvaccinated adults ages 30-39 and 800 percent for adults ages 40-49, according to data from MHA. Between March 1 and March 23. In comparison, hospitalizations increased by just 37 percent among those 80 and older over the same time period. It is possible from this data to infer that younger people are more vulnerable to the new variants.
Of particular concern is that the rates of Multisystem Inflammatory Syndrome in Children increase in Los Angeles County by 35 percent in early February. Though we can only speculate why, the increase may have something to do with B.1.427/B.1.429, a highly contagious variant that began circulating in Southern California in November and is now present in at least 45 states. If more children are infected with Covid-19 when returning to school, they will not only risk infecting their families but it is more likely some of these cases will result in Multisystem Inflammatory Syndrome which can lead to heart dysfunction and even death. Without vaccinating children it will be difficult for some states to reach effective population immunity. It is for this reason that we eagerly await the authorization and accelerated rollout of vaccinations for young people and children, which alongside mass testing will be the only way to truly safely reopen schools, preschools, and daycare.